[PATCH] Kconfig: Set STACK_SIZE to 16KB for STM32 MCUs

[Patrick DELAUNAY]

Hi

On 12/18/24 08:58, Patrice Chotard wrote:
> Since commit 6534d26ee9a5 ("lmb: do away with arch_lmb_reserve()"),
> STM32F746-disco hangs when loading device tree just before starting
> kernel:
>
> Retrieving file: /stm32f746-disco.dtb
> Kernel image @ 0xc0008000 [ 0x000000 - 0x19ae00 ]
> Flattened Device Tree blob at c0408000
>     Booting using the fdt blob at 0xc0408000
> Working FDT set to c0408000
>     Loading Device Tree to c05f8000, end c05ff71c ...
>
> Adjust STACK_SIZE to 16KB for STM32 MCUs (F4/F7 and H7) boards
> to fix kernel boot process as some of these boards embeds a limited
> amount of memory.
>
> Fixes: 6534d26ee9a5 ("lmb: do away with arch_lmb_reserve()")


I think it is also linked to an other commit

Fixes:74b869bae74c ("efi_loader: use CONFIG_STACK_SIZE in the UEFI sub-system")

before the patch CONFIG_SET_STACK_SIZE was not defined for ALL ARM platform

So CONFIG_STACK_SIZE was not defined  / and was no used in platform

(U-Boot stack up to end of the U-Boot area)

after the patch the CONFIG_STACK_SIZEis set a 16MB for all platform, 
even if EFI is not used


+config STACK_SIZE
+    hex "Define max stack size that can be used by U-Boot"

+    default 0x4000000 if ARCH_VERSAL || ARCH_ZYNQMP
+    default 0x200000 if MICROBLAZE
+    default 0x1000000


16MB is needed ONLY for EFI loader cases, for other platform that seems 
huge.


@Heinrich: do you think you can add this condition CONFIG_EFI_LOADER to 
avoid issue for other platforms =

So use 16MB (previously hardcoded in lib/efi_loader/efi_memory.c with 
add_u_boot_and_runtime() )

     default 0x1000000 if EFI_LOADER


and so force the other platforms to define the CONFIG_STACK_SIZE (now 
used in LMB) with an adequate value ?


>
> Signed-off-by: Patrice Chotard <patrice.chotard at foss.st.com>
> ---
>
>   Kconfig | 1 +
>   1 file changed, 1 insertion(+)
>
> diff --git a/Kconfig b/Kconfig
> index 1f5b0f1972d..c087a420a24 100644
> --- a/Kconfig
> +++ b/Kconfig
> @@ -578,6 +578,7 @@ config STACK_SIZE
>   	hex "Define max stack size that can be used by U-Boot"
>   	default 0x4000000 if ARCH_VERSAL_NET || ARCH_VERSAL || ARCH_ZYNQMP
>   	default 0x200000 if MICROBLAZE
> +	default 0x4000 if ARCH_STM32
>   	default 0x1000000
>   	help
>   	  Define Max stack size that can be used by U-Boot. This value is used


Anyway for this STM32 MCU patch:


Reviewed-by: Patrick Delaunay <patrick.delaunay at foss.st.com>

Thanks
Patrick