Thanks All

I will try the patch suggested by Julien and update you.

As of now I am running dom0(Linux 4.11-rc5) without early printk enabled in
xen which is working absolutely fine.


On Wed, Apr 5, 2017 at 2:32 AM, Julien Grall <julien.grall@arm.com> wrote:

> Hi,
>
> On 04/04/2017 21:45, Stefano Stabellini wrote:
> > On Tue, 4 Apr 2017, Andre Przywara wrote:
> >> Hi,
> >>
> >> On 04/04/17 20:02, Stefano Stabellini wrote:
> >>> Also CC'ing Andre that I think has a pine64.
> >>>
> >>> On Tue, 4 Apr 2017, Stefano Stabellini wrote:
> >>>> On Sat, 1 Apr 2017, bharat gohil wrote:
> >>>>> Hello
> >>>>
> >>>> Hello Bharat, thanks for your email.
> >>>>
> >>>>
> >>>>> I am trying to boot xen(debug build) on pine64 ARM64 based board but
> its hangs at following position,
> >>>>>
> >>>>> - UART enabled -
> >>>>> - CPU 00000000 booting -
> >>>>> - Current EL 00000008 -
> >>>>> - Xen starting at EL2 -
> >>>>> - Zero BSS -
> >>>>> - Setting up control registers -
> >>>>> - Turning on paging -
> >>>>> - Ready -
> >>>>> (XEN) Checking for initrd in /chosen
> >>>>> (XEN) RAM: 0000000041000000 - 000000007fffffff
> >>>>> (XEN)
> >>>>> (XEN) MODULE[0]: 000000007e200000 - 000000007e202000 Device Tree
> >>>>> (XEN) MODULE[1]: 000000007e400000 - 000000007ef46a00 Kernel
>  console=hvc0 ro root=/dev/mmcblk0p2 clk_ignore_unused rootwait
> >>>>> (XEN)  RESVD[0]: 000000007e200000 - 000000007e202000
> >>>>> (XEN)
> >>>>> (XEN) Command line: dtuart=serial0 earlyprint loglvl=all conswitch=x
> dom0_mem=128M
> >>>>> (XEN) Placing Xen at 0x000000007fc00000-0x000000007fe00000
> >>>>> (XEN) Update BOOTMOD_XEN from 000000007fe00000-000000007fefad81 =>
> 000000007fc00000-000000007fcfad81
> >>>>> (XEN) Booting using Device Tree
> >>>>> (XEN) Domain heap initialised
> >>>>> (XEN) Platform: Generic System
> >>>>> (XEN) Looking for dtuart at "serial0", options ""
> >>>>>  Xen 4.9-unstable
> >>>>> (XEN) Xen version 4.9-unstable (bgohil@) (aarch64-linux-gnu-gcc
> (Linaro GCC 6.2-2016.11) 6.2.1 20161016) debug=n  Tue Mar 28 16:12:32 IST
> 2017
> >>>>> (XEN) Latest ChangeSet: Fri Mar 24 14:19:47 2017 +0100 git:5b08f85
> >>>>> (XEN) Processor: 410fd034: "ARM Limited", variant: 0x0, part 0xd03,
> rev 0x4
> >>>>> (XEN) 64-bit Execution:
> >>>>> (XEN)   Processor Features: 0000000000002222 0000000000000000
> >>>>> (XEN)     Exception Levels: EL3:64+32 EL2:64+32 EL1:64+32 EL0:64+32
> >>>>> (XEN)     Extensions: FloatingPoint AdvancedSIMD
> >>>>> (XEN)   Debug Features: 0000000010305106 0000000000000000
> >>>>> (XEN)   Auxiliary Features: 0000000000000000 0000000000000000
> >>>>> (XEN)   Memory Model Features: 0000000000001122 0000000000000000
> >>>>> (XEN)   ISA Features:  0000000000011120 0000000000000000
> >>>>> (XEN) 32-bit Execution:
> >>>>> (XEN)   Processor Features: 00000131:00011011
> >>>>> (XEN)     Instruction Sets: AArch32 A32 Thumb Thumb-2 Jazelle
> >>>>> (XEN)     Extensions: GenericTimer Security
> >>>>> (XEN)   Debug Features: 03010066
> >>>>> (XEN)   Auxiliary Features: 00000000
> >>>>> (XEN)   Memory Model Features: 10201105 40000000 01260000 02102211
> >>>>> (XEN)  ISA Features: 02101110 13112111 21232042 01112131 00011142
> 00011121
> >>>>> (XEN) Using PSCI-0.2 for SMP bringup
> >>>>> (XEN) SMP: Allowing 4 CPUs
> >>>>> (XEN) Generic Timer IRQ: phys=30 hyp=26 virt=27 Freq: 24000 KHz
> >>>>> (XEN) GICv2 initialization:
> >>>>> (XEN)         gic_dist_addr=0000000001c81000
> >>>>> (XEN)         gic_cpu_addr=0000000001c82000
> >>>>> (XEN)         gic_hyp_addr=0000000001c84000
> >>>>> (XEN)         gic_vcpu_addr=0000000001c86000
> >>>>> (XEN)         gic_maintenance_irq=25
> >>>>> (XEN) GICv2: 224 lines, 4 cpus, secure (IID 0200143b).
> >>>>> (XEN) Using scheduler: SMP Credit Scheduler (credit)
> >>>>>
> >>>>> but when I boot dtuart=<unknown value> say duart=xyz instead of
> dtuart=serial0, xen booted successfully but Dom0 crash while probing
> 'serial0' driver.
> >>>>>
> >>>>> If I remove 'serial0' node from device tree, Dom0 boot successfully
> but unable to enter input into 'hvc' console.
> >>>>>
> >>>>> what could be wrong here or missing something?
> >>>>
> >>>> What is your dom0 command line? Are you passing console=hvc0?
> >>>>
> >>>> It looks like pine64 is using an allwinner sun50i-uart, for which we
> >>>> don't have a proper driver in Xen yet. That is probably the reason why
> >>>> you can see some output from Xen, but you cannot type anything in
> later
> >>>> in Dom0 (which is sent to Xen via the HVC console).  Please send a
> patch
> >>>> to add a simple sun50i-uart driver (see xen/drivers/char/). Given that
> >>>> both Xen and Linux are GPLv2, you can import code from Linux if you
> find
> >>>> it appropriate.
> >>
> >> The UART is exactly the same as in the other Allwinner SoCs, so there is
> >> no need for a new UART driver.
> >> Another issue inherited from the 32-bit Allwinner chips is that the
> >> first four UARTs share a page, so they have to be blacklisted, as Xen
> >> can't properly separate them.
> >> You might want to look at xen/arch/arm/platforms/sunxi.c. Not sure if
> >> this needs to be tied in arm64 somehow.
> >
> > No, it doesn't, it should work on arm64 out of the box. But the platform
> > compatible string is different: "sun7i-a20" in sunxi.c and "sun50iw1p1"
> > on the pine64 dts. If the board is exactly the same, then we only need
> > to add "sun50iw1p1" to sunxi_dt_compat.
> >
> > What do you do to boot it with Xen?
>
> I played with the Pine64 and Xen last year. There are some work to do in
> order to get Xen booting on the board. It is not fully complete as I lacked
> of time. For instance the clock frequency has been hardcoded in the ns16550
> driver (the UART for pine64 is a derivation of ns16550)...
>
> Below the changes I had to made to get DOM0 booting. IIRC I was struggling
> to get the input working. The UART is the same as the cubietruck, but
> somehow it behaves differently (not sure why) and therefore there is some
> missing pieces in the driver.
>
> I hope this helps.
>
> Cheers,
>
> diff --git a/xen/arch/arm/arm64/head.S b/xen/arch/arm/arm64/head.S
> index 5c28c20..af4db28 100644
> --- a/xen/arch/arm/arm64/head.S
> +++ b/xen/arch/arm/arm64/head.S
> @@ -115,7 +115,7 @@ efi_head:
>          add     x13, x18, #0x16
>          b       real_start           /* branch to kernel start */
>          .quad   0x80000              /* Image load offset from start of
> RAM */
> -        .quad   0                    /* reserved */
> +        .quad   _end - start        /* reserved */
>          .quad   0                    /* reserved */
>          .quad   0                    /* reserved */
>          .quad   0                    /* reserved */
> diff --git a/xen/arch/arm/platforms/Makefile b/xen/arch/arm/platforms/
> Makefile
> index 3689eec..99d6ab1 100644
> --- a/xen/arch/arm/platforms/Makefile
> +++ b/xen/arch/arm/platforms/Makefile
> @@ -3,7 +3,7 @@ obj-$(CONFIG_ARM_32) += brcm.o
>  obj-$(CONFIG_ARM_32) += exynos5.o
>  obj-$(CONFIG_ARM_32) += midway.o
>  obj-$(CONFIG_ARM_32) += omap5.o
> -obj-$(CONFIG_ARM_32) += sunxi.o
> +obj-y += sunxi.o
>  obj-$(CONFIG_ARM_32) += rcar2.o
>  obj-$(CONFIG_ARM_64) += seattle.o
>  obj-$(CONFIG_ARM_64) += xgene-storm.o
> diff --git a/xen/arch/arm/platforms/sunxi.c b/xen/arch/arm/platforms/
> sunxi.c
> index 0ba7b3d..cee31c7 100644
> --- a/xen/arch/arm/platforms/sunxi.c
> +++ b/xen/arch/arm/platforms/sunxi.c
> @@ -52,6 +52,7 @@ static void sunxi_reset(void)
>  static const char * const sunxi_dt_compat[] __initconst =
>  {
>      "allwinner,sun7i-a20",
> +    "allwinner,sun50i-a64",
>      NULL
>  };
>
> diff --git a/xen/drivers/char/ns16550.c b/xen/drivers/char/ns16550.c
> index b2b5f56..9933c7e 100644
> --- a/xen/drivers/char/ns16550.c
> +++ b/xen/drivers/char/ns16550.c
> @@ -461,6 +461,8 @@ static int ns16550_ioport_invalid(struct ns16550 *uart)
>      return ns_read_reg(uart, UART_IER) == 0xff;
>  }
>
> +#include <xen/early_printk.h>
> +
>  static void ns16550_interrupt(
>      int irq, void *dev_id, struct cpu_user_regs *regs)
>  {
> @@ -476,7 +478,17 @@ static void ns16550_interrupt(
>          if ( (lsr & uart->lsr_mask) == uart->lsr_mask )
>              serial_tx_interrupt(port, regs);
>          if ( lsr & UART_LSR_DR )
> +        {
> +            early_puts("Receive data\n");
>              serial_rx_interrupt(port, regs);
> +        }
> +    }
> +
> +    if ( uart->dw_usr_bsy &&
> +         (ns_read_reg(uart, UART_IIR) & UART_IIR_BSY) == UART_IIR_BSY)
> +    {
> +        ns_read_reg(uart, UART_USR);
> +        return;
>      }
>  }
>
> @@ -1217,7 +1229,7 @@ static int __init ns16550_uart_dt_init(struct
> dt_device_node *dev,
>
>      ns16550_init_common(uart);
>
> -    uart->baud      = BAUD_AUTO;
> +    uart->baud      = 115200;
>      uart->data_bits = 8;
>      uart->parity    = UART_PARITY_NONE;
>      uart->stop_bits = 1;
>
> >
>
> --
> Julien Grall
>



-- 
Regards,
Bharat Gohil
Sr.Software Engineer
bharat.gohil@harman.com
+919427054633