* Debugging early SError exception
@ 2023-12-17 21:32 Lior Weintraub
2023-12-19 7:09 ` Dirk Behme
0 siblings, 1 reply; 16+ messages in thread
From: Lior Weintraub @ 2023-12-17 21:32 UTC (permalink / raw)
To: linux-embedded
Hi,
We have a new SoC with eLinux porting (kernel v6.5).
This SoC is ARM64 (A53) single core based device.
It runs correctly on QEMU but fails with SError on emulation platform (Synopsys Zebu running our SoC model).
There is no debugger connected to this emulation but there are several debug capabilities we can use:
1. Generating wave dump of CPU signals
2. Generate a Tarmac log
3. UART
Since the SError happens at early stages of Linux boot the UART is not enabled yet.
From the Tarmac log we can see:
3824884521 ps ES (ffff800080760888:d65f03c0) O el1h_ns: ret (parse_early_param)
3824884522 ps ES (ffff800080763a60:d2801800) O el1h_ns: mov x0, #0xc0 // #192 (setup_arch)
R X0 (AARCH64) 00000000 000000c0
3824884523 ps ES (ffff800080763a64:d51b4220) O el1h_ns: msr daif, x0 (setup_arch)
R CPSR 600000c5
3824884529 ps ES System Error (Abort)
EXC [0x380] SError/vSError Current EL with SP_ELx
R ESR_EL1 (AARCH64) bf000002
R CPSR 600003c5
R SPSR_EL1 (AARCH64) 600000c5
R ELR_EL1 (AARCH64) ffff8000 80763a68
3824884925 ps ES (ffff800080010b80:d10543ff) O el1h_ns: sub sp, sp, #0x150 (vectors)
R SP_EL1 (AARCH64) ffff8000 808f3c50
3824884925 ps ES (ffff800080010b84:8b2063ff) O el1h_ns: add sp, sp, x0 (vectors)
R SP_EL1 (AARCH64) ffff8000 808f3d10
3824884926 ps ES (ffff800080010b88:cb2063e0) O el1h_ns: sub x0, sp, x0 (vectors)
R X0 (AARCH64) ffff8000 808f3c50
3824884927 ps ES (ffff800080010b8c:37700080) O el1h_ns: tbnz w0, #14, ffff800080010b9c <vectors+0x39c> (vectors)
3824884935 ps ES (ffff800080010b90:cb2063e0) O el1h_ns: sub x0, sp, x0 (vectors)
R X0 (AARCH64) 00000000 000000c0
3824884937 ps ES (ffff800080010b94:cb2063ff) O el1h_ns: sub sp, sp, x0 (vectors)
R SP_EL1 (AARCH64) ffff8000 808f3c50
3824884938 ps ES (ffff800080010b98:140001ef) O el1h_ns: b ffff800080011354 <el1h_64_error> (vectors)
If I understand correctly, the exception happened sometime earlier and only now Linux boot code (setup_arch) opened the exception handling and as a result we immediately jump to the SError exception handler.
From the Linux source:
parse_early_param();
dynamic_scs_init();
/*
* Unmask asynchronous aborts and fiq after bringing up possible
* earlycon. (Report possible System Errors once we can report this
* occurred).
*/
local_daif_restore(DAIF_PROCCTX_NOIRQ); <---- This is when we get the exception.
After some kernel hacking (replacing printk) we could extract the logs:
6Booting Linux on physical CPU 0x0000000000 [0x410fd034]
5Linux version 6.5.0 (pliops@dev-liorw) (aarch64-buildroot-linux-gnu-gcc.br_real (Buildroot 2023.02.1-95-g8391404e23) 11.3.0, GNU ld (GNU Binutils) 2.38) #101 SMP Sun Dec 17 20:09:06 IST 2023
6Machine model: Pliops Spider MK-I EVK
2SError Interrupt on CPU0, code 0x00000000bf000002 -- SError
CPU: 0 PID: 0 Comm: swapper Not tainted 6.5.0 #101
Hardware name: Pliops Spider MK-I EVK (DT)
pstate: 600000c5 (nZCv daIF -PAN -UAO -TCO -DIT -SSBS BTYPE=--)
pc : setup_arch+0x13c/0x5ac
lr : setup_arch+0x134/0x5ac
sp : ffff8000808f3da0
x29: ffff8000808f3da0c x28: 0000000008758074c x27: 0000000005e31b58c
x26: 0000000000000001c x25: 0000000007e5f728c x24: ffff8000808f8000c
x23: ffff8000808f8600c x22: ffff8000807b6000c x21: ffff800080010000c
x20: ffff800080a1e000c x19: fffffbfffddfe190c x18: 000000002266684ac
x17: 00000000fcad60bbc x16: 0000000000001800c x15: 0000000000000008c
x14: ffffffffffffffffc x13: 0000000000000000c x12: 0000000000000003c
x11: 0101010101010101c x10: ffffffffffee87dfc x9 : 0000000000000038c
x8 : 0101010101010101c x7 : 7f7f7f7f7f7f7f7fc x6 : 0000000000000001c
x5 : 0000000000000000c x4 : 8000000000000000c x3 : 0000000000000065c
x2 : 0000000000000000c x1 : 0000000000000000c x0 : 00000000000000c0c
0Kernel panic - not syncing: Asynchronous SError Interrupt
CPU: 0 PID: 0 Comm: swapper Not tainted 6.5.0 #101
Hardware name: Pliops Spider MK-I EVK (DT)
Call trace:
dump_backtrace+0x9c/0xd0
show_stack+0x14/0x1c
dump_stack_lvl+0x44/0x58
dump_stack+0x14/0x1c
panic+0x2e0/0x33c
nmi_panic+0x68/0x6c
arm64_serror_panic+0x68/0x78
do_serror+0x24/0x54
el1h_64_error_handler+0x2c/0x40
el1h_64_error+0x64/0x68
setup_arch+0x13c/0x5ac
start_kernel+0x5c/0x5b8
__primary_switched+0xb4/0xbc
0---[ end Kernel panic - not syncing: Asynchronous SError Interrupt ]---
Can you please advice how to proceed with debugging?
Thanks in advanced,
Cheers,
Lior.
^ permalink raw reply [flat|nested] 16+ messages in thread
* Re: Debugging early SError exception
2023-12-17 21:32 Debugging early SError exception Lior Weintraub
@ 2023-12-19 7:09 ` Dirk Behme
2023-12-19 13:23 ` Lior Weintraub
0 siblings, 1 reply; 16+ messages in thread
From: Dirk Behme @ 2023-12-19 7:09 UTC (permalink / raw)
To: Lior Weintraub, linux-embedded
Am 17.12.23 um 22:32 schrieb Lior Weintraub:
> Hi,
>
> We have a new SoC with eLinux porting (kernel v6.5).
> This SoC is ARM64 (A53) single core based device.
> It runs correctly on QEMU but fails with SError on emulation platform (Synopsys Zebu running our SoC model).
> There is no debugger connected to this emulation but there are several debug capabilities we can use:
> 1. Generating wave dump of CPU signals
> 2. Generate a Tarmac log
> 3. UART
>
> Since the SError happens at early stages of Linux boot the UART is not enabled yet.
> From the Tarmac log we can see:
> 3824884521 ps ES (ffff800080760888:d65f03c0) O el1h_ns: ret (parse_early_param)
> 3824884522 ps ES (ffff800080763a60:d2801800) O el1h_ns: mov x0, #0xc0 // #192 (setup_arch)
> R X0 (AARCH64) 00000000 000000c0
> 3824884523 ps ES (ffff800080763a64:d51b4220) O el1h_ns: msr daif, x0 (setup_arch)
> R CPSR 600000c5
> 3824884529 ps ES System Error (Abort)
> EXC [0x380] SError/vSError Current EL with SP_ELx
> R ESR_EL1 (AARCH64) bf000002
> R CPSR 600003c5
> R SPSR_EL1 (AARCH64) 600000c5
> R ELR_EL1 (AARCH64) ffff8000 80763a68
> 3824884925 ps ES (ffff800080010b80:d10543ff) O el1h_ns: sub sp, sp, #0x150 (vectors)
> R SP_EL1 (AARCH64) ffff8000 808f3c50
> 3824884925 ps ES (ffff800080010b84:8b2063ff) O el1h_ns: add sp, sp, x0 (vectors)
> R SP_EL1 (AARCH64) ffff8000 808f3d10
> 3824884926 ps ES (ffff800080010b88:cb2063e0) O el1h_ns: sub x0, sp, x0 (vectors)
> R X0 (AARCH64) ffff8000 808f3c50
> 3824884927 ps ES (ffff800080010b8c:37700080) O el1h_ns: tbnz w0, #14, ffff800080010b9c <vectors+0x39c> (vectors)
> 3824884935 ps ES (ffff800080010b90:cb2063e0) O el1h_ns: sub x0, sp, x0 (vectors)
> R X0 (AARCH64) 00000000 000000c0
> 3824884937 ps ES (ffff800080010b94:cb2063ff) O el1h_ns: sub sp, sp, x0 (vectors)
> R SP_EL1 (AARCH64) ffff8000 808f3c50
> 3824884938 ps ES (ffff800080010b98:140001ef) O el1h_ns: b ffff800080011354 <el1h_64_error> (vectors)
>
> If I understand correctly, the exception happened sometime earlier and only now Linux boot code (setup_arch) opened the exception handling and as a result we immediately jump to the SError exception handler.
Yes, that sounds reasonable. If I understood correctly, you are
running something "quite new" on some software (QEMU) and hardware
(Synopsis) simulators.
That would mean that you have new hardware with e.g. new memory map
not used before. What you describe might sound like in the code before
Linux (boot loader) there is anything resulting in the SError. This
might be an access to non-existing or non-enabled hardware. I.e. it
might be that you try to access (read/write) an address what is not
available, yet (or just invalid). It's hard to debug that. In case you
are able to modify the code before Linux (the boot loader?) you might
try to enable SError exceptions, there, too. To get it earlier and
with that make the search window smaller. I'm not that familiar with
QEMU, but could you try to trace which (all?) hardware accesses your
code does. And with that analyse all accesses and with that check if
all these accesses are valid even on the hardware (Synopsis) emulation
system? That should be checked from valid address and from hardware
subsystem enablement point of view.
Hth,
Dirk
> From the Linux source:
> parse_early_param();
>
> dynamic_scs_init();
>
> /*
> * Unmask asynchronous aborts and fiq after bringing up possible
> * earlycon. (Report possible System Errors once we can report this
> * occurred).
> */
> local_daif_restore(DAIF_PROCCTX_NOIRQ); <---- This is when we get the exception.
>
> After some kernel hacking (replacing printk) we could extract the logs:
> 6Booting Linux on physical CPU 0x0000000000 [0x410fd034]
> 5Linux version 6.5.0 (pliops@dev-liorw) (aarch64-buildroot-linux-gnu-gcc.br_real (Buildroot 2023.02.1-95-g8391404e23) 11.3.0, GNU ld (GNU Binutils) 2.38) #101 SMP Sun Dec 17 20:09:06 IST 2023
> 6Machine model: Pliops Spider MK-I EVK
> 2SError Interrupt on CPU0, code 0x00000000bf000002 -- SError
> CPU: 0 PID: 0 Comm: swapper Not tainted 6.5.0 #101
> Hardware name: Pliops Spider MK-I EVK (DT)
> pstate: 600000c5 (nZCv daIF -PAN -UAO -TCO -DIT -SSBS BTYPE=--)
> pc : setup_arch+0x13c/0x5ac
> lr : setup_arch+0x134/0x5ac
> sp : ffff8000808f3da0
> x29: ffff8000808f3da0c x28: 0000000008758074c x27: 0000000005e31b58c
> x26: 0000000000000001c x25: 0000000007e5f728c x24: ffff8000808f8000c
> x23: ffff8000808f8600c x22: ffff8000807b6000c x21: ffff800080010000c
> x20: ffff800080a1e000c x19: fffffbfffddfe190c x18: 000000002266684ac
> x17: 00000000fcad60bbc x16: 0000000000001800c x15: 0000000000000008c
> x14: ffffffffffffffffc x13: 0000000000000000c x12: 0000000000000003c
> x11: 0101010101010101c x10: ffffffffffee87dfc x9 : 0000000000000038c
> x8 : 0101010101010101c x7 : 7f7f7f7f7f7f7f7fc x6 : 0000000000000001c
> x5 : 0000000000000000c x4 : 8000000000000000c x3 : 0000000000000065c
> x2 : 0000000000000000c x1 : 0000000000000000c x0 : 00000000000000c0c
> 0Kernel panic - not syncing: Asynchronous SError Interrupt
> CPU: 0 PID: 0 Comm: swapper Not tainted 6.5.0 #101
> Hardware name: Pliops Spider MK-I EVK (DT)
> Call trace:
> dump_backtrace+0x9c/0xd0
> show_stack+0x14/0x1c
> dump_stack_lvl+0x44/0x58
> dump_stack+0x14/0x1c
> panic+0x2e0/0x33c
> nmi_panic+0x68/0x6c
> arm64_serror_panic+0x68/0x78
> do_serror+0x24/0x54
> el1h_64_error_handler+0x2c/0x40
> el1h_64_error+0x64/0x68
> setup_arch+0x13c/0x5ac
> start_kernel+0x5c/0x5b8
> __primary_switched+0xb4/0xbc
> 0---[ end Kernel panic - not syncing: Asynchronous SError Interrupt ]---
>
> Can you please advice how to proceed with debugging?
>
> Thanks in advanced,
> Cheers,
> Lior.
>
>
^ permalink raw reply [flat|nested] 16+ messages in thread
* RE: Debugging early SError exception
2023-12-19 7:09 ` Dirk Behme
@ 2023-12-19 13:23 ` Lior Weintraub
2023-12-19 13:37 ` Dirk Behme
0 siblings, 1 reply; 16+ messages in thread
From: Lior Weintraub @ 2023-12-19 13:23 UTC (permalink / raw)
To: Dirk Behme, linux-embedded
Thanks Dirk,
Cheers,
Lior.
> -----Original Message-----
> From: Dirk Behme <dirk.behme@gmail.com>
> Sent: Tuesday, December 19, 2023 9:09 AM
> To: Lior Weintraub <liorw@pliops.com>; linux-embedded@vger.kernel.org
> Subject: Re: Debugging early SError exception
>
> [You don't often get email from dirk.behme@gmail.com. Learn why this is
> important at https://aka.ms/LearnAboutSenderIdentification ]
>
> CAUTION: External Sender
>
> Am 17.12.23 um 22:32 schrieb Lior Weintraub:
> > Hi,
> >
> > We have a new SoC with eLinux porting (kernel v6.5).
> > This SoC is ARM64 (A53) single core based device.
> > It runs correctly on QEMU but fails with SError on emulation platform
> (Synopsys Zebu running our SoC model).
> > There is no debugger connected to this emulation but there are several
> debug capabilities we can use:
> > 1. Generating wave dump of CPU signals
> > 2. Generate a Tarmac log
> > 3. UART
> >
> > Since the SError happens at early stages of Linux boot the UART is not
> enabled yet.
> > From the Tarmac log we can see:
> > 3824884521 ps ES (ffff800080760888:d65f03c0) O el1h_ns: ret
> (parse_early_param)
> > 3824884522 ps ES (ffff800080763a60:d2801800) O el1h_ns: mov x0,
> #0xc0 // #192 (setup_arch)
> > R X0 (AARCH64) 00000000 000000c0
> > 3824884523 ps ES (ffff800080763a64:d51b4220) O el1h_ns: msr
> daif, x0 (setup_arch)
> > R CPSR 600000c5
> > 3824884529 ps ES System Error (Abort)
> > EXC [0x380] SError/vSError Current EL with SP_ELx
> > R ESR_EL1 (AARCH64) bf000002
> > R CPSR 600003c5
> > R SPSR_EL1 (AARCH64) 600000c5
> > R ELR_EL1 (AARCH64) ffff8000 80763a68
> > 3824884925 ps ES (ffff800080010b80:d10543ff) O el1h_ns: sub sp,
> sp, #0x150 (vectors)
> > R SP_EL1 (AARCH64) ffff8000 808f3c50
> > 3824884925 ps ES (ffff800080010b84:8b2063ff) O el1h_ns: add sp,
> sp, x0 (vectors)
> > R SP_EL1 (AARCH64) ffff8000 808f3d10
> > 3824884926 ps ES (ffff800080010b88:cb2063e0) O el1h_ns: sub x0,
> sp, x0 (vectors)
> > R X0 (AARCH64) ffff8000 808f3c50
> > 3824884927 ps ES (ffff800080010b8c:37700080) O el1h_ns: tbnz w0,
> #14, ffff800080010b9c <vectors+0x39c> (vectors)
> > 3824884935 ps ES (ffff800080010b90:cb2063e0) O el1h_ns: sub x0,
> sp, x0 (vectors)
> > R X0 (AARCH64) 00000000 000000c0
> > 3824884937 ps ES (ffff800080010b94:cb2063ff) O el1h_ns: sub sp,
> sp, x0 (vectors)
> > R SP_EL1 (AARCH64) ffff8000 808f3c50
> > 3824884938 ps ES (ffff800080010b98:140001ef) O el1h_ns: b
> ffff800080011354 <el1h_64_error> (vectors)
> >
> > If I understand correctly, the exception happened sometime earlier and only
> now Linux boot code (setup_arch) opened the exception handling and as a
> result we immediately jump to the SError exception handler.
>
>
> Yes, that sounds reasonable. If I understood correctly, you are
> running something "quite new" on some software (QEMU) and hardware
> (Synopsis) simulators.
>
> That would mean that you have new hardware with e.g. new memory map
> not used before. What you describe might sound like in the code before
> Linux (boot loader) there is anything resulting in the SError. This
> might be an access to non-existing or non-enabled hardware. I.e. it
> might be that you try to access (read/write) an address what is not
> available, yet (or just invalid). It's hard to debug that. In case you
> are able to modify the code before Linux (the boot loader?) you might
> try to enable SError exceptions, there, too. To get it earlier and
> with that make the search window smaller. I'm not that familiar with
> QEMU, but could you try to trace which (all?) hardware accesses your
> code does. And with that analyse all accesses and with that check if
> all these accesses are valid even on the hardware (Synopsis) emulation
> system? That should be checked from valid address and from hardware
> subsystem enablement point of view.
>
> Hth,
>
> Dirk
>
>
> > From the Linux source:
> > parse_early_param();
> >
> > dynamic_scs_init();
> >
> > /*
> > * Unmask asynchronous aborts and fiq after bringing up possible
> > * earlycon. (Report possible System Errors once we can report this
> > * occurred).
> > */
> > local_daif_restore(DAIF_PROCCTX_NOIRQ); <---- This is when we get the
> exception.
> >
> > After some kernel hacking (replacing printk) we could extract the logs:
> > 6Booting Linux on physical CPU 0x0000000000 [0x410fd034]
> > 5Linux version 6.5.0 (pliops@dev-liorw) (aarch64-buildroot-linux-gnu-
> gcc.br_real (Buildroot 2023.02.1-95-g8391404e23) 11.3.0, GNU ld (GNU
> Binutils) 2.38) #101 SMP Sun Dec 17 20:09:06 IST 2023
> > 6Machine model: Pliops Spider MK-I EVK
> > 2SError Interrupt on CPU0, code 0x00000000bf000002 -- SError
> > CPU: 0 PID: 0 Comm: swapper Not tainted 6.5.0 #101
> > Hardware name: Pliops Spider MK-I EVK (DT)
> > pstate: 600000c5 (nZCv daIF -PAN -UAO -TCO -DIT -SSBS BTYPE=--)
> > pc : setup_arch+0x13c/0x5ac
> > lr : setup_arch+0x134/0x5ac
> > sp : ffff8000808f3da0
> > x29: ffff8000808f3da0c x28: 0000000008758074c x27:
> 0000000005e31b58c
> > x26: 0000000000000001c x25: 0000000007e5f728c x24:
> ffff8000808f8000c
> > x23: ffff8000808f8600c x22: ffff8000807b6000c x21: ffff800080010000c
> > x20: ffff800080a1e000c x19: fffffbfffddfe190c x18: 000000002266684ac
> > x17: 00000000fcad60bbc x16: 0000000000001800c x15:
> 0000000000000008c
> > x14: ffffffffffffffffc x13: 0000000000000000c x12: 0000000000000003c
> > x11: 0101010101010101c x10: ffffffffffee87dfc x9 : 0000000000000038c
> > x8 : 0101010101010101c x7 : 7f7f7f7f7f7f7f7fc x6 : 0000000000000001c
> > x5 : 0000000000000000c x4 : 8000000000000000c x3 :
> 0000000000000065c
> > x2 : 0000000000000000c x1 : 0000000000000000c x0 :
> 00000000000000c0c
> > 0Kernel panic - not syncing: Asynchronous SError Interrupt
> > CPU: 0 PID: 0 Comm: swapper Not tainted 6.5.0 #101
> > Hardware name: Pliops Spider MK-I EVK (DT)
> > Call trace:
> > dump_backtrace+0x9c/0xd0
> > show_stack+0x14/0x1c
> > dump_stack_lvl+0x44/0x58
> > dump_stack+0x14/0x1c
> > panic+0x2e0/0x33c
> > nmi_panic+0x68/0x6c
> > arm64_serror_panic+0x68/0x78
> > do_serror+0x24/0x54
> > el1h_64_error_handler+0x2c/0x40
> > el1h_64_error+0x64/0x68
> > setup_arch+0x13c/0x5ac
> > start_kernel+0x5c/0x5b8
> > __primary_switched+0xb4/0xbc
> > 0---[ end Kernel panic - not syncing: Asynchronous SError Interrupt ]---
> >
> > Can you please advice how to proceed with debugging?
> >
> > Thanks in advanced,
> > Cheers,
> > Lior.
> >
> >
>
^ permalink raw reply [flat|nested] 16+ messages in thread
* Re: Debugging early SError exception
2023-12-19 13:23 ` Lior Weintraub
@ 2023-12-19 13:37 ` Dirk Behme
2023-12-21 7:43 ` Lior Weintraub
0 siblings, 1 reply; 16+ messages in thread
From: Dirk Behme @ 2023-12-19 13:37 UTC (permalink / raw)
To: Lior Weintraub, linux-embedded
Am 19.12.23 um 14:23 schrieb Lior Weintraub:
> Thanks Dirk,
Welcome :)
In case you find the root cause it would be nice to get some generic
description of it so that we can learn something :)
Best regards
Dirk
>> -----Original Message-----
>> From: Dirk Behme <dirk.behme@gmail.com>
>> Sent: Tuesday, December 19, 2023 9:09 AM
>> To: Lior Weintraub <liorw@pliops.com>; linux-embedded@vger.kernel.org
>> Subject: Re: Debugging early SError exception
>>
>> [You don't often get email from dirk.behme@gmail.com. Learn why this is
>> important at https://aka.ms/LearnAboutSenderIdentification ]
>>
>> CAUTION: External Sender
>>
>> Am 17.12.23 um 22:32 schrieb Lior Weintraub:
>>> Hi,
>>>
>>> We have a new SoC with eLinux porting (kernel v6.5).
>>> This SoC is ARM64 (A53) single core based device.
>>> It runs correctly on QEMU but fails with SError on emulation platform
>> (Synopsys Zebu running our SoC model).
>>> There is no debugger connected to this emulation but there are several
>> debug capabilities we can use:
>>> 1. Generating wave dump of CPU signals
>>> 2. Generate a Tarmac log
>>> 3. UART
>>>
>>> Since the SError happens at early stages of Linux boot the UART is not
>> enabled yet.
>>> From the Tarmac log we can see:
>>> 3824884521 ps ES (ffff800080760888:d65f03c0) O el1h_ns: ret
>> (parse_early_param)
>>> 3824884522 ps ES (ffff800080763a60:d2801800) O el1h_ns: mov x0,
>> #0xc0 // #192 (setup_arch)
>>> R X0 (AARCH64) 00000000 000000c0
>>> 3824884523 ps ES (ffff800080763a64:d51b4220) O el1h_ns: msr
>> daif, x0 (setup_arch)
>>> R CPSR 600000c5
>>> 3824884529 ps ES System Error (Abort)
>>> EXC [0x380] SError/vSError Current EL with SP_ELx
>>> R ESR_EL1 (AARCH64) bf000002
>>> R CPSR 600003c5
>>> R SPSR_EL1 (AARCH64) 600000c5
>>> R ELR_EL1 (AARCH64) ffff8000 80763a68
>>> 3824884925 ps ES (ffff800080010b80:d10543ff) O el1h_ns: sub sp,
>> sp, #0x150 (vectors)
>>> R SP_EL1 (AARCH64) ffff8000 808f3c50
>>> 3824884925 ps ES (ffff800080010b84:8b2063ff) O el1h_ns: add sp,
>> sp, x0 (vectors)
>>> R SP_EL1 (AARCH64) ffff8000 808f3d10
>>> 3824884926 ps ES (ffff800080010b88:cb2063e0) O el1h_ns: sub x0,
>> sp, x0 (vectors)
>>> R X0 (AARCH64) ffff8000 808f3c50
>>> 3824884927 ps ES (ffff800080010b8c:37700080) O el1h_ns: tbnz w0,
>> #14, ffff800080010b9c <vectors+0x39c> (vectors)
>>> 3824884935 ps ES (ffff800080010b90:cb2063e0) O el1h_ns: sub x0,
>> sp, x0 (vectors)
>>> R X0 (AARCH64) 00000000 000000c0
>>> 3824884937 ps ES (ffff800080010b94:cb2063ff) O el1h_ns: sub sp,
>> sp, x0 (vectors)
>>> R SP_EL1 (AARCH64) ffff8000 808f3c50
>>> 3824884938 ps ES (ffff800080010b98:140001ef) O el1h_ns: b
>> ffff800080011354 <el1h_64_error> (vectors)
>>>
>>> If I understand correctly, the exception happened sometime earlier and only
>> now Linux boot code (setup_arch) opened the exception handling and as a
>> result we immediately jump to the SError exception handler.
>>
>>
>> Yes, that sounds reasonable. If I understood correctly, you are
>> running something "quite new" on some software (QEMU) and hardware
>> (Synopsis) simulators.
>>
>> That would mean that you have new hardware with e.g. new memory map
>> not used before. What you describe might sound like in the code before
>> Linux (boot loader) there is anything resulting in the SError. This
>> might be an access to non-existing or non-enabled hardware. I.e. it
>> might be that you try to access (read/write) an address what is not
>> available, yet (or just invalid). It's hard to debug that. In case you
>> are able to modify the code before Linux (the boot loader?) you might
>> try to enable SError exceptions, there, too. To get it earlier and
>> with that make the search window smaller. I'm not that familiar with
>> QEMU, but could you try to trace which (all?) hardware accesses your
>> code does. And with that analyse all accesses and with that check if
>> all these accesses are valid even on the hardware (Synopsis) emulation
>> system? That should be checked from valid address and from hardware
>> subsystem enablement point of view.
>>
>> Hth,
>>
>> Dirk
>>
>>
>>> From the Linux source:
>>> parse_early_param();
>>>
>>> dynamic_scs_init();
>>>
>>> /*
>>> * Unmask asynchronous aborts and fiq after bringing up possible
>>> * earlycon. (Report possible System Errors once we can report this
>>> * occurred).
>>> */
>>> local_daif_restore(DAIF_PROCCTX_NOIRQ); <---- This is when we get the
>> exception.
>>>
>>> After some kernel hacking (replacing printk) we could extract the logs:
>>> 6Booting Linux on physical CPU 0x0000000000 [0x410fd034]
>>> 5Linux version 6.5.0 (pliops@dev-liorw) (aarch64-buildroot-linux-gnu-
>> gcc.br_real (Buildroot 2023.02.1-95-g8391404e23) 11.3.0, GNU ld (GNU
>> Binutils) 2.38) #101 SMP Sun Dec 17 20:09:06 IST 2023
>>> 6Machine model: Pliops Spider MK-I EVK
>>> 2SError Interrupt on CPU0, code 0x00000000bf000002 -- SError
>>> CPU: 0 PID: 0 Comm: swapper Not tainted 6.5.0 #101
>>> Hardware name: Pliops Spider MK-I EVK (DT)
>>> pstate: 600000c5 (nZCv daIF -PAN -UAO -TCO -DIT -SSBS BTYPE=--)
>>> pc : setup_arch+0x13c/0x5ac
>>> lr : setup_arch+0x134/0x5ac
>>> sp : ffff8000808f3da0
>>> x29: ffff8000808f3da0c x28: 0000000008758074c x27:
>> 0000000005e31b58c
>>> x26: 0000000000000001c x25: 0000000007e5f728c x24:
>> ffff8000808f8000c
>>> x23: ffff8000808f8600c x22: ffff8000807b6000c x21: ffff800080010000c
>>> x20: ffff800080a1e000c x19: fffffbfffddfe190c x18: 000000002266684ac
>>> x17: 00000000fcad60bbc x16: 0000000000001800c x15:
>> 0000000000000008c
>>> x14: ffffffffffffffffc x13: 0000000000000000c x12: 0000000000000003c
>>> x11: 0101010101010101c x10: ffffffffffee87dfc x9 : 0000000000000038c
>>> x8 : 0101010101010101c x7 : 7f7f7f7f7f7f7f7fc x6 : 0000000000000001c
>>> x5 : 0000000000000000c x4 : 8000000000000000c x3 :
>> 0000000000000065c
>>> x2 : 0000000000000000c x1 : 0000000000000000c x0 :
>> 00000000000000c0c
>>> 0Kernel panic - not syncing: Asynchronous SError Interrupt
>>> CPU: 0 PID: 0 Comm: swapper Not tainted 6.5.0 #101
>>> Hardware name: Pliops Spider MK-I EVK (DT)
>>> Call trace:
>>> dump_backtrace+0x9c/0xd0
>>> show_stack+0x14/0x1c
>>> dump_stack_lvl+0x44/0x58
>>> dump_stack+0x14/0x1c
>>> panic+0x2e0/0x33c
>>> nmi_panic+0x68/0x6c
>>> arm64_serror_panic+0x68/0x78
>>> do_serror+0x24/0x54
>>> el1h_64_error_handler+0x2c/0x40
>>> el1h_64_error+0x64/0x68
>>> setup_arch+0x13c/0x5ac
>>> start_kernel+0x5c/0x5b8
>>> __primary_switched+0xb4/0xbc
>>> 0---[ end Kernel panic - not syncing: Asynchronous SError Interrupt ]---
>>>
>>> Can you please advice how to proceed with debugging?
>>>
>>> Thanks in advanced,
>>> Cheers,
>>> Lior.
>>>
>>>
>>
>
^ permalink raw reply [flat|nested] 16+ messages in thread
* RE: Debugging early SError exception
2023-12-19 13:37 ` Dirk Behme
@ 2023-12-21 7:43 ` Lior Weintraub
2023-12-21 8:29 ` Dirk Behme
0 siblings, 1 reply; 16+ messages in thread
From: Lior Weintraub @ 2023-12-21 7:43 UTC (permalink / raw)
To: Dirk Behme, linux-embedded
Hi Dirk,
We found that the issue was at the early stages of Barebox (a.k.a U-BOOT v2).
Our implementation of putc_ll (on debug_ll) was writing into the UART Tx FIFO without checking if the FIFO is full.
Once the fifo got full it caused this SError probably because the UART IP generated an apberror signal.
Now the Linux is running and doesn't report the SError again but now we face another issue.
We see that the PC is getting into a "report_bug" function.
The Linux doesn't print anything to the UART (probably since it hasn't got to the point where the console is configured?).
Since our debug means are limited it can take some time to find the root cause.
I will keep you posted and update our findings.
Love to hear your thoughts,
Cheers,
Lior.
> -----Original Message-----
> From: Dirk Behme <dirk.behme@gmail.com>
> Sent: Tuesday, December 19, 2023 3:37 PM
> To: Lior Weintraub <liorw@pliops.com>; linux-embedded@vger.kernel.org
> Subject: Re: Debugging early SError exception
>
> [You don't often get email from dirk.behme@gmail.com. Learn why this is
> important at https://aka.ms/LearnAboutSenderIdentification ]
>
> CAUTION: External Sender
>
> Am 19.12.23 um 14:23 schrieb Lior Weintraub:
> > Thanks Dirk,
>
> Welcome :)
>
> In case you find the root cause it would be nice to get some generic
> description of it so that we can learn something :)
>
> Best regards
>
> Dirk
>
>
> >> -----Original Message-----
> >> From: Dirk Behme <dirk.behme@gmail.com>
> >> Sent: Tuesday, December 19, 2023 9:09 AM
> >> To: Lior Weintraub <liorw@pliops.com>; linux-embedded@vger.kernel.org
> >> Subject: Re: Debugging early SError exception
> >>
> >> [You don't often get email from dirk.behme@gmail.com. Learn why this is
> >> important at https://aka.ms/LearnAboutSenderIdentification ]
> >>
> >> CAUTION: External Sender
> >>
> >> Am 17.12.23 um 22:32 schrieb Lior Weintraub:
> >>> Hi,
> >>>
> >>> We have a new SoC with eLinux porting (kernel v6.5).
> >>> This SoC is ARM64 (A53) single core based device.
> >>> It runs correctly on QEMU but fails with SError on emulation platform
> >> (Synopsys Zebu running our SoC model).
> >>> There is no debugger connected to this emulation but there are several
> >> debug capabilities we can use:
> >>> 1. Generating wave dump of CPU signals
> >>> 2. Generate a Tarmac log
> >>> 3. UART
> >>>
> >>> Since the SError happens at early stages of Linux boot the UART is not
> >> enabled yet.
> >>> From the Tarmac log we can see:
> >>> 3824884521 ps ES (ffff800080760888:d65f03c0) O el1h_ns: ret
> >> (parse_early_param)
> >>> 3824884522 ps ES (ffff800080763a60:d2801800) O el1h_ns: mov
> x0,
> >> #0xc0 // #192 (setup_arch)
> >>> R X0 (AARCH64) 00000000 000000c0
> >>> 3824884523 ps ES (ffff800080763a64:d51b4220) O el1h_ns: msr
> >> daif, x0 (setup_arch)
> >>> R CPSR 600000c5
> >>> 3824884529 ps ES System Error (Abort)
> >>> EXC [0x380] SError/vSError Current EL with SP_ELx
> >>> R ESR_EL1 (AARCH64) bf000002
> >>> R CPSR 600003c5
> >>> R SPSR_EL1 (AARCH64) 600000c5
> >>> R ELR_EL1 (AARCH64) ffff8000 80763a68
> >>> 3824884925 ps ES (ffff800080010b80:d10543ff) O el1h_ns: sub
> sp,
> >> sp, #0x150 (vectors)
> >>> R SP_EL1 (AARCH64) ffff8000 808f3c50
> >>> 3824884925 ps ES (ffff800080010b84:8b2063ff) O el1h_ns: add
> sp,
> >> sp, x0 (vectors)
> >>> R SP_EL1 (AARCH64) ffff8000 808f3d10
> >>> 3824884926 ps ES (ffff800080010b88:cb2063e0) O el1h_ns: sub
> x0,
> >> sp, x0 (vectors)
> >>> R X0 (AARCH64) ffff8000 808f3c50
> >>> 3824884927 ps ES (ffff800080010b8c:37700080) O el1h_ns: tbnz
> w0,
> >> #14, ffff800080010b9c <vectors+0x39c> (vectors)
> >>> 3824884935 ps ES (ffff800080010b90:cb2063e0) O el1h_ns: sub
> x0,
> >> sp, x0 (vectors)
> >>> R X0 (AARCH64) 00000000 000000c0
> >>> 3824884937 ps ES (ffff800080010b94:cb2063ff) O el1h_ns: sub sp,
> >> sp, x0 (vectors)
> >>> R SP_EL1 (AARCH64) ffff8000 808f3c50
> >>> 3824884938 ps ES (ffff800080010b98:140001ef) O el1h_ns: b
> >> ffff800080011354 <el1h_64_error> (vectors)
> >>>
> >>> If I understand correctly, the exception happened sometime earlier and
> only
> >> now Linux boot code (setup_arch) opened the exception handling and as a
> >> result we immediately jump to the SError exception handler.
> >>
> >>
> >> Yes, that sounds reasonable. If I understood correctly, you are
> >> running something "quite new" on some software (QEMU) and hardware
> >> (Synopsis) simulators.
> >>
> >> That would mean that you have new hardware with e.g. new memory map
> >> not used before. What you describe might sound like in the code before
> >> Linux (boot loader) there is anything resulting in the SError. This
> >> might be an access to non-existing or non-enabled hardware. I.e. it
> >> might be that you try to access (read/write) an address what is not
> >> available, yet (or just invalid). It's hard to debug that. In case you
> >> are able to modify the code before Linux (the boot loader?) you might
> >> try to enable SError exceptions, there, too. To get it earlier and
> >> with that make the search window smaller. I'm not that familiar with
> >> QEMU, but could you try to trace which (all?) hardware accesses your
> >> code does. And with that analyse all accesses and with that check if
> >> all these accesses are valid even on the hardware (Synopsis) emulation
> >> system? That should be checked from valid address and from hardware
> >> subsystem enablement point of view.
> >>
> >> Hth,
> >>
> >> Dirk
> >>
> >>
> >>> From the Linux source:
> >>> parse_early_param();
> >>>
> >>> dynamic_scs_init();
> >>>
> >>> /*
> >>> * Unmask asynchronous aborts and fiq after bringing up possible
> >>> * earlycon. (Report possible System Errors once we can report this
> >>> * occurred).
> >>> */
> >>> local_daif_restore(DAIF_PROCCTX_NOIRQ); <---- This is when we get
> the
> >> exception.
> >>>
> >>> After some kernel hacking (replacing printk) we could extract the logs:
> >>> 6Booting Linux on physical CPU 0x0000000000 [0x410fd034]
> >>> 5Linux version 6.5.0 (pliops@dev-liorw) (aarch64-buildroot-linux-gnu-
> >> gcc.br_real (Buildroot 2023.02.1-95-g8391404e23) 11.3.0, GNU ld (GNU
> >> Binutils) 2.38) #101 SMP Sun Dec 17 20:09:06 IST 2023
> >>> 6Machine model: Pliops Spider MK-I EVK
> >>> 2SError Interrupt on CPU0, code 0x00000000bf000002 -- SError
> >>> CPU: 0 PID: 0 Comm: swapper Not tainted 6.5.0 #101
> >>> Hardware name: Pliops Spider MK-I EVK (DT)
> >>> pstate: 600000c5 (nZCv daIF -PAN -UAO -TCO -DIT -SSBS BTYPE=--)
> >>> pc : setup_arch+0x13c/0x5ac
> >>> lr : setup_arch+0x134/0x5ac
> >>> sp : ffff8000808f3da0
> >>> x29: ffff8000808f3da0c x28: 0000000008758074c x27:
> >> 0000000005e31b58c
> >>> x26: 0000000000000001c x25: 0000000007e5f728c x24:
> >> ffff8000808f8000c
> >>> x23: ffff8000808f8600c x22: ffff8000807b6000c x21:
> ffff800080010000c
> >>> x20: ffff800080a1e000c x19: fffffbfffddfe190c x18: 000000002266684ac
> >>> x17: 00000000fcad60bbc x16: 0000000000001800c x15:
> >> 0000000000000008c
> >>> x14: ffffffffffffffffc x13: 0000000000000000c x12: 0000000000000003c
> >>> x11: 0101010101010101c x10: ffffffffffee87dfc x9 :
> 0000000000000038c
> >>> x8 : 0101010101010101c x7 : 7f7f7f7f7f7f7f7fc x6 :
> 0000000000000001c
> >>> x5 : 0000000000000000c x4 : 8000000000000000c x3 :
> >> 0000000000000065c
> >>> x2 : 0000000000000000c x1 : 0000000000000000c x0 :
> >> 00000000000000c0c
> >>> 0Kernel panic - not syncing: Asynchronous SError Interrupt
> >>> CPU: 0 PID: 0 Comm: swapper Not tainted 6.5.0 #101
> >>> Hardware name: Pliops Spider MK-I EVK (DT)
> >>> Call trace:
> >>> dump_backtrace+0x9c/0xd0
> >>> show_stack+0x14/0x1c
> >>> dump_stack_lvl+0x44/0x58
> >>> dump_stack+0x14/0x1c
> >>> panic+0x2e0/0x33c
> >>> nmi_panic+0x68/0x6c
> >>> arm64_serror_panic+0x68/0x78
> >>> do_serror+0x24/0x54
> >>> el1h_64_error_handler+0x2c/0x40
> >>> el1h_64_error+0x64/0x68
> >>> setup_arch+0x13c/0x5ac
> >>> start_kernel+0x5c/0x5b8
> >>> __primary_switched+0xb4/0xbc
> >>> 0---[ end Kernel panic - not syncing: Asynchronous SError Interrupt ]---
> >>>
> >>> Can you please advice how to proceed with debugging?
> >>>
> >>> Thanks in advanced,
> >>> Cheers,
> >>> Lior.
> >>>
> >>>
> >>
> >
^ permalink raw reply [flat|nested] 16+ messages in thread
* Re: Debugging early SError exception
2023-12-21 7:43 ` Lior Weintraub
@ 2023-12-21 8:29 ` Dirk Behme
2023-12-21 10:04 ` Lior Weintraub
0 siblings, 1 reply; 16+ messages in thread
From: Dirk Behme @ 2023-12-21 8:29 UTC (permalink / raw)
To: Lior Weintraub, linux-embedded
Am 21.12.23 um 08:43 schrieb Lior Weintraub:
> Hi Dirk,
>
> We found that the issue was at the early stages of Barebox (a.k.a U-BOOT v2).
Glad to hear that! :)
> Our implementation of putc_ll (on debug_ll) was writing into the UART Tx FIFO without checking if the FIFO is full.
> Once the fifo got full it caused this SError probably because the UART IP generated an apberror signal.
Thanks for the report!
> Now the Linux is running and doesn't report the SError again but now we face another issue.
> We see that the PC is getting into a "report_bug" function.
> The Linux doesn't print anything to the UART (probably since it hasn't got to the point where the console is configured?).
For cases like this using earlyprintk is usually a good option. Check
the Linux kernel serial console (UART) dirver of you SoC if it
supports it. In the end it should be "just" a function in the serial
console driver which outputs the console data via polling before
(later) the interrupt driven console part takes over.
Best regards
Dirk
> Since our debug means are limited it can take some time to find the root cause.
>
> I will keep you posted and update our findings.
> Love to hear your thoughts,
>
> Cheers,
> Lior.
>
>
>> -----Original Message-----
>> From: Dirk Behme <dirk.behme@gmail.com>
>> Sent: Tuesday, December 19, 2023 3:37 PM
>> To: Lior Weintraub <liorw@pliops.com>; linux-embedded@vger.kernel.org
>> Subject: Re: Debugging early SError exception
>>
>> [You don't often get email from dirk.behme@gmail.com. Learn why this is
>> important at https://aka.ms/LearnAboutSenderIdentification ]
>>
>> CAUTION: External Sender
>>
>> Am 19.12.23 um 14:23 schrieb Lior Weintraub:
>>> Thanks Dirk,
>>
>> Welcome :)
>>
>> In case you find the root cause it would be nice to get some generic
>> description of it so that we can learn something :)
>>
>> Best regards
>>
>> Dirk
>>
>>
>>>> -----Original Message-----
>>>> From: Dirk Behme <dirk.behme@gmail.com>
>>>> Sent: Tuesday, December 19, 2023 9:09 AM
>>>> To: Lior Weintraub <liorw@pliops.com>; linux-embedded@vger.kernel.org
>>>> Subject: Re: Debugging early SError exception
>>>>
>>>> [You don't often get email from dirk.behme@gmail.com. Learn why this is
>>>> important at https://aka.ms/LearnAboutSenderIdentification ]
>>>>
>>>> CAUTION: External Sender
>>>>
>>>> Am 17.12.23 um 22:32 schrieb Lior Weintraub:
>>>>> Hi,
>>>>>
>>>>> We have a new SoC with eLinux porting (kernel v6.5).
>>>>> This SoC is ARM64 (A53) single core based device.
>>>>> It runs correctly on QEMU but fails with SError on emulation platform
>>>> (Synopsys Zebu running our SoC model).
>>>>> There is no debugger connected to this emulation but there are several
>>>> debug capabilities we can use:
>>>>> 1. Generating wave dump of CPU signals
>>>>> 2. Generate a Tarmac log
>>>>> 3. UART
>>>>>
>>>>> Since the SError happens at early stages of Linux boot the UART is not
>>>> enabled yet.
>>>>> From the Tarmac log we can see:
>>>>> 3824884521 ps ES (ffff800080760888:d65f03c0) O el1h_ns: ret
>>>> (parse_early_param)
>>>>> 3824884522 ps ES (ffff800080763a60:d2801800) O el1h_ns: mov
>> x0,
>>>> #0xc0 // #192 (setup_arch)
>>>>> R X0 (AARCH64) 00000000 000000c0
>>>>> 3824884523 ps ES (ffff800080763a64:d51b4220) O el1h_ns: msr
>>>> daif, x0 (setup_arch)
>>>>> R CPSR 600000c5
>>>>> 3824884529 ps ES System Error (Abort)
>>>>> EXC [0x380] SError/vSError Current EL with SP_ELx
>>>>> R ESR_EL1 (AARCH64) bf000002
>>>>> R CPSR 600003c5
>>>>> R SPSR_EL1 (AARCH64) 600000c5
>>>>> R ELR_EL1 (AARCH64) ffff8000 80763a68
>>>>> 3824884925 ps ES (ffff800080010b80:d10543ff) O el1h_ns: sub
>> sp,
>>>> sp, #0x150 (vectors)
>>>>> R SP_EL1 (AARCH64) ffff8000 808f3c50
>>>>> 3824884925 ps ES (ffff800080010b84:8b2063ff) O el1h_ns: add
>> sp,
>>>> sp, x0 (vectors)
>>>>> R SP_EL1 (AARCH64) ffff8000 808f3d10
>>>>> 3824884926 ps ES (ffff800080010b88:cb2063e0) O el1h_ns: sub
>> x0,
>>>> sp, x0 (vectors)
>>>>> R X0 (AARCH64) ffff8000 808f3c50
>>>>> 3824884927 ps ES (ffff800080010b8c:37700080) O el1h_ns: tbnz
>> w0,
>>>> #14, ffff800080010b9c <vectors+0x39c> (vectors)
>>>>> 3824884935 ps ES (ffff800080010b90:cb2063e0) O el1h_ns: sub
>> x0,
>>>> sp, x0 (vectors)
>>>>> R X0 (AARCH64) 00000000 000000c0
>>>>> 3824884937 ps ES (ffff800080010b94:cb2063ff) O el1h_ns: sub sp,
>>>> sp, x0 (vectors)
>>>>> R SP_EL1 (AARCH64) ffff8000 808f3c50
>>>>> 3824884938 ps ES (ffff800080010b98:140001ef) O el1h_ns: b
>>>> ffff800080011354 <el1h_64_error> (vectors)
>>>>>
>>>>> If I understand correctly, the exception happened sometime earlier and
>> only
>>>> now Linux boot code (setup_arch) opened the exception handling and as a
>>>> result we immediately jump to the SError exception handler.
>>>>
>>>>
>>>> Yes, that sounds reasonable. If I understood correctly, you are
>>>> running something "quite new" on some software (QEMU) and hardware
>>>> (Synopsis) simulators.
>>>>
>>>> That would mean that you have new hardware with e.g. new memory map
>>>> not used before. What you describe might sound like in the code before
>>>> Linux (boot loader) there is anything resulting in the SError. This
>>>> might be an access to non-existing or non-enabled hardware. I.e. it
>>>> might be that you try to access (read/write) an address what is not
>>>> available, yet (or just invalid). It's hard to debug that. In case you
>>>> are able to modify the code before Linux (the boot loader?) you might
>>>> try to enable SError exceptions, there, too. To get it earlier and
>>>> with that make the search window smaller. I'm not that familiar with
>>>> QEMU, but could you try to trace which (all?) hardware accesses your
>>>> code does. And with that analyse all accesses and with that check if
>>>> all these accesses are valid even on the hardware (Synopsis) emulation
>>>> system? That should be checked from valid address and from hardware
>>>> subsystem enablement point of view.
>>>>
>>>> Hth,
>>>>
>>>> Dirk
>>>>
>>>>
>>>>> From the Linux source:
>>>>> parse_early_param();
>>>>>
>>>>> dynamic_scs_init();
>>>>>
>>>>> /*
>>>>> * Unmask asynchronous aborts and fiq after bringing up possible
>>>>> * earlycon. (Report possible System Errors once we can report this
>>>>> * occurred).
>>>>> */
>>>>> local_daif_restore(DAIF_PROCCTX_NOIRQ); <---- This is when we get
>> the
>>>> exception.
>>>>>
>>>>> After some kernel hacking (replacing printk) we could extract the logs:
>>>>> 6Booting Linux on physical CPU 0x0000000000 [0x410fd034]
>>>>> 5Linux version 6.5.0 (pliops@dev-liorw) (aarch64-buildroot-linux-gnu-
>>>> gcc.br_real (Buildroot 2023.02.1-95-g8391404e23) 11.3.0, GNU ld (GNU
>>>> Binutils) 2.38) #101 SMP Sun Dec 17 20:09:06 IST 2023
>>>>> 6Machine model: Pliops Spider MK-I EVK
>>>>> 2SError Interrupt on CPU0, code 0x00000000bf000002 -- SError
>>>>> CPU: 0 PID: 0 Comm: swapper Not tainted 6.5.0 #101
>>>>> Hardware name: Pliops Spider MK-I EVK (DT)
>>>>> pstate: 600000c5 (nZCv daIF -PAN -UAO -TCO -DIT -SSBS BTYPE=--)
>>>>> pc : setup_arch+0x13c/0x5ac
>>>>> lr : setup_arch+0x134/0x5ac
>>>>> sp : ffff8000808f3da0
>>>>> x29: ffff8000808f3da0c x28: 0000000008758074c x27:
>>>> 0000000005e31b58c
>>>>> x26: 0000000000000001c x25: 0000000007e5f728c x24:
>>>> ffff8000808f8000c
>>>>> x23: ffff8000808f8600c x22: ffff8000807b6000c x21:
>> ffff800080010000c
>>>>> x20: ffff800080a1e000c x19: fffffbfffddfe190c x18: 000000002266684ac
>>>>> x17: 00000000fcad60bbc x16: 0000000000001800c x15:
>>>> 0000000000000008c
>>>>> x14: ffffffffffffffffc x13: 0000000000000000c x12: 0000000000000003c
>>>>> x11: 0101010101010101c x10: ffffffffffee87dfc x9 :
>> 0000000000000038c
>>>>> x8 : 0101010101010101c x7 : 7f7f7f7f7f7f7f7fc x6 :
>> 0000000000000001c
>>>>> x5 : 0000000000000000c x4 : 8000000000000000c x3 :
>>>> 0000000000000065c
>>>>> x2 : 0000000000000000c x1 : 0000000000000000c x0 :
>>>> 00000000000000c0c
>>>>> 0Kernel panic - not syncing: Asynchronous SError Interrupt
>>>>> CPU: 0 PID: 0 Comm: swapper Not tainted 6.5.0 #101
>>>>> Hardware name: Pliops Spider MK-I EVK (DT)
>>>>> Call trace:
>>>>> dump_backtrace+0x9c/0xd0
>>>>> show_stack+0x14/0x1c
>>>>> dump_stack_lvl+0x44/0x58
>>>>> dump_stack+0x14/0x1c
>>>>> panic+0x2e0/0x33c
>>>>> nmi_panic+0x68/0x6c
>>>>> arm64_serror_panic+0x68/0x78
>>>>> do_serror+0x24/0x54
>>>>> el1h_64_error_handler+0x2c/0x40
>>>>> el1h_64_error+0x64/0x68
>>>>> setup_arch+0x13c/0x5ac
>>>>> start_kernel+0x5c/0x5b8
>>>>> __primary_switched+0xb4/0xbc
>>>>> 0---[ end Kernel panic - not syncing: Asynchronous SError Interrupt ]---
>>>>>
>>>>> Can you please advice how to proceed with debugging?
>>>>>
>>>>> Thanks in advanced,
>>>>> Cheers,
>>>>> Lior.
>>>>>
>>>>>
>>>>
>>>
>
^ permalink raw reply [flat|nested] 16+ messages in thread
* RE: Debugging early SError exception
2023-12-21 8:29 ` Dirk Behme
@ 2023-12-21 10:04 ` Lior Weintraub
2023-12-21 11:19 ` Dirk Behme
0 siblings, 1 reply; 16+ messages in thread
From: Lior Weintraub @ 2023-12-21 10:04 UTC (permalink / raw)
To: Dirk Behme, linux-embedded
Thanks Dirk,
Regarding the earlyprintk, not sure I know how to make it work.
I have defined CONFIG_EARLY_PRINTK=y and CONFIG_DEBUG_LL=y on my config but it doesn't seem to work.
Do I need to pass something in the bootargs from the U-BOOT?
Do I need to add that into my device tree?
(Tried to set bootargs = "console=ttyS0,115200 earlyprintk"; under "chosen" on my DT but it didn't work)
The UART I am using is "snps,dw-apb-uart".
Last week, to output the early logs I have implemented this hack:
1. Modify printk macro to run my print_func
2. This print_func wrote the characters into a single global variable (u32 simul_uart;)
3. Get the address location of this global variable and extract all writes to it from the Tarmac logs.
This is a very slow and tedious process but it helped me identify the initial SError.
Initially I thought I can write directly into the UART FIFO register (which I know the address) but this didn't work because Linux already setup the MMU so I guess I need to know the virtual address of this FIFO.
Do I need to use __phys_to_virt of some sort?
Cheers,
Lior.
> -----Original Message-----
> From: Dirk Behme <dirk.behme@gmail.com>
> Sent: Thursday, December 21, 2023 10:30 AM
> To: Lior Weintraub <liorw@pliops.com>; linux-embedded@vger.kernel.org
> Subject: Re: Debugging early SError exception
>
> [You don't often get email from dirk.behme@gmail.com. Learn why this is
> important at https://aka.ms/LearnAboutSenderIdentification ]
>
> CAUTION: External Sender
>
> Am 21.12.23 um 08:43 schrieb Lior Weintraub:
> > Hi Dirk,
> >
> > We found that the issue was at the early stages of Barebox (a.k.a U-BOOT
> v2).
>
> Glad to hear that! :)
>
> > Our implementation of putc_ll (on debug_ll) was writing into the UART Tx
> FIFO without checking if the FIFO is full.
> > Once the fifo got full it caused this SError probably because the UART IP
> generated an apberror signal.
>
> Thanks for the report!
>
> > Now the Linux is running and doesn't report the SError again but now we
> face another issue.
> > We see that the PC is getting into a "report_bug" function.
> > The Linux doesn't print anything to the UART (probably since it hasn't got to
> the point where the console is configured?).
>
> For cases like this using earlyprintk is usually a good option. Check
> the Linux kernel serial console (UART) dirver of you SoC if it
> supports it. In the end it should be "just" a function in the serial
> console driver which outputs the console data via polling before
> (later) the interrupt driven console part takes over.
>
> Best regards
>
> Dirk
>
>
> > Since our debug means are limited it can take some time to find the root
> cause.
> >
> > I will keep you posted and update our findings.
> > Love to hear your thoughts,
> >
> > Cheers,
> > Lior.
> >
> >
> >> -----Original Message-----
> >> From: Dirk Behme <dirk.behme@gmail.com>
> >> Sent: Tuesday, December 19, 2023 3:37 PM
> >> To: Lior Weintraub <liorw@pliops.com>; linux-embedded@vger.kernel.org
> >> Subject: Re: Debugging early SError exception
> >>
> >> [You don't often get email from dirk.behme@gmail.com. Learn why this is
> >> important at https://aka.ms/LearnAboutSenderIdentification ]
> >>
> >> CAUTION: External Sender
> >>
> >> Am 19.12.23 um 14:23 schrieb Lior Weintraub:
> >>> Thanks Dirk,
> >>
> >> Welcome :)
> >>
> >> In case you find the root cause it would be nice to get some generic
> >> description of it so that we can learn something :)
> >>
> >> Best regards
> >>
> >> Dirk
> >>
> >>
> >>>> -----Original Message-----
> >>>> From: Dirk Behme <dirk.behme@gmail.com>
> >>>> Sent: Tuesday, December 19, 2023 9:09 AM
> >>>> To: Lior Weintraub <liorw@pliops.com>; linux-
> embedded@vger.kernel.org
> >>>> Subject: Re: Debugging early SError exception
> >>>>
> >>>> [You don't often get email from dirk.behme@gmail.com. Learn why this
> is
> >>>> important at https://aka.ms/LearnAboutSenderIdentification ]
> >>>>
> >>>> CAUTION: External Sender
> >>>>
> >>>> Am 17.12.23 um 22:32 schrieb Lior Weintraub:
> >>>>> Hi,
> >>>>>
> >>>>> We have a new SoC with eLinux porting (kernel v6.5).
> >>>>> This SoC is ARM64 (A53) single core based device.
> >>>>> It runs correctly on QEMU but fails with SError on emulation platform
> >>>> (Synopsys Zebu running our SoC model).
> >>>>> There is no debugger connected to this emulation but there are several
> >>>> debug capabilities we can use:
> >>>>> 1. Generating wave dump of CPU signals
> >>>>> 2. Generate a Tarmac log
> >>>>> 3. UART
> >>>>>
> >>>>> Since the SError happens at early stages of Linux boot the UART is not
> >>>> enabled yet.
> >>>>> From the Tarmac log we can see:
> >>>>> 3824884521 ps ES (ffff800080760888:d65f03c0) O el1h_ns: ret
> >>>> (parse_early_param)
> >>>>> 3824884522 ps ES (ffff800080763a60:d2801800) O el1h_ns: mov
> >> x0,
> >>>> #0xc0 // #192 (setup_arch)
> >>>>> R X0 (AARCH64) 00000000 000000c0
> >>>>> 3824884523 ps ES (ffff800080763a64:d51b4220) O el1h_ns: msr
> >>>> daif, x0 (setup_arch)
> >>>>> R CPSR 600000c5
> >>>>> 3824884529 ps ES System Error (Abort)
> >>>>> EXC [0x380] SError/vSError Current EL with SP_ELx
> >>>>> R ESR_EL1 (AARCH64) bf000002
> >>>>> R CPSR 600003c5
> >>>>> R SPSR_EL1 (AARCH64) 600000c5
> >>>>> R ELR_EL1 (AARCH64) ffff8000 80763a68
> >>>>> 3824884925 ps ES (ffff800080010b80:d10543ff) O el1h_ns: sub
> >> sp,
> >>>> sp, #0x150 (vectors)
> >>>>> R SP_EL1 (AARCH64) ffff8000 808f3c50
> >>>>> 3824884925 ps ES (ffff800080010b84:8b2063ff) O el1h_ns: add
> >> sp,
> >>>> sp, x0 (vectors)
> >>>>> R SP_EL1 (AARCH64) ffff8000 808f3d10
> >>>>> 3824884926 ps ES (ffff800080010b88:cb2063e0) O el1h_ns: sub
> >> x0,
> >>>> sp, x0 (vectors)
> >>>>> R X0 (AARCH64) ffff8000 808f3c50
> >>>>> 3824884927 ps ES (ffff800080010b8c:37700080) O el1h_ns: tbnz
> >> w0,
> >>>> #14, ffff800080010b9c <vectors+0x39c> (vectors)
> >>>>> 3824884935 ps ES (ffff800080010b90:cb2063e0) O el1h_ns: sub
> >> x0,
> >>>> sp, x0 (vectors)
> >>>>> R X0 (AARCH64) 00000000 000000c0
> >>>>> 3824884937 ps ES (ffff800080010b94:cb2063ff) O el1h_ns: sub
> sp,
> >>>> sp, x0 (vectors)
> >>>>> R SP_EL1 (AARCH64) ffff8000 808f3c50
> >>>>> 3824884938 ps ES (ffff800080010b98:140001ef) O el1h_ns: b
> >>>> ffff800080011354 <el1h_64_error> (vectors)
> >>>>>
> >>>>> If I understand correctly, the exception happened sometime earlier and
> >> only
> >>>> now Linux boot code (setup_arch) opened the exception handling and as
> a
> >>>> result we immediately jump to the SError exception handler.
> >>>>
> >>>>
> >>>> Yes, that sounds reasonable. If I understood correctly, you are
> >>>> running something "quite new" on some software (QEMU) and
> hardware
> >>>> (Synopsis) simulators.
> >>>>
> >>>> That would mean that you have new hardware with e.g. new memory
> map
> >>>> not used before. What you describe might sound like in the code before
> >>>> Linux (boot loader) there is anything resulting in the SError. This
> >>>> might be an access to non-existing or non-enabled hardware. I.e. it
> >>>> might be that you try to access (read/write) an address what is not
> >>>> available, yet (or just invalid). It's hard to debug that. In case you
> >>>> are able to modify the code before Linux (the boot loader?) you might
> >>>> try to enable SError exceptions, there, too. To get it earlier and
> >>>> with that make the search window smaller. I'm not that familiar with
> >>>> QEMU, but could you try to trace which (all?) hardware accesses your
> >>>> code does. And with that analyse all accesses and with that check if
> >>>> all these accesses are valid even on the hardware (Synopsis) emulation
> >>>> system? That should be checked from valid address and from hardware
> >>>> subsystem enablement point of view.
> >>>>
> >>>> Hth,
> >>>>
> >>>> Dirk
> >>>>
> >>>>
> >>>>> From the Linux source:
> >>>>> parse_early_param();
> >>>>>
> >>>>> dynamic_scs_init();
> >>>>>
> >>>>> /*
> >>>>> * Unmask asynchronous aborts and fiq after bringing up possible
> >>>>> * earlycon. (Report possible System Errors once we can report this
> >>>>> * occurred).
> >>>>> */
> >>>>> local_daif_restore(DAIF_PROCCTX_NOIRQ); <---- This is when we
> get
> >> the
> >>>> exception.
> >>>>>
> >>>>> After some kernel hacking (replacing printk) we could extract the logs:
> >>>>> 6Booting Linux on physical CPU 0x0000000000 [0x410fd034]
> >>>>> 5Linux version 6.5.0 (pliops@dev-liorw) (aarch64-buildroot-linux-gnu-
> >>>> gcc.br_real (Buildroot 2023.02.1-95-g8391404e23) 11.3.0, GNU ld
> (GNU
> >>>> Binutils) 2.38) #101 SMP Sun Dec 17 20:09:06 IST 2023
> >>>>> 6Machine model: Pliops Spider MK-I EVK
> >>>>> 2SError Interrupt on CPU0, code 0x00000000bf000002 -- SError
> >>>>> CPU: 0 PID: 0 Comm: swapper Not tainted 6.5.0 #101
> >>>>> Hardware name: Pliops Spider MK-I EVK (DT)
> >>>>> pstate: 600000c5 (nZCv daIF -PAN -UAO -TCO -DIT -SSBS BTYPE=--)
> >>>>> pc : setup_arch+0x13c/0x5ac
> >>>>> lr : setup_arch+0x134/0x5ac
> >>>>> sp : ffff8000808f3da0
> >>>>> x29: ffff8000808f3da0c x28: 0000000008758074c x27:
> >>>> 0000000005e31b58c
> >>>>> x26: 0000000000000001c x25: 0000000007e5f728c x24:
> >>>> ffff8000808f8000c
> >>>>> x23: ffff8000808f8600c x22: ffff8000807b6000c x21:
> >> ffff800080010000c
> >>>>> x20: ffff800080a1e000c x19: fffffbfffddfe190c x18:
> 000000002266684ac
> >>>>> x17: 00000000fcad60bbc x16: 0000000000001800c x15:
> >>>> 0000000000000008c
> >>>>> x14: ffffffffffffffffc x13: 0000000000000000c x12:
> 0000000000000003c
> >>>>> x11: 0101010101010101c x10: ffffffffffee87dfc x9 :
> >> 0000000000000038c
> >>>>> x8 : 0101010101010101c x7 : 7f7f7f7f7f7f7f7fc x6 :
> >> 0000000000000001c
> >>>>> x5 : 0000000000000000c x4 : 8000000000000000c x3 :
> >>>> 0000000000000065c
> >>>>> x2 : 0000000000000000c x1 : 0000000000000000c x0 :
> >>>> 00000000000000c0c
> >>>>> 0Kernel panic - not syncing: Asynchronous SError Interrupt
> >>>>> CPU: 0 PID: 0 Comm: swapper Not tainted 6.5.0 #101
> >>>>> Hardware name: Pliops Spider MK-I EVK (DT)
> >>>>> Call trace:
> >>>>> dump_backtrace+0x9c/0xd0
> >>>>> show_stack+0x14/0x1c
> >>>>> dump_stack_lvl+0x44/0x58
> >>>>> dump_stack+0x14/0x1c
> >>>>> panic+0x2e0/0x33c
> >>>>> nmi_panic+0x68/0x6c
> >>>>> arm64_serror_panic+0x68/0x78
> >>>>> do_serror+0x24/0x54
> >>>>> el1h_64_error_handler+0x2c/0x40
> >>>>> el1h_64_error+0x64/0x68
> >>>>> setup_arch+0x13c/0x5ac
> >>>>> start_kernel+0x5c/0x5b8
> >>>>> __primary_switched+0xb4/0xbc
> >>>>> 0---[ end Kernel panic - not syncing: Asynchronous SError Interrupt ]---
> >>>>>
> >>>>> Can you please advice how to proceed with debugging?
> >>>>>
> >>>>> Thanks in advanced,
> >>>>> Cheers,
> >>>>> Lior.
> >>>>>
> >>>>>
> >>>>
> >>>
> >
^ permalink raw reply [flat|nested] 16+ messages in thread
* Re: Debugging early SError exception
2023-12-21 10:04 ` Lior Weintraub
@ 2023-12-21 11:19 ` Dirk Behme
2023-12-21 11:36 ` Heiko Schocher
0 siblings, 1 reply; 16+ messages in thread
From: Dirk Behme @ 2023-12-21 11:19 UTC (permalink / raw)
To: Lior Weintraub, linux-embedded
Am 21.12.23 um 11:04 schrieb Lior Weintraub:
> Thanks Dirk,
>
> Regarding the earlyprintk, not sure I know how to make it work.
> I have defined CONFIG_EARLY_PRINTK=y and CONFIG_DEBUG_LL=y on my config but it doesn't seem to work.
> Do I need to pass something in the bootargs from the U-BOOT?
> Do I need to add that into my device tree?
> (Tried to set bootargs = "console=ttyS0,115200 earlyprintk"; under "chosen" on my DT but it didn't work)
Yes, what has to be enabled and what not and what has to be set how is
often confusing. I think this is not common for all systems, so I
think to be on the safe side you have to look into the code for you
system. Or short; The code is the documentation ;)
> The UART I am using is "snps,dw-apb-uart".
>
> Last week, to output the early logs I have implemented this hack:
> 1. Modify printk macro to run my print_func
> 2. This print_func wrote the characters into a single global variable (u32 simul_uart;)
> 3. Get the address location of this global variable and extract all writes to it from the Tarmac logs.
>
> This is a very slow and tedious process but it helped me identify the initial SError.
> Initially I thought I can write directly into the UART FIFO register (which I know the address) but this didn't work because Linux already setup the MMU so I guess I need to know the virtual address of this FIFO.
> Do I need to use __phys_to_virt of some sort?
Yes, I think so. Have a look to the existing serial driver, too. It
should do whats needed, and you can borrow that, then.
Best regards
Dirk
> Cheers,
> Lior.
>
>> -----Original Message-----
>> From: Dirk Behme <dirk.behme@gmail.com>
>> Sent: Thursday, December 21, 2023 10:30 AM
>> To: Lior Weintraub <liorw@pliops.com>; linux-embedded@vger.kernel.org
>> Subject: Re: Debugging early SError exception
>>
>> [You don't often get email from dirk.behme@gmail.com. Learn why this is
>> important at https://aka.ms/LearnAboutSenderIdentification ]
>>
>> CAUTION: External Sender
>>
>> Am 21.12.23 um 08:43 schrieb Lior Weintraub:
>>> Hi Dirk,
>>>
>>> We found that the issue was at the early stages of Barebox (a.k.a U-BOOT
>> v2).
>>
>> Glad to hear that! :)
>>
>>> Our implementation of putc_ll (on debug_ll) was writing into the UART Tx
>> FIFO without checking if the FIFO is full.
>>> Once the fifo got full it caused this SError probably because the UART IP
>> generated an apberror signal.
>>
>> Thanks for the report!
>>
>>> Now the Linux is running and doesn't report the SError again but now we
>> face another issue.
>>> We see that the PC is getting into a "report_bug" function.
>>> The Linux doesn't print anything to the UART (probably since it hasn't got to
>> the point where the console is configured?).
>>
>> For cases like this using earlyprintk is usually a good option. Check
>> the Linux kernel serial console (UART) dirver of you SoC if it
>> supports it. In the end it should be "just" a function in the serial
>> console driver which outputs the console data via polling before
>> (later) the interrupt driven console part takes over.
>>
>> Best regards
>>
>> Dirk
>>
>>
>>> Since our debug means are limited it can take some time to find the root
>> cause.
>>>
>>> I will keep you posted and update our findings.
>>> Love to hear your thoughts,
>>>
>>> Cheers,
>>> Lior.
>>>
>>>
>>>> -----Original Message-----
>>>> From: Dirk Behme <dirk.behme@gmail.com>
>>>> Sent: Tuesday, December 19, 2023 3:37 PM
>>>> To: Lior Weintraub <liorw@pliops.com>; linux-embedded@vger.kernel.org
>>>> Subject: Re: Debugging early SError exception
>>>>
>>>> [You don't often get email from dirk.behme@gmail.com. Learn why this is
>>>> important at https://aka.ms/LearnAboutSenderIdentification ]
>>>>
>>>> CAUTION: External Sender
>>>>
>>>> Am 19.12.23 um 14:23 schrieb Lior Weintraub:
>>>>> Thanks Dirk,
>>>>
>>>> Welcome :)
>>>>
>>>> In case you find the root cause it would be nice to get some generic
>>>> description of it so that we can learn something :)
>>>>
>>>> Best regards
>>>>
>>>> Dirk
>>>>
>>>>
>>>>>> -----Original Message-----
>>>>>> From: Dirk Behme <dirk.behme@gmail.com>
>>>>>> Sent: Tuesday, December 19, 2023 9:09 AM
>>>>>> To: Lior Weintraub <liorw@pliops.com>; linux-
>> embedded@vger.kernel.org
>>>>>> Subject: Re: Debugging early SError exception
>>>>>>
>>>>>> [You don't often get email from dirk.behme@gmail.com. Learn why this
>> is
>>>>>> important at https://aka.ms/LearnAboutSenderIdentification ]
>>>>>>
>>>>>> CAUTION: External Sender
>>>>>>
>>>>>> Am 17.12.23 um 22:32 schrieb Lior Weintraub:
>>>>>>> Hi,
>>>>>>>
>>>>>>> We have a new SoC with eLinux porting (kernel v6.5).
>>>>>>> This SoC is ARM64 (A53) single core based device.
>>>>>>> It runs correctly on QEMU but fails with SError on emulation platform
>>>>>> (Synopsys Zebu running our SoC model).
>>>>>>> There is no debugger connected to this emulation but there are several
>>>>>> debug capabilities we can use:
>>>>>>> 1. Generating wave dump of CPU signals
>>>>>>> 2. Generate a Tarmac log
>>>>>>> 3. UART
>>>>>>>
>>>>>>> Since the SError happens at early stages of Linux boot the UART is not
>>>>>> enabled yet.
>>>>>>> From the Tarmac log we can see:
>>>>>>> 3824884521 ps ES (ffff800080760888:d65f03c0) O el1h_ns: ret
>>>>>> (parse_early_param)
>>>>>>> 3824884522 ps ES (ffff800080763a60:d2801800) O el1h_ns: mov
>>>> x0,
>>>>>> #0xc0 // #192 (setup_arch)
>>>>>>> R X0 (AARCH64) 00000000 000000c0
>>>>>>> 3824884523 ps ES (ffff800080763a64:d51b4220) O el1h_ns: msr
>>>>>> daif, x0 (setup_arch)
>>>>>>> R CPSR 600000c5
>>>>>>> 3824884529 ps ES System Error (Abort)
>>>>>>> EXC [0x380] SError/vSError Current EL with SP_ELx
>>>>>>> R ESR_EL1 (AARCH64) bf000002
>>>>>>> R CPSR 600003c5
>>>>>>> R SPSR_EL1 (AARCH64) 600000c5
>>>>>>> R ELR_EL1 (AARCH64) ffff8000 80763a68
>>>>>>> 3824884925 ps ES (ffff800080010b80:d10543ff) O el1h_ns: sub
>>>> sp,
>>>>>> sp, #0x150 (vectors)
>>>>>>> R SP_EL1 (AARCH64) ffff8000 808f3c50
>>>>>>> 3824884925 ps ES (ffff800080010b84:8b2063ff) O el1h_ns: add
>>>> sp,
>>>>>> sp, x0 (vectors)
>>>>>>> R SP_EL1 (AARCH64) ffff8000 808f3d10
>>>>>>> 3824884926 ps ES (ffff800080010b88:cb2063e0) O el1h_ns: sub
>>>> x0,
>>>>>> sp, x0 (vectors)
>>>>>>> R X0 (AARCH64) ffff8000 808f3c50
>>>>>>> 3824884927 ps ES (ffff800080010b8c:37700080) O el1h_ns: tbnz
>>>> w0,
>>>>>> #14, ffff800080010b9c <vectors+0x39c> (vectors)
>>>>>>> 3824884935 ps ES (ffff800080010b90:cb2063e0) O el1h_ns: sub
>>>> x0,
>>>>>> sp, x0 (vectors)
>>>>>>> R X0 (AARCH64) 00000000 000000c0
>>>>>>> 3824884937 ps ES (ffff800080010b94:cb2063ff) O el1h_ns: sub
>> sp,
>>>>>> sp, x0 (vectors)
>>>>>>> R SP_EL1 (AARCH64) ffff8000 808f3c50
>>>>>>> 3824884938 ps ES (ffff800080010b98:140001ef) O el1h_ns: b
>>>>>> ffff800080011354 <el1h_64_error> (vectors)
>>>>>>>
>>>>>>> If I understand correctly, the exception happened sometime earlier and
>>>> only
>>>>>> now Linux boot code (setup_arch) opened the exception handling and as
>> a
>>>>>> result we immediately jump to the SError exception handler.
>>>>>>
>>>>>>
>>>>>> Yes, that sounds reasonable. If I understood correctly, you are
>>>>>> running something "quite new" on some software (QEMU) and
>> hardware
>>>>>> (Synopsis) simulators.
>>>>>>
>>>>>> That would mean that you have new hardware with e.g. new memory
>> map
>>>>>> not used before. What you describe might sound like in the code before
>>>>>> Linux (boot loader) there is anything resulting in the SError. This
>>>>>> might be an access to non-existing or non-enabled hardware. I.e. it
>>>>>> might be that you try to access (read/write) an address what is not
>>>>>> available, yet (or just invalid). It's hard to debug that. In case you
>>>>>> are able to modify the code before Linux (the boot loader?) you might
>>>>>> try to enable SError exceptions, there, too. To get it earlier and
>>>>>> with that make the search window smaller. I'm not that familiar with
>>>>>> QEMU, but could you try to trace which (all?) hardware accesses your
>>>>>> code does. And with that analyse all accesses and with that check if
>>>>>> all these accesses are valid even on the hardware (Synopsis) emulation
>>>>>> system? That should be checked from valid address and from hardware
>>>>>> subsystem enablement point of view.
>>>>>>
>>>>>> Hth,
>>>>>>
>>>>>> Dirk
>>>>>>
>>>>>>
>>>>>>> From the Linux source:
>>>>>>> parse_early_param();
>>>>>>>
>>>>>>> dynamic_scs_init();
>>>>>>>
>>>>>>> /*
>>>>>>> * Unmask asynchronous aborts and fiq after bringing up possible
>>>>>>> * earlycon. (Report possible System Errors once we can report this
>>>>>>> * occurred).
>>>>>>> */
>>>>>>> local_daif_restore(DAIF_PROCCTX_NOIRQ); <---- This is when we
>> get
>>>> the
>>>>>> exception.
>>>>>>>
>>>>>>> After some kernel hacking (replacing printk) we could extract the logs:
>>>>>>> 6Booting Linux on physical CPU 0x0000000000 [0x410fd034]
>>>>>>> 5Linux version 6.5.0 (pliops@dev-liorw) (aarch64-buildroot-linux-gnu-
>>>>>> gcc.br_real (Buildroot 2023.02.1-95-g8391404e23) 11.3.0, GNU ld
>> (GNU
>>>>>> Binutils) 2.38) #101 SMP Sun Dec 17 20:09:06 IST 2023
>>>>>>> 6Machine model: Pliops Spider MK-I EVK
>>>>>>> 2SError Interrupt on CPU0, code 0x00000000bf000002 -- SError
>>>>>>> CPU: 0 PID: 0 Comm: swapper Not tainted 6.5.0 #101
>>>>>>> Hardware name: Pliops Spider MK-I EVK (DT)
>>>>>>> pstate: 600000c5 (nZCv daIF -PAN -UAO -TCO -DIT -SSBS BTYPE=--)
>>>>>>> pc : setup_arch+0x13c/0x5ac
>>>>>>> lr : setup_arch+0x134/0x5ac
>>>>>>> sp : ffff8000808f3da0
>>>>>>> x29: ffff8000808f3da0c x28: 0000000008758074c x27:
>>>>>> 0000000005e31b58c
>>>>>>> x26: 0000000000000001c x25: 0000000007e5f728c x24:
>>>>>> ffff8000808f8000c
>>>>>>> x23: ffff8000808f8600c x22: ffff8000807b6000c x21:
>>>> ffff800080010000c
>>>>>>> x20: ffff800080a1e000c x19: fffffbfffddfe190c x18:
>> 000000002266684ac
>>>>>>> x17: 00000000fcad60bbc x16: 0000000000001800c x15:
>>>>>> 0000000000000008c
>>>>>>> x14: ffffffffffffffffc x13: 0000000000000000c x12:
>> 0000000000000003c
>>>>>>> x11: 0101010101010101c x10: ffffffffffee87dfc x9 :
>>>> 0000000000000038c
>>>>>>> x8 : 0101010101010101c x7 : 7f7f7f7f7f7f7f7fc x6 :
>>>> 0000000000000001c
>>>>>>> x5 : 0000000000000000c x4 : 8000000000000000c x3 :
>>>>>> 0000000000000065c
>>>>>>> x2 : 0000000000000000c x1 : 0000000000000000c x0 :
>>>>>> 00000000000000c0c
>>>>>>> 0Kernel panic - not syncing: Asynchronous SError Interrupt
>>>>>>> CPU: 0 PID: 0 Comm: swapper Not tainted 6.5.0 #101
>>>>>>> Hardware name: Pliops Spider MK-I EVK (DT)
>>>>>>> Call trace:
>>>>>>> dump_backtrace+0x9c/0xd0
>>>>>>> show_stack+0x14/0x1c
>>>>>>> dump_stack_lvl+0x44/0x58
>>>>>>> dump_stack+0x14/0x1c
>>>>>>> panic+0x2e0/0x33c
>>>>>>> nmi_panic+0x68/0x6c
>>>>>>> arm64_serror_panic+0x68/0x78
>>>>>>> do_serror+0x24/0x54
>>>>>>> el1h_64_error_handler+0x2c/0x40
>>>>>>> el1h_64_error+0x64/0x68
>>>>>>> setup_arch+0x13c/0x5ac
>>>>>>> start_kernel+0x5c/0x5b8
>>>>>>> __primary_switched+0xb4/0xbc
>>>>>>> 0---[ end Kernel panic - not syncing: Asynchronous SError Interrupt ]---
>>>>>>>
>>>>>>> Can you please advice how to proceed with debugging?
>>>>>>>
>>>>>>> Thanks in advanced,
>>>>>>> Cheers,
>>>>>>> Lior.
>>>>>>>
>>>>>>>
>>>>>>
>>>>>
>>>
>
^ permalink raw reply [flat|nested] 16+ messages in thread
* Re: Debugging early SError exception
2023-12-21 11:19 ` Dirk Behme
@ 2023-12-21 11:36 ` Heiko Schocher
2023-12-21 12:04 ` Lior Weintraub
2023-12-22 7:03 ` Lior Weintraub
0 siblings, 2 replies; 16+ messages in thread
From: Heiko Schocher @ 2023-12-21 11:36 UTC (permalink / raw)
To: Lior Weintraub; +Cc: Dirk Behme, linux-embedded
Hi Lior,
On 21.12.23 12:19, Dirk Behme wrote:
> Am 21.12.23 um 11:04 schrieb Lior Weintraub:
>> Thanks Dirk,
>>
>> Regarding the earlyprintk, not sure I know how to make it work.
>> I have defined CONFIG_EARLY_PRINTK=y and CONFIG_DEBUG_LL=y on my config but it doesn't seem to work.
>> Do I need to pass something in the bootargs from the U-BOOT?
>> Do I need to add that into my device tree?
>> (Tried to set bootargs = "console=ttyS0,115200 earlyprintk"; under "chosen" on my DT but it didn't
>> work)
>
> Yes, what has to be enabled and what not and what has to be set how is often confusing. I think this
> is not common for all systems, so I think to be on the safe side you have to look into the code for
> you system. Or short; The code is the documentation ;)
>
>
>> The UART I am using is "snps,dw-apb-uart".
>>
>> Last week, to output the early logs I have implemented this hack:
>> 1. Modify printk macro to run my print_func
>> 2. This print_func wrote the characters into a single global variable (u32 simul_uart;)
>> 3. Get the address location of this global variable and extract all writes to it from the Tarmac
>> logs.
>>
>> This is a very slow and tedious process but it helped me identify the initial SError.
>> Initially I thought I can write directly into the UART FIFO register (which I know the address)
>> but this didn't work because Linux already setup the MMU so I guess I need to know the virtual
>> address of this FIFO.
>> Do I need to use __phys_to_virt of some sort?
>
> Yes, I think so. Have a look to the existing serial driver, too. It should do whats needed, and you
> can borrow that, then.
If you have access to the RAM after the crash (through a debugger or in
your bootloader) and your mem is stable, find out the address of __log_buf
in System.map. Thats the buffer where printk writes into it, and so dumping
the content is what you would see in case uart works...
Hope it helps!
bye,
Heiko
>
> Best regards
>
> Dirk
>
>
>> Cheers,
>> Lior.
>>
>>> -----Original Message-----
>>> From: Dirk Behme <dirk.behme@gmail.com>
>>> Sent: Thursday, December 21, 2023 10:30 AM
>>> To: Lior Weintraub <liorw@pliops.com>; linux-embedded@vger.kernel.org
>>> Subject: Re: Debugging early SError exception
>>>
>>> [You don't often get email from dirk.behme@gmail.com. Learn why this is
>>> important at https://aka.ms/LearnAboutSenderIdentification ]
>>>
>>> CAUTION: External Sender
>>>
>>> Am 21.12.23 um 08:43 schrieb Lior Weintraub:
>>>> Hi Dirk,
>>>>
>>>> We found that the issue was at the early stages of Barebox (a.k.a U-BOOT
>>> v2).
>>>
>>> Glad to hear that! :)
>>>
>>>> Our implementation of putc_ll (on debug_ll) was writing into the UART Tx
>>> FIFO without checking if the FIFO is full.
>>>> Once the fifo got full it caused this SError probably because the UART IP
>>> generated an apberror signal.
>>>
>>> Thanks for the report!
>>>
>>>> Now the Linux is running and doesn't report the SError again but now we
>>> face another issue.
>>>> We see that the PC is getting into a "report_bug" function.
>>>> The Linux doesn't print anything to the UART (probably since it hasn't got to
>>> the point where the console is configured?).
>>>
>>> For cases like this using earlyprintk is usually a good option. Check
>>> the Linux kernel serial console (UART) dirver of you SoC if it
>>> supports it. In the end it should be "just" a function in the serial
>>> console driver which outputs the console data via polling before
>>> (later) the interrupt driven console part takes over.
>>>
>>> Best regards
>>>
>>> Dirk
>>>
>>>
>>>> Since our debug means are limited it can take some time to find the root
>>> cause.
>>>>
>>>> I will keep you posted and update our findings.
>>>> Love to hear your thoughts,
>>>>
>>>> Cheers,
>>>> Lior.
>>>>
>>>>
>>>>> -----Original Message-----
>>>>> From: Dirk Behme <dirk.behme@gmail.com>
>>>>> Sent: Tuesday, December 19, 2023 3:37 PM
>>>>> To: Lior Weintraub <liorw@pliops.com>; linux-embedded@vger.kernel.org
>>>>> Subject: Re: Debugging early SError exception
>>>>>
>>>>> [You don't often get email from dirk.behme@gmail.com. Learn why this is
>>>>> important at https://aka.ms/LearnAboutSenderIdentification ]
>>>>>
>>>>> CAUTION: External Sender
>>>>>
>>>>> Am 19.12.23 um 14:23 schrieb Lior Weintraub:
>>>>>> Thanks Dirk,
>>>>>
>>>>> Welcome :)
>>>>>
>>>>> In case you find the root cause it would be nice to get some generic
>>>>> description of it so that we can learn something :)
>>>>>
>>>>> Best regards
>>>>>
>>>>> Dirk
>>>>>
>>>>>
>>>>>>> -----Original Message-----
>>>>>>> From: Dirk Behme <dirk.behme@gmail.com>
>>>>>>> Sent: Tuesday, December 19, 2023 9:09 AM
>>>>>>> To: Lior Weintraub <liorw@pliops.com>; linux-
>>> embedded@vger.kernel.org
>>>>>>> Subject: Re: Debugging early SError exception
>>>>>>>
>>>>>>> [You don't often get email from dirk.behme@gmail.com. Learn why this
>>> is
>>>>>>> important at https://aka.ms/LearnAboutSenderIdentification ]
>>>>>>>
>>>>>>> CAUTION: External Sender
>>>>>>>
>>>>>>> Am 17.12.23 um 22:32 schrieb Lior Weintraub:
>>>>>>>> Hi,
>>>>>>>>
>>>>>>>> We have a new SoC with eLinux porting (kernel v6.5).
>>>>>>>> This SoC is ARM64 (A53) single core based device.
>>>>>>>> It runs correctly on QEMU but fails with SError on emulation platform
>>>>>>> (Synopsys Zebu running our SoC model).
>>>>>>>> There is no debugger connected to this emulation but there are several
>>>>>>> debug capabilities we can use:
>>>>>>>> 1. Generating wave dump of CPU signals
>>>>>>>> 2. Generate a Tarmac log
>>>>>>>> 3. UART
>>>>>>>>
>>>>>>>> Since the SError happens at early stages of Linux boot the UART is not
>>>>>>> enabled yet.
>>>>>>>> From the Tarmac log we can see:
>>>>>>>> 3824884521 ps ES (ffff800080760888:d65f03c0) O el1h_ns: ret
>>>>>>> (parse_early_param)
>>>>>>>> 3824884522 ps ES (ffff800080763a60:d2801800) O el1h_ns: mov
>>>>> x0,
>>>>>>> #0xc0 // #192 (setup_arch)
>>>>>>>> R X0 (AARCH64) 00000000 000000c0
>>>>>>>> 3824884523 ps ES (ffff800080763a64:d51b4220) O el1h_ns: msr
>>>>>>> daif, x0 (setup_arch)
>>>>>>>> R CPSR 600000c5
>>>>>>>> 3824884529 ps ES System Error (Abort)
>>>>>>>> EXC [0x380] SError/vSError Current EL with SP_ELx
>>>>>>>> R ESR_EL1 (AARCH64) bf000002
>>>>>>>> R CPSR 600003c5
>>>>>>>> R SPSR_EL1 (AARCH64) 600000c5
>>>>>>>> R ELR_EL1 (AARCH64) ffff8000 80763a68
>>>>>>>> 3824884925 ps ES (ffff800080010b80:d10543ff) O el1h_ns: sub
>>>>> sp,
>>>>>>> sp, #0x150 (vectors)
>>>>>>>> R SP_EL1 (AARCH64) ffff8000 808f3c50
>>>>>>>> 3824884925 ps ES (ffff800080010b84:8b2063ff) O el1h_ns: add
>>>>> sp,
>>>>>>> sp, x0 (vectors)
>>>>>>>> R SP_EL1 (AARCH64) ffff8000 808f3d10
>>>>>>>> 3824884926 ps ES (ffff800080010b88:cb2063e0) O el1h_ns: sub
>>>>> x0,
>>>>>>> sp, x0 (vectors)
>>>>>>>> R X0 (AARCH64) ffff8000 808f3c50
>>>>>>>> 3824884927 ps ES (ffff800080010b8c:37700080) O el1h_ns: tbnz
>>>>> w0,
>>>>>>> #14, ffff800080010b9c <vectors+0x39c> (vectors)
>>>>>>>> 3824884935 ps ES (ffff800080010b90:cb2063e0) O el1h_ns: sub
>>>>> x0,
>>>>>>> sp, x0 (vectors)
>>>>>>>> R X0 (AARCH64) 00000000 000000c0
>>>>>>>> 3824884937 ps ES (ffff800080010b94:cb2063ff) O el1h_ns: sub
>>> sp,
>>>>>>> sp, x0 (vectors)
>>>>>>>> R SP_EL1 (AARCH64) ffff8000 808f3c50
>>>>>>>> 3824884938 ps ES (ffff800080010b98:140001ef) O el1h_ns: b
>>>>>>> ffff800080011354 <el1h_64_error> (vectors)
>>>>>>>>
>>>>>>>> If I understand correctly, the exception happened sometime earlier and
>>>>> only
>>>>>>> now Linux boot code (setup_arch) opened the exception handling and as
>>> a
>>>>>>> result we immediately jump to the SError exception handler.
>>>>>>>
>>>>>>>
>>>>>>> Yes, that sounds reasonable. If I understood correctly, you are
>>>>>>> running something "quite new" on some software (QEMU) and
>>> hardware
>>>>>>> (Synopsis) simulators.
>>>>>>>
>>>>>>> That would mean that you have new hardware with e.g. new memory
>>> map
>>>>>>> not used before. What you describe might sound like in the code before
>>>>>>> Linux (boot loader) there is anything resulting in the SError. This
>>>>>>> might be an access to non-existing or non-enabled hardware. I.e. it
>>>>>>> might be that you try to access (read/write) an address what is not
>>>>>>> available, yet (or just invalid). It's hard to debug that. In case you
>>>>>>> are able to modify the code before Linux (the boot loader?) you might
>>>>>>> try to enable SError exceptions, there, too. To get it earlier and
>>>>>>> with that make the search window smaller. I'm not that familiar with
>>>>>>> QEMU, but could you try to trace which (all?) hardware accesses your
>>>>>>> code does. And with that analyse all accesses and with that check if
>>>>>>> all these accesses are valid even on the hardware (Synopsis) emulation
>>>>>>> system? That should be checked from valid address and from hardware
>>>>>>> subsystem enablement point of view.
>>>>>>>
>>>>>>> Hth,
>>>>>>>
>>>>>>> Dirk
>>>>>>>
>>>>>>>
>>>>>>>> From the Linux source:
>>>>>>>> parse_early_param();
>>>>>>>>
>>>>>>>> dynamic_scs_init();
>>>>>>>>
>>>>>>>> /*
>>>>>>>> * Unmask asynchronous aborts and fiq after bringing up possible
>>>>>>>> * earlycon. (Report possible System Errors once we can report this
>>>>>>>> * occurred).
>>>>>>>> */
>>>>>>>> local_daif_restore(DAIF_PROCCTX_NOIRQ); <---- This is when we
>>> get
>>>>> the
>>>>>>> exception.
>>>>>>>>
>>>>>>>> After some kernel hacking (replacing printk) we could extract the logs:
>>>>>>>> 6Booting Linux on physical CPU 0x0000000000 [0x410fd034]
>>>>>>>> 5Linux version 6.5.0 (pliops@dev-liorw) (aarch64-buildroot-linux-gnu-
>>>>>>> gcc.br_real (Buildroot 2023.02.1-95-g8391404e23) 11.3.0, GNU ld
>>> (GNU
>>>>>>> Binutils) 2.38) #101 SMP Sun Dec 17 20:09:06 IST 2023
>>>>>>>> 6Machine model: Pliops Spider MK-I EVK
>>>>>>>> 2SError Interrupt on CPU0, code 0x00000000bf000002 -- SError
>>>>>>>> CPU: 0 PID: 0 Comm: swapper Not tainted 6.5.0 #101
>>>>>>>> Hardware name: Pliops Spider MK-I EVK (DT)
>>>>>>>> pstate: 600000c5 (nZCv daIF -PAN -UAO -TCO -DIT -SSBS BTYPE=--)
>>>>>>>> pc : setup_arch+0x13c/0x5ac
>>>>>>>> lr : setup_arch+0x134/0x5ac
>>>>>>>> sp : ffff8000808f3da0
>>>>>>>> x29: ffff8000808f3da0c x28: 0000000008758074c x27:
>>>>>>> 0000000005e31b58c
>>>>>>>> x26: 0000000000000001c x25: 0000000007e5f728c x24:
>>>>>>> ffff8000808f8000c
>>>>>>>> x23: ffff8000808f8600c x22: ffff8000807b6000c x21:
>>>>> ffff800080010000c
>>>>>>>> x20: ffff800080a1e000c x19: fffffbfffddfe190c x18:
>>> 000000002266684ac
>>>>>>>> x17: 00000000fcad60bbc x16: 0000000000001800c x15:
>>>>>>> 0000000000000008c
>>>>>>>> x14: ffffffffffffffffc x13: 0000000000000000c x12:
>>> 0000000000000003c
>>>>>>>> x11: 0101010101010101c x10: ffffffffffee87dfc x9 :
>>>>> 0000000000000038c
>>>>>>>> x8 : 0101010101010101c x7 : 7f7f7f7f7f7f7f7fc x6 :
>>>>> 0000000000000001c
>>>>>>>> x5 : 0000000000000000c x4 : 8000000000000000c x3 :
>>>>>>> 0000000000000065c
>>>>>>>> x2 : 0000000000000000c x1 : 0000000000000000c x0 :
>>>>>>> 00000000000000c0c
>>>>>>>> 0Kernel panic - not syncing: Asynchronous SError Interrupt
>>>>>>>> CPU: 0 PID: 0 Comm: swapper Not tainted 6.5.0 #101
>>>>>>>> Hardware name: Pliops Spider MK-I EVK (DT)
>>>>>>>> Call trace:
>>>>>>>> dump_backtrace+0x9c/0xd0
>>>>>>>> show_stack+0x14/0x1c
>>>>>>>> dump_stack_lvl+0x44/0x58
>>>>>>>> dump_stack+0x14/0x1c
>>>>>>>> panic+0x2e0/0x33c
>>>>>>>> nmi_panic+0x68/0x6c
>>>>>>>> arm64_serror_panic+0x68/0x78
>>>>>>>> do_serror+0x24/0x54
>>>>>>>> el1h_64_error_handler+0x2c/0x40
>>>>>>>> el1h_64_error+0x64/0x68
>>>>>>>> setup_arch+0x13c/0x5ac
>>>>>>>> start_kernel+0x5c/0x5b8
>>>>>>>> __primary_switched+0xb4/0xbc
>>>>>>>> 0---[ end Kernel panic - not syncing: Asynchronous SError Interrupt ]---
>>>>>>>>
>>>>>>>> Can you please advice how to proceed with debugging?
>>>>>>>>
>>>>>>>> Thanks in advanced,
>>>>>>>> Cheers,
>>>>>>>> Lior.
>>>>>>>>
>>>>>>>>
>>>>>>>
>>>>>>
>>>>
>>
>
--
DENX Software Engineering GmbH, Managing Director: Erika Unter
HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany
Phone: +49-8142-66989-52 Fax: +49-8142-66989-80 Email: hs@denx.de
^ permalink raw reply [flat|nested] 16+ messages in thread
* RE: Debugging early SError exception
2023-12-21 11:36 ` Heiko Schocher
@ 2023-12-21 12:04 ` Lior Weintraub
2023-12-22 7:03 ` Lior Weintraub
1 sibling, 0 replies; 16+ messages in thread
From: Lior Weintraub @ 2023-12-21 12:04 UTC (permalink / raw)
To: hs; +Cc: Dirk Behme, linux-embedded
Thanks Heiko,
Will do that.
Cheers,
Lior.
> -----Original Message-----
> From: Heiko Schocher <hs@denx.de>
> Sent: Thursday, December 21, 2023 1:37 PM
> To: Lior Weintraub <liorw@pliops.com>
> Cc: Dirk Behme <dirk.behme@gmail.com>; linux-embedded@vger.kernel.org
> Subject: Re: Debugging early SError exception
>
> [You don't often get email from hs@denx.de. Learn why this is important at
> https://aka.ms/LearnAboutSenderIdentification ]
>
> CAUTION: External Sender
>
> Hi Lior,
>
> On 21.12.23 12:19, Dirk Behme wrote:
> > Am 21.12.23 um 11:04 schrieb Lior Weintraub:
> >> Thanks Dirk,
> >>
> >> Regarding the earlyprintk, not sure I know how to make it work.
> >> I have defined CONFIG_EARLY_PRINTK=y and CONFIG_DEBUG_LL=y on my
> config but it doesn't seem to work.
> >> Do I need to pass something in the bootargs from the U-BOOT?
> >> Do I need to add that into my device tree?
> >> (Tried to set bootargs = "console=ttyS0,115200 earlyprintk"; under
> "chosen" on my DT but it didn't
> >> work)
> >
> > Yes, what has to be enabled and what not and what has to be set how is
> often confusing. I think this
> > is not common for all systems, so I think to be on the safe side you have to
> look into the code for
> > you system. Or short; The code is the documentation ;)
> >
> >
> >> The UART I am using is "snps,dw-apb-uart".
> >>
> >> Last week, to output the early logs I have implemented this hack:
> >> 1. Modify printk macro to run my print_func
> >> 2. This print_func wrote the characters into a single global variable (u32
> simul_uart;)
> >> 3. Get the address location of this global variable and extract all writes to it
> from the Tarmac
> >> logs.
> >>
> >> This is a very slow and tedious process but it helped me identify the initial
> SError.
> >> Initially I thought I can write directly into the UART FIFO register (which I
> know the address)
> >> but this didn't work because Linux already setup the MMU so I guess I need
> to know the virtual
> >> address of this FIFO.
> >> Do I need to use __phys_to_virt of some sort?
> >
> > Yes, I think so. Have a look to the existing serial driver, too. It should do
> whats needed, and you
> > can borrow that, then.
>
> If you have access to the RAM after the crash (through a debugger or in
> your bootloader) and your mem is stable, find out the address of __log_buf
> in System.map. Thats the buffer where printk writes into it, and so dumping
> the content is what you would see in case uart works...
>
> Hope it helps!
>
> bye,
> Heiko
> >
> > Best regards
> >
> > Dirk
> >
> >
> >> Cheers,
> >> Lior.
> >>
> >>> -----Original Message-----
> >>> From: Dirk Behme <dirk.behme@gmail.com>
> >>> Sent: Thursday, December 21, 2023 10:30 AM
> >>> To: Lior Weintraub <liorw@pliops.com>; linux-embedded@vger.kernel.org
> >>> Subject: Re: Debugging early SError exception
> >>>
> >>> [You don't often get email from dirk.behme@gmail.com. Learn why this is
> >>> important at https://aka.ms/LearnAboutSenderIdentification ]
> >>>
> >>> CAUTION: External Sender
> >>>
> >>> Am 21.12.23 um 08:43 schrieb Lior Weintraub:
> >>>> Hi Dirk,
> >>>>
> >>>> We found that the issue was at the early stages of Barebox (a.k.a U-
> BOOT
> >>> v2).
> >>>
> >>> Glad to hear that! :)
> >>>
> >>>> Our implementation of putc_ll (on debug_ll) was writing into the UART Tx
> >>> FIFO without checking if the FIFO is full.
> >>>> Once the fifo got full it caused this SError probably because the UART IP
> >>> generated an apberror signal.
> >>>
> >>> Thanks for the report!
> >>>
> >>>> Now the Linux is running and doesn't report the SError again but now we
> >>> face another issue.
> >>>> We see that the PC is getting into a "report_bug" function.
> >>>> The Linux doesn't print anything to the UART (probably since it hasn't got
> to
> >>> the point where the console is configured?).
> >>>
> >>> For cases like this using earlyprintk is usually a good option. Check
> >>> the Linux kernel serial console (UART) dirver of you SoC if it
> >>> supports it. In the end it should be "just" a function in the serial
> >>> console driver which outputs the console data via polling before
> >>> (later) the interrupt driven console part takes over.
> >>>
> >>> Best regards
> >>>
> >>> Dirk
> >>>
> >>>
> >>>> Since our debug means are limited it can take some time to find the root
> >>> cause.
> >>>>
> >>>> I will keep you posted and update our findings.
> >>>> Love to hear your thoughts,
> >>>>
> >>>> Cheers,
> >>>> Lior.
> >>>>
> >>>>
> >>>>> -----Original Message-----
> >>>>> From: Dirk Behme <dirk.behme@gmail.com>
> >>>>> Sent: Tuesday, December 19, 2023 3:37 PM
> >>>>> To: Lior Weintraub <liorw@pliops.com>; linux-
> embedded@vger.kernel.org
> >>>>> Subject: Re: Debugging early SError exception
> >>>>>
> >>>>> [You don't often get email from dirk.behme@gmail.com. Learn why this
> is
> >>>>> important at https://aka.ms/LearnAboutSenderIdentification ]
> >>>>>
> >>>>> CAUTION: External Sender
> >>>>>
> >>>>> Am 19.12.23 um 14:23 schrieb Lior Weintraub:
> >>>>>> Thanks Dirk,
> >>>>>
> >>>>> Welcome :)
> >>>>>
> >>>>> In case you find the root cause it would be nice to get some generic
> >>>>> description of it so that we can learn something :)
> >>>>>
> >>>>> Best regards
> >>>>>
> >>>>> Dirk
> >>>>>
> >>>>>
> >>>>>>> -----Original Message-----
> >>>>>>> From: Dirk Behme <dirk.behme@gmail.com>
> >>>>>>> Sent: Tuesday, December 19, 2023 9:09 AM
> >>>>>>> To: Lior Weintraub <liorw@pliops.com>; linux-
> >>> embedded@vger.kernel.org
> >>>>>>> Subject: Re: Debugging early SError exception
> >>>>>>>
> >>>>>>> [You don't often get email from dirk.behme@gmail.com. Learn why
> this
> >>> is
> >>>>>>> important at https://aka.ms/LearnAboutSenderIdentification ]
> >>>>>>>
> >>>>>>> CAUTION: External Sender
> >>>>>>>
> >>>>>>> Am 17.12.23 um 22:32 schrieb Lior Weintraub:
> >>>>>>>> Hi,
> >>>>>>>>
> >>>>>>>> We have a new SoC with eLinux porting (kernel v6.5).
> >>>>>>>> This SoC is ARM64 (A53) single core based device.
> >>>>>>>> It runs correctly on QEMU but fails with SError on emulation
> platform
> >>>>>>> (Synopsys Zebu running our SoC model).
> >>>>>>>> There is no debugger connected to this emulation but there are
> several
> >>>>>>> debug capabilities we can use:
> >>>>>>>> 1. Generating wave dump of CPU signals
> >>>>>>>> 2. Generate a Tarmac log
> >>>>>>>> 3. UART
> >>>>>>>>
> >>>>>>>> Since the SError happens at early stages of Linux boot the UART is
> not
> >>>>>>> enabled yet.
> >>>>>>>> From the Tarmac log we can see:
> >>>>>>>> 3824884521 ps ES (ffff800080760888:d65f03c0) O el1h_ns:
> ret
> >>>>>>> (parse_early_param)
> >>>>>>>> 3824884522 ps ES (ffff800080763a60:d2801800) O el1h_ns:
> mov
> >>>>> x0,
> >>>>>>> #0xc0 // #192 (setup_arch)
> >>>>>>>> R X0 (AARCH64) 00000000 000000c0
> >>>>>>>> 3824884523 ps ES (ffff800080763a64:d51b4220) O el1h_ns:
> msr
> >>>>>>> daif, x0 (setup_arch)
> >>>>>>>> R CPSR 600000c5
> >>>>>>>> 3824884529 ps ES System Error (Abort)
> >>>>>>>> EXC [0x380] SError/vSError Current EL with SP_ELx
> >>>>>>>> R ESR_EL1 (AARCH64) bf000002
> >>>>>>>> R CPSR 600003c5
> >>>>>>>> R SPSR_EL1 (AARCH64) 600000c5
> >>>>>>>> R ELR_EL1 (AARCH64) ffff8000 80763a68
> >>>>>>>> 3824884925 ps ES (ffff800080010b80:d10543ff) O el1h_ns:
> sub
> >>>>> sp,
> >>>>>>> sp, #0x150 (vectors)
> >>>>>>>> R SP_EL1 (AARCH64) ffff8000 808f3c50
> >>>>>>>> 3824884925 ps ES (ffff800080010b84:8b2063ff) O el1h_ns:
> add
> >>>>> sp,
> >>>>>>> sp, x0 (vectors)
> >>>>>>>> R SP_EL1 (AARCH64) ffff8000 808f3d10
> >>>>>>>> 3824884926 ps ES (ffff800080010b88:cb2063e0) O el1h_ns:
> sub
> >>>>> x0,
> >>>>>>> sp, x0 (vectors)
> >>>>>>>> R X0 (AARCH64) ffff8000 808f3c50
> >>>>>>>> 3824884927 ps ES (ffff800080010b8c:37700080) O el1h_ns:
> tbnz
> >>>>> w0,
> >>>>>>> #14, ffff800080010b9c <vectors+0x39c> (vectors)
> >>>>>>>> 3824884935 ps ES (ffff800080010b90:cb2063e0) O el1h_ns:
> sub
> >>>>> x0,
> >>>>>>> sp, x0 (vectors)
> >>>>>>>> R X0 (AARCH64) 00000000 000000c0
> >>>>>>>> 3824884937 ps ES (ffff800080010b94:cb2063ff) O el1h_ns:
> sub
> >>> sp,
> >>>>>>> sp, x0 (vectors)
> >>>>>>>> R SP_EL1 (AARCH64) ffff8000 808f3c50
> >>>>>>>> 3824884938 ps ES (ffff800080010b98:140001ef) O el1h_ns: b
> >>>>>>> ffff800080011354 <el1h_64_error> (vectors)
> >>>>>>>>
> >>>>>>>> If I understand correctly, the exception happened sometime earlier
> and
> >>>>> only
> >>>>>>> now Linux boot code (setup_arch) opened the exception handling
> and as
> >>> a
> >>>>>>> result we immediately jump to the SError exception handler.
> >>>>>>>
> >>>>>>>
> >>>>>>> Yes, that sounds reasonable. If I understood correctly, you are
> >>>>>>> running something "quite new" on some software (QEMU) and
> >>> hardware
> >>>>>>> (Synopsis) simulators.
> >>>>>>>
> >>>>>>> That would mean that you have new hardware with e.g. new
> memory
> >>> map
> >>>>>>> not used before. What you describe might sound like in the code
> before
> >>>>>>> Linux (boot loader) there is anything resulting in the SError. This
> >>>>>>> might be an access to non-existing or non-enabled hardware. I.e. it
> >>>>>>> might be that you try to access (read/write) an address what is not
> >>>>>>> available, yet (or just invalid). It's hard to debug that. In case you
> >>>>>>> are able to modify the code before Linux (the boot loader?) you might
> >>>>>>> try to enable SError exceptions, there, too. To get it earlier and
> >>>>>>> with that make the search window smaller. I'm not that familiar with
> >>>>>>> QEMU, but could you try to trace which (all?) hardware accesses your
> >>>>>>> code does. And with that analyse all accesses and with that check if
> >>>>>>> all these accesses are valid even on the hardware (Synopsis)
> emulation
> >>>>>>> system? That should be checked from valid address and from
> hardware
> >>>>>>> subsystem enablement point of view.
> >>>>>>>
> >>>>>>> Hth,
> >>>>>>>
> >>>>>>> Dirk
> >>>>>>>
> >>>>>>>
> >>>>>>>> From the Linux source:
> >>>>>>>> parse_early_param();
> >>>>>>>>
> >>>>>>>> dynamic_scs_init();
> >>>>>>>>
> >>>>>>>> /*
> >>>>>>>> * Unmask asynchronous aborts and fiq after bringing up
> possible
> >>>>>>>> * earlycon. (Report possible System Errors once we can report
> this
> >>>>>>>> * occurred).
> >>>>>>>> */
> >>>>>>>> local_daif_restore(DAIF_PROCCTX_NOIRQ); <---- This is when
> we
> >>> get
> >>>>> the
> >>>>>>> exception.
> >>>>>>>>
> >>>>>>>> After some kernel hacking (replacing printk) we could extract the
> logs:
> >>>>>>>> 6Booting Linux on physical CPU 0x0000000000 [0x410fd034]
> >>>>>>>> 5Linux version 6.5.0 (pliops@dev-liorw) (aarch64-buildroot-linux-
> gnu-
> >>>>>>> gcc.br_real (Buildroot 2023.02.1-95-g8391404e23) 11.3.0, GNU ld
> >>> (GNU
> >>>>>>> Binutils) 2.38) #101 SMP Sun Dec 17 20:09:06 IST 2023
> >>>>>>>> 6Machine model: Pliops Spider MK-I EVK
> >>>>>>>> 2SError Interrupt on CPU0, code 0x00000000bf000002 -- SError
> >>>>>>>> CPU: 0 PID: 0 Comm: swapper Not tainted 6.5.0 #101
> >>>>>>>> Hardware name: Pliops Spider MK-I EVK (DT)
> >>>>>>>> pstate: 600000c5 (nZCv daIF -PAN -UAO -TCO -DIT -SSBS BTYPE=--)
> >>>>>>>> pc : setup_arch+0x13c/0x5ac
> >>>>>>>> lr : setup_arch+0x134/0x5ac
> >>>>>>>> sp : ffff8000808f3da0
> >>>>>>>> x29: ffff8000808f3da0c x28: 0000000008758074c x27:
> >>>>>>> 0000000005e31b58c
> >>>>>>>> x26: 0000000000000001c x25: 0000000007e5f728c x24:
> >>>>>>> ffff8000808f8000c
> >>>>>>>> x23: ffff8000808f8600c x22: ffff8000807b6000c x21:
> >>>>> ffff800080010000c
> >>>>>>>> x20: ffff800080a1e000c x19: fffffbfffddfe190c x18:
> >>> 000000002266684ac
> >>>>>>>> x17: 00000000fcad60bbc x16: 0000000000001800c x15:
> >>>>>>> 0000000000000008c
> >>>>>>>> x14: ffffffffffffffffc x13: 0000000000000000c x12:
> >>> 0000000000000003c
> >>>>>>>> x11: 0101010101010101c x10: ffffffffffee87dfc x9 :
> >>>>> 0000000000000038c
> >>>>>>>> x8 : 0101010101010101c x7 : 7f7f7f7f7f7f7f7fc x6 :
> >>>>> 0000000000000001c
> >>>>>>>> x5 : 0000000000000000c x4 : 8000000000000000c x3 :
> >>>>>>> 0000000000000065c
> >>>>>>>> x2 : 0000000000000000c x1 : 0000000000000000c x0 :
> >>>>>>> 00000000000000c0c
> >>>>>>>> 0Kernel panic - not syncing: Asynchronous SError Interrupt
> >>>>>>>> CPU: 0 PID: 0 Comm: swapper Not tainted 6.5.0 #101
> >>>>>>>> Hardware name: Pliops Spider MK-I EVK (DT)
> >>>>>>>> Call trace:
> >>>>>>>> dump_backtrace+0x9c/0xd0
> >>>>>>>> show_stack+0x14/0x1c
> >>>>>>>> dump_stack_lvl+0x44/0x58
> >>>>>>>> dump_stack+0x14/0x1c
> >>>>>>>> panic+0x2e0/0x33c
> >>>>>>>> nmi_panic+0x68/0x6c
> >>>>>>>> arm64_serror_panic+0x68/0x78
> >>>>>>>> do_serror+0x24/0x54
> >>>>>>>> el1h_64_error_handler+0x2c/0x40
> >>>>>>>> el1h_64_error+0x64/0x68
> >>>>>>>> setup_arch+0x13c/0x5ac
> >>>>>>>> start_kernel+0x5c/0x5b8
> >>>>>>>> __primary_switched+0xb4/0xbc
> >>>>>>>> 0---[ end Kernel panic - not syncing: Asynchronous SError Interrupt
> ]---
> >>>>>>>>
> >>>>>>>> Can you please advice how to proceed with debugging?
> >>>>>>>>
> >>>>>>>> Thanks in advanced,
> >>>>>>>> Cheers,
> >>>>>>>> Lior.
> >>>>>>>>
> >>>>>>>>
> >>>>>>>
> >>>>>>
> >>>>
> >>
> >
>
> --
> DENX Software Engineering GmbH, Managing Director: Erika Unter
> HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany
> Phone: +49-8142-66989-52 Fax: +49-8142-66989-80 Email: hs@denx.de
^ permalink raw reply [flat|nested] 16+ messages in thread
* RE: Debugging early SError exception
2023-12-21 11:36 ` Heiko Schocher
2023-12-21 12:04 ` Lior Weintraub
@ 2023-12-22 7:03 ` Lior Weintraub
2023-12-22 7:48 ` Dirk Behme
1 sibling, 1 reply; 16+ messages in thread
From: Lior Weintraub @ 2023-12-22 7:03 UTC (permalink / raw)
To: hs, Dirk Behme; +Cc: linux-embedded
Hi,
I managed to dump the __log_buf but for some reason the UART is still not working.
Please note that UART printed all the U-BOOT traces so AFAIU, the device tree is set correctly.
(Barebox is passing it's DTB into kernel).
To enable the earlyprintk I have:
1. Compiled the kernel with CONFIG_EARLY_PRINTK=y and CONFIG_DEBUG_LL=y
2. Modified the boot args to include: "console=ttyS0,115200n8 earlycon=dw-apb-uart,0xd000307000"
3. Verified that dw-apb-uart driver (8250_early.c) supports earlycon:
OF_EARLYCON_DECLARE(uart, "snps,dw-apb-uart", early_serial8250_setup);
From __log_buf dump:
Booting Linux on physical CPU 0x0000000000 [0x410fd034]4]
Linux version 6.5.0 (pliops@dev-liorw) (aarch64-buildroot-linux-gnu-gcc.br_real (Buildroot 2023.02.1-95-g8391404e23) 11.3.0, GNU ld (GNU Binutils) 2.38) #107 SMP Thu Dec 21 17:33:12 IST 202323
Machine model: Pliops Spider MK-I EVKVK
efi: UEFI not found.d.
Zone ranges:s:
DMA [mem 0x0000000000000000-0x000000002fffffff]f]
DMA32 emptyty
Normal emptyty
Movable zone start for each nodede
Early memory node rangeses
node 0: [mem 0x0000000000000000-0x000000002fffffff]f]
Initmem setup node 0 [mem 0x0000000000000000-0x000000002fffffff]f]
percpu: Embedded 25 pages/cpu s64800 r8192 d29408 u10240000
pcpu-alloc: s64800 r8192 d29408 u102400 alloc=25*4096
pcpu-alloc: [0] 0
Detected VIPT I-cache on CPU0U0
CPU features: GIC system register CPU interface present but disabled by higher exception levelel
CPU features: detected: ARM erratum 84571919
alternatives: applying boot alternativeses
Kernel command line: console=ttyS0,115200n8 earlycon=dw-apb-uart,0xd00030700000
Dentry cache hash table entries: 131072 (order: 8, 1048576 bytes, linear)r)
Inode-cache hash table entries: 65536 (order: 7, 524288 bytes, linear)r)
Built 1 zonelists, mobility grouping on. Total pages: 19353636
mem auto-init: stack:off, heap alloc:off, heap free:offff
software IO TLB: area num 1.1.
software IO TLB: mapped [mem 0x000000002b080000-0x000000002f080000] (64MB)B)
Memory: 689240K/786432K available (5824K kernel code, 1186K rwdata, 1612K rodata, 1600K init, 400K bss, 97192K reserved, 0K cma-reserved)d)
SLUB: HWalign=64, Order=0-3, MinObjects=0, CPUs=1, Nodes=1=1
trace event string verifier disableded
rcu: Hierarchical RCU implementation.n.
rcu: RCU event tracing is enabled.d.
rcu: RCU restricting CPUs from NR_CPUS=256 to nr_cpu_ids=1.1.
rcu: RCU calculated value of scheduler-enlistment delay is 25 jiffies.s.
rcu: Adjusting geometry for rcu_fanout_leaf=16, nr_cpu_ids=1=1
NR_IRQS: 64, nr_irqs: 64, preallocated irqs: 0 0
GICv3: 96 SPIs implementeded
GICv3: 0 Extended SPIs implementeded
Root IRQ handler: gic_handle_irqrq
GICv3: GICv3 features: 16 PPIsIs
GICv3: CPU0: found redistributor 0 region 0:0x000000e00006000000
GICv3: redistributor failed to wakeup.....
GICv3: GIC: unable to set SRE (disabled at EL2), panic aheadad
Internal error: Oops - Undefined instruction: 0000000062383019 [#1] SMPMP
Modules linked in:
CPU: 0 PID: 0 Comm: swapper/0 Not tainted 6.5.0 #107
Hardware name: Pliops Spider MK-I EVK (DT)
pstate: 600000c5 (nZCv daIF -PAN -UAO -TCO -DIT -SSBS BTYPE=--)
pc : gic_cpu_sys_reg_init+0x58/0x2e4
lr : gic_cpu_sys_reg_init+0x2a4/0x2e4
sp : ffff8000808f3b40
x29: ffff8000808f3b40 x28: 0000000000000000 x27: 0000000000000001
x26: ffff000000016040 x25: 0000000000000000 x24: ffff800080a6b000
x23: ffff8000808fc320 x22: ffff8000809cc000 x21: ffff00002fe74670
x20: ffff800080a90000 x19: 0000000000000000 x18: fffffffffffe0b10
x17: ffff8000809f9480 x16: fffffc0000002248 x15: ffff80008090af28
x14: fffffffffffc0b0f x13: 6461656861206369 x12: 6e6170202c29324c
x11: 452074612064656c x10: 6261736964282045 x9 : 6428204552532074
x8 : ffff80008090af28 x7 : ffff8000808f3970 x6 : 000000000000000c
x5 : 000000000000002a x4 : 0000000000000000 x3 : 0000000000000000
x2 : 0000000000000000 x1 : ffff8000808fd0c0 x0 : 000000000000003c
Call trace:
gic_cpu_sys_reg_init+0x58/0x2e4
gic_cpu_init.part.0+0xa8/0x114
gic_init_bases+0x408/0x684
gic_of_init+0x298/0x300
of_irq_init+0x1c8/0x368
irqchip_init+0x14/0x1c
init_IRQ+0x98/0xac
start_kernel+0x250/0x5b8
__primary_switched+0xb4/0xbc
Code: 9260df39 d3441f33 d538cca0 36001180 (d538cc80) )
---[ end trace 0000000000000000 ]-----
Kernel panic - not syncing: Attempted to kill the idle task!k!
---[ end Kernel panic - not syncing: Attempted to kill the idle task! ]-----
The kernel panic is related to GIC distributor (currently under debug) but AFAIU,
this has nothing to do with the UART not working on early stages.
Thanks in advanced for your advice,
Cheers,
Lior.
> -----Original Message-----
> From: Heiko Schocher <hs@denx.de>
> Sent: Thursday, December 21, 2023 1:37 PM
> To: Lior Weintraub <liorw@pliops.com>
> Cc: Dirk Behme <dirk.behme@gmail.com>; linux-embedded@vger.kernel.org
> Subject: Re: Debugging early SError exception
>
> [You don't often get email from hs@denx.de. Learn why this is important at
> https://aka.ms/LearnAboutSenderIdentification ]
>
> CAUTION: External Sender
>
> Hi Lior,
>
> On 21.12.23 12:19, Dirk Behme wrote:
> > Am 21.12.23 um 11:04 schrieb Lior Weintraub:
> >> Thanks Dirk,
> >>
> >> Regarding the earlyprintk, not sure I know how to make it work.
> >> I have defined CONFIG_EARLY_PRINTK=y and CONFIG_DEBUG_LL=y on my
> config but it doesn't seem to work.
> >> Do I need to pass something in the bootargs from the U-BOOT?
> >> Do I need to add that into my device tree?
> >> (Tried to set bootargs = "console=ttyS0,115200 earlyprintk"; under "chosen"
> on my DT but it didn't
> >> work)
> >
> > Yes, what has to be enabled and what not and what has to be set how is often
> confusing. I think this
> > is not common for all systems, so I think to be on the safe side you have to look
> into the code for
> > you system. Or short; The code is the documentation ;)
> >
> >
> >> The UART I am using is "snps,dw-apb-uart".
> >>
> >> Last week, to output the early logs I have implemented this hack:
> >> 1. Modify printk macro to run my print_func
> >> 2. This print_func wrote the characters into a single global variable (u32
> simul_uart;)
> >> 3. Get the address location of this global variable and extract all writes to it
> from the Tarmac
> >> logs.
> >>
> >> This is a very slow and tedious process but it helped me identify the initial
> SError.
> >> Initially I thought I can write directly into the UART FIFO register (which I know
> the address)
> >> but this didn't work because Linux already setup the MMU so I guess I need to
> know the virtual
> >> address of this FIFO.
> >> Do I need to use __phys_to_virt of some sort?
> >
> > Yes, I think so. Have a look to the existing serial driver, too. It should do whats
> needed, and you
> > can borrow that, then.
>
> If you have access to the RAM after the crash (through a debugger or in
> your bootloader) and your mem is stable, find out the address of __log_buf
> in System.map. Thats the buffer where printk writes into it, and so dumping
> the content is what you would see in case uart works...
>
> Hope it helps!
>
> bye,
> Heiko
> >
> > Best regards
> >
> > Dirk
> >
> >
> >> Cheers,
> >> Lior.
> >>
> >>> -----Original Message-----
> >>> From: Dirk Behme <dirk.behme@gmail.com>
> >>> Sent: Thursday, December 21, 2023 10:30 AM
> >>> To: Lior Weintraub <liorw@pliops.com>; linux-embedded@vger.kernel.org
> >>> Subject: Re: Debugging early SError exception
> >>>
> >>> [You don't often get email from dirk.behme@gmail.com. Learn why this is
> >>> important at https://aka.ms/LearnAboutSenderIdentification ]
> >>>
> >>> CAUTION: External Sender
> >>>
> >>> Am 21.12.23 um 08:43 schrieb Lior Weintraub:
> >>>> Hi Dirk,
> >>>>
> >>>> We found that the issue was at the early stages of Barebox (a.k.a U-BOOT
> >>> v2).
> >>>
> >>> Glad to hear that! :)
> >>>
> >>>> Our implementation of putc_ll (on debug_ll) was writing into the UART Tx
> >>> FIFO without checking if the FIFO is full.
> >>>> Once the fifo got full it caused this SError probably because the UART IP
> >>> generated an apberror signal.
> >>>
> >>> Thanks for the report!
> >>>
> >>>> Now the Linux is running and doesn't report the SError again but now we
> >>> face another issue.
> >>>> We see that the PC is getting into a "report_bug" function.
> >>>> The Linux doesn't print anything to the UART (probably since it hasn't got to
> >>> the point where the console is configured?).
> >>>
> >>> For cases like this using earlyprintk is usually a good option. Check
> >>> the Linux kernel serial console (UART) dirver of you SoC if it
> >>> supports it. In the end it should be "just" a function in the serial
> >>> console driver which outputs the console data via polling before
> >>> (later) the interrupt driven console part takes over.
> >>>
> >>> Best regards
> >>>
> >>> Dirk
> >>>
> >>>
> >>>> Since our debug means are limited it can take some time to find the root
> >>> cause.
> >>>>
> >>>> I will keep you posted and update our findings.
> >>>> Love to hear your thoughts,
> >>>>
> >>>> Cheers,
> >>>> Lior.
> >>>>
> >>>>
> >>>>> -----Original Message-----
> >>>>> From: Dirk Behme <dirk.behme@gmail.com>
> >>>>> Sent: Tuesday, December 19, 2023 3:37 PM
> >>>>> To: Lior Weintraub <liorw@pliops.com>; linux-embedded@vger.kernel.org
> >>>>> Subject: Re: Debugging early SError exception
> >>>>>
> >>>>> [You don't often get email from dirk.behme@gmail.com. Learn why this is
> >>>>> important at https://aka.ms/LearnAboutSenderIdentification ]
> >>>>>
> >>>>> CAUTION: External Sender
> >>>>>
> >>>>> Am 19.12.23 um 14:23 schrieb Lior Weintraub:
> >>>>>> Thanks Dirk,
> >>>>>
> >>>>> Welcome :)
> >>>>>
> >>>>> In case you find the root cause it would be nice to get some generic
> >>>>> description of it so that we can learn something :)
> >>>>>
> >>>>> Best regards
> >>>>>
> >>>>> Dirk
> >>>>>
> >>>>>
> >>>>>>> -----Original Message-----
> >>>>>>> From: Dirk Behme <dirk.behme@gmail.com>
> >>>>>>> Sent: Tuesday, December 19, 2023 9:09 AM
> >>>>>>> To: Lior Weintraub <liorw@pliops.com>; linux-
> >>> embedded@vger.kernel.org
> >>>>>>> Subject: Re: Debugging early SError exception
> >>>>>>>
> >>>>>>> [You don't often get email from dirk.behme@gmail.com. Learn why this
> >>> is
> >>>>>>> important at https://aka.ms/LearnAboutSenderIdentification ]
> >>>>>>>
> >>>>>>> CAUTION: External Sender
> >>>>>>>
> >>>>>>> Am 17.12.23 um 22:32 schrieb Lior Weintraub:
> >>>>>>>> Hi,
> >>>>>>>>
> >>>>>>>> We have a new SoC with eLinux porting (kernel v6.5).
> >>>>>>>> This SoC is ARM64 (A53) single core based device.
> >>>>>>>> It runs correctly on QEMU but fails with SError on emulation platform
> >>>>>>> (Synopsys Zebu running our SoC model).
> >>>>>>>> There is no debugger connected to this emulation but there are several
> >>>>>>> debug capabilities we can use:
> >>>>>>>> 1. Generating wave dump of CPU signals
> >>>>>>>> 2. Generate a Tarmac log
> >>>>>>>> 3. UART
> >>>>>>>>
> >>>>>>>> Since the SError happens at early stages of Linux boot the UART is not
> >>>>>>> enabled yet.
> >>>>>>>> From the Tarmac log we can see:
> >>>>>>>> 3824884521 ps ES (ffff800080760888:d65f03c0) O el1h_ns: ret
> >>>>>>> (parse_early_param)
> >>>>>>>> 3824884522 ps ES (ffff800080763a60:d2801800) O el1h_ns: mov
> >>>>> x0,
> >>>>>>> #0xc0 // #192 (setup_arch)
> >>>>>>>> R X0 (AARCH64) 00000000 000000c0
> >>>>>>>> 3824884523 ps ES (ffff800080763a64:d51b4220) O el1h_ns: msr
> >>>>>>> daif, x0 (setup_arch)
> >>>>>>>> R CPSR 600000c5
> >>>>>>>> 3824884529 ps ES System Error (Abort)
> >>>>>>>> EXC [0x380] SError/vSError Current EL with SP_ELx
> >>>>>>>> R ESR_EL1 (AARCH64) bf000002
> >>>>>>>> R CPSR 600003c5
> >>>>>>>> R SPSR_EL1 (AARCH64) 600000c5
> >>>>>>>> R ELR_EL1 (AARCH64) ffff8000 80763a68
> >>>>>>>> 3824884925 ps ES (ffff800080010b80:d10543ff) O el1h_ns: sub
> >>>>> sp,
> >>>>>>> sp, #0x150 (vectors)
> >>>>>>>> R SP_EL1 (AARCH64) ffff8000 808f3c50
> >>>>>>>> 3824884925 ps ES (ffff800080010b84:8b2063ff) O el1h_ns: add
> >>>>> sp,
> >>>>>>> sp, x0 (vectors)
> >>>>>>>> R SP_EL1 (AARCH64) ffff8000 808f3d10
> >>>>>>>> 3824884926 ps ES (ffff800080010b88:cb2063e0) O el1h_ns: sub
> >>>>> x0,
> >>>>>>> sp, x0 (vectors)
> >>>>>>>> R X0 (AARCH64) ffff8000 808f3c50
> >>>>>>>> 3824884927 ps ES (ffff800080010b8c:37700080) O el1h_ns: tbnz
> >>>>> w0,
> >>>>>>> #14, ffff800080010b9c <vectors+0x39c> (vectors)
> >>>>>>>> 3824884935 ps ES (ffff800080010b90:cb2063e0) O el1h_ns: sub
> >>>>> x0,
> >>>>>>> sp, x0 (vectors)
> >>>>>>>> R X0 (AARCH64) 00000000 000000c0
> >>>>>>>> 3824884937 ps ES (ffff800080010b94:cb2063ff) O el1h_ns: sub
> >>> sp,
> >>>>>>> sp, x0 (vectors)
> >>>>>>>> R SP_EL1 (AARCH64) ffff8000 808f3c50
> >>>>>>>> 3824884938 ps ES (ffff800080010b98:140001ef) O el1h_ns: b
> >>>>>>> ffff800080011354 <el1h_64_error> (vectors)
> >>>>>>>>
> >>>>>>>> If I understand correctly, the exception happened sometime earlier
> and
> >>>>> only
> >>>>>>> now Linux boot code (setup_arch) opened the exception handling and as
> >>> a
> >>>>>>> result we immediately jump to the SError exception handler.
> >>>>>>>
> >>>>>>>
> >>>>>>> Yes, that sounds reasonable. If I understood correctly, you are
> >>>>>>> running something "quite new" on some software (QEMU) and
> >>> hardware
> >>>>>>> (Synopsis) simulators.
> >>>>>>>
> >>>>>>> That would mean that you have new hardware with e.g. new memory
> >>> map
> >>>>>>> not used before. What you describe might sound like in the code before
> >>>>>>> Linux (boot loader) there is anything resulting in the SError. This
> >>>>>>> might be an access to non-existing or non-enabled hardware. I.e. it
> >>>>>>> might be that you try to access (read/write) an address what is not
> >>>>>>> available, yet (or just invalid). It's hard to debug that. In case you
> >>>>>>> are able to modify the code before Linux (the boot loader?) you might
> >>>>>>> try to enable SError exceptions, there, too. To get it earlier and
> >>>>>>> with that make the search window smaller. I'm not that familiar with
> >>>>>>> QEMU, but could you try to trace which (all?) hardware accesses your
> >>>>>>> code does. And with that analyse all accesses and with that check if
> >>>>>>> all these accesses are valid even on the hardware (Synopsis) emulation
> >>>>>>> system? That should be checked from valid address and from hardware
> >>>>>>> subsystem enablement point of view.
> >>>>>>>
> >>>>>>> Hth,
> >>>>>>>
> >>>>>>> Dirk
> >>>>>>>
> >>>>>>>
> >>>>>>>> From the Linux source:
> >>>>>>>> parse_early_param();
> >>>>>>>>
> >>>>>>>> dynamic_scs_init();
> >>>>>>>>
> >>>>>>>> /*
> >>>>>>>> * Unmask asynchronous aborts and fiq after bringing up possible
> >>>>>>>> * earlycon. (Report possible System Errors once we can report
> this
> >>>>>>>> * occurred).
> >>>>>>>> */
> >>>>>>>> local_daif_restore(DAIF_PROCCTX_NOIRQ); <---- This is when we
> >>> get
> >>>>> the
> >>>>>>> exception.
> >>>>>>>>
> >>>>>>>> After some kernel hacking (replacing printk) we could extract the logs:
> >>>>>>>> 6Booting Linux on physical CPU 0x0000000000 [0x410fd034]
> >>>>>>>> 5Linux version 6.5.0 (pliops@dev-liorw) (aarch64-buildroot-linux-gnu-
> >>>>>>> gcc.br_real (Buildroot 2023.02.1-95-g8391404e23) 11.3.0, GNU ld
> >>> (GNU
> >>>>>>> Binutils) 2.38) #101 SMP Sun Dec 17 20:09:06 IST 2023
> >>>>>>>> 6Machine model: Pliops Spider MK-I EVK
> >>>>>>>> 2SError Interrupt on CPU0, code 0x00000000bf000002 -- SError
> >>>>>>>> CPU: 0 PID: 0 Comm: swapper Not tainted 6.5.0 #101
> >>>>>>>> Hardware name: Pliops Spider MK-I EVK (DT)
> >>>>>>>> pstate: 600000c5 (nZCv daIF -PAN -UAO -TCO -DIT -SSBS BTYPE=--)
> >>>>>>>> pc : setup_arch+0x13c/0x5ac
> >>>>>>>> lr : setup_arch+0x134/0x5ac
> >>>>>>>> sp : ffff8000808f3da0
> >>>>>>>> x29: ffff8000808f3da0c x28: 0000000008758074c x27:
> >>>>>>> 0000000005e31b58c
> >>>>>>>> x26: 0000000000000001c x25: 0000000007e5f728c x24:
> >>>>>>> ffff8000808f8000c
> >>>>>>>> x23: ffff8000808f8600c x22: ffff8000807b6000c x21:
> >>>>> ffff800080010000c
> >>>>>>>> x20: ffff800080a1e000c x19: fffffbfffddfe190c x18:
> >>> 000000002266684ac
> >>>>>>>> x17: 00000000fcad60bbc x16: 0000000000001800c x15:
> >>>>>>> 0000000000000008c
> >>>>>>>> x14: ffffffffffffffffc x13: 0000000000000000c x12:
> >>> 0000000000000003c
> >>>>>>>> x11: 0101010101010101c x10: ffffffffffee87dfc x9 :
> >>>>> 0000000000000038c
> >>>>>>>> x8 : 0101010101010101c x7 : 7f7f7f7f7f7f7f7fc x6 :
> >>>>> 0000000000000001c
> >>>>>>>> x5 : 0000000000000000c x4 : 8000000000000000c x3 :
> >>>>>>> 0000000000000065c
> >>>>>>>> x2 : 0000000000000000c x1 : 0000000000000000c x0 :
> >>>>>>> 00000000000000c0c
> >>>>>>>> 0Kernel panic - not syncing: Asynchronous SError Interrupt
> >>>>>>>> CPU: 0 PID: 0 Comm: swapper Not tainted 6.5.0 #101
> >>>>>>>> Hardware name: Pliops Spider MK-I EVK (DT)
> >>>>>>>> Call trace:
> >>>>>>>> dump_backtrace+0x9c/0xd0
> >>>>>>>> show_stack+0x14/0x1c
> >>>>>>>> dump_stack_lvl+0x44/0x58
> >>>>>>>> dump_stack+0x14/0x1c
> >>>>>>>> panic+0x2e0/0x33c
> >>>>>>>> nmi_panic+0x68/0x6c
> >>>>>>>> arm64_serror_panic+0x68/0x78
> >>>>>>>> do_serror+0x24/0x54
> >>>>>>>> el1h_64_error_handler+0x2c/0x40
> >>>>>>>> el1h_64_error+0x64/0x68
> >>>>>>>> setup_arch+0x13c/0x5ac
> >>>>>>>> start_kernel+0x5c/0x5b8
> >>>>>>>> __primary_switched+0xb4/0xbc
> >>>>>>>> 0---[ end Kernel panic - not syncing: Asynchronous SError Interrupt ]---
> >>>>>>>>
> >>>>>>>> Can you please advice how to proceed with debugging?
> >>>>>>>>
> >>>>>>>> Thanks in advanced,
> >>>>>>>> Cheers,
> >>>>>>>> Lior.
> >>>>>>>>
> >>>>>>>>
> >>>>>>>
> >>>>>>
> >>>>
> >>
> >
>
> --
> DENX Software Engineering GmbH, Managing Director: Erika Unter
> HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany
> Phone: +49-8142-66989-52 Fax: +49-8142-66989-80 Email: hs@denx.de
^ permalink raw reply [flat|nested] 16+ messages in thread
* Re: Debugging early SError exception
2023-12-22 7:03 ` Lior Weintraub
@ 2023-12-22 7:48 ` Dirk Behme
2023-12-22 8:04 ` Heiko Schocher
0 siblings, 1 reply; 16+ messages in thread
From: Dirk Behme @ 2023-12-22 7:48 UTC (permalink / raw)
To: Lior Weintraub, hs; +Cc: linux-embedded
Am 22.12.23 um 08:03 schrieb Lior Weintraub:
> Hi,
>
> I managed to dump the __log_buf but for some reason the UART is still not working.
> Please note that UART printed all the U-BOOT traces so AFAIU, the device tree is set correctly.
> (Barebox is passing it's DTB into kernel).
>
> To enable the earlyprintk I have:
> 1. Compiled the kernel with CONFIG_EARLY_PRINTK=y and CONFIG_DEBUG_LL=y
> 2. Modified the boot args to include: "console=ttyS0,115200n8 earlycon=dw-apb-uart,0xd000307000"
> 3. Verified that dw-apb-uart driver (8250_early.c) supports earlycon:
> OF_EARLYCON_DECLARE(uart, "snps,dw-apb-uart", early_serial8250_setup);
>
> From __log_buf dump:
> Booting Linux on physical CPU 0x0000000000 [0x410fd034]4]
> Linux version 6.5.0 (pliops@dev-liorw) (aarch64-buildroot-linux-gnu-gcc.br_real (Buildroot 2023.02.1-95-g8391404e23) 11.3.0, GNU ld (GNU Binutils) 2.38) #107 SMP Thu Dec 21 17:33:12 IST 202323
> Machine model: Pliops Spider MK-I EVKVK
> efi: UEFI not found.d.
> Zone ranges:s:
> DMA [mem 0x0000000000000000-0x000000002fffffff]f]
> DMA32 emptyty
> Normal emptyty
> Movable zone start for each nodede
> Early memory node rangeses
> node 0: [mem 0x0000000000000000-0x000000002fffffff]f]
> Initmem setup node 0 [mem 0x0000000000000000-0x000000002fffffff]f]
> percpu: Embedded 25 pages/cpu s64800 r8192 d29408 u10240000
> pcpu-alloc: s64800 r8192 d29408 u102400 alloc=25*4096
> pcpu-alloc: [0] 0
> Detected VIPT I-cache on CPU0U0
> CPU features: GIC system register CPU interface present but disabled by higher exception levelel
> CPU features: detected: ARM erratum 84571919
> alternatives: applying boot alternativeses
> Kernel command line: console=ttyS0,115200n8 earlycon=dw-apb-uart,0xd00030700000
> Dentry cache hash table entries: 131072 (order: 8, 1048576 bytes, linear)r)
> Inode-cache hash table entries: 65536 (order: 7, 524288 bytes, linear)r)
> Built 1 zonelists, mobility grouping on. Total pages: 19353636
> mem auto-init: stack:off, heap alloc:off, heap free:offff
> software IO TLB: area num 1.1.
> software IO TLB: mapped [mem 0x000000002b080000-0x000000002f080000] (64MB)B)
> Memory: 689240K/786432K available (5824K kernel code, 1186K rwdata, 1612K rodata, 1600K init, 400K bss, 97192K reserved, 0K cma-reserved)d)
> SLUB: HWalign=64, Order=0-3, MinObjects=0, CPUs=1, Nodes=1=1
> trace event string verifier disableded
> rcu: Hierarchical RCU implementation.n.
> rcu: RCU event tracing is enabled.d.
> rcu: RCU restricting CPUs from NR_CPUS=256 to nr_cpu_ids=1.1.
> rcu: RCU calculated value of scheduler-enlistment delay is 25 jiffies.s.
> rcu: Adjusting geometry for rcu_fanout_leaf=16, nr_cpu_ids=1=1
> NR_IRQS: 64, nr_irqs: 64, preallocated irqs: 0 0
> GICv3: 96 SPIs implementeded
> GICv3: 0 Extended SPIs implementeded
> Root IRQ handler: gic_handle_irqrq
> GICv3: GICv3 features: 16 PPIsIs
> GICv3: CPU0: found redistributor 0 region 0:0x000000e00006000000
> GICv3: redistributor failed to wakeup.....
> GICv3: GIC: unable to set SRE (disabled at EL2), panic aheadad
I think the two messages above are the essential ones.
Maybe it helps to check
https://www.kernel.org/doc/html/v5.3/arm64/booting.html
In the middle of that page in the "Call the kernel image" it has
something about GIC:
-- cut --
If the kernel is entered at EL1:
ICC.SRE_EL2.Enable (bit 3) must be initialised to 0b1
ICC_SRE_EL2.SRE (bit 0) must be initialised to 0b1.
-- cut --
> Internal error: Oops - Undefined instruction: 0000000062383019 [#1] SMPMP
> Modules linked in:
> CPU: 0 PID: 0 Comm: swapper/0 Not tainted 6.5.0 #107
> Hardware name: Pliops Spider MK-I EVK (DT)
> pstate: 600000c5 (nZCv daIF -PAN -UAO -TCO -DIT -SSBS BTYPE=--)
> pc : gic_cpu_sys_reg_init+0x58/0x2e4
> lr : gic_cpu_sys_reg_init+0x2a4/0x2e4
> sp : ffff8000808f3b40
> x29: ffff8000808f3b40 x28: 0000000000000000 x27: 0000000000000001
> x26: ffff000000016040 x25: 0000000000000000 x24: ffff800080a6b000
> x23: ffff8000808fc320 x22: ffff8000809cc000 x21: ffff00002fe74670
> x20: ffff800080a90000 x19: 0000000000000000 x18: fffffffffffe0b10
> x17: ffff8000809f9480 x16: fffffc0000002248 x15: ffff80008090af28
> x14: fffffffffffc0b0f x13: 6461656861206369 x12: 6e6170202c29324c
> x11: 452074612064656c x10: 6261736964282045 x9 : 6428204552532074
> x8 : ffff80008090af28 x7 : ffff8000808f3970 x6 : 000000000000000c
> x5 : 000000000000002a x4 : 0000000000000000 x3 : 0000000000000000
> x2 : 0000000000000000 x1 : ffff8000808fd0c0 x0 : 000000000000003c
> Call trace:
> gic_cpu_sys_reg_init+0x58/0x2e4
> gic_cpu_init.part.0+0xa8/0x114
> gic_init_bases+0x408/0x684
> gic_of_init+0x298/0x300
> of_irq_init+0x1c8/0x368
> irqchip_init+0x14/0x1c
> init_IRQ+0x98/0xac
> start_kernel+0x250/0x5b8
> __primary_switched+0xb4/0xbc
> Code: 9260df39 d3441f33 d538cca0 36001180 (d538cc80) )
> ---[ end trace 0000000000000000 ]-----
> Kernel panic - not syncing: Attempted to kill the idle task!k!
> ---[ end Kernel panic - not syncing: Attempted to kill the idle task! ]-----
>
>
> The kernel panic is related to GIC distributor (currently under debug) but AFAIU,
> this has nothing to do with the UART not working on early stages.
Yes, I agree. GIC issue and UART (at least the polling mode) should be
indendent.
Best regards
Dirk
> Thanks in advanced for your advice,
> Cheers,
> Lior.
>
>
>
>> -----Original Message-----
>> From: Heiko Schocher <hs@denx.de>
>> Sent: Thursday, December 21, 2023 1:37 PM
>> To: Lior Weintraub <liorw@pliops.com>
>> Cc: Dirk Behme <dirk.behme@gmail.com>; linux-embedded@vger.kernel.org
>> Subject: Re: Debugging early SError exception
>>
>> [You don't often get email from hs@denx.de. Learn why this is important at
>> https://aka.ms/LearnAboutSenderIdentification ]
>>
>> CAUTION: External Sender
>>
>> Hi Lior,
>>
>> On 21.12.23 12:19, Dirk Behme wrote:
>>> Am 21.12.23 um 11:04 schrieb Lior Weintraub:
>>>> Thanks Dirk,
>>>>
>>>> Regarding the earlyprintk, not sure I know how to make it work.
>>>> I have defined CONFIG_EARLY_PRINTK=y and CONFIG_DEBUG_LL=y on my
>> config but it doesn't seem to work.
>>>> Do I need to pass something in the bootargs from the U-BOOT?
>>>> Do I need to add that into my device tree?
>>>> (Tried to set bootargs = "console=ttyS0,115200 earlyprintk"; under "chosen"
>> on my DT but it didn't
>>>> work)
>>>
>>> Yes, what has to be enabled and what not and what has to be set how is often
>> confusing. I think this
>>> is not common for all systems, so I think to be on the safe side you have to look
>> into the code for
>>> you system. Or short; The code is the documentation ;)
>>>
>>>
>>>> The UART I am using is "snps,dw-apb-uart".
>>>>
>>>> Last week, to output the early logs I have implemented this hack:
>>>> 1. Modify printk macro to run my print_func
>>>> 2. This print_func wrote the characters into a single global variable (u32
>> simul_uart;)
>>>> 3. Get the address location of this global variable and extract all writes to it
>> from the Tarmac
>>>> logs.
>>>>
>>>> This is a very slow and tedious process but it helped me identify the initial
>> SError.
>>>> Initially I thought I can write directly into the UART FIFO register (which I know
>> the address)
>>>> but this didn't work because Linux already setup the MMU so I guess I need to
>> know the virtual
>>>> address of this FIFO.
>>>> Do I need to use __phys_to_virt of some sort?
>>>
>>> Yes, I think so. Have a look to the existing serial driver, too. It should do whats
>> needed, and you
>>> can borrow that, then.
>>
>> If you have access to the RAM after the crash (through a debugger or in
>> your bootloader) and your mem is stable, find out the address of __log_buf
>> in System.map. Thats the buffer where printk writes into it, and so dumping
>> the content is what you would see in case uart works...
>>
>> Hope it helps!
>>
>> bye,
>> Heiko
>>>
>>> Best regards
>>>
>>> Dirk
>>>
>>>
>>>> Cheers,
>>>> Lior.
>>>>
>>>>> -----Original Message-----
>>>>> From: Dirk Behme <dirk.behme@gmail.com>
>>>>> Sent: Thursday, December 21, 2023 10:30 AM
>>>>> To: Lior Weintraub <liorw@pliops.com>; linux-embedded@vger.kernel.org
>>>>> Subject: Re: Debugging early SError exception
>>>>>
>>>>> [You don't often get email from dirk.behme@gmail.com. Learn why this is
>>>>> important at https://aka.ms/LearnAboutSenderIdentification ]
>>>>>
>>>>> CAUTION: External Sender
>>>>>
>>>>> Am 21.12.23 um 08:43 schrieb Lior Weintraub:
>>>>>> Hi Dirk,
>>>>>>
>>>>>> We found that the issue was at the early stages of Barebox (a.k.a U-BOOT
>>>>> v2).
>>>>>
>>>>> Glad to hear that! :)
>>>>>
>>>>>> Our implementation of putc_ll (on debug_ll) was writing into the UART Tx
>>>>> FIFO without checking if the FIFO is full.
>>>>>> Once the fifo got full it caused this SError probably because the UART IP
>>>>> generated an apberror signal.
>>>>>
>>>>> Thanks for the report!
>>>>>
>>>>>> Now the Linux is running and doesn't report the SError again but now we
>>>>> face another issue.
>>>>>> We see that the PC is getting into a "report_bug" function.
>>>>>> The Linux doesn't print anything to the UART (probably since it hasn't got to
>>>>> the point where the console is configured?).
>>>>>
>>>>> For cases like this using earlyprintk is usually a good option. Check
>>>>> the Linux kernel serial console (UART) dirver of you SoC if it
>>>>> supports it. In the end it should be "just" a function in the serial
>>>>> console driver which outputs the console data via polling before
>>>>> (later) the interrupt driven console part takes over.
>>>>>
>>>>> Best regards
>>>>>
>>>>> Dirk
>>>>>
>>>>>
>>>>>> Since our debug means are limited it can take some time to find the root
>>>>> cause.
>>>>>>
>>>>>> I will keep you posted and update our findings.
>>>>>> Love to hear your thoughts,
>>>>>>
>>>>>> Cheers,
>>>>>> Lior.
>>>>>>
>>>>>>
>>>>>>> -----Original Message-----
>>>>>>> From: Dirk Behme <dirk.behme@gmail.com>
>>>>>>> Sent: Tuesday, December 19, 2023 3:37 PM
>>>>>>> To: Lior Weintraub <liorw@pliops.com>; linux-embedded@vger.kernel.org
>>>>>>> Subject: Re: Debugging early SError exception
>>>>>>>
>>>>>>> [You don't often get email from dirk.behme@gmail.com. Learn why this is
>>>>>>> important at https://aka.ms/LearnAboutSenderIdentification ]
>>>>>>>
>>>>>>> CAUTION: External Sender
>>>>>>>
>>>>>>> Am 19.12.23 um 14:23 schrieb Lior Weintraub:
>>>>>>>> Thanks Dirk,
>>>>>>>
>>>>>>> Welcome :)
>>>>>>>
>>>>>>> In case you find the root cause it would be nice to get some generic
>>>>>>> description of it so that we can learn something :)
>>>>>>>
>>>>>>> Best regards
>>>>>>>
>>>>>>> Dirk
>>>>>>>
>>>>>>>
>>>>>>>>> -----Original Message-----
>>>>>>>>> From: Dirk Behme <dirk.behme@gmail.com>
>>>>>>>>> Sent: Tuesday, December 19, 2023 9:09 AM
>>>>>>>>> To: Lior Weintraub <liorw@pliops.com>; linux-
>>>>> embedded@vger.kernel.org
>>>>>>>>> Subject: Re: Debugging early SError exception
>>>>>>>>>
>>>>>>>>> [You don't often get email from dirk.behme@gmail.com. Learn why this
>>>>> is
>>>>>>>>> important at https://aka.ms/LearnAboutSenderIdentification ]
>>>>>>>>>
>>>>>>>>> CAUTION: External Sender
>>>>>>>>>
>>>>>>>>> Am 17.12.23 um 22:32 schrieb Lior Weintraub:
>>>>>>>>>> Hi,
>>>>>>>>>>
>>>>>>>>>> We have a new SoC with eLinux porting (kernel v6.5).
>>>>>>>>>> This SoC is ARM64 (A53) single core based device.
>>>>>>>>>> It runs correctly on QEMU but fails with SError on emulation platform
>>>>>>>>> (Synopsys Zebu running our SoC model).
>>>>>>>>>> There is no debugger connected to this emulation but there are several
>>>>>>>>> debug capabilities we can use:
>>>>>>>>>> 1. Generating wave dump of CPU signals
>>>>>>>>>> 2. Generate a Tarmac log
>>>>>>>>>> 3. UART
>>>>>>>>>>
>>>>>>>>>> Since the SError happens at early stages of Linux boot the UART is not
>>>>>>>>> enabled yet.
>>>>>>>>>> From the Tarmac log we can see:
>>>>>>>>>> 3824884521 ps ES (ffff800080760888:d65f03c0) O el1h_ns: ret
>>>>>>>>> (parse_early_param)
>>>>>>>>>> 3824884522 ps ES (ffff800080763a60:d2801800) O el1h_ns: mov
>>>>>>> x0,
>>>>>>>>> #0xc0 // #192 (setup_arch)
>>>>>>>>>> R X0 (AARCH64) 00000000 000000c0
>>>>>>>>>> 3824884523 ps ES (ffff800080763a64:d51b4220) O el1h_ns: msr
>>>>>>>>> daif, x0 (setup_arch)
>>>>>>>>>> R CPSR 600000c5
>>>>>>>>>> 3824884529 ps ES System Error (Abort)
>>>>>>>>>> EXC [0x380] SError/vSError Current EL with SP_ELx
>>>>>>>>>> R ESR_EL1 (AARCH64) bf000002
>>>>>>>>>> R CPSR 600003c5
>>>>>>>>>> R SPSR_EL1 (AARCH64) 600000c5
>>>>>>>>>> R ELR_EL1 (AARCH64) ffff8000 80763a68
>>>>>>>>>> 3824884925 ps ES (ffff800080010b80:d10543ff) O el1h_ns: sub
>>>>>>> sp,
>>>>>>>>> sp, #0x150 (vectors)
>>>>>>>>>> R SP_EL1 (AARCH64) ffff8000 808f3c50
>>>>>>>>>> 3824884925 ps ES (ffff800080010b84:8b2063ff) O el1h_ns: add
>>>>>>> sp,
>>>>>>>>> sp, x0 (vectors)
>>>>>>>>>> R SP_EL1 (AARCH64) ffff8000 808f3d10
>>>>>>>>>> 3824884926 ps ES (ffff800080010b88:cb2063e0) O el1h_ns: sub
>>>>>>> x0,
>>>>>>>>> sp, x0 (vectors)
>>>>>>>>>> R X0 (AARCH64) ffff8000 808f3c50
>>>>>>>>>> 3824884927 ps ES (ffff800080010b8c:37700080) O el1h_ns: tbnz
>>>>>>> w0,
>>>>>>>>> #14, ffff800080010b9c <vectors+0x39c> (vectors)
>>>>>>>>>> 3824884935 ps ES (ffff800080010b90:cb2063e0) O el1h_ns: sub
>>>>>>> x0,
>>>>>>>>> sp, x0 (vectors)
>>>>>>>>>> R X0 (AARCH64) 00000000 000000c0
>>>>>>>>>> 3824884937 ps ES (ffff800080010b94:cb2063ff) O el1h_ns: sub
>>>>> sp,
>>>>>>>>> sp, x0 (vectors)
>>>>>>>>>> R SP_EL1 (AARCH64) ffff8000 808f3c50
>>>>>>>>>> 3824884938 ps ES (ffff800080010b98:140001ef) O el1h_ns: b
>>>>>>>>> ffff800080011354 <el1h_64_error> (vectors)
>>>>>>>>>>
>>>>>>>>>> If I understand correctly, the exception happened sometime earlier
>> and
>>>>>>> only
>>>>>>>>> now Linux boot code (setup_arch) opened the exception handling and as
>>>>> a
>>>>>>>>> result we immediately jump to the SError exception handler.
>>>>>>>>>
>>>>>>>>>
>>>>>>>>> Yes, that sounds reasonable. If I understood correctly, you are
>>>>>>>>> running something "quite new" on some software (QEMU) and
>>>>> hardware
>>>>>>>>> (Synopsis) simulators.
>>>>>>>>>
>>>>>>>>> That would mean that you have new hardware with e.g. new memory
>>>>> map
>>>>>>>>> not used before. What you describe might sound like in the code before
>>>>>>>>> Linux (boot loader) there is anything resulting in the SError. This
>>>>>>>>> might be an access to non-existing or non-enabled hardware. I.e. it
>>>>>>>>> might be that you try to access (read/write) an address what is not
>>>>>>>>> available, yet (or just invalid). It's hard to debug that. In case you
>>>>>>>>> are able to modify the code before Linux (the boot loader?) you might
>>>>>>>>> try to enable SError exceptions, there, too. To get it earlier and
>>>>>>>>> with that make the search window smaller. I'm not that familiar with
>>>>>>>>> QEMU, but could you try to trace which (all?) hardware accesses your
>>>>>>>>> code does. And with that analyse all accesses and with that check if
>>>>>>>>> all these accesses are valid even on the hardware (Synopsis) emulation
>>>>>>>>> system? That should be checked from valid address and from hardware
>>>>>>>>> subsystem enablement point of view.
>>>>>>>>>
>>>>>>>>> Hth,
>>>>>>>>>
>>>>>>>>> Dirk
>>>>>>>>>
>>>>>>>>>
>>>>>>>>>> From the Linux source:
>>>>>>>>>> parse_early_param();
>>>>>>>>>>
>>>>>>>>>> dynamic_scs_init();
>>>>>>>>>>
>>>>>>>>>> /*
>>>>>>>>>> * Unmask asynchronous aborts and fiq after bringing up possible
>>>>>>>>>> * earlycon. (Report possible System Errors once we can report
>> this
>>>>>>>>>> * occurred).
>>>>>>>>>> */
>>>>>>>>>> local_daif_restore(DAIF_PROCCTX_NOIRQ); <---- This is when we
>>>>> get
>>>>>>> the
>>>>>>>>> exception.
>>>>>>>>>>
>>>>>>>>>> After some kernel hacking (replacing printk) we could extract the logs:
>>>>>>>>>> 6Booting Linux on physical CPU 0x0000000000 [0x410fd034]
>>>>>>>>>> 5Linux version 6.5.0 (pliops@dev-liorw) (aarch64-buildroot-linux-gnu-
>>>>>>>>> gcc.br_real (Buildroot 2023.02.1-95-g8391404e23) 11.3.0, GNU ld
>>>>> (GNU
>>>>>>>>> Binutils) 2.38) #101 SMP Sun Dec 17 20:09:06 IST 2023
>>>>>>>>>> 6Machine model: Pliops Spider MK-I EVK
>>>>>>>>>> 2SError Interrupt on CPU0, code 0x00000000bf000002 -- SError
>>>>>>>>>> CPU: 0 PID: 0 Comm: swapper Not tainted 6.5.0 #101
>>>>>>>>>> Hardware name: Pliops Spider MK-I EVK (DT)
>>>>>>>>>> pstate: 600000c5 (nZCv daIF -PAN -UAO -TCO -DIT -SSBS BTYPE=--)
>>>>>>>>>> pc : setup_arch+0x13c/0x5ac
>>>>>>>>>> lr : setup_arch+0x134/0x5ac
>>>>>>>>>> sp : ffff8000808f3da0
>>>>>>>>>> x29: ffff8000808f3da0c x28: 0000000008758074c x27:
>>>>>>>>> 0000000005e31b58c
>>>>>>>>>> x26: 0000000000000001c x25: 0000000007e5f728c x24:
>>>>>>>>> ffff8000808f8000c
>>>>>>>>>> x23: ffff8000808f8600c x22: ffff8000807b6000c x21:
>>>>>>> ffff800080010000c
>>>>>>>>>> x20: ffff800080a1e000c x19: fffffbfffddfe190c x18:
>>>>> 000000002266684ac
>>>>>>>>>> x17: 00000000fcad60bbc x16: 0000000000001800c x15:
>>>>>>>>> 0000000000000008c
>>>>>>>>>> x14: ffffffffffffffffc x13: 0000000000000000c x12:
>>>>> 0000000000000003c
>>>>>>>>>> x11: 0101010101010101c x10: ffffffffffee87dfc x9 :
>>>>>>> 0000000000000038c
>>>>>>>>>> x8 : 0101010101010101c x7 : 7f7f7f7f7f7f7f7fc x6 :
>>>>>>> 0000000000000001c
>>>>>>>>>> x5 : 0000000000000000c x4 : 8000000000000000c x3 :
>>>>>>>>> 0000000000000065c
>>>>>>>>>> x2 : 0000000000000000c x1 : 0000000000000000c x0 :
>>>>>>>>> 00000000000000c0c
>>>>>>>>>> 0Kernel panic - not syncing: Asynchronous SError Interrupt
>>>>>>>>>> CPU: 0 PID: 0 Comm: swapper Not tainted 6.5.0 #101
>>>>>>>>>> Hardware name: Pliops Spider MK-I EVK (DT)
>>>>>>>>>> Call trace:
>>>>>>>>>> dump_backtrace+0x9c/0xd0
>>>>>>>>>> show_stack+0x14/0x1c
>>>>>>>>>> dump_stack_lvl+0x44/0x58
>>>>>>>>>> dump_stack+0x14/0x1c
>>>>>>>>>> panic+0x2e0/0x33c
>>>>>>>>>> nmi_panic+0x68/0x6c
>>>>>>>>>> arm64_serror_panic+0x68/0x78
>>>>>>>>>> do_serror+0x24/0x54
>>>>>>>>>> el1h_64_error_handler+0x2c/0x40
>>>>>>>>>> el1h_64_error+0x64/0x68
>>>>>>>>>> setup_arch+0x13c/0x5ac
>>>>>>>>>> start_kernel+0x5c/0x5b8
>>>>>>>>>> __primary_switched+0xb4/0xbc
>>>>>>>>>> 0---[ end Kernel panic - not syncing: Asynchronous SError Interrupt ]---
>>>>>>>>>>
>>>>>>>>>> Can you please advice how to proceed with debugging?
>>>>>>>>>>
>>>>>>>>>> Thanks in advanced,
>>>>>>>>>> Cheers,
>>>>>>>>>> Lior.
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>
>>>>>>>>
>>>>>>
>>>>
>>>
>>
>> --
>> DENX Software Engineering GmbH, Managing Director: Erika Unter
>> HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany
>> Phone: +49-8142-66989-52 Fax: +49-8142-66989-80 Email: hs@denx.de
^ permalink raw reply [flat|nested] 16+ messages in thread
* Re: Debugging early SError exception
2023-12-22 7:48 ` Dirk Behme
@ 2023-12-22 8:04 ` Heiko Schocher
2023-12-24 15:41 ` Lior Weintraub
0 siblings, 1 reply; 16+ messages in thread
From: Heiko Schocher @ 2023-12-22 8:04 UTC (permalink / raw)
To: Dirk Behme, Lior Weintraub; +Cc: linux-embedded
Hello Dirk, Lior,
On 22.12.23 08:48, Dirk Behme wrote:
> Am 22.12.23 um 08:03 schrieb Lior Weintraub:
>> Hi,
>>
>> I managed to dump the __log_buf but for some reason the UART is still not working.
>> Please note that UART printed all the U-BOOT traces so AFAIU, the device tree is set correctly.
>> (Barebox is passing it's DTB into kernel).
>>
>> To enable the earlyprintk I have:
>> 1. Compiled the kernel with CONFIG_EARLY_PRINTK=y and CONFIG_DEBUG_LL=y
>> 2. Modified the boot args to include: "console=ttyS0,115200n8 earlycon=dw-apb-uart,0xd000307000"
>> 3. Verified that dw-apb-uart driver (8250_early.c) supports earlycon:
>> OF_EARLYCON_DECLARE(uart, "snps,dw-apb-uart", early_serial8250_setup);
>>
>> From __log_buf dump:
>> Booting Linux on physical CPU 0x0000000000 [0x410fd034]4]
>> Linux version 6.5.0 (pliops@dev-liorw) (aarch64-buildroot-linux-gnu-gcc.br_real (Buildroot
>> 2023.02.1-95-g8391404e23) 11.3.0, GNU ld (GNU Binutils) 2.38) #107 SMP Thu Dec 21 17:33:12 IST 202323
>> Machine model: Pliops Spider MK-I EVKVK
>> efi: UEFI not found.d.
>> Zone ranges:s:
>> DMA [mem 0x0000000000000000-0x000000002fffffff]f]
>> DMA32 emptyty
>> Normal emptyty
>> Movable zone start for each nodede
>> Early memory node rangeses
>> node 0: [mem 0x0000000000000000-0x000000002fffffff]f]
>> Initmem setup node 0 [mem 0x0000000000000000-0x000000002fffffff]f]
>> percpu: Embedded 25 pages/cpu s64800 r8192 d29408 u10240000
>> pcpu-alloc: s64800 r8192 d29408 u102400 alloc=25*4096
>> pcpu-alloc: [0] 0
>> Detected VIPT I-cache on CPU0U0
>> CPU features: GIC system register CPU interface present but disabled by higher exception levelel
>> CPU features: detected: ARM erratum 84571919
>> alternatives: applying boot alternativeses
>> Kernel command line: console=ttyS0,115200n8 earlycon=dw-apb-uart,0xd00030700000
>> Dentry cache hash table entries: 131072 (order: 8, 1048576 bytes, linear)r)
>> Inode-cache hash table entries: 65536 (order: 7, 524288 bytes, linear)r)
>> Built 1 zonelists, mobility grouping on. Total pages: 19353636
>> mem auto-init: stack:off, heap alloc:off, heap free:offff
>> software IO TLB: area num 1.1.
>> software IO TLB: mapped [mem 0x000000002b080000-0x000000002f080000] (64MB)B)
>> Memory: 689240K/786432K available (5824K kernel code, 1186K rwdata, 1612K rodata, 1600K init, 400K
>> bss, 97192K reserved, 0K cma-reserved)d)
>> SLUB: HWalign=64, Order=0-3, MinObjects=0, CPUs=1, Nodes=1=1
>> trace event string verifier disableded
>> rcu: Hierarchical RCU implementation.n.
>> rcu: RCU event tracing is enabled.d.
>> rcu: RCU restricting CPUs from NR_CPUS=256 to nr_cpu_ids=1.1.
>> rcu: RCU calculated value of scheduler-enlistment delay is 25 jiffies.s.
>> rcu: Adjusting geometry for rcu_fanout_leaf=16, nr_cpu_ids=1=1
>> NR_IRQS: 64, nr_irqs: 64, preallocated irqs: 0 0
>> GICv3: 96 SPIs implementeded
>> GICv3: 0 Extended SPIs implementeded
>> Root IRQ handler: gic_handle_irqrq
>> GICv3: GICv3 features: 16 PPIsIs
>> GICv3: CPU0: found redistributor 0 region 0:0x000000e00006000000
>> GICv3: redistributor failed to wakeup.....
>> GICv3: GIC: unable to set SRE (disabled at EL2), panic aheadad
>
> I think the two messages above are the essential ones.
+1
> Maybe it helps to check
>
> https://www.kernel.org/doc/html/v5.3/arm64/booting.html
>
> In the middle of that page in the "Call the kernel image" it has something about GIC:
>
> -- cut --
> If the kernel is entered at EL1:
>
> ICC.SRE_EL2.Enable (bit 3) must be initialised to 0b1
> ICC_SRE_EL2.SRE (bit 0) must be initialised to 0b1.
> -- cut --
Also may it makes sense to check your firmware (bootloader, ATF?) ... may
there is some setting missing for your SoC/Board ?
bye,
Heiko
>
>> Internal error: Oops - Undefined instruction: 0000000062383019 [#1] SMPMP
>> Modules linked in:
>> CPU: 0 PID: 0 Comm: swapper/0 Not tainted 6.5.0 #107
>> Hardware name: Pliops Spider MK-I EVK (DT)
>> pstate: 600000c5 (nZCv daIF -PAN -UAO -TCO -DIT -SSBS BTYPE=--)
>> pc : gic_cpu_sys_reg_init+0x58/0x2e4
>> lr : gic_cpu_sys_reg_init+0x2a4/0x2e4
>> sp : ffff8000808f3b40
>> x29: ffff8000808f3b40 x28: 0000000000000000 x27: 0000000000000001
>> x26: ffff000000016040 x25: 0000000000000000 x24: ffff800080a6b000
>> x23: ffff8000808fc320 x22: ffff8000809cc000 x21: ffff00002fe74670
>> x20: ffff800080a90000 x19: 0000000000000000 x18: fffffffffffe0b10
>> x17: ffff8000809f9480 x16: fffffc0000002248 x15: ffff80008090af28
>> x14: fffffffffffc0b0f x13: 6461656861206369 x12: 6e6170202c29324c
>> x11: 452074612064656c x10: 6261736964282045 x9 : 6428204552532074
>> x8 : ffff80008090af28 x7 : ffff8000808f3970 x6 : 000000000000000c
>> x5 : 000000000000002a x4 : 0000000000000000 x3 : 0000000000000000
>> x2 : 0000000000000000 x1 : ffff8000808fd0c0 x0 : 000000000000003c
>> Call trace:
>> gic_cpu_sys_reg_init+0x58/0x2e4
>> gic_cpu_init.part.0+0xa8/0x114
>> gic_init_bases+0x408/0x684
>> gic_of_init+0x298/0x300
>> of_irq_init+0x1c8/0x368
>> irqchip_init+0x14/0x1c
>> init_IRQ+0x98/0xac
>> start_kernel+0x250/0x5b8
>> __primary_switched+0xb4/0xbc
>> Code: 9260df39 d3441f33 d538cca0 36001180 (d538cc80) )
>> ---[ end trace 0000000000000000 ]-----
>> Kernel panic - not syncing: Attempted to kill the idle task!k!
>> ---[ end Kernel panic - not syncing: Attempted to kill the idle task! ]-----
>>
>>
>> The kernel panic is related to GIC distributor (currently under debug) but AFAIU,
>> this has nothing to do with the UART not working on early stages.
>
>
> Yes, I agree. GIC issue and UART (at least the polling mode) should be indendent.
>
> Best regards
>
> Dirk
>
>
>> Thanks in advanced for your advice,
>> Cheers,
>> Lior.
>>
>>
>>> -----Original Message-----
>>> From: Heiko Schocher <hs@denx.de>
>>> Sent: Thursday, December 21, 2023 1:37 PM
>>> To: Lior Weintraub <liorw@pliops.com>
>>> Cc: Dirk Behme <dirk.behme@gmail.com>; linux-embedded@vger.kernel.org
>>> Subject: Re: Debugging early SError exception
>>>
>>> [You don't often get email from hs@denx.de. Learn why this is important at
>>> https://aka.ms/LearnAboutSenderIdentification ]
>>>
>>> CAUTION: External Sender
>>>
>>> Hi Lior,
>>>
>>> On 21.12.23 12:19, Dirk Behme wrote:
>>>> Am 21.12.23 um 11:04 schrieb Lior Weintraub:
>>>>> Thanks Dirk,
>>>>>
>>>>> Regarding the earlyprintk, not sure I know how to make it work.
>>>>> I have defined CONFIG_EARLY_PRINTK=y and CONFIG_DEBUG_LL=y on my
>>> config but it doesn't seem to work.
>>>>> Do I need to pass something in the bootargs from the U-BOOT?
>>>>> Do I need to add that into my device tree?
>>>>> (Tried to set bootargs = "console=ttyS0,115200 earlyprintk"; under "chosen"
>>> on my DT but it didn't
>>>>> work)
>>>>
>>>> Yes, what has to be enabled and what not and what has to be set how is often
>>> confusing. I think this
>>>> is not common for all systems, so I think to be on the safe side you have to look
>>> into the code for
>>>> you system. Or short; The code is the documentation ;)
>>>>
>>>>
>>>>> The UART I am using is "snps,dw-apb-uart".
>>>>>
>>>>> Last week, to output the early logs I have implemented this hack:
>>>>> 1. Modify printk macro to run my print_func
>>>>> 2. This print_func wrote the characters into a single global variable (u32
>>> simul_uart;)
>>>>> 3. Get the address location of this global variable and extract all writes to it
>>> from the Tarmac
>>>>> logs.
>>>>>
>>>>> This is a very slow and tedious process but it helped me identify the initial
>>> SError.
>>>>> Initially I thought I can write directly into the UART FIFO register (which I know
>>> the address)
>>>>> but this didn't work because Linux already setup the MMU so I guess I need to
>>> know the virtual
>>>>> address of this FIFO.
>>>>> Do I need to use __phys_to_virt of some sort?
>>>>
>>>> Yes, I think so. Have a look to the existing serial driver, too. It should do whats
>>> needed, and you
>>>> can borrow that, then.
>>>
>>> If you have access to the RAM after the crash (through a debugger or in
>>> your bootloader) and your mem is stable, find out the address of __log_buf
>>> in System.map. Thats the buffer where printk writes into it, and so dumping
>>> the content is what you would see in case uart works...
>>>
>>> Hope it helps!
>>>
>>> bye,
>>> Heiko
>>>>
>>>> Best regards
>>>>
>>>> Dirk
>>>>
>>>>
>>>>> Cheers,
>>>>> Lior.
>>>>>
>>>>>> -----Original Message-----
>>>>>> From: Dirk Behme <dirk.behme@gmail.com>
>>>>>> Sent: Thursday, December 21, 2023 10:30 AM
>>>>>> To: Lior Weintraub <liorw@pliops.com>; linux-embedded@vger.kernel.org
>>>>>> Subject: Re: Debugging early SError exception
>>>>>>
>>>>>> [You don't often get email from dirk.behme@gmail.com. Learn why this is
>>>>>> important at https://aka.ms/LearnAboutSenderIdentification ]
>>>>>>
>>>>>> CAUTION: External Sender
>>>>>>
>>>>>> Am 21.12.23 um 08:43 schrieb Lior Weintraub:
>>>>>>> Hi Dirk,
>>>>>>>
>>>>>>> We found that the issue was at the early stages of Barebox (a.k.a U-BOOT
>>>>>> v2).
>>>>>>
>>>>>> Glad to hear that! :)
>>>>>>
>>>>>>> Our implementation of putc_ll (on debug_ll) was writing into the UART Tx
>>>>>> FIFO without checking if the FIFO is full.
>>>>>>> Once the fifo got full it caused this SError probably because the UART IP
>>>>>> generated an apberror signal.
>>>>>>
>>>>>> Thanks for the report!
>>>>>>
>>>>>>> Now the Linux is running and doesn't report the SError again but now we
>>>>>> face another issue.
>>>>>>> We see that the PC is getting into a "report_bug" function.
>>>>>>> The Linux doesn't print anything to the UART (probably since it hasn't got to
>>>>>> the point where the console is configured?).
>>>>>>
>>>>>> For cases like this using earlyprintk is usually a good option. Check
>>>>>> the Linux kernel serial console (UART) dirver of you SoC if it
>>>>>> supports it. In the end it should be "just" a function in the serial
>>>>>> console driver which outputs the console data via polling before
>>>>>> (later) the interrupt driven console part takes over.
>>>>>>
>>>>>> Best regards
>>>>>>
>>>>>> Dirk
>>>>>>
>>>>>>
>>>>>>> Since our debug means are limited it can take some time to find the root
>>>>>> cause.
>>>>>>>
>>>>>>> I will keep you posted and update our findings.
>>>>>>> Love to hear your thoughts,
>>>>>>>
>>>>>>> Cheers,
>>>>>>> Lior.
>>>>>>>
>>>>>>>
>>>>>>>> -----Original Message-----
>>>>>>>> From: Dirk Behme <dirk.behme@gmail.com>
>>>>>>>> Sent: Tuesday, December 19, 2023 3:37 PM
>>>>>>>> To: Lior Weintraub <liorw@pliops.com>; linux-embedded@vger.kernel.org
>>>>>>>> Subject: Re: Debugging early SError exception
>>>>>>>>
>>>>>>>> [You don't often get email from dirk.behme@gmail.com. Learn why this is
>>>>>>>> important at https://aka.ms/LearnAboutSenderIdentification ]
>>>>>>>>
>>>>>>>> CAUTION: External Sender
>>>>>>>>
>>>>>>>> Am 19.12.23 um 14:23 schrieb Lior Weintraub:
>>>>>>>>> Thanks Dirk,
>>>>>>>>
>>>>>>>> Welcome :)
>>>>>>>>
>>>>>>>> In case you find the root cause it would be nice to get some generic
>>>>>>>> description of it so that we can learn something :)
>>>>>>>>
>>>>>>>> Best regards
>>>>>>>>
>>>>>>>> Dirk
>>>>>>>>
>>>>>>>>
>>>>>>>>>> -----Original Message-----
>>>>>>>>>> From: Dirk Behme <dirk.behme@gmail.com>
>>>>>>>>>> Sent: Tuesday, December 19, 2023 9:09 AM
>>>>>>>>>> To: Lior Weintraub <liorw@pliops.com>; linux-
>>>>>> embedded@vger.kernel.org
>>>>>>>>>> Subject: Re: Debugging early SError exception
>>>>>>>>>>
>>>>>>>>>> [You don't often get email from dirk.behme@gmail.com. Learn why this
>>>>>> is
>>>>>>>>>> important at https://aka.ms/LearnAboutSenderIdentification ]
>>>>>>>>>>
>>>>>>>>>> CAUTION: External Sender
>>>>>>>>>>
>>>>>>>>>> Am 17.12.23 um 22:32 schrieb Lior Weintraub:
>>>>>>>>>>> Hi,
>>>>>>>>>>>
>>>>>>>>>>> We have a new SoC with eLinux porting (kernel v6.5).
>>>>>>>>>>> This SoC is ARM64 (A53) single core based device.
>>>>>>>>>>> It runs correctly on QEMU but fails with SError on emulation platform
>>>>>>>>>> (Synopsys Zebu running our SoC model).
>>>>>>>>>>> There is no debugger connected to this emulation but there are several
>>>>>>>>>> debug capabilities we can use:
>>>>>>>>>>> 1. Generating wave dump of CPU signals
>>>>>>>>>>> 2. Generate a Tarmac log
>>>>>>>>>>> 3. UART
>>>>>>>>>>>
>>>>>>>>>>> Since the SError happens at early stages of Linux boot the UART is not
>>>>>>>>>> enabled yet.
>>>>>>>>>>> From the Tarmac log we can see:
>>>>>>>>>>> 3824884521 ps ES (ffff800080760888:d65f03c0) O el1h_ns: ret
>>>>>>>>>> (parse_early_param)
>>>>>>>>>>> 3824884522 ps ES (ffff800080763a60:d2801800) O el1h_ns: mov
>>>>>>>> x0,
>>>>>>>>>> #0xc0 // #192 (setup_arch)
>>>>>>>>>>> R X0 (AARCH64) 00000000 000000c0
>>>>>>>>>>> 3824884523 ps ES (ffff800080763a64:d51b4220) O el1h_ns: msr
>>>>>>>>>> daif, x0 (setup_arch)
>>>>>>>>>>> R CPSR 600000c5
>>>>>>>>>>> 3824884529 ps ES System Error (Abort)
>>>>>>>>>>> EXC [0x380] SError/vSError Current EL with SP_ELx
>>>>>>>>>>> R ESR_EL1 (AARCH64) bf000002
>>>>>>>>>>> R CPSR 600003c5
>>>>>>>>>>> R SPSR_EL1 (AARCH64) 600000c5
>>>>>>>>>>> R ELR_EL1 (AARCH64) ffff8000 80763a68
>>>>>>>>>>> 3824884925 ps ES (ffff800080010b80:d10543ff) O el1h_ns: sub
>>>>>>>> sp,
>>>>>>>>>> sp, #0x150 (vectors)
>>>>>>>>>>> R SP_EL1 (AARCH64) ffff8000 808f3c50
>>>>>>>>>>> 3824884925 ps ES (ffff800080010b84:8b2063ff) O el1h_ns: add
>>>>>>>> sp,
>>>>>>>>>> sp, x0 (vectors)
>>>>>>>>>>> R SP_EL1 (AARCH64) ffff8000 808f3d10
>>>>>>>>>>> 3824884926 ps ES (ffff800080010b88:cb2063e0) O el1h_ns: sub
>>>>>>>> x0,
>>>>>>>>>> sp, x0 (vectors)
>>>>>>>>>>> R X0 (AARCH64) ffff8000 808f3c50
>>>>>>>>>>> 3824884927 ps ES (ffff800080010b8c:37700080) O el1h_ns: tbnz
>>>>>>>> w0,
>>>>>>>>>> #14, ffff800080010b9c <vectors+0x39c> (vectors)
>>>>>>>>>>> 3824884935 ps ES (ffff800080010b90:cb2063e0) O el1h_ns: sub
>>>>>>>> x0,
>>>>>>>>>> sp, x0 (vectors)
>>>>>>>>>>> R X0 (AARCH64) 00000000 000000c0
>>>>>>>>>>> 3824884937 ps ES (ffff800080010b94:cb2063ff) O el1h_ns: sub
>>>>>> sp,
>>>>>>>>>> sp, x0 (vectors)
>>>>>>>>>>> R SP_EL1 (AARCH64) ffff8000 808f3c50
>>>>>>>>>>> 3824884938 ps ES (ffff800080010b98:140001ef) O el1h_ns: b
>>>>>>>>>> ffff800080011354 <el1h_64_error> (vectors)
>>>>>>>>>>>
>>>>>>>>>>> If I understand correctly, the exception happened sometime earlier
>>> and
>>>>>>>> only
>>>>>>>>>> now Linux boot code (setup_arch) opened the exception handling and as
>>>>>> a
>>>>>>>>>> result we immediately jump to the SError exception handler.
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>> Yes, that sounds reasonable. If I understood correctly, you are
>>>>>>>>>> running something "quite new" on some software (QEMU) and
>>>>>> hardware
>>>>>>>>>> (Synopsis) simulators.
>>>>>>>>>>
>>>>>>>>>> That would mean that you have new hardware with e.g. new memory
>>>>>> map
>>>>>>>>>> not used before. What you describe might sound like in the code before
>>>>>>>>>> Linux (boot loader) there is anything resulting in the SError. This
>>>>>>>>>> might be an access to non-existing or non-enabled hardware. I.e. it
>>>>>>>>>> might be that you try to access (read/write) an address what is not
>>>>>>>>>> available, yet (or just invalid). It's hard to debug that. In case you
>>>>>>>>>> are able to modify the code before Linux (the boot loader?) you might
>>>>>>>>>> try to enable SError exceptions, there, too. To get it earlier and
>>>>>>>>>> with that make the search window smaller. I'm not that familiar with
>>>>>>>>>> QEMU, but could you try to trace which (all?) hardware accesses your
>>>>>>>>>> code does. And with that analyse all accesses and with that check if
>>>>>>>>>> all these accesses are valid even on the hardware (Synopsis) emulation
>>>>>>>>>> system? That should be checked from valid address and from hardware
>>>>>>>>>> subsystem enablement point of view.
>>>>>>>>>>
>>>>>>>>>> Hth,
>>>>>>>>>>
>>>>>>>>>> Dirk
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>>> From the Linux source:
>>>>>>>>>>> parse_early_param();
>>>>>>>>>>>
>>>>>>>>>>> dynamic_scs_init();
>>>>>>>>>>>
>>>>>>>>>>> /*
>>>>>>>>>>> * Unmask asynchronous aborts and fiq after bringing up possible
>>>>>>>>>>> * earlycon. (Report possible System Errors once we can report
>>> this
>>>>>>>>>>> * occurred).
>>>>>>>>>>> */
>>>>>>>>>>> local_daif_restore(DAIF_PROCCTX_NOIRQ); <---- This is when we
>>>>>> get
>>>>>>>> the
>>>>>>>>>> exception.
>>>>>>>>>>>
>>>>>>>>>>> After some kernel hacking (replacing printk) we could extract the logs:
>>>>>>>>>>> 6Booting Linux on physical CPU 0x0000000000 [0x410fd034]
>>>>>>>>>>> 5Linux version 6.5.0 (pliops@dev-liorw) (aarch64-buildroot-linux-gnu-
>>>>>>>>>> gcc.br_real (Buildroot 2023.02.1-95-g8391404e23) 11.3.0, GNU ld
>>>>>> (GNU
>>>>>>>>>> Binutils) 2.38) #101 SMP Sun Dec 17 20:09:06 IST 2023
>>>>>>>>>>> 6Machine model: Pliops Spider MK-I EVK
>>>>>>>>>>> 2SError Interrupt on CPU0, code 0x00000000bf000002 -- SError
>>>>>>>>>>> CPU: 0 PID: 0 Comm: swapper Not tainted 6.5.0 #101
>>>>>>>>>>> Hardware name: Pliops Spider MK-I EVK (DT)
>>>>>>>>>>> pstate: 600000c5 (nZCv daIF -PAN -UAO -TCO -DIT -SSBS BTYPE=--)
>>>>>>>>>>> pc : setup_arch+0x13c/0x5ac
>>>>>>>>>>> lr : setup_arch+0x134/0x5ac
>>>>>>>>>>> sp : ffff8000808f3da0
>>>>>>>>>>> x29: ffff8000808f3da0c x28: 0000000008758074c x27:
>>>>>>>>>> 0000000005e31b58c
>>>>>>>>>>> x26: 0000000000000001c x25: 0000000007e5f728c x24:
>>>>>>>>>> ffff8000808f8000c
>>>>>>>>>>> x23: ffff8000808f8600c x22: ffff8000807b6000c x21:
>>>>>>>> ffff800080010000c
>>>>>>>>>>> x20: ffff800080a1e000c x19: fffffbfffddfe190c x18:
>>>>>> 000000002266684ac
>>>>>>>>>>> x17: 00000000fcad60bbc x16: 0000000000001800c x15:
>>>>>>>>>> 0000000000000008c
>>>>>>>>>>> x14: ffffffffffffffffc x13: 0000000000000000c x12:
>>>>>> 0000000000000003c
>>>>>>>>>>> x11: 0101010101010101c x10: ffffffffffee87dfc x9 :
>>>>>>>> 0000000000000038c
>>>>>>>>>>> x8 : 0101010101010101c x7 : 7f7f7f7f7f7f7f7fc x6 :
>>>>>>>> 0000000000000001c
>>>>>>>>>>> x5 : 0000000000000000c x4 : 8000000000000000c x3 :
>>>>>>>>>> 0000000000000065c
>>>>>>>>>>> x2 : 0000000000000000c x1 : 0000000000000000c x0 :
>>>>>>>>>> 00000000000000c0c
>>>>>>>>>>> 0Kernel panic - not syncing: Asynchronous SError Interrupt
>>>>>>>>>>> CPU: 0 PID: 0 Comm: swapper Not tainted 6.5.0 #101
>>>>>>>>>>> Hardware name: Pliops Spider MK-I EVK (DT)
>>>>>>>>>>> Call trace:
>>>>>>>>>>> dump_backtrace+0x9c/0xd0
>>>>>>>>>>> show_stack+0x14/0x1c
>>>>>>>>>>> dump_stack_lvl+0x44/0x58
>>>>>>>>>>> dump_stack+0x14/0x1c
>>>>>>>>>>> panic+0x2e0/0x33c
>>>>>>>>>>> nmi_panic+0x68/0x6c
>>>>>>>>>>> arm64_serror_panic+0x68/0x78
>>>>>>>>>>> do_serror+0x24/0x54
>>>>>>>>>>> el1h_64_error_handler+0x2c/0x40
>>>>>>>>>>> el1h_64_error+0x64/0x68
>>>>>>>>>>> setup_arch+0x13c/0x5ac
>>>>>>>>>>> start_kernel+0x5c/0x5b8
>>>>>>>>>>> __primary_switched+0xb4/0xbc
>>>>>>>>>>> 0---[ end Kernel panic - not syncing: Asynchronous SError Interrupt ]---
>>>>>>>>>>>
>>>>>>>>>>> Can you please advice how to proceed with debugging?
>>>>>>>>>>>
>>>>>>>>>>> Thanks in advanced,
>>>>>>>>>>> Cheers,
>>>>>>>>>>> Lior.
>>>>>>>>>>>
>>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>
>>>>>>>
>>>>>
>>>>
>>>
>>> --
>>> DENX Software Engineering GmbH, Managing Director: Erika Unter
>>> HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany
>>> Phone: +49-8142-66989-52 Fax: +49-8142-66989-80 Email: hs@denx.de
>
--
DENX Software Engineering GmbH, Managing Director: Erika Unter
HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany
Phone: +49-8142-66989-52 Fax: +49-8142-66989-80 Email: hs@denx.de
^ permalink raw reply [flat|nested] 16+ messages in thread
* RE: Debugging early SError exception
2023-12-22 8:04 ` Heiko Schocher
@ 2023-12-24 15:41 ` Lior Weintraub
2023-12-24 19:12 ` Lior Weintraub
0 siblings, 1 reply; 16+ messages in thread
From: Lior Weintraub @ 2023-12-24 15:41 UTC (permalink / raw)
To: hs, Dirk Behme; +Cc: linux-embedded
Hi,
The GICv3 issue was resolved after:
1. Setting bit 0 and bit 3 on ICC_SRE_EL3 (we don't have virtualization support and hence ICC_SRE_EL2 is not supported).
2. Power up the GICR on EL3
The earlycon issue was resolved after:
1. Add to "earlycon=uart8250,mmio32,0xd000307000,115200n8" to boot args.
2. Add "CONFIG_SERIAL_8250_CONSOLE=y" to config (previously had only CONFIG_SERIAL_8250=y)
Now I face a new issue:
Linux boot hangs on "wait for interrupt" at cpu_do_idle.
The program counter is stuck at 0xffff8000805ae45c.
ffff8000805ae454 <cpu_do_idle>:
ffff8000805ae454: d5033f9f dsb sy
ffff8000805ae458: d503207f wfi
ffff8000805ae45c: d65f03c0 ret
I think that something is wrong with the timers or gic setting and as a result the scheduler doesn't get the interrupts (timer ticks).
Additional info that might be relevant to this issue:
The emulation platform runs at about 2.8MHz.
The CNTFRQ_EL0 is set to 2M (because the emulation platform running freq varies between 1.9-2.8MHz).
The reason for those settings is to allow Linux to run as it would on the "real" world.
It is my understanding that there are 2 issues here:
1. Something is wrong with Timers\Interrupt setting (note that same configuration runs correctly on QEMU)
2. Something is wrong with initramfs - according kernel source it seems to fail to open "/dev/console"
The full Linux boot log:
Booting Linux on physical CPU 0x0000000000 [0x410fd034]
Linux version 6.5.0 (pliops@dev-liorw) (aarch64-buildroot-linux-gnu-gcc.br_real (Buildroot 2023.02.1-95-g8391404e23) 11.3.0, GNU ld (GNU Binuti) 2.38) #112 SMP Sun Dec 24 15:44:56 IST 2023
Machine model: Pliops Spider MK-I EVK
earlycon: uart8250 at MMIO32 0x000000d000307000 (options '115200n8')
printk: bootconsole [uart8250] enabled
efi: UEFI not found.
Zone ranges:
DMA [mem 0x0000000000000000-0x000000002fffffff]
DMA32 empty
Normal empty
Movable zone start for each node
Early memory node ranges
node 0: [mem 0x0000000000000000-0x000000002fffffff]
Initmem setup node 0 [mem 0x0000000000000000-0x000000002fffffff]
percpu: Embedded 25 pages/cpu s64800 r8192 d29408 u102400
Detected VIPT I-cache on CPU0
CPU features: detected: GIC system register CPU interface
CPU features: detected: ARM erratum 845719
alternatives: applying boot alternatives
Kernel command line: console=ttyS0,115200n8 earlycon=uart8250,mmio32,0xd000307000,115200n8
Dentry cache hash table entries: 131072 (order: 8, 1048576 bytes, linear)
Inode-cache hash table entries: 65536 (order: 7, 524288 bytes, linear)
Built 1 zonelists, mobility grouping on. Total pages: 193536
mem auto-init: stack:off, heap alloc:off, heap free:off
software IO TLB: area num 1.
software IO TLB: mapped [mem 0x000000002b080000-0x000000002f080000] (64MB)
Memory: 689240K/786432K available (5824K kernel code, 1186K rwdata, 1612K rodata, 1600K init, 400K bss, 97192K reserved, 0K cma-reserved)
SLUB: HWalign=64, Order=0-3, MinObjects=0, CPUs=1, Nodes=1
trace event string verifier disabled
rcu: Hierarchical RCU implementation.
rcu: RCU event tracing is enabled.
rcu: RCU restricting CPUs from NR_CPUS=256 to nr_cpu_ids=1.
rcu: RCU calculated value of scheduler-enlistment delay is 25 jiffies.
rcu: Adjusting geometry for rcu_fanout_leaf=16, nr_cpu_ids=1
NR_IRQS: 64, nr_irqs: 64, preallocated irqs: 0
GICv3: 96 SPIs implemented
GICv3: 0 Extended SPIs implemented
Root IRQ handler: gic_handle_irq
GICv3: GICv3 features: 16 PPIs
GICv3: CPU0: found redistributor 0 region 0:0x000000e000060000
ITS [mem 0xe000040000-0xe00005ffff]
ITS@0x000000e000040000: allocated 8192 Devices @a0000 (indirect, esz 8, psz 64K, shr 1)
ITS@0x000000e000040000: allocated 32768 Interrupt Collections @b0000 (flat, esz 2, psz 64K, shr 1)
GICv3: Expected reserved range [0x00000000000c0000:0x00000000000cffff], not found
GICv3: using LPI property table @0x00000000000c0000
GICv3: CPU0: Booted with LPIs enabled, memory probably corrupted
CPU0: Failed to disable LPIs
rcu: srcu_init: Setting srcu_struct sizes based on contention.
arch_timer: cp15 timer(s) running at 62.50MHz (virt).
clocksource: arch_sys_counter: mask: 0x1ffffffffffffff max_cycles: 0x1cd42e208c, max_idle_ns: 881590405314 ns
sched_clock: 57 bits at 63MHz, resolution 16ns, wraps every 4398046511096ns
Console: colour dummy device 80x25
Calibrating delay loop (skipped), value calculated using timer frequency.. 125.00 BogoMIPS (lpj=250000)
pid_max: default: 32768 minimum: 301
Mount-cache hash table entries: 2048 (order: 2, 16384 bytes, linear)
Mountpoint-cache hash table entries: 2048 (order: 2, 16384 bytes, linear)
cacheinfo: Unable to detect cache hierarchy for CPU 0
rcu: Hierarchical SRCU implementation.
rcu: Max phase no-delay instances is 1000.
Platform MSI: gic-its@E000040000 domain created
PCI/MSI: /soc/interrupt-controller@E000000000/gic-its@E000040000 domain created
EFI services will not be available.
smp: Bringing up secondary CPUs ...
smp: Brought up 1 node, 1 CPU
SMP: Total of 1 processors activated.
CPU features: detected: 32-bit EL0 Support
CPU features: detected: CRC32 instructions
CPU: All CPU(s) started at EL1
alternatives: applying system-wide alternatives
devtmpfs: initialized
clocksource: jiffies: mask: 0xffffffff max_cycles: 0xffffffff, max_idle_ns: 7645041785100000 ns
futex hash table entries: 256 (order: 2, 16384 bytes, linear)
DMI not present or invalid.
DMA: preallocated 128 KiB GFP_KERNEL pool for atomic allocations
DMA: preallocated 128 KiB GFP_KERNEL|GFP_DMA pool for atomic allocations
DMA: preallocated 128 KiB GFP_KERNEL|GFP_DMA32 pool for atomic allocations
hw-breakpoint: found 6 breakpoint and 4 watchpoint registers.
ASID allocator initialised with 65536 entries
Serial: AMBA PL011 UART driver
Modules: 30080 pages in range for non-PLT usage
Modules: 521600 pages in range for PLT usage
iommu: Default domain type: Translated
iommu: DMA domain TLB invalidation policy: strict mode
SCSI subsystem initialized
vgaarb: loaded
clocksource: Switched to clocksource arch_sys_counter
PCI: CLS 0 bytes, default 64
workingset: timestamp_bits=46 max_order=18 bucket_order=0
fuse: init (API version 7.38)
Block layer SCSI generic (bsg) driver version 0.4 loaded (major 251)
io scheduler mq-deadline registered
io scheduler kyber registered
Unpacking initramfs...
Freeing initrd memory: 4596K
Serial: 8250/16550 driver, 4 ports, IRQ sharing disabled
hw perfevents: enabled with armv8_cortex_a53 PMU driver, 7 counters available
clk: Disabling unused clocks
Warning: unable to open an initial console.
Freeing unused kernel memory: 1600K
Thanks in advance for your great advice and support,
Cheers,
Lior.
> -----Original Message-----
> From: Heiko Schocher <hs@denx.de>
> Sent: Friday, December 22, 2023 10:04 AM
> To: Dirk Behme <dirk.behme@gmail.com>; Lior Weintraub
> <liorw@pliops.com>
> Cc: linux-embedded@vger.kernel.org
> Subject: Re: Debugging early SError exception
>
> [You don't often get email from hs@denx.de. Learn why this is important at
> https://aka.ms/LearnAboutSenderIdentification ]
>
> CAUTION: External Sender
>
> Hello Dirk, Lior,
>
> On 22.12.23 08:48, Dirk Behme wrote:
> > Am 22.12.23 um 08:03 schrieb Lior Weintraub:
> >> Hi,
> >>
> >> I managed to dump the __log_buf but for some reason the UART is still not
> working.
> >> Please note that UART printed all the U-BOOT traces so AFAIU, the device
> tree is set correctly.
> >> (Barebox is passing it's DTB into kernel).
> >>
> >> To enable the earlyprintk I have:
> >> 1. Compiled the kernel with CONFIG_EARLY_PRINTK=y and
> CONFIG_DEBUG_LL=y
> >> 2. Modified the boot args to include: "console=ttyS0,115200n8
> earlycon=dw-apb-uart,0xd000307000"
> >> 3. Verified that dw-apb-uart driver (8250_early.c) supports earlycon:
> >> OF_EARLYCON_DECLARE(uart, "snps,dw-apb-uart",
> early_serial8250_setup);
> >>
> >> From __log_buf dump:
> >> Booting Linux on physical CPU 0x0000000000 [0x410fd034]4]
> >> Linux version 6.5.0 (pliops@dev-liorw) (aarch64-buildroot-linux-gnu-
> gcc.br_real (Buildroot
> >> 2023.02.1-95-g8391404e23) 11.3.0, GNU ld (GNU Binutils) 2.38) #107
> SMP Thu Dec 21 17:33:12 IST 202323
> >> Machine model: Pliops Spider MK-I EVKVK
> >> efi: UEFI not found.d.
> >> Zone ranges:s:
> >> DMA [mem 0x0000000000000000-0x000000002fffffff]f]
> >> DMA32 emptyty
> >> Normal emptyty
> >> Movable zone start for each nodede
> >> Early memory node rangeses
> >> node 0: [mem 0x0000000000000000-0x000000002fffffff]f]
> >> Initmem setup node 0 [mem 0x0000000000000000-
> 0x000000002fffffff]f]
> >> percpu: Embedded 25 pages/cpu s64800 r8192 d29408 u10240000
> >> pcpu-alloc: s64800 r8192 d29408 u102400 alloc=25*4096
> >> pcpu-alloc: [0] 0
> >> Detected VIPT I-cache on CPU0U0
> >> CPU features: GIC system register CPU interface present but disabled by
> higher exception levelel
> >> CPU features: detected: ARM erratum 84571919
> >> alternatives: applying boot alternativeses
> >> Kernel command line: console=ttyS0,115200n8 earlycon=dw-apb-
> uart,0xd00030700000
> >> Dentry cache hash table entries: 131072 (order: 8, 1048576 bytes, linear)r)
> >> Inode-cache hash table entries: 65536 (order: 7, 524288 bytes, linear)r)
> >> Built 1 zonelists, mobility grouping on. Total pages: 19353636
> >> mem auto-init: stack:off, heap alloc:off, heap free:offff
> >> software IO TLB: area num 1.1.
> >> software IO TLB: mapped [mem 0x000000002b080000-
> 0x000000002f080000] (64MB)B)
> >> Memory: 689240K/786432K available (5824K kernel code, 1186K rwdata,
> 1612K rodata, 1600K init, 400K
> >> bss, 97192K reserved, 0K cma-reserved)d)
> >> SLUB: HWalign=64, Order=0-3, MinObjects=0, CPUs=1, Nodes=1=1
> >> trace event string verifier disableded
> >> rcu: Hierarchical RCU implementation.n.
> >> rcu: RCU event tracing is enabled.d.
> >> rcu: RCU restricting CPUs from NR_CPUS=256 to nr_cpu_ids=1.1.
> >> rcu: RCU calculated value of scheduler-enlistment delay is 25 jiffies.s.
> >> rcu: Adjusting geometry for rcu_fanout_leaf=16, nr_cpu_ids=1=1
> >> NR_IRQS: 64, nr_irqs: 64, preallocated irqs: 0 0
> >> GICv3: 96 SPIs implementeded
> >> GICv3: 0 Extended SPIs implementeded
> >> Root IRQ handler: gic_handle_irqrq
> >> GICv3: GICv3 features: 16 PPIsIs
> >> GICv3: CPU0: found redistributor 0 region 0:0x000000e00006000000
> >> GICv3: redistributor failed to wakeup.....
> >> GICv3: GIC: unable to set SRE (disabled at EL2), panic aheadad
> >
> > I think the two messages above are the essential ones.
>
> +1
>
> > Maybe it helps to check
> >
> > https://secure-web.cisco.com/1VmuNXQkE6u---G9xsJ8CPb6-
> aguDK_MyJeUn43QsTaafgaifoFTAvcD4vQefYzFntmjc8L_J46du6-
> DYArOlFkq__OwCChpFf-nXIyddL3MCQMsTZ9hIk_WCfDqIi1wSEmPSBClIYS0-
> SAjwPiOf7sA2wLvt_5ehGaTHO61NJEWdOrfKy9pBT1_RDyQGXi7kz8XuAUpu
> Whhipp-
> ngljUJcxkHkmWDvpocGule5ZNEe5UZ3nGNjUnqCU8J_bXtCgNPEk4CyorLt7g4
> F5Ks85tlVEEutu8vyJXu8_TUacURkRnQgjvood6iVOn5w2TpSRn/https%3A%2
> F%2Fwww.kernel.org%2Fdoc%2Fhtml%2Fv5.3%2Farm64%2Fbooting.html
> >
> > In the middle of that page in the "Call the kernel image" it has something
> about GIC:
> >
> > -- cut --
> > If the kernel is entered at EL1:
> >
> > ICC.SRE_EL2.Enable (bit 3) must be initialised to 0b1
> > ICC_SRE_EL2.SRE (bit 0) must be initialised to 0b1.
> > -- cut --
>
> Also may it makes sense to check your firmware (bootloader, ATF?) ... may
> there is some setting missing for your SoC/Board ?
>
> bye,
> Heiko
>
> >
> >> Internal error: Oops - Undefined instruction: 0000000062383019 [#1]
> SMPMP
> >> Modules linked in:
> >> CPU: 0 PID: 0 Comm: swapper/0 Not tainted 6.5.0 #107
> >> Hardware name: Pliops Spider MK-I EVK (DT)
> >> pstate: 600000c5 (nZCv daIF -PAN -UAO -TCO -DIT -SSBS BTYPE=--)
> >> pc : gic_cpu_sys_reg_init+0x58/0x2e4
> >> lr : gic_cpu_sys_reg_init+0x2a4/0x2e4
> >> sp : ffff8000808f3b40
> >> x29: ffff8000808f3b40 x28: 0000000000000000 x27:
> 0000000000000001
> >> x26: ffff000000016040 x25: 0000000000000000 x24: ffff800080a6b000
> >> x23: ffff8000808fc320 x22: ffff8000809cc000 x21: ffff00002fe74670
> >> x20: ffff800080a90000 x19: 0000000000000000 x18: fffffffffffe0b10
> >> x17: ffff8000809f9480 x16: fffffc0000002248 x15: ffff80008090af28
> >> x14: fffffffffffc0b0f x13: 6461656861206369 x12: 6e6170202c29324c
> >> x11: 452074612064656c x10: 6261736964282045 x9 :
> 6428204552532074
> >> x8 : ffff80008090af28 x7 : ffff8000808f3970 x6 : 000000000000000c
> >> x5 : 000000000000002a x4 : 0000000000000000 x3 :
> 0000000000000000
> >> x2 : 0000000000000000 x1 : ffff8000808fd0c0 x0 : 000000000000003c
> >> Call trace:
> >> gic_cpu_sys_reg_init+0x58/0x2e4
> >> gic_cpu_init.part.0+0xa8/0x114
> >> gic_init_bases+0x408/0x684
> >> gic_of_init+0x298/0x300
> >> of_irq_init+0x1c8/0x368
> >> irqchip_init+0x14/0x1c
> >> init_IRQ+0x98/0xac
> >> start_kernel+0x250/0x5b8
> >> __primary_switched+0xb4/0xbc
> >> Code: 9260df39 d3441f33 d538cca0 36001180 (d538cc80) )
> >> ---[ end trace 0000000000000000 ]-----
> >> Kernel panic - not syncing: Attempted to kill the idle task!k!
> >> ---[ end Kernel panic - not syncing: Attempted to kill the idle task! ]-----
> >>
> >>
> >> The kernel panic is related to GIC distributor (currently under debug) but
> AFAIU,
> >> this has nothing to do with the UART not working on early stages.
> >
> >
> > Yes, I agree. GIC issue and UART (at least the polling mode) should be
> indendent.
> >
> > Best regards
> >
> > Dirk
> >
> >
> >> Thanks in advanced for your advice,
> >> Cheers,
> >> Lior.
> >>
> >>
> >>> -----Original Message-----
> >>> From: Heiko Schocher <hs@denx.de>
> >>> Sent: Thursday, December 21, 2023 1:37 PM
> >>> To: Lior Weintraub <liorw@pliops.com>
> >>> Cc: Dirk Behme <dirk.behme@gmail.com>; linux-
> embedded@vger.kernel.org
> >>> Subject: Re: Debugging early SError exception
> >>>
> >>> [You don't often get email from hs@denx.de. Learn why this is important
> at
> >>> https://aka.ms/LearnAboutSenderIdentification ]
> >>>
> >>> CAUTION: External Sender
> >>>
> >>> Hi Lior,
> >>>
> >>> On 21.12.23 12:19, Dirk Behme wrote:
> >>>> Am 21.12.23 um 11:04 schrieb Lior Weintraub:
> >>>>> Thanks Dirk,
> >>>>>
> >>>>> Regarding the earlyprintk, not sure I know how to make it work.
> >>>>> I have defined CONFIG_EARLY_PRINTK=y and CONFIG_DEBUG_LL=y on
> my
> >>> config but it doesn't seem to work.
> >>>>> Do I need to pass something in the bootargs from the U-BOOT?
> >>>>> Do I need to add that into my device tree?
> >>>>> (Tried to set bootargs = "console=ttyS0,115200 earlyprintk"; under
> "chosen"
> >>> on my DT but it didn't
> >>>>> work)
> >>>>
> >>>> Yes, what has to be enabled and what not and what has to be set how is
> often
> >>> confusing. I think this
> >>>> is not common for all systems, so I think to be on the safe side you have
> to look
> >>> into the code for
> >>>> you system. Or short; The code is the documentation ;)
> >>>>
> >>>>
> >>>>> The UART I am using is "snps,dw-apb-uart".
> >>>>>
> >>>>> Last week, to output the early logs I have implemented this hack:
> >>>>> 1. Modify printk macro to run my print_func
> >>>>> 2. This print_func wrote the characters into a single global variable (u32
> >>> simul_uart;)
> >>>>> 3. Get the address location of this global variable and extract all writes to
> it
> >>> from the Tarmac
> >>>>> logs.
> >>>>>
> >>>>> This is a very slow and tedious process but it helped me identify the
> initial
> >>> SError.
> >>>>> Initially I thought I can write directly into the UART FIFO register (which I
> know
> >>> the address)
> >>>>> but this didn't work because Linux already setup the MMU so I guess I
> need to
> >>> know the virtual
> >>>>> address of this FIFO.
> >>>>> Do I need to use __phys_to_virt of some sort?
> >>>>
> >>>> Yes, I think so. Have a look to the existing serial driver, too. It should do
> whats
> >>> needed, and you
> >>>> can borrow that, then.
> >>>
> >>> If you have access to the RAM after the crash (through a debugger or in
> >>> your bootloader) and your mem is stable, find out the address of
> __log_buf
> >>> in System.map. Thats the buffer where printk writes into it, and so
> dumping
> >>> the content is what you would see in case uart works...
> >>>
> >>> Hope it helps!
> >>>
> >>> bye,
> >>> Heiko
> >>>>
> >>>> Best regards
> >>>>
> >>>> Dirk
> >>>>
> >>>>
> >>>>> Cheers,
> >>>>> Lior.
> >>>>>
> >>>>>> -----Original Message-----
> >>>>>> From: Dirk Behme <dirk.behme@gmail.com>
> >>>>>> Sent: Thursday, December 21, 2023 10:30 AM
> >>>>>> To: Lior Weintraub <liorw@pliops.com>; linux-
> embedded@vger.kernel.org
> >>>>>> Subject: Re: Debugging early SError exception
> >>>>>>
> >>>>>> [You don't often get email from dirk.behme@gmail.com. Learn why
> this is
> >>>>>> important at https://aka.ms/LearnAboutSenderIdentification ]
> >>>>>>
> >>>>>> CAUTION: External Sender
> >>>>>>
> >>>>>> Am 21.12.23 um 08:43 schrieb Lior Weintraub:
> >>>>>>> Hi Dirk,
> >>>>>>>
> >>>>>>> We found that the issue was at the early stages of Barebox (a.k.a U-
> BOOT
> >>>>>> v2).
> >>>>>>
> >>>>>> Glad to hear that! :)
> >>>>>>
> >>>>>>> Our implementation of putc_ll (on debug_ll) was writing into the
> UART Tx
> >>>>>> FIFO without checking if the FIFO is full.
> >>>>>>> Once the fifo got full it caused this SError probably because the UART
> IP
> >>>>>> generated an apberror signal.
> >>>>>>
> >>>>>> Thanks for the report!
> >>>>>>
> >>>>>>> Now the Linux is running and doesn't report the SError again but now
> we
> >>>>>> face another issue.
> >>>>>>> We see that the PC is getting into a "report_bug" function.
> >>>>>>> The Linux doesn't print anything to the UART (probably since it hasn't
> got to
> >>>>>> the point where the console is configured?).
> >>>>>>
> >>>>>> For cases like this using earlyprintk is usually a good option. Check
> >>>>>> the Linux kernel serial console (UART) dirver of you SoC if it
> >>>>>> supports it. In the end it should be "just" a function in the serial
> >>>>>> console driver which outputs the console data via polling before
> >>>>>> (later) the interrupt driven console part takes over.
> >>>>>>
> >>>>>> Best regards
> >>>>>>
> >>>>>> Dirk
> >>>>>>
> >>>>>>
> >>>>>>> Since our debug means are limited it can take some time to find the
> root
> >>>>>> cause.
> >>>>>>>
> >>>>>>> I will keep you posted and update our findings.
> >>>>>>> Love to hear your thoughts,
> >>>>>>>
> >>>>>>> Cheers,
> >>>>>>> Lior.
> >>>>>>>
> >>>>>>>
> >>>>>>>> -----Original Message-----
> >>>>>>>> From: Dirk Behme <dirk.behme@gmail.com>
> >>>>>>>> Sent: Tuesday, December 19, 2023 3:37 PM
> >>>>>>>> To: Lior Weintraub <liorw@pliops.com>; linux-
> embedded@vger.kernel.org
> >>>>>>>> Subject: Re: Debugging early SError exception
> >>>>>>>>
> >>>>>>>> [You don't often get email from dirk.behme@gmail.com. Learn why
> this is
> >>>>>>>> important at https://aka.ms/LearnAboutSenderIdentification ]
> >>>>>>>>
> >>>>>>>> CAUTION: External Sender
> >>>>>>>>
> >>>>>>>> Am 19.12.23 um 14:23 schrieb Lior Weintraub:
> >>>>>>>>> Thanks Dirk,
> >>>>>>>>
> >>>>>>>> Welcome :)
> >>>>>>>>
> >>>>>>>> In case you find the root cause it would be nice to get some generic
> >>>>>>>> description of it so that we can learn something :)
> >>>>>>>>
> >>>>>>>> Best regards
> >>>>>>>>
> >>>>>>>> Dirk
> >>>>>>>>
> >>>>>>>>
> >>>>>>>>>> -----Original Message-----
> >>>>>>>>>> From: Dirk Behme <dirk.behme@gmail.com>
> >>>>>>>>>> Sent: Tuesday, December 19, 2023 9:09 AM
> >>>>>>>>>> To: Lior Weintraub <liorw@pliops.com>; linux-
> >>>>>> embedded@vger.kernel.org
> >>>>>>>>>> Subject: Re: Debugging early SError exception
> >>>>>>>>>>
> >>>>>>>>>> [You don't often get email from dirk.behme@gmail.com. Learn
> why this
> >>>>>> is
> >>>>>>>>>> important at https://aka.ms/LearnAboutSenderIdentification ]
> >>>>>>>>>>
> >>>>>>>>>> CAUTION: External Sender
> >>>>>>>>>>
> >>>>>>>>>> Am 17.12.23 um 22:32 schrieb Lior Weintraub:
> >>>>>>>>>>> Hi,
> >>>>>>>>>>>
> >>>>>>>>>>> We have a new SoC with eLinux porting (kernel v6.5).
> >>>>>>>>>>> This SoC is ARM64 (A53) single core based device.
> >>>>>>>>>>> It runs correctly on QEMU but fails with SError on emulation
> platform
> >>>>>>>>>> (Synopsys Zebu running our SoC model).
> >>>>>>>>>>> There is no debugger connected to this emulation but there are
> several
> >>>>>>>>>> debug capabilities we can use:
> >>>>>>>>>>> 1. Generating wave dump of CPU signals
> >>>>>>>>>>> 2. Generate a Tarmac log
> >>>>>>>>>>> 3. UART
> >>>>>>>>>>>
> >>>>>>>>>>> Since the SError happens at early stages of Linux boot the UART
> is not
> >>>>>>>>>> enabled yet.
> >>>>>>>>>>> From the Tarmac log we can see:
> >>>>>>>>>>> 3824884521 ps ES (ffff800080760888:d65f03c0) O
> el1h_ns: ret
> >>>>>>>>>> (parse_early_param)
> >>>>>>>>>>> 3824884522 ps ES (ffff800080763a60:d2801800) O
> el1h_ns: mov
> >>>>>>>> x0,
> >>>>>>>>>> #0xc0 // #192 (setup_arch)
> >>>>>>>>>>> R X0 (AARCH64) 00000000 000000c0
> >>>>>>>>>>> 3824884523 ps ES (ffff800080763a64:d51b4220) O
> el1h_ns: msr
> >>>>>>>>>> daif, x0 (setup_arch)
> >>>>>>>>>>> R CPSR 600000c5
> >>>>>>>>>>> 3824884529 ps ES System Error (Abort)
> >>>>>>>>>>> EXC [0x380] SError/vSError Current EL with SP_ELx
> >>>>>>>>>>> R ESR_EL1 (AARCH64) bf000002
> >>>>>>>>>>> R CPSR 600003c5
> >>>>>>>>>>> R SPSR_EL1 (AARCH64) 600000c5
> >>>>>>>>>>> R ELR_EL1 (AARCH64) ffff8000 80763a68
> >>>>>>>>>>> 3824884925 ps ES (ffff800080010b80:d10543ff) O
> el1h_ns: sub
> >>>>>>>> sp,
> >>>>>>>>>> sp, #0x150 (vectors)
> >>>>>>>>>>> R SP_EL1 (AARCH64) ffff8000 808f3c50
> >>>>>>>>>>> 3824884925 ps ES (ffff800080010b84:8b2063ff) O
> el1h_ns: add
> >>>>>>>> sp,
> >>>>>>>>>> sp, x0 (vectors)
> >>>>>>>>>>> R SP_EL1 (AARCH64) ffff8000 808f3d10
> >>>>>>>>>>> 3824884926 ps ES (ffff800080010b88:cb2063e0) O
> el1h_ns: sub
> >>>>>>>> x0,
> >>>>>>>>>> sp, x0 (vectors)
> >>>>>>>>>>> R X0 (AARCH64) ffff8000 808f3c50
> >>>>>>>>>>> 3824884927 ps ES (ffff800080010b8c:37700080) O
> el1h_ns: tbnz
> >>>>>>>> w0,
> >>>>>>>>>> #14, ffff800080010b9c <vectors+0x39c> (vectors)
> >>>>>>>>>>> 3824884935 ps ES (ffff800080010b90:cb2063e0) O
> el1h_ns: sub
> >>>>>>>> x0,
> >>>>>>>>>> sp, x0 (vectors)
> >>>>>>>>>>> R X0 (AARCH64) 00000000 000000c0
> >>>>>>>>>>> 3824884937 ps ES (ffff800080010b94:cb2063ff) O
> el1h_ns: sub
> >>>>>> sp,
> >>>>>>>>>> sp, x0 (vectors)
> >>>>>>>>>>> R SP_EL1 (AARCH64) ffff8000 808f3c50
> >>>>>>>>>>> 3824884938 ps ES (ffff800080010b98:140001ef) O
> el1h_ns: b
> >>>>>>>>>> ffff800080011354 <el1h_64_error> (vectors)
> >>>>>>>>>>>
> >>>>>>>>>>> If I understand correctly, the exception happened sometime
> earlier
> >>> and
> >>>>>>>> only
> >>>>>>>>>> now Linux boot code (setup_arch) opened the exception handling
> and as
> >>>>>> a
> >>>>>>>>>> result we immediately jump to the SError exception handler.
> >>>>>>>>>>
> >>>>>>>>>>
> >>>>>>>>>> Yes, that sounds reasonable. If I understood correctly, you are
> >>>>>>>>>> running something "quite new" on some software (QEMU) and
> >>>>>> hardware
> >>>>>>>>>> (Synopsis) simulators.
> >>>>>>>>>>
> >>>>>>>>>> That would mean that you have new hardware with e.g. new
> memory
> >>>>>> map
> >>>>>>>>>> not used before. What you describe might sound like in the code
> before
> >>>>>>>>>> Linux (boot loader) there is anything resulting in the SError. This
> >>>>>>>>>> might be an access to non-existing or non-enabled hardware. I.e.
> it
> >>>>>>>>>> might be that you try to access (read/write) an address what is
> not
> >>>>>>>>>> available, yet (or just invalid). It's hard to debug that. In case you
> >>>>>>>>>> are able to modify the code before Linux (the boot loader?) you
> might
> >>>>>>>>>> try to enable SError exceptions, there, too. To get it earlier and
> >>>>>>>>>> with that make the search window smaller. I'm not that familiar
> with
> >>>>>>>>>> QEMU, but could you try to trace which (all?) hardware accesses
> your
> >>>>>>>>>> code does. And with that analyse all accesses and with that check
> if
> >>>>>>>>>> all these accesses are valid even on the hardware (Synopsis)
> emulation
> >>>>>>>>>> system? That should be checked from valid address and from
> hardware
> >>>>>>>>>> subsystem enablement point of view.
> >>>>>>>>>>
> >>>>>>>>>> Hth,
> >>>>>>>>>>
> >>>>>>>>>> Dirk
> >>>>>>>>>>
> >>>>>>>>>>
> >>>>>>>>>>> From the Linux source:
> >>>>>>>>>>> parse_early_param();
> >>>>>>>>>>>
> >>>>>>>>>>> dynamic_scs_init();
> >>>>>>>>>>>
> >>>>>>>>>>> /*
> >>>>>>>>>>> * Unmask asynchronous aborts and fiq after bringing up
> possible
> >>>>>>>>>>> * earlycon. (Report possible System Errors once we can
> report
> >>> this
> >>>>>>>>>>> * occurred).
> >>>>>>>>>>> */
> >>>>>>>>>>> local_daif_restore(DAIF_PROCCTX_NOIRQ); <---- This is
> when we
> >>>>>> get
> >>>>>>>> the
> >>>>>>>>>> exception.
> >>>>>>>>>>>
> >>>>>>>>>>> After some kernel hacking (replacing printk) we could extract the
> logs:
> >>>>>>>>>>> 6Booting Linux on physical CPU 0x0000000000 [0x410fd034]
> >>>>>>>>>>> 5Linux version 6.5.0 (pliops@dev-liorw) (aarch64-buildroot-
> linux-gnu-
> >>>>>>>>>> gcc.br_real (Buildroot 2023.02.1-95-g8391404e23) 11.3.0, GNU
> ld
> >>>>>> (GNU
> >>>>>>>>>> Binutils) 2.38) #101 SMP Sun Dec 17 20:09:06 IST 2023
> >>>>>>>>>>> 6Machine model: Pliops Spider MK-I EVK
> >>>>>>>>>>> 2SError Interrupt on CPU0, code 0x00000000bf000002 -- SError
> >>>>>>>>>>> CPU: 0 PID: 0 Comm: swapper Not tainted 6.5.0 #101
> >>>>>>>>>>> Hardware name: Pliops Spider MK-I EVK (DT)
> >>>>>>>>>>> pstate: 600000c5 (nZCv daIF -PAN -UAO -TCO -DIT -SSBS
> BTYPE=--)
> >>>>>>>>>>> pc : setup_arch+0x13c/0x5ac
> >>>>>>>>>>> lr : setup_arch+0x134/0x5ac
> >>>>>>>>>>> sp : ffff8000808f3da0
> >>>>>>>>>>> x29: ffff8000808f3da0c x28: 0000000008758074c x27:
> >>>>>>>>>> 0000000005e31b58c
> >>>>>>>>>>> x26: 0000000000000001c x25: 0000000007e5f728c x24:
> >>>>>>>>>> ffff8000808f8000c
> >>>>>>>>>>> x23: ffff8000808f8600c x22: ffff8000807b6000c x21:
> >>>>>>>> ffff800080010000c
> >>>>>>>>>>> x20: ffff800080a1e000c x19: fffffbfffddfe190c x18:
> >>>>>> 000000002266684ac
> >>>>>>>>>>> x17: 00000000fcad60bbc x16: 0000000000001800c x15:
> >>>>>>>>>> 0000000000000008c
> >>>>>>>>>>> x14: ffffffffffffffffc x13: 0000000000000000c x12:
> >>>>>> 0000000000000003c
> >>>>>>>>>>> x11: 0101010101010101c x10: ffffffffffee87dfc x9 :
> >>>>>>>> 0000000000000038c
> >>>>>>>>>>> x8 : 0101010101010101c x7 : 7f7f7f7f7f7f7f7fc x6 :
> >>>>>>>> 0000000000000001c
> >>>>>>>>>>> x5 : 0000000000000000c x4 : 8000000000000000c x3 :
> >>>>>>>>>> 0000000000000065c
> >>>>>>>>>>> x2 : 0000000000000000c x1 : 0000000000000000c x0 :
> >>>>>>>>>> 00000000000000c0c
> >>>>>>>>>>> 0Kernel panic - not syncing: Asynchronous SError Interrupt
> >>>>>>>>>>> CPU: 0 PID: 0 Comm: swapper Not tainted 6.5.0 #101
> >>>>>>>>>>> Hardware name: Pliops Spider MK-I EVK (DT)
> >>>>>>>>>>> Call trace:
> >>>>>>>>>>> dump_backtrace+0x9c/0xd0
> >>>>>>>>>>> show_stack+0x14/0x1c
> >>>>>>>>>>> dump_stack_lvl+0x44/0x58
> >>>>>>>>>>> dump_stack+0x14/0x1c
> >>>>>>>>>>> panic+0x2e0/0x33c
> >>>>>>>>>>> nmi_panic+0x68/0x6c
> >>>>>>>>>>> arm64_serror_panic+0x68/0x78
> >>>>>>>>>>> do_serror+0x24/0x54
> >>>>>>>>>>> el1h_64_error_handler+0x2c/0x40
> >>>>>>>>>>> el1h_64_error+0x64/0x68
> >>>>>>>>>>> setup_arch+0x13c/0x5ac
> >>>>>>>>>>> start_kernel+0x5c/0x5b8
> >>>>>>>>>>> __primary_switched+0xb4/0xbc
> >>>>>>>>>>> 0---[ end Kernel panic - not syncing: Asynchronous SError
> Interrupt ]---
> >>>>>>>>>>>
> >>>>>>>>>>> Can you please advice how to proceed with debugging?
> >>>>>>>>>>>
> >>>>>>>>>>> Thanks in advanced,
> >>>>>>>>>>> Cheers,
> >>>>>>>>>>> Lior.
> >>>>>>>>>>>
> >>>>>>>>>>>
> >>>>>>>>>>
> >>>>>>>>>
> >>>>>>>
> >>>>>
> >>>>
> >>>
> >>> --
> >>> DENX Software Engineering GmbH, Managing Director: Erika Unter
> >>> HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany
> >>> Phone: +49-8142-66989-52 Fax: +49-8142-66989-80 Email:
> hs@denx.de
> >
>
> --
> DENX Software Engineering GmbH, Managing Director: Erika Unter
> HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany
> Phone: +49-8142-66989-52 Fax: +49-8142-66989-80 Email: hs@denx.de
^ permalink raw reply [flat|nested] 16+ messages in thread
* RE: Debugging early SError exception
2023-12-24 15:41 ` Lior Weintraub
@ 2023-12-24 19:12 ` Lior Weintraub
2023-12-26 7:48 ` Lior Weintraub
0 siblings, 1 reply; 16+ messages in thread
From: Lior Weintraub @ 2023-12-24 19:12 UTC (permalink / raw)
To: hs, Dirk Behme; +Cc: linux-embedded
Update:
UART issue ("unable to open an initial console") was resolved.
I was missing CONFIG_SERIAL_8250_DW=y on my config.
Now only issue left is the CPU idle ("wfi") and no interrupts are coming.
> -----Original Message-----
> From: Lior Weintraub
> Sent: Sunday, December 24, 2023 5:42 PM
> To: hs@denx.de; Dirk Behme <dirk.behme@gmail.com>
> Cc: linux-embedded@vger.kernel.org
> Subject: RE: Debugging early SError exception
>
> Hi,
>
> The GICv3 issue was resolved after:
> 1. Setting bit 0 and bit 3 on ICC_SRE_EL3 (we don't have virtualization support
> and hence ICC_SRE_EL2 is not supported).
> 2. Power up the GICR on EL3
>
> The earlycon issue was resolved after:
> 1. Add to "earlycon=uart8250,mmio32,0xd000307000,115200n8" to boot
> args.
> 2. Add "CONFIG_SERIAL_8250_CONSOLE=y" to config (previously had only
> CONFIG_SERIAL_8250=y)
>
> Now I face a new issue:
> Linux boot hangs on "wait for interrupt" at cpu_do_idle.
>
> The program counter is stuck at 0xffff8000805ae45c.
> ffff8000805ae454 <cpu_do_idle>:
> ffff8000805ae454: d5033f9f dsb sy
> ffff8000805ae458: d503207f wfi
> ffff8000805ae45c: d65f03c0 ret
>
> I think that something is wrong with the timers or gic setting and as a result
> the scheduler doesn't get the interrupts (timer ticks).
>
> Additional info that might be relevant to this issue:
> The emulation platform runs at about 2.8MHz.
> The CNTFRQ_EL0 is set to 2M (because the emulation platform running freq
> varies between 1.9-2.8MHz).
> The reason for those settings is to allow Linux to run as it would on the "real"
> world.
>
> It is my understanding that there are 2 issues here:
> 1. Something is wrong with Timers\Interrupt setting (note that same
> configuration runs correctly on QEMU)
> 2. Something is wrong with initramfs - according kernel source it seems to fail
> to open "/dev/console"
>
> The full Linux boot log:
> Booting Linux on physical CPU 0x0000000000 [0x410fd034]
> Linux version 6.5.0 (pliops@dev-liorw) (aarch64-buildroot-linux-gnu-
> gcc.br_real (Buildroot 2023.02.1-95-g8391404e23) 11.3.0, GNU ld (GNU
> Binuti) 2.38) #112 SMP Sun Dec 24 15:44:56 IST 2023
> Machine model: Pliops Spider MK-I EVK
> earlycon: uart8250 at MMIO32 0x000000d000307000 (options '115200n8')
> printk: bootconsole [uart8250] enabled
> efi: UEFI not found.
> Zone ranges:
> DMA [mem 0x0000000000000000-0x000000002fffffff]
> DMA32 empty
> Normal empty
> Movable zone start for each node
> Early memory node ranges
> node 0: [mem 0x0000000000000000-0x000000002fffffff]
> Initmem setup node 0 [mem 0x0000000000000000-0x000000002fffffff]
> percpu: Embedded 25 pages/cpu s64800 r8192 d29408 u102400
> Detected VIPT I-cache on CPU0
> CPU features: detected: GIC system register CPU interface
> CPU features: detected: ARM erratum 845719
> alternatives: applying boot alternatives
> Kernel command line: console=ttyS0,115200n8
> earlycon=uart8250,mmio32,0xd000307000,115200n8
> Dentry cache hash table entries: 131072 (order: 8, 1048576 bytes, linear)
> Inode-cache hash table entries: 65536 (order: 7, 524288 bytes, linear)
> Built 1 zonelists, mobility grouping on. Total pages: 193536
> mem auto-init: stack:off, heap alloc:off, heap free:off
> software IO TLB: area num 1.
> software IO TLB: mapped [mem 0x000000002b080000-
> 0x000000002f080000] (64MB)
> Memory: 689240K/786432K available (5824K kernel code, 1186K rwdata,
> 1612K rodata, 1600K init, 400K bss, 97192K reserved, 0K cma-reserved)
> SLUB: HWalign=64, Order=0-3, MinObjects=0, CPUs=1, Nodes=1
> trace event string verifier disabled
> rcu: Hierarchical RCU implementation.
> rcu: RCU event tracing is enabled.
> rcu: RCU restricting CPUs from NR_CPUS=256 to nr_cpu_ids=1.
> rcu: RCU calculated value of scheduler-enlistment delay is 25 jiffies.
> rcu: Adjusting geometry for rcu_fanout_leaf=16, nr_cpu_ids=1
> NR_IRQS: 64, nr_irqs: 64, preallocated irqs: 0
> GICv3: 96 SPIs implemented
> GICv3: 0 Extended SPIs implemented
> Root IRQ handler: gic_handle_irq
> GICv3: GICv3 features: 16 PPIs
> GICv3: CPU0: found redistributor 0 region 0:0x000000e000060000
> ITS [mem 0xe000040000-0xe00005ffff]
> ITS@0x000000e000040000: allocated 8192 Devices @a0000 (indirect, esz 8,
> psz 64K, shr 1)
> ITS@0x000000e000040000: allocated 32768 Interrupt Collections @b0000
> (flat, esz 2, psz 64K, shr 1)
> GICv3: Expected reserved range
> [0x00000000000c0000:0x00000000000cffff], not found
> GICv3: using LPI property table @0x00000000000c0000
> GICv3: CPU0: Booted with LPIs enabled, memory probably corrupted
> CPU0: Failed to disable LPIs
> rcu: srcu_init: Setting srcu_struct sizes based on contention.
> arch_timer: cp15 timer(s) running at 62.50MHz (virt).
> clocksource: arch_sys_counter: mask: 0x1ffffffffffffff max_cycles:
> 0x1cd42e208c, max_idle_ns: 881590405314 ns
> sched_clock: 57 bits at 63MHz, resolution 16ns, wraps every
> 4398046511096ns
> Console: colour dummy device 80x25
> Calibrating delay loop (skipped), value calculated using timer frequency..
> 125.00 BogoMIPS (lpj=250000)
> pid_max: default: 32768 minimum: 301
> Mount-cache hash table entries: 2048 (order: 2, 16384 bytes, linear)
> Mountpoint-cache hash table entries: 2048 (order: 2, 16384 bytes, linear)
> cacheinfo: Unable to detect cache hierarchy for CPU 0
> rcu: Hierarchical SRCU implementation.
> rcu: Max phase no-delay instances is 1000.
> Platform MSI: gic-its@E000040000 domain created
> PCI/MSI: /soc/interrupt-controller@E000000000/gic-its@E000040000
> domain created
> EFI services will not be available.
> smp: Bringing up secondary CPUs ...
> smp: Brought up 1 node, 1 CPU
> SMP: Total of 1 processors activated.
> CPU features: detected: 32-bit EL0 Support
> CPU features: detected: CRC32 instructions
> CPU: All CPU(s) started at EL1
> alternatives: applying system-wide alternatives
> devtmpfs: initialized
> clocksource: jiffies: mask: 0xffffffff max_cycles: 0xffffffff, max_idle_ns:
> 7645041785100000 ns
> futex hash table entries: 256 (order: 2, 16384 bytes, linear)
> DMI not present or invalid.
> DMA: preallocated 128 KiB GFP_KERNEL pool for atomic allocations
> DMA: preallocated 128 KiB GFP_KERNEL|GFP_DMA pool for atomic
> allocations
> DMA: preallocated 128 KiB GFP_KERNEL|GFP_DMA32 pool for atomic
> allocations
> hw-breakpoint: found 6 breakpoint and 4 watchpoint registers.
> ASID allocator initialised with 65536 entries
> Serial: AMBA PL011 UART driver
> Modules: 30080 pages in range for non-PLT usage
> Modules: 521600 pages in range for PLT usage
> iommu: Default domain type: Translated
> iommu: DMA domain TLB invalidation policy: strict mode
> SCSI subsystem initialized
> vgaarb: loaded
> clocksource: Switched to clocksource arch_sys_counter
> PCI: CLS 0 bytes, default 64
> workingset: timestamp_bits=46 max_order=18 bucket_order=0
> fuse: init (API version 7.38)
> Block layer SCSI generic (bsg) driver version 0.4 loaded (major 251)
> io scheduler mq-deadline registered
> io scheduler kyber registered
> Unpacking initramfs...
> Freeing initrd memory: 4596K
> Serial: 8250/16550 driver, 4 ports, IRQ sharing disabled
> hw perfevents: enabled with armv8_cortex_a53 PMU driver, 7 counters
> available
> clk: Disabling unused clocks
> Warning: unable to open an initial console.
> Freeing unused kernel memory: 1600K
>
> Thanks in advance for your great advice and support,
> Cheers,
> Lior.
>
> > -----Original Message-----
> > From: Heiko Schocher <hs@denx.de>
> > Sent: Friday, December 22, 2023 10:04 AM
> > To: Dirk Behme <dirk.behme@gmail.com>; Lior Weintraub
> > <liorw@pliops.com>
> > Cc: linux-embedded@vger.kernel.org
> > Subject: Re: Debugging early SError exception
> >
> > [You don't often get email from hs@denx.de. Learn why this is important at
> > https://aka.ms/LearnAboutSenderIdentification ]
> >
> > CAUTION: External Sender
> >
> > Hello Dirk, Lior,
> >
> > On 22.12.23 08:48, Dirk Behme wrote:
> > > Am 22.12.23 um 08:03 schrieb Lior Weintraub:
> > >> Hi,
> > >>
> > >> I managed to dump the __log_buf but for some reason the UART is still
> not
> > working.
> > >> Please note that UART printed all the U-BOOT traces so AFAIU, the device
> > tree is set correctly.
> > >> (Barebox is passing it's DTB into kernel).
> > >>
> > >> To enable the earlyprintk I have:
> > >> 1. Compiled the kernel with CONFIG_EARLY_PRINTK=y and
> > CONFIG_DEBUG_LL=y
> > >> 2. Modified the boot args to include: "console=ttyS0,115200n8
> > earlycon=dw-apb-uart,0xd000307000"
> > >> 3. Verified that dw-apb-uart driver (8250_early.c) supports earlycon:
> > >> OF_EARLYCON_DECLARE(uart, "snps,dw-apb-uart",
> > early_serial8250_setup);
> > >>
> > >> From __log_buf dump:
> > >> Booting Linux on physical CPU 0x0000000000 [0x410fd034]4]
> > >> Linux version 6.5.0 (pliops@dev-liorw) (aarch64-buildroot-linux-gnu-
> > gcc.br_real (Buildroot
> > >> 2023.02.1-95-g8391404e23) 11.3.0, GNU ld (GNU Binutils) 2.38) #107
> > SMP Thu Dec 21 17:33:12 IST 202323
> > >> Machine model: Pliops Spider MK-I EVKVK
> > >> efi: UEFI not found.d.
> > >> Zone ranges:s:
> > >> DMA [mem 0x0000000000000000-0x000000002fffffff]f]
> > >> DMA32 emptyty
> > >> Normal emptyty
> > >> Movable zone start for each nodede
> > >> Early memory node rangeses
> > >> node 0: [mem 0x0000000000000000-0x000000002fffffff]f]
> > >> Initmem setup node 0 [mem 0x0000000000000000-
> > 0x000000002fffffff]f]
> > >> percpu: Embedded 25 pages/cpu s64800 r8192 d29408 u10240000
> > >> pcpu-alloc: s64800 r8192 d29408 u102400 alloc=25*4096
> > >> pcpu-alloc: [0] 0
> > >> Detected VIPT I-cache on CPU0U0
> > >> CPU features: GIC system register CPU interface present but disabled by
> > higher exception levelel
> > >> CPU features: detected: ARM erratum 84571919
> > >> alternatives: applying boot alternativeses
> > >> Kernel command line: console=ttyS0,115200n8 earlycon=dw-apb-
> > uart,0xd00030700000
> > >> Dentry cache hash table entries: 131072 (order: 8, 1048576 bytes,
> linear)r)
> > >> Inode-cache hash table entries: 65536 (order: 7, 524288 bytes, linear)r)
> > >> Built 1 zonelists, mobility grouping on. Total pages: 19353636
> > >> mem auto-init: stack:off, heap alloc:off, heap free:offff
> > >> software IO TLB: area num 1.1.
> > >> software IO TLB: mapped [mem 0x000000002b080000-
> > 0x000000002f080000] (64MB)B)
> > >> Memory: 689240K/786432K available (5824K kernel code, 1186K
> rwdata,
> > 1612K rodata, 1600K init, 400K
> > >> bss, 97192K reserved, 0K cma-reserved)d)
> > >> SLUB: HWalign=64, Order=0-3, MinObjects=0, CPUs=1, Nodes=1=1
> > >> trace event string verifier disableded
> > >> rcu: Hierarchical RCU implementation.n.
> > >> rcu: RCU event tracing is enabled.d.
> > >> rcu: RCU restricting CPUs from NR_CPUS=256 to nr_cpu_ids=1.1.
> > >> rcu: RCU calculated value of scheduler-enlistment delay is 25 jiffies.s.
> > >> rcu: Adjusting geometry for rcu_fanout_leaf=16, nr_cpu_ids=1=1
> > >> NR_IRQS: 64, nr_irqs: 64, preallocated irqs: 0 0
> > >> GICv3: 96 SPIs implementeded
> > >> GICv3: 0 Extended SPIs implementeded
> > >> Root IRQ handler: gic_handle_irqrq
> > >> GICv3: GICv3 features: 16 PPIsIs
> > >> GICv3: CPU0: found redistributor 0 region 0:0x000000e00006000000
> > >> GICv3: redistributor failed to wakeup.....
> > >> GICv3: GIC: unable to set SRE (disabled at EL2), panic aheadad
> > >
> > > I think the two messages above are the essential ones.
> >
> > +1
> >
> > > Maybe it helps to check
> > >
> > > https://secure-web.cisco.com/1VmuNXQkE6u---G9xsJ8CPb6-
> > aguDK_MyJeUn43QsTaafgaifoFTAvcD4vQefYzFntmjc8L_J46du6-
> > DYArOlFkq__OwCChpFf-
> nXIyddL3MCQMsTZ9hIk_WCfDqIi1wSEmPSBClIYS0-
> >
> SAjwPiOf7sA2wLvt_5ehGaTHO61NJEWdOrfKy9pBT1_RDyQGXi7kz8XuAUpu
> > Whhipp-
> >
> ngljUJcxkHkmWDvpocGule5ZNEe5UZ3nGNjUnqCU8J_bXtCgNPEk4CyorLt7g4
> >
> F5Ks85tlVEEutu8vyJXu8_TUacURkRnQgjvood6iVOn5w2TpSRn/https%3A%2
> > F%2Fwww.kernel.org%2Fdoc%2Fhtml%2Fv5.3%2Farm64%2Fbooting.html
> > >
> > > In the middle of that page in the "Call the kernel image" it has something
> > about GIC:
> > >
> > > -- cut --
> > > If the kernel is entered at EL1:
> > >
> > > ICC.SRE_EL2.Enable (bit 3) must be initialised to 0b1
> > > ICC_SRE_EL2.SRE (bit 0) must be initialised to 0b1.
> > > -- cut --
> >
> > Also may it makes sense to check your firmware (bootloader, ATF?) ... may
> > there is some setting missing for your SoC/Board ?
> >
> > bye,
> > Heiko
> >
> > >
> > >> Internal error: Oops - Undefined instruction: 0000000062383019 [#1]
> > SMPMP
> > >> Modules linked in:
> > >> CPU: 0 PID: 0 Comm: swapper/0 Not tainted 6.5.0 #107
> > >> Hardware name: Pliops Spider MK-I EVK (DT)
> > >> pstate: 600000c5 (nZCv daIF -PAN -UAO -TCO -DIT -SSBS BTYPE=--)
> > >> pc : gic_cpu_sys_reg_init+0x58/0x2e4
> > >> lr : gic_cpu_sys_reg_init+0x2a4/0x2e4
> > >> sp : ffff8000808f3b40
> > >> x29: ffff8000808f3b40 x28: 0000000000000000 x27:
> > 0000000000000001
> > >> x26: ffff000000016040 x25: 0000000000000000 x24:
> ffff800080a6b000
> > >> x23: ffff8000808fc320 x22: ffff8000809cc000 x21: ffff00002fe74670
> > >> x20: ffff800080a90000 x19: 0000000000000000 x18: fffffffffffe0b10
> > >> x17: ffff8000809f9480 x16: fffffc0000002248 x15: ffff80008090af28
> > >> x14: fffffffffffc0b0f x13: 6461656861206369 x12: 6e6170202c29324c
> > >> x11: 452074612064656c x10: 6261736964282045 x9 :
> > 6428204552532074
> > >> x8 : ffff80008090af28 x7 : ffff8000808f3970 x6 : 000000000000000c
> > >> x5 : 000000000000002a x4 : 0000000000000000 x3 :
> > 0000000000000000
> > >> x2 : 0000000000000000 x1 : ffff8000808fd0c0 x0 : 000000000000003c
> > >> Call trace:
> > >> gic_cpu_sys_reg_init+0x58/0x2e4
> > >> gic_cpu_init.part.0+0xa8/0x114
> > >> gic_init_bases+0x408/0x684
> > >> gic_of_init+0x298/0x300
> > >> of_irq_init+0x1c8/0x368
> > >> irqchip_init+0x14/0x1c
> > >> init_IRQ+0x98/0xac
> > >> start_kernel+0x250/0x5b8
> > >> __primary_switched+0xb4/0xbc
> > >> Code: 9260df39 d3441f33 d538cca0 36001180 (d538cc80) )
> > >> ---[ end trace 0000000000000000 ]-----
> > >> Kernel panic - not syncing: Attempted to kill the idle task!k!
> > >> ---[ end Kernel panic - not syncing: Attempted to kill the idle task! ]-----
> > >>
> > >>
> > >> The kernel panic is related to GIC distributor (currently under debug) but
> > AFAIU,
> > >> this has nothing to do with the UART not working on early stages.
> > >
> > >
> > > Yes, I agree. GIC issue and UART (at least the polling mode) should be
> > indendent.
> > >
> > > Best regards
> > >
> > > Dirk
> > >
> > >
> > >> Thanks in advanced for your advice,
> > >> Cheers,
> > >> Lior.
> > >>
> > >>
> > >>> -----Original Message-----
> > >>> From: Heiko Schocher <hs@denx.de>
> > >>> Sent: Thursday, December 21, 2023 1:37 PM
> > >>> To: Lior Weintraub <liorw@pliops.com>
> > >>> Cc: Dirk Behme <dirk.behme@gmail.com>; linux-
> > embedded@vger.kernel.org
> > >>> Subject: Re: Debugging early SError exception
> > >>>
> > >>> [You don't often get email from hs@denx.de. Learn why this is important
> > at
> > >>> https://aka.ms/LearnAboutSenderIdentification ]
> > >>>
> > >>> CAUTION: External Sender
> > >>>
> > >>> Hi Lior,
> > >>>
> > >>> On 21.12.23 12:19, Dirk Behme wrote:
> > >>>> Am 21.12.23 um 11:04 schrieb Lior Weintraub:
> > >>>>> Thanks Dirk,
> > >>>>>
> > >>>>> Regarding the earlyprintk, not sure I know how to make it work.
> > >>>>> I have defined CONFIG_EARLY_PRINTK=y and CONFIG_DEBUG_LL=y
> on
> > my
> > >>> config but it doesn't seem to work.
> > >>>>> Do I need to pass something in the bootargs from the U-BOOT?
> > >>>>> Do I need to add that into my device tree?
> > >>>>> (Tried to set bootargs = "console=ttyS0,115200 earlyprintk"; under
> > "chosen"
> > >>> on my DT but it didn't
> > >>>>> work)
> > >>>>
> > >>>> Yes, what has to be enabled and what not and what has to be set how
> is
> > often
> > >>> confusing. I think this
> > >>>> is not common for all systems, so I think to be on the safe side you
> have
> > to look
> > >>> into the code for
> > >>>> you system. Or short; The code is the documentation ;)
> > >>>>
> > >>>>
> > >>>>> The UART I am using is "snps,dw-apb-uart".
> > >>>>>
> > >>>>> Last week, to output the early logs I have implemented this hack:
> > >>>>> 1. Modify printk macro to run my print_func
> > >>>>> 2. This print_func wrote the characters into a single global variable
> (u32
> > >>> simul_uart;)
> > >>>>> 3. Get the address location of this global variable and extract all writes
> to
> > it
> > >>> from the Tarmac
> > >>>>> logs.
> > >>>>>
> > >>>>> This is a very slow and tedious process but it helped me identify the
> > initial
> > >>> SError.
> > >>>>> Initially I thought I can write directly into the UART FIFO register
> (which I
> > know
> > >>> the address)
> > >>>>> but this didn't work because Linux already setup the MMU so I guess I
> > need to
> > >>> know the virtual
> > >>>>> address of this FIFO.
> > >>>>> Do I need to use __phys_to_virt of some sort?
> > >>>>
> > >>>> Yes, I think so. Have a look to the existing serial driver, too. It should do
> > whats
> > >>> needed, and you
> > >>>> can borrow that, then.
> > >>>
> > >>> If you have access to the RAM after the crash (through a debugger or in
> > >>> your bootloader) and your mem is stable, find out the address of
> > __log_buf
> > >>> in System.map. Thats the buffer where printk writes into it, and so
> > dumping
> > >>> the content is what you would see in case uart works...
> > >>>
> > >>> Hope it helps!
> > >>>
> > >>> bye,
> > >>> Heiko
> > >>>>
> > >>>> Best regards
> > >>>>
> > >>>> Dirk
> > >>>>
> > >>>>
> > >>>>> Cheers,
> > >>>>> Lior.
> > >>>>>
> > >>>>>> -----Original Message-----
> > >>>>>> From: Dirk Behme <dirk.behme@gmail.com>
> > >>>>>> Sent: Thursday, December 21, 2023 10:30 AM
> > >>>>>> To: Lior Weintraub <liorw@pliops.com>; linux-
> > embedded@vger.kernel.org
> > >>>>>> Subject: Re: Debugging early SError exception
> > >>>>>>
> > >>>>>> [You don't often get email from dirk.behme@gmail.com. Learn why
> > this is
> > >>>>>> important at https://aka.ms/LearnAboutSenderIdentification ]
> > >>>>>>
> > >>>>>> CAUTION: External Sender
> > >>>>>>
> > >>>>>> Am 21.12.23 um 08:43 schrieb Lior Weintraub:
> > >>>>>>> Hi Dirk,
> > >>>>>>>
> > >>>>>>> We found that the issue was at the early stages of Barebox (a.k.a U-
> > BOOT
> > >>>>>> v2).
> > >>>>>>
> > >>>>>> Glad to hear that! :)
> > >>>>>>
> > >>>>>>> Our implementation of putc_ll (on debug_ll) was writing into the
> > UART Tx
> > >>>>>> FIFO without checking if the FIFO is full.
> > >>>>>>> Once the fifo got full it caused this SError probably because the
> UART
> > IP
> > >>>>>> generated an apberror signal.
> > >>>>>>
> > >>>>>> Thanks for the report!
> > >>>>>>
> > >>>>>>> Now the Linux is running and doesn't report the SError again but
> now
> > we
> > >>>>>> face another issue.
> > >>>>>>> We see that the PC is getting into a "report_bug" function.
> > >>>>>>> The Linux doesn't print anything to the UART (probably since it
> hasn't
> > got to
> > >>>>>> the point where the console is configured?).
> > >>>>>>
> > >>>>>> For cases like this using earlyprintk is usually a good option. Check
> > >>>>>> the Linux kernel serial console (UART) dirver of you SoC if it
> > >>>>>> supports it. In the end it should be "just" a function in the serial
> > >>>>>> console driver which outputs the console data via polling before
> > >>>>>> (later) the interrupt driven console part takes over.
> > >>>>>>
> > >>>>>> Best regards
> > >>>>>>
> > >>>>>> Dirk
> > >>>>>>
> > >>>>>>
> > >>>>>>> Since our debug means are limited it can take some time to find the
> > root
> > >>>>>> cause.
> > >>>>>>>
> > >>>>>>> I will keep you posted and update our findings.
> > >>>>>>> Love to hear your thoughts,
> > >>>>>>>
> > >>>>>>> Cheers,
> > >>>>>>> Lior.
> > >>>>>>>
> > >>>>>>>
> > >>>>>>>> -----Original Message-----
> > >>>>>>>> From: Dirk Behme <dirk.behme@gmail.com>
> > >>>>>>>> Sent: Tuesday, December 19, 2023 3:37 PM
> > >>>>>>>> To: Lior Weintraub <liorw@pliops.com>; linux-
> > embedded@vger.kernel.org
> > >>>>>>>> Subject: Re: Debugging early SError exception
> > >>>>>>>>
> > >>>>>>>> [You don't often get email from dirk.behme@gmail.com. Learn
> why
> > this is
> > >>>>>>>> important at https://aka.ms/LearnAboutSenderIdentification ]
> > >>>>>>>>
> > >>>>>>>> CAUTION: External Sender
> > >>>>>>>>
> > >>>>>>>> Am 19.12.23 um 14:23 schrieb Lior Weintraub:
> > >>>>>>>>> Thanks Dirk,
> > >>>>>>>>
> > >>>>>>>> Welcome :)
> > >>>>>>>>
> > >>>>>>>> In case you find the root cause it would be nice to get some generic
> > >>>>>>>> description of it so that we can learn something :)
> > >>>>>>>>
> > >>>>>>>> Best regards
> > >>>>>>>>
> > >>>>>>>> Dirk
> > >>>>>>>>
> > >>>>>>>>
> > >>>>>>>>>> -----Original Message-----
> > >>>>>>>>>> From: Dirk Behme <dirk.behme@gmail.com>
> > >>>>>>>>>> Sent: Tuesday, December 19, 2023 9:09 AM
> > >>>>>>>>>> To: Lior Weintraub <liorw@pliops.com>; linux-
> > >>>>>> embedded@vger.kernel.org
> > >>>>>>>>>> Subject: Re: Debugging early SError exception
> > >>>>>>>>>>
> > >>>>>>>>>> [You don't often get email from dirk.behme@gmail.com. Learn
> > why this
> > >>>>>> is
> > >>>>>>>>>> important at https://aka.ms/LearnAboutSenderIdentification ]
> > >>>>>>>>>>
> > >>>>>>>>>> CAUTION: External Sender
> > >>>>>>>>>>
> > >>>>>>>>>> Am 17.12.23 um 22:32 schrieb Lior Weintraub:
> > >>>>>>>>>>> Hi,
> > >>>>>>>>>>>
> > >>>>>>>>>>> We have a new SoC with eLinux porting (kernel v6.5).
> > >>>>>>>>>>> This SoC is ARM64 (A53) single core based device.
> > >>>>>>>>>>> It runs correctly on QEMU but fails with SError on emulation
> > platform
> > >>>>>>>>>> (Synopsys Zebu running our SoC model).
> > >>>>>>>>>>> There is no debugger connected to this emulation but there are
> > several
> > >>>>>>>>>> debug capabilities we can use:
> > >>>>>>>>>>> 1. Generating wave dump of CPU signals
> > >>>>>>>>>>> 2. Generate a Tarmac log
> > >>>>>>>>>>> 3. UART
> > >>>>>>>>>>>
> > >>>>>>>>>>> Since the SError happens at early stages of Linux boot the UART
> > is not
> > >>>>>>>>>> enabled yet.
> > >>>>>>>>>>> From the Tarmac log we can see:
> > >>>>>>>>>>> 3824884521 ps ES (ffff800080760888:d65f03c0) O
> > el1h_ns: ret
> > >>>>>>>>>> (parse_early_param)
> > >>>>>>>>>>> 3824884522 ps ES (ffff800080763a60:d2801800) O
> > el1h_ns: mov
> > >>>>>>>> x0,
> > >>>>>>>>>> #0xc0 // #192 (setup_arch)
> > >>>>>>>>>>> R X0 (AARCH64) 00000000 000000c0
> > >>>>>>>>>>> 3824884523 ps ES (ffff800080763a64:d51b4220) O
> > el1h_ns: msr
> > >>>>>>>>>> daif, x0 (setup_arch)
> > >>>>>>>>>>> R CPSR 600000c5
> > >>>>>>>>>>> 3824884529 ps ES System Error (Abort)
> > >>>>>>>>>>> EXC [0x380] SError/vSError Current EL with SP_ELx
> > >>>>>>>>>>> R ESR_EL1 (AARCH64) bf000002
> > >>>>>>>>>>> R CPSR 600003c5
> > >>>>>>>>>>> R SPSR_EL1 (AARCH64) 600000c5
> > >>>>>>>>>>> R ELR_EL1 (AARCH64) ffff8000 80763a68
> > >>>>>>>>>>> 3824884925 ps ES (ffff800080010b80:d10543ff) O
> > el1h_ns: sub
> > >>>>>>>> sp,
> > >>>>>>>>>> sp, #0x150 (vectors)
> > >>>>>>>>>>> R SP_EL1 (AARCH64) ffff8000 808f3c50
> > >>>>>>>>>>> 3824884925 ps ES (ffff800080010b84:8b2063ff) O
> > el1h_ns: add
> > >>>>>>>> sp,
> > >>>>>>>>>> sp, x0 (vectors)
> > >>>>>>>>>>> R SP_EL1 (AARCH64) ffff8000 808f3d10
> > >>>>>>>>>>> 3824884926 ps ES (ffff800080010b88:cb2063e0) O
> > el1h_ns: sub
> > >>>>>>>> x0,
> > >>>>>>>>>> sp, x0 (vectors)
> > >>>>>>>>>>> R X0 (AARCH64) ffff8000 808f3c50
> > >>>>>>>>>>> 3824884927 ps ES (ffff800080010b8c:37700080) O
> > el1h_ns: tbnz
> > >>>>>>>> w0,
> > >>>>>>>>>> #14, ffff800080010b9c <vectors+0x39c> (vectors)
> > >>>>>>>>>>> 3824884935 ps ES (ffff800080010b90:cb2063e0) O
> > el1h_ns: sub
> > >>>>>>>> x0,
> > >>>>>>>>>> sp, x0 (vectors)
> > >>>>>>>>>>> R X0 (AARCH64) 00000000 000000c0
> > >>>>>>>>>>> 3824884937 ps ES (ffff800080010b94:cb2063ff) O
> > el1h_ns: sub
> > >>>>>> sp,
> > >>>>>>>>>> sp, x0 (vectors)
> > >>>>>>>>>>> R SP_EL1 (AARCH64) ffff8000 808f3c50
> > >>>>>>>>>>> 3824884938 ps ES (ffff800080010b98:140001ef) O
> > el1h_ns: b
> > >>>>>>>>>> ffff800080011354 <el1h_64_error> (vectors)
> > >>>>>>>>>>>
> > >>>>>>>>>>> If I understand correctly, the exception happened sometime
> > earlier
> > >>> and
> > >>>>>>>> only
> > >>>>>>>>>> now Linux boot code (setup_arch) opened the exception
> handling
> > and as
> > >>>>>> a
> > >>>>>>>>>> result we immediately jump to the SError exception handler.
> > >>>>>>>>>>
> > >>>>>>>>>>
> > >>>>>>>>>> Yes, that sounds reasonable. If I understood correctly, you are
> > >>>>>>>>>> running something "quite new" on some software (QEMU) and
> > >>>>>> hardware
> > >>>>>>>>>> (Synopsis) simulators.
> > >>>>>>>>>>
> > >>>>>>>>>> That would mean that you have new hardware with e.g. new
> > memory
> > >>>>>> map
> > >>>>>>>>>> not used before. What you describe might sound like in the code
> > before
> > >>>>>>>>>> Linux (boot loader) there is anything resulting in the SError. This
> > >>>>>>>>>> might be an access to non-existing or non-enabled hardware.
> I.e.
> > it
> > >>>>>>>>>> might be that you try to access (read/write) an address what is
> > not
> > >>>>>>>>>> available, yet (or just invalid). It's hard to debug that. In case you
> > >>>>>>>>>> are able to modify the code before Linux (the boot loader?) you
> > might
> > >>>>>>>>>> try to enable SError exceptions, there, too. To get it earlier and
> > >>>>>>>>>> with that make the search window smaller. I'm not that familiar
> > with
> > >>>>>>>>>> QEMU, but could you try to trace which (all?) hardware accesses
> > your
> > >>>>>>>>>> code does. And with that analyse all accesses and with that
> check
> > if
> > >>>>>>>>>> all these accesses are valid even on the hardware (Synopsis)
> > emulation
> > >>>>>>>>>> system? That should be checked from valid address and from
> > hardware
> > >>>>>>>>>> subsystem enablement point of view.
> > >>>>>>>>>>
> > >>>>>>>>>> Hth,
> > >>>>>>>>>>
> > >>>>>>>>>> Dirk
> > >>>>>>>>>>
> > >>>>>>>>>>
> > >>>>>>>>>>> From the Linux source:
> > >>>>>>>>>>> parse_early_param();
> > >>>>>>>>>>>
> > >>>>>>>>>>> dynamic_scs_init();
> > >>>>>>>>>>>
> > >>>>>>>>>>> /*
> > >>>>>>>>>>> * Unmask asynchronous aborts and fiq after bringing up
> > possible
> > >>>>>>>>>>> * earlycon. (Report possible System Errors once we can
> > report
> > >>> this
> > >>>>>>>>>>> * occurred).
> > >>>>>>>>>>> */
> > >>>>>>>>>>> local_daif_restore(DAIF_PROCCTX_NOIRQ); <---- This is
> > when we
> > >>>>>> get
> > >>>>>>>> the
> > >>>>>>>>>> exception.
> > >>>>>>>>>>>
> > >>>>>>>>>>> After some kernel hacking (replacing printk) we could extract
> the
> > logs:
> > >>>>>>>>>>> 6Booting Linux on physical CPU 0x0000000000 [0x410fd034]
> > >>>>>>>>>>> 5Linux version 6.5.0 (pliops@dev-liorw) (aarch64-buildroot-
> > linux-gnu-
> > >>>>>>>>>> gcc.br_real (Buildroot 2023.02.1-95-g8391404e23) 11.3.0,
> GNU
> > ld
> > >>>>>> (GNU
> > >>>>>>>>>> Binutils) 2.38) #101 SMP Sun Dec 17 20:09:06 IST 2023
> > >>>>>>>>>>> 6Machine model: Pliops Spider MK-I EVK
> > >>>>>>>>>>> 2SError Interrupt on CPU0, code 0x00000000bf000002 --
> SError
> > >>>>>>>>>>> CPU: 0 PID: 0 Comm: swapper Not tainted 6.5.0 #101
> > >>>>>>>>>>> Hardware name: Pliops Spider MK-I EVK (DT)
> > >>>>>>>>>>> pstate: 600000c5 (nZCv daIF -PAN -UAO -TCO -DIT -SSBS
> > BTYPE=--)
> > >>>>>>>>>>> pc : setup_arch+0x13c/0x5ac
> > >>>>>>>>>>> lr : setup_arch+0x134/0x5ac
> > >>>>>>>>>>> sp : ffff8000808f3da0
> > >>>>>>>>>>> x29: ffff8000808f3da0c x28: 0000000008758074c x27:
> > >>>>>>>>>> 0000000005e31b58c
> > >>>>>>>>>>> x26: 0000000000000001c x25: 0000000007e5f728c x24:
> > >>>>>>>>>> ffff8000808f8000c
> > >>>>>>>>>>> x23: ffff8000808f8600c x22: ffff8000807b6000c x21:
> > >>>>>>>> ffff800080010000c
> > >>>>>>>>>>> x20: ffff800080a1e000c x19: fffffbfffddfe190c x18:
> > >>>>>> 000000002266684ac
> > >>>>>>>>>>> x17: 00000000fcad60bbc x16: 0000000000001800c x15:
> > >>>>>>>>>> 0000000000000008c
> > >>>>>>>>>>> x14: ffffffffffffffffc x13: 0000000000000000c x12:
> > >>>>>> 0000000000000003c
> > >>>>>>>>>>> x11: 0101010101010101c x10: ffffffffffee87dfc x9 :
> > >>>>>>>> 0000000000000038c
> > >>>>>>>>>>> x8 : 0101010101010101c x7 : 7f7f7f7f7f7f7f7fc x6 :
> > >>>>>>>> 0000000000000001c
> > >>>>>>>>>>> x5 : 0000000000000000c x4 : 8000000000000000c x3 :
> > >>>>>>>>>> 0000000000000065c
> > >>>>>>>>>>> x2 : 0000000000000000c x1 : 0000000000000000c x0 :
> > >>>>>>>>>> 00000000000000c0c
> > >>>>>>>>>>> 0Kernel panic - not syncing: Asynchronous SError Interrupt
> > >>>>>>>>>>> CPU: 0 PID: 0 Comm: swapper Not tainted 6.5.0 #101
> > >>>>>>>>>>> Hardware name: Pliops Spider MK-I EVK (DT)
> > >>>>>>>>>>> Call trace:
> > >>>>>>>>>>> dump_backtrace+0x9c/0xd0
> > >>>>>>>>>>> show_stack+0x14/0x1c
> > >>>>>>>>>>> dump_stack_lvl+0x44/0x58
> > >>>>>>>>>>> dump_stack+0x14/0x1c
> > >>>>>>>>>>> panic+0x2e0/0x33c
> > >>>>>>>>>>> nmi_panic+0x68/0x6c
> > >>>>>>>>>>> arm64_serror_panic+0x68/0x78
> > >>>>>>>>>>> do_serror+0x24/0x54
> > >>>>>>>>>>> el1h_64_error_handler+0x2c/0x40
> > >>>>>>>>>>> el1h_64_error+0x64/0x68
> > >>>>>>>>>>> setup_arch+0x13c/0x5ac
> > >>>>>>>>>>> start_kernel+0x5c/0x5b8
> > >>>>>>>>>>> __primary_switched+0xb4/0xbc
> > >>>>>>>>>>> 0---[ end Kernel panic - not syncing: Asynchronous SError
> > Interrupt ]---
> > >>>>>>>>>>>
> > >>>>>>>>>>> Can you please advice how to proceed with debugging?
> > >>>>>>>>>>>
> > >>>>>>>>>>> Thanks in advanced,
> > >>>>>>>>>>> Cheers,
> > >>>>>>>>>>> Lior.
> > >>>>>>>>>>>
> > >>>>>>>>>>>
> > >>>>>>>>>>
> > >>>>>>>>>
> > >>>>>>>
> > >>>>>
> > >>>>
> > >>>
> > >>> --
> > >>> DENX Software Engineering GmbH, Managing Director: Erika Unter
> > >>> HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell,
> Germany
> > >>> Phone: +49-8142-66989-52 Fax: +49-8142-66989-80 Email:
> > hs@denx.de
> > >
> >
> > --
> > DENX Software Engineering GmbH, Managing Director: Erika Unter
> > HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany
> > Phone: +49-8142-66989-52 Fax: +49-8142-66989-80 Email: hs@denx.de
^ permalink raw reply [flat|nested] 16+ messages in thread
* RE: Debugging early SError exception
2023-12-24 19:12 ` Lior Weintraub
@ 2023-12-26 7:48 ` Lior Weintraub
0 siblings, 0 replies; 16+ messages in thread
From: Lior Weintraub @ 2023-12-26 7:48 UTC (permalink / raw)
To: hs, Dirk Behme; +Cc: linux-embedded
Update:
Issue with CPU idle was found.
It was related to our SoC changes in timers interrupt connectivity (which makes sense :-)).
Marry XMAS all.
> -----Original Message-----
> From: Lior Weintraub
> Sent: Sunday, December 24, 2023 9:12 PM
> To: hs@denx.de; Dirk Behme <dirk.behme@gmail.com>
> Cc: linux-embedded@vger.kernel.org
> Subject: RE: Debugging early SError exception
>
> Update:
> UART issue ("unable to open an initial console") was resolved.
> I was missing CONFIG_SERIAL_8250_DW=y on my config.
>
> Now only issue left is the CPU idle ("wfi") and no interrupts are coming.
>
> > -----Original Message-----
> > From: Lior Weintraub
> > Sent: Sunday, December 24, 2023 5:42 PM
> > To: hs@denx.de; Dirk Behme <dirk.behme@gmail.com>
> > Cc: linux-embedded@vger.kernel.org
> > Subject: RE: Debugging early SError exception
> >
> > Hi,
> >
> > The GICv3 issue was resolved after:
> > 1. Setting bit 0 and bit 3 on ICC_SRE_EL3 (we don't have virtualization
> support
> > and hence ICC_SRE_EL2 is not supported).
> > 2. Power up the GICR on EL3
> >
> > The earlycon issue was resolved after:
> > 1. Add to "earlycon=uart8250,mmio32,0xd000307000,115200n8" to boot
> > args.
> > 2. Add "CONFIG_SERIAL_8250_CONSOLE=y" to config (previously had only
> > CONFIG_SERIAL_8250=y)
> >
> > Now I face a new issue:
> > Linux boot hangs on "wait for interrupt" at cpu_do_idle.
> >
> > The program counter is stuck at 0xffff8000805ae45c.
> > ffff8000805ae454 <cpu_do_idle>:
> > ffff8000805ae454: d5033f9f dsb sy
> > ffff8000805ae458: d503207f wfi
> > ffff8000805ae45c: d65f03c0 ret
> >
> > I think that something is wrong with the timers or gic setting and as a result
> > the scheduler doesn't get the interrupts (timer ticks).
> >
> > Additional info that might be relevant to this issue:
> > The emulation platform runs at about 2.8MHz.
> > The CNTFRQ_EL0 is set to 2M (because the emulation platform running freq
> > varies between 1.9-2.8MHz).
> > The reason for those settings is to allow Linux to run as it would on the "real"
> > world.
> >
> > It is my understanding that there are 2 issues here:
> > 1. Something is wrong with Timers\Interrupt setting (note that same
> > configuration runs correctly on QEMU)
> > 2. Something is wrong with initramfs - according kernel source it seems to
> fail
> > to open "/dev/console"
> >
> > The full Linux boot log:
> > Booting Linux on physical CPU 0x0000000000 [0x410fd034]
> > Linux version 6.5.0 (pliops@dev-liorw) (aarch64-buildroot-linux-gnu-
> > gcc.br_real (Buildroot 2023.02.1-95-g8391404e23) 11.3.0, GNU ld (GNU
> > Binuti) 2.38) #112 SMP Sun Dec 24 15:44:56 IST 2023
> > Machine model: Pliops Spider MK-I EVK
> > earlycon: uart8250 at MMIO32 0x000000d000307000 (options
> '115200n8')
> > printk: bootconsole [uart8250] enabled
> > efi: UEFI not found.
> > Zone ranges:
> > DMA [mem 0x0000000000000000-0x000000002fffffff]
> > DMA32 empty
> > Normal empty
> > Movable zone start for each node
> > Early memory node ranges
> > node 0: [mem 0x0000000000000000-0x000000002fffffff]
> > Initmem setup node 0 [mem 0x0000000000000000-0x000000002fffffff]
> > percpu: Embedded 25 pages/cpu s64800 r8192 d29408 u102400
> > Detected VIPT I-cache on CPU0
> > CPU features: detected: GIC system register CPU interface
> > CPU features: detected: ARM erratum 845719
> > alternatives: applying boot alternatives
> > Kernel command line: console=ttyS0,115200n8
> > earlycon=uart8250,mmio32,0xd000307000,115200n8
> > Dentry cache hash table entries: 131072 (order: 8, 1048576 bytes, linear)
> > Inode-cache hash table entries: 65536 (order: 7, 524288 bytes, linear)
> > Built 1 zonelists, mobility grouping on. Total pages: 193536
> > mem auto-init: stack:off, heap alloc:off, heap free:off
> > software IO TLB: area num 1.
> > software IO TLB: mapped [mem 0x000000002b080000-
> > 0x000000002f080000] (64MB)
> > Memory: 689240K/786432K available (5824K kernel code, 1186K rwdata,
> > 1612K rodata, 1600K init, 400K bss, 97192K reserved, 0K cma-reserved)
> > SLUB: HWalign=64, Order=0-3, MinObjects=0, CPUs=1, Nodes=1
> > trace event string verifier disabled
> > rcu: Hierarchical RCU implementation.
> > rcu: RCU event tracing is enabled.
> > rcu: RCU restricting CPUs from NR_CPUS=256 to nr_cpu_ids=1.
> > rcu: RCU calculated value of scheduler-enlistment delay is 25 jiffies.
> > rcu: Adjusting geometry for rcu_fanout_leaf=16, nr_cpu_ids=1
> > NR_IRQS: 64, nr_irqs: 64, preallocated irqs: 0
> > GICv3: 96 SPIs implemented
> > GICv3: 0 Extended SPIs implemented
> > Root IRQ handler: gic_handle_irq
> > GICv3: GICv3 features: 16 PPIs
> > GICv3: CPU0: found redistributor 0 region 0:0x000000e000060000
> > ITS [mem 0xe000040000-0xe00005ffff]
> > ITS@0x000000e000040000: allocated 8192 Devices @a0000 (indirect, esz
> 8,
> > psz 64K, shr 1)
> > ITS@0x000000e000040000: allocated 32768 Interrupt Collections @b0000
> > (flat, esz 2, psz 64K, shr 1)
> > GICv3: Expected reserved range
> > [0x00000000000c0000:0x00000000000cffff], not found
> > GICv3: using LPI property table @0x00000000000c0000
> > GICv3: CPU0: Booted with LPIs enabled, memory probably corrupted
> > CPU0: Failed to disable LPIs
> > rcu: srcu_init: Setting srcu_struct sizes based on contention.
> > arch_timer: cp15 timer(s) running at 62.50MHz (virt).
> > clocksource: arch_sys_counter: mask: 0x1ffffffffffffff max_cycles:
> > 0x1cd42e208c, max_idle_ns: 881590405314 ns
> > sched_clock: 57 bits at 63MHz, resolution 16ns, wraps every
> > 4398046511096ns
> > Console: colour dummy device 80x25
> > Calibrating delay loop (skipped), value calculated using timer frequency..
> > 125.00 BogoMIPS (lpj=250000)
> > pid_max: default: 32768 minimum: 301
> > Mount-cache hash table entries: 2048 (order: 2, 16384 bytes, linear)
> > Mountpoint-cache hash table entries: 2048 (order: 2, 16384 bytes, linear)
> > cacheinfo: Unable to detect cache hierarchy for CPU 0
> > rcu: Hierarchical SRCU implementation.
> > rcu: Max phase no-delay instances is 1000.
> > Platform MSI: gic-its@E000040000 domain created
> > PCI/MSI: /soc/interrupt-controller@E000000000/gic-its@E000040000
> > domain created
> > EFI services will not be available.
> > smp: Bringing up secondary CPUs ...
> > smp: Brought up 1 node, 1 CPU
> > SMP: Total of 1 processors activated.
> > CPU features: detected: 32-bit EL0 Support
> > CPU features: detected: CRC32 instructions
> > CPU: All CPU(s) started at EL1
> > alternatives: applying system-wide alternatives
> > devtmpfs: initialized
> > clocksource: jiffies: mask: 0xffffffff max_cycles: 0xffffffff, max_idle_ns:
> > 7645041785100000 ns
> > futex hash table entries: 256 (order: 2, 16384 bytes, linear)
> > DMI not present or invalid.
> > DMA: preallocated 128 KiB GFP_KERNEL pool for atomic allocations
> > DMA: preallocated 128 KiB GFP_KERNEL|GFP_DMA pool for atomic
> > allocations
> > DMA: preallocated 128 KiB GFP_KERNEL|GFP_DMA32 pool for atomic
> > allocations
> > hw-breakpoint: found 6 breakpoint and 4 watchpoint registers.
> > ASID allocator initialised with 65536 entries
> > Serial: AMBA PL011 UART driver
> > Modules: 30080 pages in range for non-PLT usage
> > Modules: 521600 pages in range for PLT usage
> > iommu: Default domain type: Translated
> > iommu: DMA domain TLB invalidation policy: strict mode
> > SCSI subsystem initialized
> > vgaarb: loaded
> > clocksource: Switched to clocksource arch_sys_counter
> > PCI: CLS 0 bytes, default 64
> > workingset: timestamp_bits=46 max_order=18 bucket_order=0
> > fuse: init (API version 7.38)
> > Block layer SCSI generic (bsg) driver version 0.4 loaded (major 251)
> > io scheduler mq-deadline registered
> > io scheduler kyber registered
> > Unpacking initramfs...
> > Freeing initrd memory: 4596K
> > Serial: 8250/16550 driver, 4 ports, IRQ sharing disabled
> > hw perfevents: enabled with armv8_cortex_a53 PMU driver, 7 counters
> > available
> > clk: Disabling unused clocks
> > Warning: unable to open an initial console.
> > Freeing unused kernel memory: 1600K
> >
> > Thanks in advance for your great advice and support,
> > Cheers,
> > Lior.
> >
> > > -----Original Message-----
> > > From: Heiko Schocher <hs@denx.de>
> > > Sent: Friday, December 22, 2023 10:04 AM
> > > To: Dirk Behme <dirk.behme@gmail.com>; Lior Weintraub
> > > <liorw@pliops.com>
> > > Cc: linux-embedded@vger.kernel.org
> > > Subject: Re: Debugging early SError exception
> > >
> > > [You don't often get email from hs@denx.de. Learn why this is important
> at
> > > https://aka.ms/LearnAboutSenderIdentification ]
> > >
> > > CAUTION: External Sender
> > >
> > > Hello Dirk, Lior,
> > >
> > > On 22.12.23 08:48, Dirk Behme wrote:
> > > > Am 22.12.23 um 08:03 schrieb Lior Weintraub:
> > > >> Hi,
> > > >>
> > > >> I managed to dump the __log_buf but for some reason the UART is still
> > not
> > > working.
> > > >> Please note that UART printed all the U-BOOT traces so AFAIU, the
> device
> > > tree is set correctly.
> > > >> (Barebox is passing it's DTB into kernel).
> > > >>
> > > >> To enable the earlyprintk I have:
> > > >> 1. Compiled the kernel with CONFIG_EARLY_PRINTK=y and
> > > CONFIG_DEBUG_LL=y
> > > >> 2. Modified the boot args to include: "console=ttyS0,115200n8
> > > earlycon=dw-apb-uart,0xd000307000"
> > > >> 3. Verified that dw-apb-uart driver (8250_early.c) supports earlycon:
> > > >> OF_EARLYCON_DECLARE(uart, "snps,dw-apb-uart",
> > > early_serial8250_setup);
> > > >>
> > > >> From __log_buf dump:
> > > >> Booting Linux on physical CPU 0x0000000000 [0x410fd034]4]
> > > >> Linux version 6.5.0 (pliops@dev-liorw) (aarch64-buildroot-linux-gnu-
> > > gcc.br_real (Buildroot
> > > >> 2023.02.1-95-g8391404e23) 11.3.0, GNU ld (GNU Binutils) 2.38) #107
> > > SMP Thu Dec 21 17:33:12 IST 202323
> > > >> Machine model: Pliops Spider MK-I EVKVK
> > > >> efi: UEFI not found.d.
> > > >> Zone ranges:s:
> > > >> DMA [mem 0x0000000000000000-0x000000002fffffff]f]
> > > >> DMA32 emptyty
> > > >> Normal emptyty
> > > >> Movable zone start for each nodede
> > > >> Early memory node rangeses
> > > >> node 0: [mem 0x0000000000000000-0x000000002fffffff]f]
> > > >> Initmem setup node 0 [mem 0x0000000000000000-
> > > 0x000000002fffffff]f]
> > > >> percpu: Embedded 25 pages/cpu s64800 r8192 d29408 u10240000
> > > >> pcpu-alloc: s64800 r8192 d29408 u102400 alloc=25*4096
> > > >> pcpu-alloc: [0] 0
> > > >> Detected VIPT I-cache on CPU0U0
> > > >> CPU features: GIC system register CPU interface present but disabled by
> > > higher exception levelel
> > > >> CPU features: detected: ARM erratum 84571919
> > > >> alternatives: applying boot alternativeses
> > > >> Kernel command line: console=ttyS0,115200n8 earlycon=dw-apb-
> > > uart,0xd00030700000
> > > >> Dentry cache hash table entries: 131072 (order: 8, 1048576 bytes,
> > linear)r)
> > > >> Inode-cache hash table entries: 65536 (order: 7, 524288 bytes, linear)r)
> > > >> Built 1 zonelists, mobility grouping on. Total pages: 19353636
> > > >> mem auto-init: stack:off, heap alloc:off, heap free:offff
> > > >> software IO TLB: area num 1.1.
> > > >> software IO TLB: mapped [mem 0x000000002b080000-
> > > 0x000000002f080000] (64MB)B)
> > > >> Memory: 689240K/786432K available (5824K kernel code, 1186K
> > rwdata,
> > > 1612K rodata, 1600K init, 400K
> > > >> bss, 97192K reserved, 0K cma-reserved)d)
> > > >> SLUB: HWalign=64, Order=0-3, MinObjects=0, CPUs=1, Nodes=1=1
> > > >> trace event string verifier disableded
> > > >> rcu: Hierarchical RCU implementation.n.
> > > >> rcu: RCU event tracing is enabled.d.
> > > >> rcu: RCU restricting CPUs from NR_CPUS=256 to nr_cpu_ids=1.1.
> > > >> rcu: RCU calculated value of scheduler-enlistment delay is 25 jiffies.s.
> > > >> rcu: Adjusting geometry for rcu_fanout_leaf=16, nr_cpu_ids=1=1
> > > >> NR_IRQS: 64, nr_irqs: 64, preallocated irqs: 0 0
> > > >> GICv3: 96 SPIs implementeded
> > > >> GICv3: 0 Extended SPIs implementeded
> > > >> Root IRQ handler: gic_handle_irqrq
> > > >> GICv3: GICv3 features: 16 PPIsIs
> > > >> GICv3: CPU0: found redistributor 0 region 0:0x000000e00006000000
> > > >> GICv3: redistributor failed to wakeup.....
> > > >> GICv3: GIC: unable to set SRE (disabled at EL2), panic aheadad
> > > >
> > > > I think the two messages above are the essential ones.
> > >
> > > +1
> > >
> > > > Maybe it helps to check
> > > >
> > > > https://secure-web.cisco.com/1VmuNXQkE6u---G9xsJ8CPb6-
> > > aguDK_MyJeUn43QsTaafgaifoFTAvcD4vQefYzFntmjc8L_J46du6-
> > > DYArOlFkq__OwCChpFf-
> > nXIyddL3MCQMsTZ9hIk_WCfDqIi1wSEmPSBClIYS0-
> > >
> >
> SAjwPiOf7sA2wLvt_5ehGaTHO61NJEWdOrfKy9pBT1_RDyQGXi7kz8XuAUpu
> > > Whhipp-
> > >
> >
> ngljUJcxkHkmWDvpocGule5ZNEe5UZ3nGNjUnqCU8J_bXtCgNPEk4CyorLt7g4
> > >
> >
> F5Ks85tlVEEutu8vyJXu8_TUacURkRnQgjvood6iVOn5w2TpSRn/https%3A%2
> > >
> F%2Fwww.kernel.org%2Fdoc%2Fhtml%2Fv5.3%2Farm64%2Fbooting.html
> > > >
> > > > In the middle of that page in the "Call the kernel image" it has something
> > > about GIC:
> > > >
> > > > -- cut --
> > > > If the kernel is entered at EL1:
> > > >
> > > > ICC.SRE_EL2.Enable (bit 3) must be initialised to 0b1
> > > > ICC_SRE_EL2.SRE (bit 0) must be initialised to 0b1.
> > > > -- cut --
> > >
> > > Also may it makes sense to check your firmware (bootloader, ATF?) ... may
> > > there is some setting missing for your SoC/Board ?
> > >
> > > bye,
> > > Heiko
> > >
> > > >
> > > >> Internal error: Oops - Undefined instruction: 0000000062383019 [#1]
> > > SMPMP
> > > >> Modules linked in:
> > > >> CPU: 0 PID: 0 Comm: swapper/0 Not tainted 6.5.0 #107
> > > >> Hardware name: Pliops Spider MK-I EVK (DT)
> > > >> pstate: 600000c5 (nZCv daIF -PAN -UAO -TCO -DIT -SSBS BTYPE=--)
> > > >> pc : gic_cpu_sys_reg_init+0x58/0x2e4
> > > >> lr : gic_cpu_sys_reg_init+0x2a4/0x2e4
> > > >> sp : ffff8000808f3b40
> > > >> x29: ffff8000808f3b40 x28: 0000000000000000 x27:
> > > 0000000000000001
> > > >> x26: ffff000000016040 x25: 0000000000000000 x24:
> > ffff800080a6b000
> > > >> x23: ffff8000808fc320 x22: ffff8000809cc000 x21: ffff00002fe74670
> > > >> x20: ffff800080a90000 x19: 0000000000000000 x18: fffffffffffe0b10
> > > >> x17: ffff8000809f9480 x16: fffffc0000002248 x15: ffff80008090af28
> > > >> x14: fffffffffffc0b0f x13: 6461656861206369 x12: 6e6170202c29324c
> > > >> x11: 452074612064656c x10: 6261736964282045 x9 :
> > > 6428204552532074
> > > >> x8 : ffff80008090af28 x7 : ffff8000808f3970 x6 : 000000000000000c
> > > >> x5 : 000000000000002a x4 : 0000000000000000 x3 :
> > > 0000000000000000
> > > >> x2 : 0000000000000000 x1 : ffff8000808fd0c0 x0 :
> 000000000000003c
> > > >> Call trace:
> > > >> gic_cpu_sys_reg_init+0x58/0x2e4
> > > >> gic_cpu_init.part.0+0xa8/0x114
> > > >> gic_init_bases+0x408/0x684
> > > >> gic_of_init+0x298/0x300
> > > >> of_irq_init+0x1c8/0x368
> > > >> irqchip_init+0x14/0x1c
> > > >> init_IRQ+0x98/0xac
> > > >> start_kernel+0x250/0x5b8
> > > >> __primary_switched+0xb4/0xbc
> > > >> Code: 9260df39 d3441f33 d538cca0 36001180 (d538cc80) )
> > > >> ---[ end trace 0000000000000000 ]-----
> > > >> Kernel panic - not syncing: Attempted to kill the idle task!k!
> > > >> ---[ end Kernel panic - not syncing: Attempted to kill the idle task! ]-----
> > > >>
> > > >>
> > > >> The kernel panic is related to GIC distributor (currently under debug) but
> > > AFAIU,
> > > >> this has nothing to do with the UART not working on early stages.
> > > >
> > > >
> > > > Yes, I agree. GIC issue and UART (at least the polling mode) should be
> > > indendent.
> > > >
> > > > Best regards
> > > >
> > > > Dirk
> > > >
> > > >
> > > >> Thanks in advanced for your advice,
> > > >> Cheers,
> > > >> Lior.
> > > >>
> > > >>
> > > >>> -----Original Message-----
> > > >>> From: Heiko Schocher <hs@denx.de>
> > > >>> Sent: Thursday, December 21, 2023 1:37 PM
> > > >>> To: Lior Weintraub <liorw@pliops.com>
> > > >>> Cc: Dirk Behme <dirk.behme@gmail.com>; linux-
> > > embedded@vger.kernel.org
> > > >>> Subject: Re: Debugging early SError exception
> > > >>>
> > > >>> [You don't often get email from hs@denx.de. Learn why this is
> important
> > > at
> > > >>> https://aka.ms/LearnAboutSenderIdentification ]
> > > >>>
> > > >>> CAUTION: External Sender
> > > >>>
> > > >>> Hi Lior,
> > > >>>
> > > >>> On 21.12.23 12:19, Dirk Behme wrote:
> > > >>>> Am 21.12.23 um 11:04 schrieb Lior Weintraub:
> > > >>>>> Thanks Dirk,
> > > >>>>>
> > > >>>>> Regarding the earlyprintk, not sure I know how to make it work.
> > > >>>>> I have defined CONFIG_EARLY_PRINTK=y and CONFIG_DEBUG_LL=y
> > on
> > > my
> > > >>> config but it doesn't seem to work.
> > > >>>>> Do I need to pass something in the bootargs from the U-BOOT?
> > > >>>>> Do I need to add that into my device tree?
> > > >>>>> (Tried to set bootargs = "console=ttyS0,115200 earlyprintk"; under
> > > "chosen"
> > > >>> on my DT but it didn't
> > > >>>>> work)
> > > >>>>
> > > >>>> Yes, what has to be enabled and what not and what has to be set
> how
> > is
> > > often
> > > >>> confusing. I think this
> > > >>>> is not common for all systems, so I think to be on the safe side you
> > have
> > > to look
> > > >>> into the code for
> > > >>>> you system. Or short; The code is the documentation ;)
> > > >>>>
> > > >>>>
> > > >>>>> The UART I am using is "snps,dw-apb-uart".
> > > >>>>>
> > > >>>>> Last week, to output the early logs I have implemented this hack:
> > > >>>>> 1. Modify printk macro to run my print_func
> > > >>>>> 2. This print_func wrote the characters into a single global variable
> > (u32
> > > >>> simul_uart;)
> > > >>>>> 3. Get the address location of this global variable and extract all
> writes
> > to
> > > it
> > > >>> from the Tarmac
> > > >>>>> logs.
> > > >>>>>
> > > >>>>> This is a very slow and tedious process but it helped me identify the
> > > initial
> > > >>> SError.
> > > >>>>> Initially I thought I can write directly into the UART FIFO register
> > (which I
> > > know
> > > >>> the address)
> > > >>>>> but this didn't work because Linux already setup the MMU so I guess
> I
> > > need to
> > > >>> know the virtual
> > > >>>>> address of this FIFO.
> > > >>>>> Do I need to use __phys_to_virt of some sort?
> > > >>>>
> > > >>>> Yes, I think so. Have a look to the existing serial driver, too. It should
> do
> > > whats
> > > >>> needed, and you
> > > >>>> can borrow that, then.
> > > >>>
> > > >>> If you have access to the RAM after the crash (through a debugger or in
> > > >>> your bootloader) and your mem is stable, find out the address of
> > > __log_buf
> > > >>> in System.map. Thats the buffer where printk writes into it, and so
> > > dumping
> > > >>> the content is what you would see in case uart works...
> > > >>>
> > > >>> Hope it helps!
> > > >>>
> > > >>> bye,
> > > >>> Heiko
> > > >>>>
> > > >>>> Best regards
> > > >>>>
> > > >>>> Dirk
> > > >>>>
> > > >>>>
> > > >>>>> Cheers,
> > > >>>>> Lior.
> > > >>>>>
> > > >>>>>> -----Original Message-----
> > > >>>>>> From: Dirk Behme <dirk.behme@gmail.com>
> > > >>>>>> Sent: Thursday, December 21, 2023 10:30 AM
> > > >>>>>> To: Lior Weintraub <liorw@pliops.com>; linux-
> > > embedded@vger.kernel.org
> > > >>>>>> Subject: Re: Debugging early SError exception
> > > >>>>>>
> > > >>>>>> [You don't often get email from dirk.behme@gmail.com. Learn why
> > > this is
> > > >>>>>> important at https://aka.ms/LearnAboutSenderIdentification ]
> > > >>>>>>
> > > >>>>>> CAUTION: External Sender
> > > >>>>>>
> > > >>>>>> Am 21.12.23 um 08:43 schrieb Lior Weintraub:
> > > >>>>>>> Hi Dirk,
> > > >>>>>>>
> > > >>>>>>> We found that the issue was at the early stages of Barebox (a.k.a
> U-
> > > BOOT
> > > >>>>>> v2).
> > > >>>>>>
> > > >>>>>> Glad to hear that! :)
> > > >>>>>>
> > > >>>>>>> Our implementation of putc_ll (on debug_ll) was writing into the
> > > UART Tx
> > > >>>>>> FIFO without checking if the FIFO is full.
> > > >>>>>>> Once the fifo got full it caused this SError probably because the
> > UART
> > > IP
> > > >>>>>> generated an apberror signal.
> > > >>>>>>
> > > >>>>>> Thanks for the report!
> > > >>>>>>
> > > >>>>>>> Now the Linux is running and doesn't report the SError again but
> > now
> > > we
> > > >>>>>> face another issue.
> > > >>>>>>> We see that the PC is getting into a "report_bug" function.
> > > >>>>>>> The Linux doesn't print anything to the UART (probably since it
> > hasn't
> > > got to
> > > >>>>>> the point where the console is configured?).
> > > >>>>>>
> > > >>>>>> For cases like this using earlyprintk is usually a good option. Check
> > > >>>>>> the Linux kernel serial console (UART) dirver of you SoC if it
> > > >>>>>> supports it. In the end it should be "just" a function in the serial
> > > >>>>>> console driver which outputs the console data via polling before
> > > >>>>>> (later) the interrupt driven console part takes over.
> > > >>>>>>
> > > >>>>>> Best regards
> > > >>>>>>
> > > >>>>>> Dirk
> > > >>>>>>
> > > >>>>>>
> > > >>>>>>> Since our debug means are limited it can take some time to find
> the
> > > root
> > > >>>>>> cause.
> > > >>>>>>>
> > > >>>>>>> I will keep you posted and update our findings.
> > > >>>>>>> Love to hear your thoughts,
> > > >>>>>>>
> > > >>>>>>> Cheers,
> > > >>>>>>> Lior.
> > > >>>>>>>
> > > >>>>>>>
> > > >>>>>>>> -----Original Message-----
> > > >>>>>>>> From: Dirk Behme <dirk.behme@gmail.com>
> > > >>>>>>>> Sent: Tuesday, December 19, 2023 3:37 PM
> > > >>>>>>>> To: Lior Weintraub <liorw@pliops.com>; linux-
> > > embedded@vger.kernel.org
> > > >>>>>>>> Subject: Re: Debugging early SError exception
> > > >>>>>>>>
> > > >>>>>>>> [You don't often get email from dirk.behme@gmail.com. Learn
> > why
> > > this is
> > > >>>>>>>> important at https://aka.ms/LearnAboutSenderIdentification ]
> > > >>>>>>>>
> > > >>>>>>>> CAUTION: External Sender
> > > >>>>>>>>
> > > >>>>>>>> Am 19.12.23 um 14:23 schrieb Lior Weintraub:
> > > >>>>>>>>> Thanks Dirk,
> > > >>>>>>>>
> > > >>>>>>>> Welcome :)
> > > >>>>>>>>
> > > >>>>>>>> In case you find the root cause it would be nice to get some
> generic
> > > >>>>>>>> description of it so that we can learn something :)
> > > >>>>>>>>
> > > >>>>>>>> Best regards
> > > >>>>>>>>
> > > >>>>>>>> Dirk
> > > >>>>>>>>
> > > >>>>>>>>
> > > >>>>>>>>>> -----Original Message-----
> > > >>>>>>>>>> From: Dirk Behme <dirk.behme@gmail.com>
> > > >>>>>>>>>> Sent: Tuesday, December 19, 2023 9:09 AM
> > > >>>>>>>>>> To: Lior Weintraub <liorw@pliops.com>; linux-
> > > >>>>>> embedded@vger.kernel.org
> > > >>>>>>>>>> Subject: Re: Debugging early SError exception
> > > >>>>>>>>>>
> > > >>>>>>>>>> [You don't often get email from dirk.behme@gmail.com. Learn
> > > why this
> > > >>>>>> is
> > > >>>>>>>>>> important at https://aka.ms/LearnAboutSenderIdentification ]
> > > >>>>>>>>>>
> > > >>>>>>>>>> CAUTION: External Sender
> > > >>>>>>>>>>
> > > >>>>>>>>>> Am 17.12.23 um 22:32 schrieb Lior Weintraub:
> > > >>>>>>>>>>> Hi,
> > > >>>>>>>>>>>
> > > >>>>>>>>>>> We have a new SoC with eLinux porting (kernel v6.5).
> > > >>>>>>>>>>> This SoC is ARM64 (A53) single core based device.
> > > >>>>>>>>>>> It runs correctly on QEMU but fails with SError on emulation
> > > platform
> > > >>>>>>>>>> (Synopsys Zebu running our SoC model).
> > > >>>>>>>>>>> There is no debugger connected to this emulation but there
> are
> > > several
> > > >>>>>>>>>> debug capabilities we can use:
> > > >>>>>>>>>>> 1. Generating wave dump of CPU signals
> > > >>>>>>>>>>> 2. Generate a Tarmac log
> > > >>>>>>>>>>> 3. UART
> > > >>>>>>>>>>>
> > > >>>>>>>>>>> Since the SError happens at early stages of Linux boot the
> UART
> > > is not
> > > >>>>>>>>>> enabled yet.
> > > >>>>>>>>>>> From the Tarmac log we can see:
> > > >>>>>>>>>>> 3824884521 ps ES (ffff800080760888:d65f03c0) O
> > > el1h_ns: ret
> > > >>>>>>>>>> (parse_early_param)
> > > >>>>>>>>>>> 3824884522 ps ES (ffff800080763a60:d2801800) O
> > > el1h_ns: mov
> > > >>>>>>>> x0,
> > > >>>>>>>>>> #0xc0 // #192 (setup_arch)
> > > >>>>>>>>>>> R X0 (AARCH64) 00000000 000000c0
> > > >>>>>>>>>>> 3824884523 ps ES (ffff800080763a64:d51b4220) O
> > > el1h_ns: msr
> > > >>>>>>>>>> daif, x0 (setup_arch)
> > > >>>>>>>>>>> R CPSR 600000c5
> > > >>>>>>>>>>> 3824884529 ps ES System Error (Abort)
> > > >>>>>>>>>>> EXC [0x380] SError/vSError Current EL with
> SP_ELx
> > > >>>>>>>>>>> R ESR_EL1 (AARCH64) bf000002
> > > >>>>>>>>>>> R CPSR 600003c5
> > > >>>>>>>>>>> R SPSR_EL1 (AARCH64) 600000c5
> > > >>>>>>>>>>> R ELR_EL1 (AARCH64) ffff8000 80763a68
> > > >>>>>>>>>>> 3824884925 ps ES (ffff800080010b80:d10543ff) O
> > > el1h_ns: sub
> > > >>>>>>>> sp,
> > > >>>>>>>>>> sp, #0x150 (vectors)
> > > >>>>>>>>>>> R SP_EL1 (AARCH64) ffff8000 808f3c50
> > > >>>>>>>>>>> 3824884925 ps ES (ffff800080010b84:8b2063ff) O
> > > el1h_ns: add
> > > >>>>>>>> sp,
> > > >>>>>>>>>> sp, x0 (vectors)
> > > >>>>>>>>>>> R SP_EL1 (AARCH64) ffff8000 808f3d10
> > > >>>>>>>>>>> 3824884926 ps ES (ffff800080010b88:cb2063e0) O
> > > el1h_ns: sub
> > > >>>>>>>> x0,
> > > >>>>>>>>>> sp, x0 (vectors)
> > > >>>>>>>>>>> R X0 (AARCH64) ffff8000 808f3c50
> > > >>>>>>>>>>> 3824884927 ps ES (ffff800080010b8c:37700080) O
> > > el1h_ns: tbnz
> > > >>>>>>>> w0,
> > > >>>>>>>>>> #14, ffff800080010b9c <vectors+0x39c> (vectors)
> > > >>>>>>>>>>> 3824884935 ps ES (ffff800080010b90:cb2063e0) O
> > > el1h_ns: sub
> > > >>>>>>>> x0,
> > > >>>>>>>>>> sp, x0 (vectors)
> > > >>>>>>>>>>> R X0 (AARCH64) 00000000 000000c0
> > > >>>>>>>>>>> 3824884937 ps ES (ffff800080010b94:cb2063ff) O
> > > el1h_ns: sub
> > > >>>>>> sp,
> > > >>>>>>>>>> sp, x0 (vectors)
> > > >>>>>>>>>>> R SP_EL1 (AARCH64) ffff8000 808f3c50
> > > >>>>>>>>>>> 3824884938 ps ES (ffff800080010b98:140001ef) O
> > > el1h_ns: b
> > > >>>>>>>>>> ffff800080011354 <el1h_64_error> (vectors)
> > > >>>>>>>>>>>
> > > >>>>>>>>>>> If I understand correctly, the exception happened sometime
> > > earlier
> > > >>> and
> > > >>>>>>>> only
> > > >>>>>>>>>> now Linux boot code (setup_arch) opened the exception
> > handling
> > > and as
> > > >>>>>> a
> > > >>>>>>>>>> result we immediately jump to the SError exception handler.
> > > >>>>>>>>>>
> > > >>>>>>>>>>
> > > >>>>>>>>>> Yes, that sounds reasonable. If I understood correctly, you are
> > > >>>>>>>>>> running something "quite new" on some software (QEMU)
> and
> > > >>>>>> hardware
> > > >>>>>>>>>> (Synopsis) simulators.
> > > >>>>>>>>>>
> > > >>>>>>>>>> That would mean that you have new hardware with e.g. new
> > > memory
> > > >>>>>> map
> > > >>>>>>>>>> not used before. What you describe might sound like in the
> code
> > > before
> > > >>>>>>>>>> Linux (boot loader) there is anything resulting in the SError.
> This
> > > >>>>>>>>>> might be an access to non-existing or non-enabled hardware.
> > I.e.
> > > it
> > > >>>>>>>>>> might be that you try to access (read/write) an address what is
> > > not
> > > >>>>>>>>>> available, yet (or just invalid). It's hard to debug that. In case
> you
> > > >>>>>>>>>> are able to modify the code before Linux (the boot loader?)
> you
> > > might
> > > >>>>>>>>>> try to enable SError exceptions, there, too. To get it earlier and
> > > >>>>>>>>>> with that make the search window smaller. I'm not that
> familiar
> > > with
> > > >>>>>>>>>> QEMU, but could you try to trace which (all?) hardware
> accesses
> > > your
> > > >>>>>>>>>> code does. And with that analyse all accesses and with that
> > check
> > > if
> > > >>>>>>>>>> all these accesses are valid even on the hardware (Synopsis)
> > > emulation
> > > >>>>>>>>>> system? That should be checked from valid address and from
> > > hardware
> > > >>>>>>>>>> subsystem enablement point of view.
> > > >>>>>>>>>>
> > > >>>>>>>>>> Hth,
> > > >>>>>>>>>>
> > > >>>>>>>>>> Dirk
> > > >>>>>>>>>>
> > > >>>>>>>>>>
> > > >>>>>>>>>>> From the Linux source:
> > > >>>>>>>>>>> parse_early_param();
> > > >>>>>>>>>>>
> > > >>>>>>>>>>> dynamic_scs_init();
> > > >>>>>>>>>>>
> > > >>>>>>>>>>> /*
> > > >>>>>>>>>>> * Unmask asynchronous aborts and fiq after bringing up
> > > possible
> > > >>>>>>>>>>> * earlycon. (Report possible System Errors once we can
> > > report
> > > >>> this
> > > >>>>>>>>>>> * occurred).
> > > >>>>>>>>>>> */
> > > >>>>>>>>>>> local_daif_restore(DAIF_PROCCTX_NOIRQ); <---- This is
> > > when we
> > > >>>>>> get
> > > >>>>>>>> the
> > > >>>>>>>>>> exception.
> > > >>>>>>>>>>>
> > > >>>>>>>>>>> After some kernel hacking (replacing printk) we could extract
> > the
> > > logs:
> > > >>>>>>>>>>> 6Booting Linux on physical CPU 0x0000000000
> [0x410fd034]
> > > >>>>>>>>>>> 5Linux version 6.5.0 (pliops@dev-liorw) (aarch64-buildroot-
> > > linux-gnu-
> > > >>>>>>>>>> gcc.br_real (Buildroot 2023.02.1-95-g8391404e23) 11.3.0,
> > GNU
> > > ld
> > > >>>>>> (GNU
> > > >>>>>>>>>> Binutils) 2.38) #101 SMP Sun Dec 17 20:09:06 IST 2023
> > > >>>>>>>>>>> 6Machine model: Pliops Spider MK-I EVK
> > > >>>>>>>>>>> 2SError Interrupt on CPU0, code 0x00000000bf000002 --
> > SError
> > > >>>>>>>>>>> CPU: 0 PID: 0 Comm: swapper Not tainted 6.5.0 #101
> > > >>>>>>>>>>> Hardware name: Pliops Spider MK-I EVK (DT)
> > > >>>>>>>>>>> pstate: 600000c5 (nZCv daIF -PAN -UAO -TCO -DIT -SSBS
> > > BTYPE=--)
> > > >>>>>>>>>>> pc : setup_arch+0x13c/0x5ac
> > > >>>>>>>>>>> lr : setup_arch+0x134/0x5ac
> > > >>>>>>>>>>> sp : ffff8000808f3da0
> > > >>>>>>>>>>> x29: ffff8000808f3da0c x28: 0000000008758074c x27:
> > > >>>>>>>>>> 0000000005e31b58c
> > > >>>>>>>>>>> x26: 0000000000000001c x25: 0000000007e5f728c x24:
> > > >>>>>>>>>> ffff8000808f8000c
> > > >>>>>>>>>>> x23: ffff8000808f8600c x22: ffff8000807b6000c x21:
> > > >>>>>>>> ffff800080010000c
> > > >>>>>>>>>>> x20: ffff800080a1e000c x19: fffffbfffddfe190c x18:
> > > >>>>>> 000000002266684ac
> > > >>>>>>>>>>> x17: 00000000fcad60bbc x16: 0000000000001800c x15:
> > > >>>>>>>>>> 0000000000000008c
> > > >>>>>>>>>>> x14: ffffffffffffffffc x13: 0000000000000000c x12:
> > > >>>>>> 0000000000000003c
> > > >>>>>>>>>>> x11: 0101010101010101c x10: ffffffffffee87dfc x9 :
> > > >>>>>>>> 0000000000000038c
> > > >>>>>>>>>>> x8 : 0101010101010101c x7 : 7f7f7f7f7f7f7f7fc x6 :
> > > >>>>>>>> 0000000000000001c
> > > >>>>>>>>>>> x5 : 0000000000000000c x4 : 8000000000000000c x3 :
> > > >>>>>>>>>> 0000000000000065c
> > > >>>>>>>>>>> x2 : 0000000000000000c x1 : 0000000000000000c x0 :
> > > >>>>>>>>>> 00000000000000c0c
> > > >>>>>>>>>>> 0Kernel panic - not syncing: Asynchronous SError Interrupt
> > > >>>>>>>>>>> CPU: 0 PID: 0 Comm: swapper Not tainted 6.5.0 #101
> > > >>>>>>>>>>> Hardware name: Pliops Spider MK-I EVK (DT)
> > > >>>>>>>>>>> Call trace:
> > > >>>>>>>>>>> dump_backtrace+0x9c/0xd0
> > > >>>>>>>>>>> show_stack+0x14/0x1c
> > > >>>>>>>>>>> dump_stack_lvl+0x44/0x58
> > > >>>>>>>>>>> dump_stack+0x14/0x1c
> > > >>>>>>>>>>> panic+0x2e0/0x33c
> > > >>>>>>>>>>> nmi_panic+0x68/0x6c
> > > >>>>>>>>>>> arm64_serror_panic+0x68/0x78
> > > >>>>>>>>>>> do_serror+0x24/0x54
> > > >>>>>>>>>>> el1h_64_error_handler+0x2c/0x40
> > > >>>>>>>>>>> el1h_64_error+0x64/0x68
> > > >>>>>>>>>>> setup_arch+0x13c/0x5ac
> > > >>>>>>>>>>> start_kernel+0x5c/0x5b8
> > > >>>>>>>>>>> __primary_switched+0xb4/0xbc
> > > >>>>>>>>>>> 0---[ end Kernel panic - not syncing: Asynchronous SError
> > > Interrupt ]---
> > > >>>>>>>>>>>
> > > >>>>>>>>>>> Can you please advice how to proceed with debugging?
> > > >>>>>>>>>>>
> > > >>>>>>>>>>> Thanks in advanced,
> > > >>>>>>>>>>> Cheers,
> > > >>>>>>>>>>> Lior.
> > > >>>>>>>>>>>
> > > >>>>>>>>>>>
> > > >>>>>>>>>>
> > > >>>>>>>>>
> > > >>>>>>>
> > > >>>>>
> > > >>>>
> > > >>>
> > > >>> --
> > > >>> DENX Software Engineering GmbH, Managing Director: Erika Unter
> > > >>> HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell,
> > Germany
> > > >>> Phone: +49-8142-66989-52 Fax: +49-8142-66989-80 Email:
> > > hs@denx.de
> > > >
> > >
> > > --
> > > DENX Software Engineering GmbH, Managing Director: Erika Unter
> > > HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany
> > > Phone: +49-8142-66989-52 Fax: +49-8142-66989-80 Email:
> hs@denx.de
^ permalink raw reply [flat|nested] 16+ messages in thread
end of thread, other threads:[~2023-12-26 7:48 UTC | newest]
Thread overview: 16+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2023-12-17 21:32 Debugging early SError exception Lior Weintraub
2023-12-19 7:09 ` Dirk Behme
2023-12-19 13:23 ` Lior Weintraub
2023-12-19 13:37 ` Dirk Behme
2023-12-21 7:43 ` Lior Weintraub
2023-12-21 8:29 ` Dirk Behme
2023-12-21 10:04 ` Lior Weintraub
2023-12-21 11:19 ` Dirk Behme
2023-12-21 11:36 ` Heiko Schocher
2023-12-21 12:04 ` Lior Weintraub
2023-12-22 7:03 ` Lior Weintraub
2023-12-22 7:48 ` Dirk Behme
2023-12-22 8:04 ` Heiko Schocher
2023-12-24 15:41 ` Lior Weintraub
2023-12-24 19:12 ` Lior Weintraub
2023-12-26 7:48 ` Lior Weintraub
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