env: Add generic redundant environment implementation

All current environments that implement redundancy use almost
identical implementations. This patch implements the env_nand
implementation as a function in env_common, and updates the
env_export function to export an env_nand-style 'flags' field by
default.

Signed-off-by: Fiach Antaw <fiach.antaw@uqconnect.edu.au>
Reviewed-by: Tom Rini <trini@konsulko.com>

diff --git a/common/env_common.c b/common/env_common.c
index 6845f8d8d542945f90b005f8fcef1e261092c9c8..d9c0c4e3f347453e704d0682df743349009bdb47 100644 (file)
--- a/common/env_common.c
+++ b/common/env_common.c
@@ -226,6 +226,53 @@ int env_import(const char *buf, int check)
        return 0;
 }
 
+#ifdef CONFIG_SYS_REDUNDAND_ENVIRONMENT
+static unsigned char env_flags;
+
+int env_import_redund(const char *buf1, const char *buf2)
+{
+       int crc1_ok, crc2_ok;
+       env_t *ep, *tmp_env1, *tmp_env2;
+
+       tmp_env1 = (env_t *)buf1;
+       tmp_env2 = (env_t *)buf2;
+
+       crc1_ok = crc32(0, tmp_env1->data, ENV_SIZE) ==
+                       tmp_env1->crc;
+       crc2_ok = crc32(0, tmp_env2->data, ENV_SIZE) ==
+                       tmp_env2->crc;
+
+       if (!crc1_ok && !crc2_ok) {
+               set_default_env("!bad CRC");
+               return 0;
+       } 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;
+       }
+
+       if (gd->env_valid == 1)
+               ep = tmp_env1;
+       else
+               ep = tmp_env2;
+
+       env_flags = ep->flags;
+       return env_import((char *)ep, 0);
+}
+#endif /* CONFIG_SYS_REDUNDAND_ENVIRONMENT */
+
 /* Export the environment and generate CRC for it. */
 int env_export(env_t *env_out)
 {
@@ -247,6 +294,10 @@ int env_export(env_t *env_out)
 
        env_out->crc = crc32(0, env_out->data, ENV_SIZE);
 
+#ifdef CONFIG_SYS_REDUNDAND_ENVIRONMENT
+       env_out->flags = ++env_flags; /* increase the serial */
+#endif
+
        return 0;
 }
 

diff --git a/include/environment.h b/include/environment.h
index 6f94986c6b3e0fca6c4954ed83fb0f9cf148cc78..d86230a2e927e311b4e44d44c3f9dae481e778f8 100644 (file)
--- a/include/environment.h
+++ b/include/environment.h
@@ -224,6 +224,11 @@ int env_import(const char *buf, int check);
 /* Export from hash table into binary representation */
 int env_export(env_t *env_out);
 
+#ifdef CONFIG_SYS_REDUNDAND_ENVIRONMENT
+/* Select and import one of two redundant environments */
+int env_import_redund(const char *buf1, const char *buf2);
+#endif
+
 #endif /* DO_DEPS_ONLY */
 
 #endif /* _ENVIRONMENT_H_ */