env: Add redundant env support to UBI env

Allow the user to specify two UBI volumes to use for the environment

Signed-off-by: Joe Hershberger <joe.hershberger@ni.com>
diff --git a/common/env_ubi.c b/common/env_ubi.c
index 0c592a6..1ed8b02 100644
--- a/common/env_ubi.c
+++ b/common/env_ubi.c
@@ -47,6 +47,58 @@
 }
 
 #ifdef CONFIG_CMD_SAVEENV
+#ifdef CONFIG_SYS_REDUNDAND_ENVIRONMENT
+static unsigned char env_flags;
+
+int saveenv(void)
+{
+	ALLOC_CACHE_ALIGN_BUFFER(env_t, env_new, 1);
+	ssize_t	len;
+	char *res;
+
+	res = (char *)&env_new->data;
+	len = hexport_r(&env_htab, '\0', 0, &res, ENV_SIZE, 0, NULL);
+	if (len < 0) {
+		error("Cannot export environment: errno = %d\n", errno);
+		return 1;
+	}
+
+	if (ubi_part(CONFIG_ENV_UBI_PART, NULL)) {
+		printf("\n** Cannot find mtd partition \"%s\"\n",
+		       CONFIG_ENV_UBI_PART);
+		return 1;
+	}
+
+	env_new->crc = crc32(0, env_new->data, ENV_SIZE);
+	env_new->flags = ++env_flags; /* increase the serial */
+
+	if (gd->env_valid == 1) {
+		puts("Writing to redundant UBI... ");
+		if (ubi_volume_write(CONFIG_ENV_UBI_VOLUME_REDUND,
+				     (void *)env_new, CONFIG_ENV_SIZE)) {
+			printf("\n** Unable to write env to %s:%s **\n",
+			       CONFIG_ENV_UBI_PART,
+			       CONFIG_ENV_UBI_VOLUME_REDUND);
+			return 1;
+		}
+	} else {
+		puts("Writing to UBI... ");
+		if (ubi_volume_write(CONFIG_ENV_UBI_VOLUME,
+				     (void *)env_new, CONFIG_ENV_SIZE)) {
+			printf("\n** Unable to write env to %s:%s **\n",
+			       CONFIG_ENV_UBI_PART,
+			       CONFIG_ENV_UBI_VOLUME);
+			return 1;
+		}
+	}
+
+	puts("done\n");
+
+	gd->env_valid = gd->env_valid == 2 ? 1 : 2;
+
+	return 0;
+}
+#else /* ! CONFIG_SYS_REDUNDAND_ENVIRONMENT */
 int saveenv(void)
 {
 	ALLOC_CACHE_ALIGN_BUFFER(env_t, env_new, 1);
@@ -78,8 +130,72 @@
 	puts("done\n");
 	return 0;
 }
+#endif /* CONFIG_SYS_REDUNDAND_ENVIRONMENT */
 #endif /* CONFIG_CMD_SAVEENV */
 
+#ifdef CONFIG_SYS_REDUNDAND_ENVIRONMENT
+void env_relocate_spec(void)
+{
+	ALLOC_CACHE_ALIGN_BUFFER(char, env1_buf, CONFIG_ENV_SIZE);
+	ALLOC_CACHE_ALIGN_BUFFER(char, env2_buf, CONFIG_ENV_SIZE);
+	int crc1_ok = 0, crc2_ok = 0;
+	env_t *ep, *tmp_env1, *tmp_env2;
+
+	tmp_env1 = (env_t *)env1_buf;
+	tmp_env2 = (env_t *)env2_buf;
+
+	if (ubi_part(CONFIG_ENV_UBI_PART, NULL)) {
+		printf("\n** Cannot find mtd partition \"%s\"\n",
+		       CONFIG_ENV_UBI_PART);
+		set_default_env(NULL);
+		return;
+	}
+
+	if (ubi_volume_read(CONFIG_ENV_UBI_VOLUME, (void *)tmp_env1,
+			    CONFIG_ENV_SIZE)) {
+		printf("\n** Unable to read env from %s:%s **\n",
+		       CONFIG_ENV_UBI_PART, CONFIG_ENV_UBI_VOLUME);
+	}
+
+	if (ubi_volume_read(CONFIG_ENV_UBI_VOLUME_REDUND, (void *)tmp_env2,
+			    CONFIG_ENV_SIZE)) {
+		printf("\n** Unable to read redundant env from %s:%s **\n",
+		       CONFIG_ENV_UBI_PART, CONFIG_ENV_UBI_VOLUME_REDUND);
+	}
+
+	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;
+	} 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;
+	env_import((char *)ep, 0);
+}
+#else /* ! CONFIG_SYS_REDUNDAND_ENVIRONMENT */
 void env_relocate_spec(void)
 {
 	ALLOC_CACHE_ALIGN_BUFFER(char, buf, CONFIG_ENV_SIZE);
@@ -101,3 +217,4 @@
 
 	env_import(buf, 1);
 }
+#endif /* CONFIG_SYS_REDUNDAND_ENVIRONMENT */