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

[AKASHI Takahiro]

On Sat, Jan 16, 2021 at 03:14:43PM -0600, Brandon Maier wrote:
> 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"

It would be better to emphasize *redundant* use here in "string,"
in addition to "help," to differentiate ENV_FAT_FILE.

-Takahiro Akashi

> +	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
>