To make eMMC partition choosing in default_spl_mmc_emmc_boot_partition() function better understandable, rewrite it via explicit switch-case code pattern.
Also indicate an error when eMMC EXT_CSD[179] register is configured by user to value which is not suitable for eMMC booting and SPL do not know how to interpret it.
Signed-off-by: Pali Rohár pali@kernel.org --- Changes in v3: * Instead of showing (verbose) warning, make them as errors and propagate them back to caller. * Add comment with explanation what happened and how to fix possible misconfigured configuration.
Changes in v2: * Disable showing warning on sama5d2_xplained due to size restrictions --- This patch depends on another patch: mmc: spl: Add comments for default_spl_mmc_emmc_boot_partition() https://patchwork.ozlabs.org/project/uboot/patch/20230404202805.8523-1-pali@... --- common/spl/spl_mmc.c | 56 +++++++++++++++++++++++++++++++++++++------- 1 file changed, 48 insertions(+), 8 deletions(-)
diff --git a/common/spl/spl_mmc.c b/common/spl/spl_mmc.c index f7a42a11477d..656363a3b51a 100644 --- a/common/spl/spl_mmc.c +++ b/common/spl/spl_mmc.c @@ -408,15 +408,46 @@ int default_spl_mmc_emmc_boot_partition(struct mmc *mmc) * * Note: See difference between EXT_CSD_EXTRACT_PARTITION_ACCESS * and EXT_CSD_EXTRACT_BOOT_PART, specially about User area value. - * - * FIXME: When booting from this eMMC device is explicitly - * disabled then we use User area for booting. This is incorrect. - * Probably we should skip this eMMC device and select the next - * one for booting. Or at least throw warning about this fallback. */ - part = EXT_CSD_EXTRACT_BOOT_PART(mmc->part_config); - if (part == 7) - part = 0; + if (mmc->part_config == MMCPART_NOAVAILABLE) + part = 0; /* If partitions are not supported then we have only User Area partition */ + else { + switch(EXT_CSD_EXTRACT_BOOT_PART(mmc->part_config)) { + case 0: /* Booting from this eMMC device is disabled */ + /* + * This eMMC device has disabled booting. + * This may happen because of misconfiguration of eMMC device or + * because user explicitly wanted to not boot from this eMMC device. + * eMMC boot configuration can be changed by "mmc partconf" command. + */ + part = -ENXIO; /* negative value indicates error */ + /* Note that error message is printed by caller of this function. */ + break; + case 1: /* Boot partition 1 is used for booting */ + part = 1; + break; + case 2: /* Boot partition 2 is used for booting */ + part = 2; + break; + case 7: /* User area is used for booting */ + part = 0; + break; + default: /* Other values are reserved */ + /* + * This eMMC device has configured booting from reserved value. + * This may happen because of misconfiguration of eMMC device or + * because this is newer eMMC device than what U-Boot understand. + * If newer eMMC specification defines meaning for some reserved + * values then switch above should be updated for new cases. + * At this stage we do not know how to interpret this reserved + * value so return error. + * eMMC boot configuration can be changed by "mmc partconf" command. + */ + part = -EINVAL; /* negative value indicates error */ + /* Note that error message is printed by caller of this function. */ + break; + } + } #endif return part; } @@ -471,6 +502,15 @@ int spl_mmc_load(struct spl_image_info *spl_image, switch (boot_mode) { case MMCSD_MODE_EMMCBOOT: part = spl_mmc_emmc_boot_partition(mmc); + if (part < 0) { +#ifdef CONFIG_SPL_LIBCOMMON_SUPPORT + if (part == -ENXIO) + puts("spl: mmc booting disabled\n"); + else + puts("spl: mmc misconfigured\n"); +#endif + return part; + }
if (CONFIG_IS_ENABLED(MMC_TINY)) err = mmc_switch_part(mmc, part);