[PATCH v3 3/6] arm: snapdragon: Add CONFIG_QCOM_SNAGBOOT_SUPPORT option

[Casey Connolly]

Hi Balaji,

On 16/06/2026 11:22, Balaji Selvanathan wrote:
> Add CONFIG_QCOM_SNAGBOOT_SUPPORT to the boot0.h workaround choice
> block to enable snagboot mode support on Qualcomm platforms.
> 
> This config option automatically selects the
> required dependencies: QCOM_COMMAND_DB_OPTIONAL,
> ENABLE_ARM_SOC_BOOT0_HOOK to enable early boot hooks, and SKIP_RELOCATE.
> 
> Signed-off-by: Balaji Selvanathan <balaji.selvanathan at oss.qualcomm.com>
> ---
> Changes in v3:
> - Newly introduced in v3
> ---
>  arch/arm/mach-snapdragon/Kconfig | 13 +++++++++++++
>  1 file changed, 13 insertions(+)
> 
> diff --git a/arch/arm/mach-snapdragon/Kconfig b/arch/arm/mach-snapdragon/Kconfig
> index 931d25c1023..e173af1ce45 100644
> --- a/arch/arm/mach-snapdragon/Kconfig
> +++ b/arch/arm/mach-snapdragon/Kconfig
> @@ -63,6 +63,19 @@ config QCOM_EL2_GUNYAH_EXIT_SUPPORT
>  	  Exit Gunyah hypervisor and switch to EL2 during early boot. This must
>  	  happen before EL register configuration in start.S so that U-Boot can
>  	  run properly at EL2.
> +
> +config QCOM_SNAGBOOT_SUPPORT

SNAGBOOT_SUPPORT implies that this adds support for some feature, but
presumably this shouldn't be enabled in normal U-Boot builds, rather
enabled to configure U-Boot for a particular usecase right?

I think it would make sense to rename this to QCOM_SNAGBOOT_MODE, then
we can probably also avoid adding "QCOM_COMMAND_DB_OPTIONAL" later and
just check this option instead.

Please also move this option out of the boot0 hook choice, since it
really doesn't belong under there, add a QCOM_BOOT0_SNAGBOOT_MODE option
there and select it instead.

> +	bool "Enable snagboot mode support"
> +	select QCOM_COMMAND_DB_OPTIONAL
> +	select ENABLE_ARM_SOC_BOOT0_HOOK
> +	select SKIP_RELOCATE

I see in the new defconfig you add later that there are some other
changes that seem to be required for snagboot, like disabling IOMMU,
those dependencies should be expressed here.

> +	help
> +	  Enable support for running U-Boot in snagboot mode on Qualcomm
> +	  platforms. In snagboot mode, XBL loads U-Boot directly for
> +	  manufacturing and recovery use cases.

This is not very clearly phrased, just be clear that this build of
U-Boot is to be loaded in EDL mode.

> +
> +	  This option performs early boot initialization to ensure a clean
> +	  state for U-Boot when loaded by XBL in snagboot mode.

I'd just drop this sentence.

>  endchoice
>  
>  endif
> 

-- 
// Casey (she/her)