env_mmc: allow environment to be in an eMMC partition

eMMC devices may have hardware-level partitions: 2 boot partitions,
up to 4 general partitions, plus the user area. This change introduces
optional config variable CONFIG_SYS_MMC_ENV_PART to indicate which
partition the environment should be stored in: 0=user, 1=boot0, 2=boot1,
4..7=general0..3. This allows the environment to be kept out of the user
area, which simplifies the management of OS-/user-level (MBR/GPT)
partitions within the user area.

Signed-off-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Andy Fleming <afleming@freescale.com>

diff --git a/common/env_mmc.c b/common/env_mmc.c
index be2f2be205a49b37d1069c5a9519598886fb2c11..a2ff90bf485eeb4d47b02a8e22865b7fec381ad3 100644 (file)
--- a/common/env_mmc.c
+++ b/common/env_mmc.c
@@ -75,9 +75,28 @@ static int init_mmc_for_env(struct mmc *mmc)
                return -1;
        }
 
+#ifdef CONFIG_SYS_MMC_ENV_PART
+       if (CONFIG_SYS_MMC_ENV_PART != mmc->part_num) {
+               if (mmc_switch_part(CONFIG_SYS_MMC_ENV_DEV,
+                                   CONFIG_SYS_MMC_ENV_PART)) {
+                       puts("MMC partition switch failed\n");
+                       return -1;
+               }
+       }
+#endif
+
        return 0;
 }
 
+static void fini_mmc_for_env(struct mmc *mmc)
+{
+#ifdef CONFIG_SYS_MMC_ENV_PART
+       if (CONFIG_SYS_MMC_ENV_PART != mmc->part_num)
+               mmc_switch_part(CONFIG_SYS_MMC_ENV_DEV,
+                               mmc->part_num);
+#endif
+}
+
 #ifdef CONFIG_CMD_SAVEENV
 static inline int write_env(struct mmc *mmc, unsigned long size,
                            unsigned long offset, const void *buffer)
@@ -100,26 +119,38 @@ int saveenv(void)
        char    *res;
        struct mmc *mmc = find_mmc_device(CONFIG_SYS_MMC_ENV_DEV);
        u32     offset;
+       int     ret;
 
-       if (init_mmc_for_env(mmc) || mmc_get_env_addr(mmc, &offset))
+       if (init_mmc_for_env(mmc))
                return 1;
 
+       if (mmc_get_env_addr(mmc, &offset)) {
+               ret = 1;
+               goto fini;
+       }
+
        res = (char *)&env_new->data;
        len = hexport_r(&env_htab, '\0', &res, ENV_SIZE, 0, NULL);
        if (len < 0) {
                error("Cannot export environment: errno = %d\n", errno);
-               return 1;
+               ret = 1;
+               goto fini;
        }
 
        env_new->crc = crc32(0, &env_new->data[0], ENV_SIZE);
        printf("Writing to MMC(%d)... ", CONFIG_SYS_MMC_ENV_DEV);
        if (write_env(mmc, CONFIG_ENV_SIZE, offset, (u_char *)env_new)) {
                puts("failed\n");
-               return 1;
+               ret = 1;
+               goto fini;
        }
 
        puts("done\n");
-       return 0;
+       ret = 0;
+
+fini:
+       fini_mmc_for_env(mmc);
+       return ret;
 }
 #endif /* CONFIG_CMD_SAVEENV */
 
@@ -143,13 +174,30 @@ void env_relocate_spec(void)
        ALLOC_CACHE_ALIGN_BUFFER(char, buf, CONFIG_ENV_SIZE);
        struct mmc *mmc = find_mmc_device(CONFIG_SYS_MMC_ENV_DEV);
        u32 offset;
+       int ret;
 
-       if (init_mmc_for_env(mmc) || mmc_get_env_addr(mmc, &offset))
-               return set_default_env(NULL);
+       if (init_mmc_for_env(mmc)) {
+               ret = 1;
+               goto err;
+       }
 
-       if (read_env(mmc, CONFIG_ENV_SIZE, offset, buf))
-               return set_default_env(NULL);
+       if (mmc_get_env_addr(mmc, &offset)) {
+               ret = 1;
+               goto fini;
+       }
+
+       if (read_env(mmc, CONFIG_ENV_SIZE, offset, buf)) {
+               ret = 1;
+               goto fini;
+       }
 
        env_import(buf, 1);
+       ret = 0;
+
+fini:
+       fini_mmc_for_env(mmc);
+err:
+       if (ret)
+               set_default_env(NULL);
 #endif
 }