[PATCH] mach-k3: am62*: Fix backup from eMMC boot mode

[Bryan Brattlof]

On August 18, 2025 thus sayeth Judith Mendez:
> Currently logic in spl_mmc_boot_mode only lookes at main devstat
> to determine the bootmode to return. Thus, when using: 'eMMC boot'
> as primary boot mode and 'MMCSD boot from eMMC UDA' as backup
> boot mode, 'eMMC boot' is always selected. Add check for bootindex
> to determine if ROM boot via backup boot mode and return MMCSD_MODE_FS
> which is the only supported backup bootmode with eMMC device.
> 
> Signed-off-by: Judith Mendez <jm at ti.com>
> ---
>  arch/arm/mach-k3/am62ax/am62a7_init.c | 22 +++++++++++++---------
>  arch/arm/mach-k3/am62px/am62p5_init.c | 24 ++++++++++++++----------
>  arch/arm/mach-k3/am62x/am625_init.c   | 22 +++++++++++++---------
>  3 files changed, 40 insertions(+), 28 deletions(-)
> 
> diff --git a/arch/arm/mach-k3/am62ax/am62a7_init.c b/arch/arm/mach-k3/am62ax/am62a7_init.c
> index 00173e6836b..fa3570d07ec 100644
> --- a/arch/arm/mach-k3/am62ax/am62a7_init.c
> +++ b/arch/arm/mach-k3/am62ax/am62a7_init.c
> @@ -218,17 +218,21 @@ u32 spl_mmc_boot_mode(struct mmc *mmc, const u32 boot_device)
>  	u32 bootmode_cfg = (devstat & MAIN_DEVSTAT_PRIMARY_BOOTMODE_CFG_MASK) >>
>  			    MAIN_DEVSTAT_PRIMARY_BOOTMODE_CFG_SHIFT;
>  
> -	switch (bootmode) {
> -	case BOOT_DEVICE_EMMC:
> -		if (IS_ENABLED(CONFIG_SUPPORT_EMMC_BOOT))
> +	if (bootindex == K3_PRIMARY_BOOTMODE) {
> +		switch (bootmode) {
> +		case BOOT_DEVICE_EMMC:
> +			if (IS_ENABLED(CONFIG_SUPPORT_EMMC_BOOT))
> +				return MMCSD_MODE_EMMCBOOT;
> +			if (IS_ENABLED(CONFIG_SPL_FS_FAT) || IS_ENABLED(CONFIG_SPL_FS_EXT4))
> +				return MMCSD_MODE_FS;
>  			return MMCSD_MODE_EMMCBOOT;
> -		if (IS_ENABLED(CONFIG_SPL_FS_FAT) || IS_ENABLED(CONFIG_SPL_FS_EXT4))
> +		case BOOT_DEVICE_MMC:
> +			if (bootmode_cfg & MAIN_DEVSTAT_PRIMARY_MMC_FS_RAW_MASK)
> +				return MMCSD_MODE_RAW;
> +		default:
>  			return MMCSD_MODE_FS;
> -		return MMCSD_MODE_EMMCBOOT;
> -	case BOOT_DEVICE_MMC:
> -		if (bootmode_cfg & MAIN_DEVSTAT_PRIMARY_MMC_FS_RAW_MASK)
> -			return MMCSD_MODE_RAW;
> -	default:
> +		}
> +	} else {
>  		return MMCSD_MODE_FS;

Is any warning given to us when we fall back to the UDA partition? How 
do people know their boot partition is dead? Could we bail out early 
with a message:

    if (bootindex != K3_PRIMARY_BOOTMODE) {
	    pr_alert("using MMC backup in UDA\n")
	    return MMCSD_MODE_FS;
    }

    switch (bootmode) {
    case BOOT_DEVICE_EMMC:

    ... bla bla bla ...

~Bryan