env_mmc: Allow board code to override the environment address

On some boards the environment may not be located at a fixed address in
the MMC/SDHC card.  This allows those boards to implement their own
means to report what address the environment is located at.

Signed-off-by: Mingkai Hu <Mingkai.hu@freescale.com>
Signed-off-by: Jerry Huang <Chang-Ming.Huang@freescale.com>
Signed-off-by: Zhao Chenhui <b35336@freescale.com>
Acked-by: Andy Fleming <afleming@freescale.com>
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>

diff --git a/common/env_mmc.c b/common/env_mmc.c
index 71dcc4c3e2547c54e104dc0ac10fac802b7a54b5..83f40f43417ef39ca88b6b94e9e03e84924da920 100644 (file)
--- a/common/env_mmc.c
+++ b/common/env_mmc.c
@@ -1,5 +1,5 @@
 /*
- * (C) Copyright 2008-2010 Freescale Semiconductor, Inc.
+ * (C) Copyright 2008-2011 Freescale Semiconductor, Inc.
  *
  * See file CREDITS for list of people who contributed to this
  * project.
@@ -51,6 +51,19 @@ static void use_default(void);
 
 DECLARE_GLOBAL_DATA_PTR;
 
+#if !defined(CONFIG_ENV_OFFSET)
+#define CONFIG_ENV_OFFSET 0
+#endif
+
+static int __mmc_get_env_addr(struct mmc *mmc, u32 *env_addr)
+{
+       *env_addr = CONFIG_ENV_OFFSET;
+       return 0;
+}
+__attribute__((weak, alias("__mmc_get_env_addr")))
+int mmc_get_env_addr(struct mmc *mmc, u32 *env_addr);
+
+
 uchar env_get_char_spec(int index)
 {
        return *((uchar *)(gd->env_addr + index));
@@ -102,10 +115,14 @@ int saveenv(void)
        ssize_t len;
        char    *res;
        struct mmc *mmc = find_mmc_device(CONFIG_SYS_MMC_ENV_DEV);
+       u32 offset;
 
        if (init_mmc_for_env(mmc))
                return 1;
 
+       if(mmc_get_env_addr(mmc, &offset))
+               return 1;
+
        res = (char *)&env_new.data;
        len = hexport_r(&env_htab, '\0', &res, ENV_SIZE);
        if (len < 0) {
@@ -114,7 +131,7 @@ int saveenv(void)
        }
        env_new.crc   = crc32(0, env_new.data, ENV_SIZE);
        printf("Writing to MMC(%d)... ", CONFIG_SYS_MMC_ENV_DEV);
-       if (write_env(mmc, CONFIG_ENV_SIZE, CONFIG_ENV_OFFSET, (u_char *)&env_new)) {
+       if (write_env(mmc, CONFIG_ENV_SIZE, offset, (u_char *)&env_new)) {
                puts("failed\n");
                return 1;
        }
@@ -141,16 +158,22 @@ inline int read_env(struct mmc *mmc, unsigned long size,
 void env_relocate_spec(void)
 {
 #if !defined(ENV_IS_EMBEDDED)
-       char buf[CONFIG_ENV_SIZE];
+       char buf[CONFIG_ENV_SIZE];
 
        struct mmc *mmc = find_mmc_device(CONFIG_SYS_MMC_ENV_DEV);
+       u32 offset;
 
        if (init_mmc_for_env(mmc)) {
                use_default();
                return;
        }
 
-       if (read_env(mmc, CONFIG_ENV_SIZE, CONFIG_ENV_OFFSET, buf)) {
+       if(mmc_get_env_addr(mmc, &offset)) {
+               use_default();
+               return ;
+       }
+
+       if (read_env(mmc, CONFIG_ENV_SIZE, offset, buf)) {
                use_default();
                return;
        }