Re: [RFC PATCH 06/10] FWU: STM32MP1: Add support to read boot index from backup register

[Patrick DELAUNAY <patrick.delaunay@foss.st.com>]

Hi Sughosh,

On 11/25/21 8:01 AM, Sughosh Ganu wrote:
> The FWU Multi Bank Update feature allows the platform to boot the
> firmware images from one of the partitions(banks). The first stage
> bootloader(fsbl) passes the value of the boot index, i.e. the bank
> from which the firmware images were booted from to U-Boot. On the
> STM32MP157C-DK2 board, this value is passed through one of the SoC's
> backup register. Add a function to read the boot index value from the
> backup register.
>
> Signed-off-by: Sughosh Ganu <sughosh.ganu@linaro.org>
> ---
>   arch/arm/mach-stm32mp/include/mach/stm32.h | 1 +
>   board/st/stm32mp1/stm32mp1.c               | 7 +++++++
>   include/fwu_metadata.h                     | 1 +
>   3 files changed, 9 insertions(+)
>
> diff --git a/arch/arm/mach-stm32mp/include/mach/stm32.h b/arch/arm/mach-stm32mp/include/mach/stm32.h
> index c11a9903f2..21ed9f12e4 100644
> --- a/arch/arm/mach-stm32mp/include/mach/stm32.h
> +++ b/arch/arm/mach-stm32mp/include/mach/stm32.h
> @@ -97,6 +97,7 @@ enum boot_device {
>   #define TAMP_BACKUP_REGISTER(x)		(STM32_TAMP_BASE + 0x100 + 4 * x)
>   #define TAMP_BACKUP_MAGIC_NUMBER	TAMP_BACKUP_REGISTER(4)
>   #define TAMP_BACKUP_BRANCH_ADDRESS	TAMP_BACKUP_REGISTER(5)
> +#define TAMP_FWU_BOOT_IDX		TAMP_BACKUP_REGISTER(10)

The used TAMP register need to be aligned with TF-A BL2, offset = 10 to 
be confirmed


>   #define TAMP_COPRO_RSC_TBL_ADDRESS	TAMP_BACKUP_REGISTER(17)
>   #define TAMP_COPRO_STATE		TAMP_BACKUP_REGISTER(18)
>   #define TAMP_BOOT_CONTEXT		TAMP_BACKUP_REGISTER(20)
> diff --git a/board/st/stm32mp1/stm32mp1.c b/board/st/stm32mp1/stm32mp1.c
> index a6884d2772..32bba71289 100644
> --- a/board/st/stm32mp1/stm32mp1.c
> +++ b/board/st/stm32mp1/stm32mp1.c
> @@ -990,6 +990,13 @@ int fwu_plat_get_blk_desc(struct blk_desc **desc)
>   	return 0;
>   }
>   
> +void fwu_plat_get_bootidx(void *boot_idx)
> +{
> +	u32 *bootidx = boot_idx;
> +
> +	*bootidx = readl(TAMP_FWU_BOOT_IDX);
> +}
> +
>   struct fwu_metadata_ops *get_plat_fwu_metadata_ops(void)
>   {
>   	if (CONFIG_IS_ENABLED(TARGET_ST_STM32MP15x) &&
> diff --git a/include/fwu_metadata.h b/include/fwu_metadata.h
> index 6a5e814ab6..44f06f4c6a 100644
> --- a/include/fwu_metadata.h
> +++ b/include/fwu_metadata.h
> @@ -124,5 +124,6 @@ int fwu_get_metadata(struct fwu_metadata **metadata);
>   
>   int fwu_plat_get_update_index(u32 *update_idx);
>   int fwu_plat_get_blk_desc(struct blk_desc **desc);
> +void fwu_plat_get_bootidx(void *boot_idx);
>   
>   #endif /* _FWU_METADATA_H_ */


Regards


Patrick