This allows to place U-Boot environment into eMMC boot partition thus saving space on user partition for the OS (or whatever.) When booting off of eMMC many (all?) MCUs can use dedicated boot0/boot1 partitions to boot so U-Boot (or SPL) is written to one (or both) such partitions. When such boot configuration is used it makes sense to place environment in the same partition where the U-Boot itself is so the entire user partition is available for the OS.
It might be not well polished yet but it is a simple patch that can be reworked later.
It uses 4 Kconfig variables right now which probably belong to the board Kconfig. Those are:
CONFIG_ENV_IN_EMMC_BOOT -- tells that environment is in eMMC boot partition if defined
CONFIG_EMMC_ENV_PART -- tells which boot partition environment should be stored in (either 1 or 2)
CONFIG_EMMC_BOOT_PART -- which boot partition will be used by eMMC to read U-Boot/SPL binary for boot protocol (either 1 or 2.) That can be different from the environment partition
CONFIG_EMMC_BOOT_ACK -- tells that eMMC should provide boot ACKs if defined
Here is an excerpt from actual board Kconfig:
=== Cut === config ENV_IN_EMMC_BOOT bool "Environment is in eMMC boot partition" default y
config EMMC_ENV_PART hex "eMMC boot partition used for environment (1 or 2)" default 1
config EMMC_BOOT_PART hex "eMMC boot partition the board boots off of (1 or 2)" default 1
config EMMC_BOOT_ACK bool "Enable ACKs from eMMC when booting off of boot partition" default n === Cut ===
Signed-off-by: Sergey Kubushyn ksi@koi8.net --- --- a/common/env_mmc.c +++ b/common/env_mmc.c @@ -68,6 +68,45 @@ int env_init(void) return 0; }
+#ifdef CONFIG_ENV_IN_EMMC_BOOT +__weak u8 mmc_get_env_part(struct mmc *mmc) +{ + return CONFIG_EMMC_ENV_PART; +} + +__weak u8 mmc_get_boot_part(struct mmc *mmc) +{ + return CONFIG_EMMC_BOOT_PART; +} + +__weak u8 mmc_get_boot_ack(struct mmc *mmc) +{ +#ifdef CONFIG_EMMC_BOOT_ACK + return 1; +#else + return 0; +#endif +} + +static int mmc_set_env_part(struct mmc *mmc) +{ + int ret = 0; + u8 boot_part = 0; + u8 boot_ack = 0; + u8 env_part = 0; + + boot_part = mmc_get_boot_part(mmc); + boot_ack = mmc_get_boot_ack(mmc); + env_part = mmc_get_env_part(mmc); + + ret = mmc_set_part_conf(mmc, boot_ack, boot_part, env_part); + + if (ret) + puts("MMC switch to boot partition failed\n"); + + return ret; +} +#else #ifdef CONFIG_SYS_MMC_ENV_PART __weak uint mmc_get_env_part(struct mmc *mmc) { @@ -96,6 +135,7 @@ static int mmc_set_env_part(struct mmc *mmc) #else static inline int mmc_set_env_part(struct mmc *mmc) {return 0; }; #endif +#endif
static const char *init_mmc_for_env(struct mmc *mmc) { @@ -113,6 +153,15 @@ static const char *init_mmc_for_env(struct mmc *mmc)
static void fini_mmc_for_env(struct mmc *mmc) { +#ifdef CONFIG_ENV_IN_EMMC_BOOT + u8 boot_part = 0; + u8 boot_ack = 0; + + boot_part = mmc_get_boot_part(mmc); + boot_ack = mmc_get_boot_ack(mmc); + + mmc_set_part_conf(mmc, boot_ack, boot_part, 0); +#else #ifdef CONFIG_SYS_MMC_ENV_PART int dev = mmc_get_env_dev();
@@ -121,6 +170,7 @@ static void fini_mmc_for_env(struct mmc *mmc) #endif blk_select_hwpart_devnum(IF_TYPE_MMC, dev, env_mmc_orig_hwpart); #endif +#endif }
#ifdef CONFIG_CMD_SAVEENV
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