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* [PATCH] arm: bootm: Disable LMB reservation for command line and board info on arm64
@ 2021-05-29 11:34 Marek Vasut
  2021-07-10  1:08 ` Tom Rini
  2021-07-20  9:08 ` Jan Kiszka
  0 siblings, 2 replies; 6+ messages in thread
From: Marek Vasut @ 2021-05-29 11:34 UTC (permalink / raw)
  To: u-boot; +Cc: Marek Vasut, Hai Pham, Simon Goldschmidt, Stephen Warren, Tom Rini

On arm64, board info is not applicable and kernel command line patched into
the DT, so the LMB reservation here makes no sense anymore. On legacy arm32,
this might still be necessary on systems which do not use DT or use legacy
ATAGS. Disable this LMB reservation on arm64.

This also permits Linux DT to specify reserved memory node at address close
to the end of DRAM bank, i.e. overlaping with U-Boot location. Since after
boot, U-Boot will be no more, this is OK.

Signed-off-by: Marek Vasut <marek.vasut+renesas@gmail.com>
Cc: Hai Pham <hai.pham.ud@renesas.com>
Cc: Simon Goldschmidt <simon.k.r.goldschmidt@gmail.com>
Cc: Stephen Warren <swarren@nvidia.com>
Cc: Tom Rini <trini@konsulko.com>
---
 arch/arm/lib/bootm.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/arch/arm/lib/bootm.c b/arch/arm/lib/bootm.c
index f60ee3a7e6..23b99a541c 100644
--- a/arch/arm/lib/bootm.c
+++ b/arch/arm/lib/bootm.c
@@ -43,6 +43,7 @@ DECLARE_GLOBAL_DATA_PTR;
 
 static struct tag *params;
 
+#ifndef CONFIG_ARM64
 static ulong get_sp(void)
 {
 	ulong ret;
@@ -86,6 +87,7 @@ void arch_lmb_reserve(struct lmb *lmb)
 		break;
 	}
 }
+#endif
 
 __weak void board_quiesce_devices(void)
 {
-- 
2.30.2


^ permalink raw reply related	[flat|nested] 6+ messages in thread

* Re: [PATCH] arm: bootm: Disable LMB reservation for command line and board info on arm64
  2021-05-29 11:34 [PATCH] arm: bootm: Disable LMB reservation for command line and board info on arm64 Marek Vasut
@ 2021-07-10  1:08 ` Tom Rini
  2021-07-20  9:08 ` Jan Kiszka
  1 sibling, 0 replies; 6+ messages in thread
From: Tom Rini @ 2021-07-10  1:08 UTC (permalink / raw)
  To: Marek Vasut
  Cc: u-boot, Marek Vasut, Hai Pham, Simon Goldschmidt, Stephen Warren

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On Sat, May 29, 2021 at 01:34:32PM +0200, Marek Vasut wrote:

> On arm64, board info is not applicable and kernel command line patched into
> the DT, so the LMB reservation here makes no sense anymore. On legacy arm32,
> this might still be necessary on systems which do not use DT or use legacy
> ATAGS. Disable this LMB reservation on arm64.
> 
> This also permits Linux DT to specify reserved memory node at address close
> to the end of DRAM bank, i.e. overlaping with U-Boot location. Since after
> boot, U-Boot will be no more, this is OK.
> 
> Signed-off-by: Marek Vasut <marek.vasut+renesas@gmail.com>
> Cc: Hai Pham <hai.pham.ud@renesas.com>
> Cc: Simon Goldschmidt <simon.k.r.goldschmidt@gmail.com>
> Cc: Stephen Warren <swarren@nvidia.com>
> Cc: Tom Rini <trini@konsulko.com>

Applied to u-boot/master, thanks!

-- 
Tom

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^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: [PATCH] arm: bootm: Disable LMB reservation for command line and board info on arm64
  2021-05-29 11:34 [PATCH] arm: bootm: Disable LMB reservation for command line and board info on arm64 Marek Vasut
  2021-07-10  1:08 ` Tom Rini
@ 2021-07-20  9:08 ` Jan Kiszka
  2021-07-20 23:34   ` Marek Vasut
  1 sibling, 1 reply; 6+ messages in thread
From: Jan Kiszka @ 2021-07-20  9:08 UTC (permalink / raw)
  To: Marek Vasut, u-boot
  Cc: Marek Vasut, Hai Pham, Simon Goldschmidt, Stephen Warren,
	Tom Rini, Lokesh Vutla

On 29.05.21 13:34, Marek Vasut wrote:
> On arm64, board info is not applicable and kernel command line patched into
> the DT, so the LMB reservation here makes no sense anymore. On legacy arm32,
> this might still be necessary on systems which do not use DT or use legacy
> ATAGS. Disable this LMB reservation on arm64.
> 
> This also permits Linux DT to specify reserved memory node at address close
> to the end of DRAM bank, i.e. overlaping with U-Boot location. Since after
> boot, U-Boot will be no more, this is OK.
> 
> Signed-off-by: Marek Vasut <marek.vasut+renesas@gmail.com>
> Cc: Hai Pham <hai.pham.ud@renesas.com>
> Cc: Simon Goldschmidt <simon.k.r.goldschmidt@gmail.com>
> Cc: Stephen Warren <swarren@nvidia.com>
> Cc: Tom Rini <trini@konsulko.com>
> ---
>  arch/arm/lib/bootm.c | 2 ++
>  1 file changed, 2 insertions(+)
> 
> diff --git a/arch/arm/lib/bootm.c b/arch/arm/lib/bootm.c
> index f60ee3a7e6..23b99a541c 100644
> --- a/arch/arm/lib/bootm.c
> +++ b/arch/arm/lib/bootm.c
> @@ -43,6 +43,7 @@ DECLARE_GLOBAL_DATA_PTR;
>  
>  static struct tag *params;
>  
> +#ifndef CONFIG_ARM64
>  static ulong get_sp(void)
>  {
>  	ulong ret;
> @@ -86,6 +87,7 @@ void arch_lmb_reserve(struct lmb *lmb)
>  		break;
>  	}
>  }
> +#endif
>  
>  __weak void board_quiesce_devices(void)
>  {
> 
This causes troubles for [1], but I have no clue yet, what is happening. 
Without the patch, we start like this:

Found U-Boot script /boot/boot.scr
889 bytes read in 21 ms (41 KiB/s)
## Executing script at 83000000
Loading /usr/lib/linux-image-4.19.94/ti/k3-am6548-iot2050-advanced.dtb...
78306 bytes read in 25 ms (3 MiB/s)
Loading /boot/vmlinux-4.19.94...
13537288 bytes read in 107 ms (120.7 MiB/s)
## Flattened Device Tree blob at 82000000
   Booting using the fdt blob at 0x82000000
   Loading Device Tree to 00000000fdefa000, end 00000000fdf101e1 ... OK

Starting kernel ...


With the patch applied, I'm getting stuck like this:

Found U-Boot script /boot/boot.scr
889 bytes read in 21 ms (41 KiB/s)
## Executing script at 83000000
Loading /usr/lib/linux-image-4.19.94/ti/k3-am6548-iot2050-advanced.dtb...
78306 bytes read in 25 ms (3 MiB/s)
Loading /boot/vmlinux-4.19.94...
13537288 bytes read in 109 ms (118.4 MiB/s)
## Flattened Device Tree blob at 82000000
   Booting using the fdt blob at 0x82000000
   Loading Device Tree to 00000000fffe9000, end 00000000fffff1e1 ...


Obviously, the DT target adress changed, possibly to an 
unsupported/reserved address. But I do not understand the mechanics 
behind all this yet. Any hints welcome on what goes wrong here and 
whether something needs to be adjusted in our board settings.

Thanks,
Jan

[1] https://patchwork.ozlabs.org/project/uboot/list/?series=248449&state=*

-- 
Siemens AG, T RDA IOT
Corporate Competence Center Embedded Linux

^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: [PATCH] arm: bootm: Disable LMB reservation for command line and board info on arm64
  2021-07-20  9:08 ` Jan Kiszka
@ 2021-07-20 23:34   ` Marek Vasut
  2021-07-21  6:08     ` Jan Kiszka
  0 siblings, 1 reply; 6+ messages in thread
From: Marek Vasut @ 2021-07-20 23:34 UTC (permalink / raw)
  To: Jan Kiszka, u-boot
  Cc: Hai Pham, Simon Goldschmidt, Stephen Warren, Tom Rini, Lokesh Vutla

On 7/20/21 11:08 AM, Jan Kiszka wrote:
[...]
>> diff --git a/arch/arm/lib/bootm.c b/arch/arm/lib/bootm.c
>> index f60ee3a7e6..23b99a541c 100644
>> --- a/arch/arm/lib/bootm.c
>> +++ b/arch/arm/lib/bootm.c
>> @@ -43,6 +43,7 @@ DECLARE_GLOBAL_DATA_PTR;
>>   
>>   static struct tag *params;
>>   
>> +#ifndef CONFIG_ARM64
>>   static ulong get_sp(void)
>>   {
>>   	ulong ret;
>> @@ -86,6 +87,7 @@ void arch_lmb_reserve(struct lmb *lmb)
>>   		break;
>>   	}
>>   }
>> +#endif
>>   
>>   __weak void board_quiesce_devices(void)
>>   {
>>
> This causes troubles for [1], but I have no clue yet, what is happening.
> Without the patch, we start like this:
> 
> Found U-Boot script /boot/boot.scr
> 889 bytes read in 21 ms (41 KiB/s)
> ## Executing script at 83000000
> Loading /usr/lib/linux-image-4.19.94/ti/k3-am6548-iot2050-advanced.dtb...
> 78306 bytes read in 25 ms (3 MiB/s)
> Loading /boot/vmlinux-4.19.94...
> 13537288 bytes read in 107 ms (120.7 MiB/s)
> ## Flattened Device Tree blob at 82000000
>     Booting using the fdt blob at 0x82000000
>     Loading Device Tree to 00000000fdefa000, end 00000000fdf101e1 ... OK
> 
> Starting kernel ...
> 
> 
> With the patch applied, I'm getting stuck like this:
> 
> Found U-Boot script /boot/boot.scr
> 889 bytes read in 21 ms (41 KiB/s)
> ## Executing script at 83000000
> Loading /usr/lib/linux-image-4.19.94/ti/k3-am6548-iot2050-advanced.dtb...
> 78306 bytes read in 25 ms (3 MiB/s)
> Loading /boot/vmlinux-4.19.94...
> 13537288 bytes read in 109 ms (118.4 MiB/s)
> ## Flattened Device Tree blob at 82000000
>     Booting using the fdt blob at 0x82000000
>     Loading Device Tree to 00000000fffe9000, end 00000000fffff1e1 ...
> 
> 
> Obviously, the DT target adress changed, possibly to an
> unsupported/reserved address. But I do not understand the mechanics
> behind all this yet. Any hints welcome on what goes wrong here and
> whether something needs to be adjusted in our board settings.

Can you share the output of bdinfo on this board ?

^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: [PATCH] arm: bootm: Disable LMB reservation for command line and board info on arm64
  2021-07-20 23:34   ` Marek Vasut
@ 2021-07-21  6:08     ` Jan Kiszka
  2021-07-28 22:09       ` Jan Kiszka
  0 siblings, 1 reply; 6+ messages in thread
From: Jan Kiszka @ 2021-07-21  6:08 UTC (permalink / raw)
  To: Marek Vasut, u-boot, Lokesh Vutla
  Cc: Hai Pham, Simon Goldschmidt, Stephen Warren, Tom Rini

On 21.07.21 01:34, Marek Vasut wrote:
> On 7/20/21 11:08 AM, Jan Kiszka wrote:
> [...]
>>> diff --git a/arch/arm/lib/bootm.c b/arch/arm/lib/bootm.c
>>> index f60ee3a7e6..23b99a541c 100644
>>> --- a/arch/arm/lib/bootm.c
>>> +++ b/arch/arm/lib/bootm.c
>>> @@ -43,6 +43,7 @@ DECLARE_GLOBAL_DATA_PTR;
>>>     static struct tag *params;
>>>   +#ifndef CONFIG_ARM64
>>>   static ulong get_sp(void)
>>>   {
>>>       ulong ret;
>>> @@ -86,6 +87,7 @@ void arch_lmb_reserve(struct lmb *lmb)
>>>           break;
>>>       }
>>>   }
>>> +#endif
>>>     __weak void board_quiesce_devices(void)
>>>   {
>>>
>> This causes troubles for [1], but I have no clue yet, what is happening.
>> Without the patch, we start like this:
>>
>> Found U-Boot script /boot/boot.scr
>> 889 bytes read in 21 ms (41 KiB/s)
>> ## Executing script at 83000000
>> Loading /usr/lib/linux-image-4.19.94/ti/k3-am6548-iot2050-advanced.dtb...
>> 78306 bytes read in 25 ms (3 MiB/s)
>> Loading /boot/vmlinux-4.19.94...
>> 13537288 bytes read in 107 ms (120.7 MiB/s)
>> ## Flattened Device Tree blob at 82000000
>>     Booting using the fdt blob at 0x82000000
>>     Loading Device Tree to 00000000fdefa000, end 00000000fdf101e1 ... OK
>>
>> Starting kernel ...
>>
>>
>> With the patch applied, I'm getting stuck like this:
>>
>> Found U-Boot script /boot/boot.scr
>> 889 bytes read in 21 ms (41 KiB/s)
>> ## Executing script at 83000000
>> Loading /usr/lib/linux-image-4.19.94/ti/k3-am6548-iot2050-advanced.dtb...
>> 78306 bytes read in 25 ms (3 MiB/s)
>> Loading /boot/vmlinux-4.19.94...
>> 13537288 bytes read in 109 ms (118.4 MiB/s)
>> ## Flattened Device Tree blob at 82000000
>>     Booting using the fdt blob at 0x82000000
>>     Loading Device Tree to 00000000fffe9000, end 00000000fffff1e1 ...
>>
>>
>> Obviously, the DT target adress changed, possibly to an
>> unsupported/reserved address. But I do not understand the mechanics
>> behind all this yet. Any hints welcome on what goes wrong here and
>> whether something needs to be adjusted in our board settings.
> 
> Can you share the output of bdinfo on this board ?

Sure (with your commit reverted for now):

IOT2050> bdinfo
boot_params = 0x0000000000000000
DRAM bank   = 0x0000000000000000
-> start    = 0x0000000080000000
-> size     = 0x0000000080000000
flashstart  = 0x0000000000000000
flashsize   = 0x0000000000000000
flashoffset = 0x0000000000000000
baudrate    = 115200 bps
relocaddr   = 0x00000000fff2d000
reloc off   = 0x000000007f72d000
Build       = 64-bit
current eth = unknown
ethaddr     = 70:77:77:77:57:70
IP addr     = <NULL>
fdt_blob    = 0x00000000fdef9f10
new_fdt     = 0x00000000fdef9f10
fdt_size    = 0x0000000000012ea0
lmb_dump_all:
 memory.cnt  = 0x1
 memory[0]      [0x80000000-0xffffffff], 0x80000000 bytes flags: 0
 reserved.cnt  = 0x2
 reserved[0]    [0x9e800000-0xa21fffff], 0x03a00000 bytes flags: 4
 reserved[1]    [0xfdef86c0-0xffffffff], 0x02107940 bytes flags: 0
arch_number = 0x0000000000000000
TLB addr    = 0x00000000ffff0000
irq_sp      = 0x00000000fdef9b20
sp start    = 0x00000000fdef9b20
Early malloc usage: 23c8 / 8000


There is some "TLB" block apparently overlapping when we move the DT.
What's this? Looking at the code, not a TLB with the usual meaning but
rather the page table U-Boot uses for itself, right?

Were we just lucky so far with side effects of the LMB reservation on
this platform (and I suspect that it affect k3 in general, not only our
board)?

Thanks,
Jan

-- 
Siemens AG, T RDA IOT
Corporate Competence Center Embedded Linux

^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: [PATCH] arm: bootm: Disable LMB reservation for command line and board info on arm64
  2021-07-21  6:08     ` Jan Kiszka
@ 2021-07-28 22:09       ` Jan Kiszka
  0 siblings, 0 replies; 6+ messages in thread
From: Jan Kiszka @ 2021-07-28 22:09 UTC (permalink / raw)
  To: u-boot, Lokesh Vutla
  Cc: Hai Pham, Simon Goldschmidt, Stephen Warren, Tom Rini, Marek Vasut

On 21.07.21 08:08, Jan Kiszka wrote:
> On 21.07.21 01:34, Marek Vasut wrote:
>> On 7/20/21 11:08 AM, Jan Kiszka wrote:
>> [...]
>>>> diff --git a/arch/arm/lib/bootm.c b/arch/arm/lib/bootm.c
>>>> index f60ee3a7e6..23b99a541c 100644
>>>> --- a/arch/arm/lib/bootm.c
>>>> +++ b/arch/arm/lib/bootm.c
>>>> @@ -43,6 +43,7 @@ DECLARE_GLOBAL_DATA_PTR;
>>>>     static struct tag *params;
>>>>   +#ifndef CONFIG_ARM64
>>>>   static ulong get_sp(void)
>>>>   {
>>>>       ulong ret;
>>>> @@ -86,6 +87,7 @@ void arch_lmb_reserve(struct lmb *lmb)
>>>>           break;
>>>>       }
>>>>   }
>>>> +#endif
>>>>     __weak void board_quiesce_devices(void)
>>>>   {
>>>>
>>> This causes troubles for [1], but I have no clue yet, what is happening.
>>> Without the patch, we start like this:
>>>
>>> Found U-Boot script /boot/boot.scr
>>> 889 bytes read in 21 ms (41 KiB/s)
>>> ## Executing script at 83000000
>>> Loading /usr/lib/linux-image-4.19.94/ti/k3-am6548-iot2050-advanced.dtb...
>>> 78306 bytes read in 25 ms (3 MiB/s)
>>> Loading /boot/vmlinux-4.19.94...
>>> 13537288 bytes read in 107 ms (120.7 MiB/s)
>>> ## Flattened Device Tree blob at 82000000
>>>     Booting using the fdt blob at 0x82000000
>>>     Loading Device Tree to 00000000fdefa000, end 00000000fdf101e1 ... OK
>>>
>>> Starting kernel ...
>>>
>>>
>>> With the patch applied, I'm getting stuck like this:
>>>
>>> Found U-Boot script /boot/boot.scr
>>> 889 bytes read in 21 ms (41 KiB/s)
>>> ## Executing script at 83000000
>>> Loading /usr/lib/linux-image-4.19.94/ti/k3-am6548-iot2050-advanced.dtb...
>>> 78306 bytes read in 25 ms (3 MiB/s)
>>> Loading /boot/vmlinux-4.19.94...
>>> 13537288 bytes read in 109 ms (118.4 MiB/s)
>>> ## Flattened Device Tree blob at 82000000
>>>     Booting using the fdt blob at 0x82000000
>>>     Loading Device Tree to 00000000fffe9000, end 00000000fffff1e1 ...
>>>
>>>
>>> Obviously, the DT target adress changed, possibly to an
>>> unsupported/reserved address. But I do not understand the mechanics
>>> behind all this yet. Any hints welcome on what goes wrong here and
>>> whether something needs to be adjusted in our board settings.
>>
>> Can you share the output of bdinfo on this board ?
> 
> Sure (with your commit reverted for now):
> 
> IOT2050> bdinfo
> boot_params = 0x0000000000000000
> DRAM bank   = 0x0000000000000000
> -> start    = 0x0000000080000000
> -> size     = 0x0000000080000000
> flashstart  = 0x0000000000000000
> flashsize   = 0x0000000000000000
> flashoffset = 0x0000000000000000
> baudrate    = 115200 bps
> relocaddr   = 0x00000000fff2d000
> reloc off   = 0x000000007f72d000
> Build       = 64-bit
> current eth = unknown
> ethaddr     = 70:77:77:77:57:70
> IP addr     = <NULL>
> fdt_blob    = 0x00000000fdef9f10
> new_fdt     = 0x00000000fdef9f10
> fdt_size    = 0x0000000000012ea0
> lmb_dump_all:
>  memory.cnt  = 0x1
>  memory[0]      [0x80000000-0xffffffff], 0x80000000 bytes flags: 0
>  reserved.cnt  = 0x2
>  reserved[0]    [0x9e800000-0xa21fffff], 0x03a00000 bytes flags: 4
>  reserved[1]    [0xfdef86c0-0xffffffff], 0x02107940 bytes flags: 0
> arch_number = 0x0000000000000000
> TLB addr    = 0x00000000ffff0000
> irq_sp      = 0x00000000fdef9b20
> sp start    = 0x00000000fdef9b20
> Early malloc usage: 23c8 / 8000
> 
> 
> There is some "TLB" block apparently overlapping when we move the DT.
> What's this? Looking at the code, not a TLB with the usual meaning but
> rather the page table U-Boot uses for itself, right?
> 
> Were we just lucky so far with side effects of the LMB reservation on
> this platform (and I suspect that it affect k3 in general, not only our
> board)?
> 

Just rebased over master, kept Marek's change, and rerun bdinfo:

IOT2050> bdinfo
boot_params = 0x0000000000000000
DRAM bank   = 0x0000000000000000
-> start    = 0x0000000080000000
-> size     = 0x0000000040000000
flashstart  = 0x0000000000000000
flashsize   = 0x0000000000000000
flashoffset = 0x0000000000000000
baudrate    = 115200 bps
relocaddr   = 0x00000000bff41000
reloc off   = 0x000000003f741000
Build       = 64-bit
fdt_blob    = 0x00000000bdf0d750
new_fdt     = 0x00000000bdf0d750
fdt_size    = 0x0000000000013660
lmb_dump_all:
 memory.cnt  = 0x1
 memory[0]      [0x80000000-0xbfffffff], 0x40000000 bytes flags: 0
 reserved.cnt  = 0x1
 reserved[0]    [0x9e800000-0xa21fffff], 0x03a00000 bytes flags: 4
arch_number = 0x0000000000000000
TLB addr    = 0x00000000bfff0000
irq_sp      = 0x00000000bdf0d360
sp start    = 0x00000000bdf0d360
Early malloc usage: 23c8 / 8000
IOT2050> boot
switch to partitions #0, OK
mmc0 is current device
Scanning mmc 0:1...
Found U-Boot script /boot/boot.scr
911 bytes read in 28 ms (31.3 KiB/s)
## Executing script at 83000000
Loading /usr/lib/linux-image-4.19.94/ti/k3-am6528-iot2050-basic.dtb...
77409 bytes read in 34 ms (2.2 MiB/s)
Loading /boot/vmlinux-4.19.94...
13537288 bytes read in 587 ms (22 MiB/s)
## Flattened Device Tree blob at 82000000
   Booting using the fdt blob at 0x82000000
   Loading Device Tree to 00000000bffea000, end 00000000bffffe60 ...


From that, I would definitely say that the fdt is loaded into the TLB
area, and that is likely the page table still in use at this stage.

Lokesh, Marek is overly busy and asked me to debug this further. But I
would need some indication if my interpretations are right and some hint
what is supposed to protect the TLB range from being used by other
things. And if that protection would be generic or board-specific.

I've checked the AM65x-SR1.0 EVM I have here, and I can see there as
well that mmu_setup() of U-Boot proper works with the same address range
the that boot_relocate_fdt() will later overwrite. It looks to me like
TLBs (the actual ones) are protecting us in some cases from the
consequences, at least on the EVM, not on our boards. Soon after the
overwriting, dcache and mmu will be turned off anyway for Linux.

Thanks,
Jan

-- 
Siemens AG, T RDA IOT
Corporate Competence Center Embedded Linux

^ permalink raw reply	[flat|nested] 6+ messages in thread

end of thread, other threads:[~2021-07-28 22:09 UTC | newest]

Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2021-05-29 11:34 [PATCH] arm: bootm: Disable LMB reservation for command line and board info on arm64 Marek Vasut
2021-07-10  1:08 ` Tom Rini
2021-07-20  9:08 ` Jan Kiszka
2021-07-20 23:34   ` Marek Vasut
2021-07-21  6:08     ` Jan Kiszka
2021-07-28 22:09       ` Jan Kiszka

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