env_mmc: add support for redundant environment

This patch add support for storing the environment redundant on
mmc devices. Substantially it re-uses the logic from the NAND implementation,
that means using an incremental counter for marking newer data.

Signed-off-by: Michael Heimpold <mhei@heimpold.de>

diff --git a/board/freescale/common/sdhc_boot.c b/board/freescale/common/sdhc_boot.c
index e432318..fd0e910 100644 (file)
--- a/board/freescale/common/sdhc_boot.c
+++ b/board/freescale/common/sdhc_boot.c
@@ -32,7 +32,7 @@
 #define ESDHC_BOOT_IMAGE_SIZE  0x48
 #define ESDHC_BOOT_IMAGE_ADDR  0x50
 
-int mmc_get_env_addr(struct mmc *mmc, u32 *env_addr)
+int mmc_get_env_addr(struct mmc *mmc, int copy, u32 *env_addr)
 {
        u8 *tmp_buf;
        u32 blklen, code_offset, code_len, n;

diff --git a/common/env_mmc.c b/common/env_mmc.c
index 02bd5ae..9ca098f 100644 (file)
--- a/common/env_mmc.c
+++ b/common/env_mmc.c
@@ -32,6 +32,11 @@
 #include <search.h>
 #include <errno.h>
 
+#if defined(CONFIG_ENV_SIZE_REDUND) &&  \
+       (CONFIG_ENV_SIZE_REDUND != CONFIG_ENV_SIZE)
+#error CONFIG_ENV_SIZE_REDUND should be the same as CONFIG_ENV_SIZE
+#endif
+
 char *env_name_spec = "MMC";
 
 #ifdef ENV_IS_EMBEDDED
@@ -46,9 +51,13 @@ DECLARE_GLOBAL_DATA_PTR;
 #define CONFIG_ENV_OFFSET 0
 #endif
 
-__weak int mmc_get_env_addr(struct mmc *mmc, u32 *env_addr)
+__weak int mmc_get_env_addr(struct mmc *mmc, int copy, u32 *env_addr)
 {
        *env_addr = CONFIG_ENV_OFFSET;
+#ifdef CONFIG_ENV_OFFSET_REDUND
+       if (copy)
+               *env_addr = CONFIG_ENV_OFFSET_REDUND;
+#endif
        return 0;
 }
 
@@ -110,6 +119,10 @@ static inline int write_env(struct mmc *mmc, unsigned long size,
        return (n == blk_cnt) ? 0 : -1;
 }
 
+#ifdef CONFIG_ENV_OFFSET_REDUND
+static unsigned char env_flags;
+#endif
+
 int saveenv(void)
 {
        ALLOC_CACHE_ALIGN_BUFFER(env_t, env_new, 1);
@@ -117,16 +130,11 @@ int saveenv(void)
        char    *res;
        struct mmc *mmc = find_mmc_device(CONFIG_SYS_MMC_ENV_DEV);
        u32     offset;
-       int     ret;
+       int     ret, copy = 0;
 
        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', 0, &res, ENV_SIZE, 0, NULL);
        if (len < 0) {
@@ -136,7 +144,21 @@ int saveenv(void)
        }
 
        env_new->crc = crc32(0, &env_new->data[0], ENV_SIZE);
-       printf("Writing to MMC(%d)... ", CONFIG_SYS_MMC_ENV_DEV);
+
+#ifdef CONFIG_ENV_OFFSET_REDUND
+       env_new->flags  = ++env_flags; /* increase the serial */
+
+       if (gd->env_valid == 1)
+               copy = 1;
+#endif
+
+       if (mmc_get_env_addr(mmc, copy, &offset)) {
+               ret = 1;
+               goto fini;
+       }
+
+       printf("Writing to %sMMC(%d)... ", copy ? "redundant " : "",
+              CONFIG_SYS_MMC_ENV_DEV);
        if (write_env(mmc, CONFIG_ENV_SIZE, offset, (u_char *)env_new)) {
                puts("failed\n");
                ret = 1;
@@ -146,6 +168,10 @@ int saveenv(void)
        puts("done\n");
        ret = 0;
 
+#ifdef CONFIG_ENV_OFFSET_REDUND
+       gd->env_valid = gd->env_valid == 2 ? 1 : 2;
+#endif
+
 fini:
        fini_mmc_for_env(mmc);
        return ret;
@@ -166,6 +192,93 @@ static inline int read_env(struct mmc *mmc, unsigned long size,
        return (n == blk_cnt) ? 0 : -1;
 }
 
+#ifdef CONFIG_ENV_OFFSET_REDUND
+void env_relocate_spec(void)
+{
+#if !defined(ENV_IS_EMBEDDED)
+       struct mmc *mmc = find_mmc_device(CONFIG_SYS_MMC_ENV_DEV);
+       u32 offset1, offset2;
+       int read1_fail = 0, read2_fail = 0;
+       int crc1_ok = 0, crc2_ok = 0;
+       env_t *ep, *tmp_env1, *tmp_env2;
+       int ret;
+
+       tmp_env1 = (env_t *)malloc(CONFIG_ENV_SIZE);
+       tmp_env2 = (env_t *)malloc(CONFIG_ENV_SIZE);
+       if (tmp_env1 == NULL || tmp_env2 == NULL) {
+               puts("Can't allocate buffers for environment\n");
+               ret = 1;
+               goto err;
+       }
+
+       if (init_mmc_for_env(mmc)) {
+               ret = 1;
+               goto err;
+       }
+
+       if (mmc_get_env_addr(mmc, 0, &offset1) ||
+           mmc_get_env_addr(mmc, 1, &offset2)) {
+               ret = 1;
+               goto fini;
+       }
+
+       read1_fail = read_env(mmc, CONFIG_ENV_SIZE, offset1, tmp_env1);
+       read2_fail = read_env(mmc, CONFIG_ENV_SIZE, offset2, tmp_env2);
+
+       if (read1_fail && read2_fail)
+               puts("*** Error - No Valid Environment Area found\n");
+       else if (read1_fail || read2_fail)
+               puts("*** Warning - some problems detected "
+                    "reading environment; recovered successfully\n");
+
+       crc1_ok = !read1_fail &&
+               (crc32(0, tmp_env1->data, ENV_SIZE) == tmp_env1->crc);
+       crc2_ok = !read2_fail &&
+               (crc32(0, tmp_env2->data, ENV_SIZE) == tmp_env2->crc);
+
+       if (!crc1_ok && !crc2_ok) {
+               ret = 1;
+               goto fini;
+       } else if (crc1_ok && !crc2_ok) {
+               gd->env_valid = 1;
+       } else if (!crc1_ok && crc2_ok) {
+               gd->env_valid = 2;
+       } else {
+               /* both ok - check serial */
+               if (tmp_env1->flags == 255 && tmp_env2->flags == 0)
+                       gd->env_valid = 2;
+               else if (tmp_env2->flags == 255 && tmp_env1->flags == 0)
+                       gd->env_valid = 1;
+               else if (tmp_env1->flags > tmp_env2->flags)
+                       gd->env_valid = 1;
+               else if (tmp_env2->flags > tmp_env1->flags)
+                       gd->env_valid = 2;
+               else /* flags are equal - almost impossible */
+                       gd->env_valid = 1;
+       }
+
+       free(env_ptr);
+
+       if (gd->env_valid == 1)
+               ep = tmp_env1;
+       else
+               ep = tmp_env2;
+
+       env_flags = ep->flags;
+       env_import((char *)ep, 0);
+       ret = 0;
+
+fini:
+       fini_mmc_for_env(mmc);
+err:
+       if (ret)
+               set_default_env(NULL);
+
+       free(tmp_env1);
+       free(tmp_env2);
+#endif
+}
+#else /* ! CONFIG_ENV_OFFSET_REDUND */
 void env_relocate_spec(void)
 {
 #if !defined(ENV_IS_EMBEDDED)
@@ -179,7 +292,7 @@ void env_relocate_spec(void)
                goto err;
        }
 
-       if (mmc_get_env_addr(mmc, &offset)) {
+       if (mmc_get_env_addr(mmc, 0, &offset)) {
                ret = 1;
                goto fini;
        }
@@ -199,3 +312,4 @@ err:
                set_default_env(NULL);
 #endif
 }
+#endif /* CONFIG_ENV_OFFSET_REDUND */