[U-Boot] [PATCH v3 09/15] env: Support multiple environments

[Simon Goldschmidt]

On 23.01.2018 21:16, Maxime Ripard wrote:
> Now that we have everything in place to support multiple environment, let's
> make sure the current code can use it.
>
> The priority used between the various environment is the same one that was
> used in the code previously.
>
> At read / init times, the highest priority environment is going to be
> detected,

Does priority handling really work here? Most env drivers seem to ignore 
the return value of env_import and may thus return success although 
importing the environment failed (only reading the data from the device 
succeeded).

This is from reading the code, I haven't had a chance to test this, yet.

>   and we'll use the same one without lookup during writes. This
> should implement the same behaviour than we currently have.

Is there a way to save the environment to drivers other than the one 
selected at init time?

Regards,
Simon

>
> Reviewed-by: Andre Przywara <andre.przywara at arm.com>
> Reviewed-by: Simon Glass <sjg at chromium.org>
> Signed-off-by: Maxime Ripard <maxime.ripard at free-electrons.com>
> ---
>   env/env.c | 80 +++++++++++++++++++++++++++++++++++---------------------
>   1 file changed, 50 insertions(+), 30 deletions(-)
>
> diff --git a/env/env.c b/env/env.c
> index 906f28ee50a1..1182fdb545db 100644
> --- a/env/env.c
> +++ b/env/env.c
> @@ -26,6 +26,41 @@ static struct env_driver *_env_driver_lookup(enum env_location loc)
>   	return NULL;
>   }
>   
> +static enum env_location env_locations[] = {
> +#ifdef CONFIG_ENV_IS_IN_EEPROM
> +	ENVL_EEPROM,
> +#endif
> +#ifdef CONFIG_ENV_IS_IN_FAT
> +	ENVL_FAT,
> +#endif
> +#ifdef CONFIG_ENV_IS_IN_FLASH
> +	ENVL_FLASH,
> +#endif
> +#ifdef CONFIG_ENV_IS_IN_MMC
> +	ENVL_MMC,
> +#endif
> +#ifdef CONFIG_ENV_IS_IN_NAND
> +	ENVL_NAND,
> +#endif
> +#ifdef CONFIG_ENV_IS_IN_NVRAM
> +	ENVL_NVRAM,
> +#endif
> +#ifdef CONFIG_ENV_IS_IN_REMOTE
> +	ENVL_REMOTE,
> +#endif
> +#ifdef CONFIG_ENV_IS_IN_SPI_FLASH
> +	ENVL_SPI_FLASH,
> +#endif
> +#ifdef CONFIG_ENV_IS_IN_UBI
> +	ENVL_UBI,
> +#endif
> +#ifdef CONFIG_ENV_IS_NOWHERE
> +	ENVL_NOWHERE,
> +#endif
> +};
> +
> +static enum env_location env_load_location = ENVL_UNKNOWN;
> +
>   /**
>    * env_get_location() - Returns the best env location for a board
>    * @op: operations performed on the environment
> @@ -45,36 +80,21 @@ static struct env_driver *_env_driver_lookup(enum env_location loc)
>    */
>   static enum env_location env_get_location(enum env_operation op, int prio)
>   {
> -	/*
> -	 * We support a single environment, so any environment asked
> -	 * with a priority that is not zero is out of our supported
> -	 * bounds.
> -	 */
> -	if (prio >= 1)
> -		return ENVL_UNKNOWN;
> -
> -	if IS_ENABLED(CONFIG_ENV_IS_IN_EEPROM)
> -		return ENVL_EEPROM;
> -	else if IS_ENABLED(CONFIG_ENV_IS_IN_FAT)
> -		return ENVL_FAT;
> -	else if IS_ENABLED(CONFIG_ENV_IS_IN_FLASH)
> -		return ENVL_FLASH;
> -	else if IS_ENABLED(CONFIG_ENV_IS_IN_MMC)
> -		return ENVL_MMC;
> -	else if IS_ENABLED(CONFIG_ENV_IS_IN_NAND)
> -		return ENVL_NAND;
> -	else if IS_ENABLED(CONFIG_ENV_IS_IN_NVRAM)
> -		return ENVL_NVRAM;
> -	else if IS_ENABLED(CONFIG_ENV_IS_IN_REMOTE)
> -		return ENVL_REMOTE;
> -	else if IS_ENABLED(CONFIG_ENV_IS_IN_SPI_FLASH)
> -		return ENVL_SPI_FLASH;
> -	else if IS_ENABLED(CONFIG_ENV_IS_IN_UBI)
> -		return ENVL_UBI;
> -	else if IS_ENABLED(CONFIG_ENV_IS_NOWHERE)
> -		return ENVL_NOWHERE;
> -	else
> -		return ENVL_UNKNOWN;
> +	switch (op) {
> +	case ENVOP_GET_CHAR:
> +	case ENVOP_INIT:
> +	case ENVOP_LOAD:
> +		if (prio >= ARRAY_SIZE(env_locations))
> +			return ENVL_UNKNOWN;
> +
> +		env_load_location = env_locations[prio];
> +		return env_load_location;
> +
> +	case ENVOP_SAVE:
> +		return env_load_location;
> +	}
> +
> +	return ENVL_UNKNOWN;
>   }
>   
>