[PATCH] env/fat.c: support redund environment

[Brandon Maier]

Signed-off-by: Brandon Maier <brandon.maier at rockwellcollins.com>
CC: Joe Hershberger <joe.hershberger at ni.com>
CC: Wolfgang Denk <wd at denx.de>
---
 env/Kconfig | 13 +++++++++++--
 env/fat.c   | 41 +++++++++++++++++++++++++++++++++--------
 2 files changed, 44 insertions(+), 10 deletions(-)

diff --git a/env/Kconfig b/env/Kconfig
index 67ce93061b..a940ddce95 100644
--- a/env/Kconfig
+++ b/env/Kconfig
@@ -411,8 +411,9 @@ config ENV_IS_IN_UBI
 
 config SYS_REDUNDAND_ENVIRONMENT
 	bool "Enable redundant environment support"
-	depends on ENV_IS_IN_EEPROM || ENV_IS_IN_FLASH || ENV_IS_IN_MMC || \
-		ENV_IS_IN_NAND || ENV_IS_IN_SPI_FLASH || ENV_IS_IN_UBI
+	depends on ENV_IS_IN_EEPROM || ENV_IS_IN_FAT || ENV_IS_IN_FLASH || \
+		ENV_IS_IN_MMC || ENV_IS_IN_NAND || ENV_IS_IN_SPI_FLASH || \
+		ENV_IS_IN_UBI
 	help
 	  Normally, the environemt is stored in a single location.  By
 	  selecting this option, you can then define where to hold a redundant
@@ -461,6 +462,14 @@ config ENV_FAT_FILE
 	  It's a string of the FAT file name. This file use to store the
 	  environment.
 
+config ENV_FAT_FILE_REDUND
+	string "Name of the FAT file to use for the environment"
+	depends on ENV_IS_IN_FAT && SYS_REDUNDAND_ENVIRONMENT
+	default "uboot-redund.env"
+	help
+	  It's a string of the FAT file name. This file use to store the
+	  redundant environment.
+
 config ENV_EXT4_INTERFACE
 	string "Name of the block device for the environment"
 	depends on ENV_IS_IN_EXT4
diff --git a/env/fat.c b/env/fat.c
index 653a38fd93..e4cd5970b4 100644
--- a/env/fat.c
+++ b/env/fat.c
@@ -29,6 +29,10 @@
 # define LOADENV
 #endif
 
+#ifdef CONFIG_SYS_REDUNDAND_ENVIRONMENT
+DECLARE_GLOBAL_DATA_PTR;
+#endif
+
 static char *env_fat_device_and_part(void)
 {
 #ifdef CONFIG_MMC
@@ -53,6 +57,7 @@ static int env_fat_save(void)
 	env_t __aligned(ARCH_DMA_MINALIGN) env_new;
 	struct blk_desc *dev_desc = NULL;
 	struct disk_partition info;
+	const char *file = CONFIG_ENV_FAT_FILE;
 	int dev, part;
 	int err;
 	loff_t size;
@@ -78,29 +83,41 @@ static int env_fat_save(void)
 		return 1;
 	}
 
-	err = file_fat_write(CONFIG_ENV_FAT_FILE, (void *)&env_new, 0, sizeof(env_t),
-			     &size);
+#ifdef CONFIG_SYS_REDUNDAND_ENVIRONMENT
+	if (gd->env_valid == ENV_VALID)
+		file = CONFIG_ENV_FAT_FILE_REDUND;
+#endif
+
+	err = file_fat_write(file, (void *)&env_new, 0, sizeof(env_t), &size);
 	if (err == -1) {
 		/*
 		 * This printf is embedded in the messages from env_save that
 		 * will calling it. The missing \n is intentional.
 		 */
 		printf("Unable to write \"%s\" from %s%d:%d... ",
-			CONFIG_ENV_FAT_FILE, CONFIG_ENV_FAT_INTERFACE, dev, part);
+			file, CONFIG_ENV_FAT_INTERFACE, dev, part);
 		return 1;
 	}
 
+#ifdef CONFIG_SYS_REDUNDAND_ENVIRONMENT
+	gd->env_valid = (gd->env_valid == ENV_REDUND) ? ENV_VALID : ENV_REDUND;
+#endif
+
 	return 0;
 }
 
 #ifdef LOADENV
 static int env_fat_load(void)
 {
-	ALLOC_CACHE_ALIGN_BUFFER(char, buf, CONFIG_ENV_SIZE);
+	ALLOC_CACHE_ALIGN_BUFFER(char, buf1, CONFIG_ENV_SIZE);
+#ifdef CONFIG_SYS_REDUNDAND_ENVIRONMENT
+	ALLOC_CACHE_ALIGN_BUFFER(char, buf2, CONFIG_ENV_SIZE);
+	int err2;
+#endif
 	struct blk_desc *dev_desc = NULL;
 	struct disk_partition info;
 	int dev, part;
-	int err;
+	int err1;
 
 #ifdef CONFIG_MMC
 	if (!strcmp(CONFIG_ENV_FAT_INTERFACE, "mmc"))
@@ -124,8 +141,15 @@ static int env_fat_load(void)
 		goto err_env_relocate;
 	}
 
-	err = file_fat_read(CONFIG_ENV_FAT_FILE, buf, CONFIG_ENV_SIZE);
-	if (err == -1) {
+	err1 = file_fat_read(CONFIG_ENV_FAT_FILE, buf1, CONFIG_ENV_SIZE);
+#ifdef CONFIG_SYS_REDUNDAND_ENVIRONMENT
+	err2 = file_fat_read(CONFIG_ENV_FAT_FILE_REDUND, buf2, CONFIG_ENV_SIZE);
+
+	err1 = (err1 >= 0) ? 0 : -1;
+	err2 = (err2 >= 0) ? 0 : -1;
+	return env_import_redund(buf1, err1, buf2, err2, H_EXTERNAL);
+#else
+	if (err1 < 0) {
 		/*
 		 * This printf is embedded in the messages from env_save that
 		 * will calling it. The missing \n is intentional.
@@ -135,7 +159,8 @@ static int env_fat_load(void)
 		goto err_env_relocate;
 	}
 
-	return env_import(buf, 1, H_EXTERNAL);
+	return env_import(buf1, 1, H_EXTERNAL);
+#endif
 
 err_env_relocate:
 	env_set_default(NULL, 0);
-- 
2.29.1