STACK_SIZE pcengines apu1

[Maxime de Roucy]

Hello,

I am building a coreboot rom for my pcengines apu1.
A bug is logged during the boot process :
http://review.coreboot.org/gitweb?p=board-status.git;a=blob;f=pcengines/apu1...

In order to solve it I applied this changed :

diff --git a/src/Kconfig b/src/Kconfig
    index 9c01687..c8b8ad2 100644
    --- a/src/Kconfig
    +++ b/src/Kconfig
    @@ -427,7 +427,7 @@ config HEAP_SIZE
     config STACK_SIZE
            hex
            default 0x0 if (ARCH_RAMSTAGE_ARM || ARCH_RAMSTAGE_MIPS || ARCH_RAMSTAGE_RISCV)
    -       default 0x1000
    +       default 0x2000

config MAX_CPUS
            int

I don't see the bug line anymore, instead I see :

CPU0: stack: 00148000 - 0014a000, lowest used address 00148d34, stack used: 4812 bytes

I now the patch is not good since it change the default stack size for
all the boards. I didn't found the right place the change the stack
size only for pcengines apu1 board.
But maybe those informations can help developers to improve coreboot.

[Aaron Durbin]

On Sun, Sep 6, 2015 at 9:10 AM, Maxime de Roucy
 wrote:
> Hello,
>
> I am building a coreboot rom for my pcengines apu1.
> A bug is logged during the boot process :
> http://review.coreboot.org/gitweb?p=board-status.git;a=blob;f=pcengines/apu1...
>
> In order to solve it I applied this changed :
> diff --git a/src/Kconfig b/src/Kconfig
> index 9c01687..c8b8ad2 100644
> --- a/src/Kconfig
> +++ b/src/Kconfig
> @@ -427,7 +427,7 @@ config HEAP_SIZE
>  config STACK_SIZE
>         hex
>         default 0x0 if (ARCH_RAMSTAGE_ARM || ARCH_RAMSTAGE_MIPS || ARCH_RAMSTAGE_RISCV)
> -       default 0x1000
> +       default 0x2000
>
>  config MAX_CPUS
>         int
>
> I don't see the bug line anymore, instead I see :
> CPU0: stack: 00148000 - 0014a000, lowest used address 00148d34, stack used: 4812 bytes
>
> I now the patch is not good since it change the default stack size for
> all the boards. I didn't found the right place the change the stack
> size only for pcengines apu1 board.
> But maybe those informations can help developers to improve coreboot.

That's quite the stack usage.  It'd be interesting to know what's
using all that stack. Could you apply this patch and run w/ it? It'd
help narrow down at what point in the boot where the stack gets used
up. Also, that you used 4812 bytes just means you overwrote the other
CPU's stack at some point when STACK_SIZE == 4KiB.

diff --git a/src/lib/hardwaremain.c b/src/lib/hardwaremain.c
index b3c0c35..8a241b2 100644
--- a/src/lib/hardwaremain.c
+++ b/src/lib/hardwaremain.c
@@ -378,6 +378,8 @@ static void bs_walk_state_machine(void)
                bs_report_time(state);

state->complete = 1;
+
+               checkstack(_estack, 0);
        }
 }
>