[U-Boot] [PATCH 13/14] sunxi: Transition from the MMC to a FAT-based environment

[Andre Przywara]

Hi,

On 28/11/17 10:24, Maxime Ripard wrote:
> The current environment has been hardcoded to an offset that starts to be
> an issue given the current size of our main U-Boot binary.
> 
> By implementing a custom environment location routine, we can always favor
> the FAT-based environment, and fallback to the MMC if we don't find
> something in the FAT partition. We also implement the same order when
> saving the environment, so that hopefully we can slowly migrate the users
> over to FAT-based environment and away from the raw MMC one.
> 
> Eventually, and hopefully before we reach that limit again, we will have
> most of our users using that setup, and we'll be able to retire the raw
> environment, and gain more room for the U-Boot binary.
> 
> Reviewed-by: Lukasz Majewski <lukma at denx.de>
> Signed-off-by: Maxime Ripard <maxime.ripard at free-electrons.com>
> ---
>  board/sunxi/board.c | 16 ++++++++++++++++
>  1 file changed, 16 insertions(+)
> 
> diff --git a/board/sunxi/board.c b/board/sunxi/board.c
> index dcacdf3e626d..8891961dcc6b 100644
> --- a/board/sunxi/board.c
> +++ b/board/sunxi/board.c
> @@ -173,6 +173,22 @@ void i2c_init_board(void)
>  #endif
>  }
>  
> +#if defined(CONFIG_ENV_IS_IN_MMC) && defined(CONFIG_ENV_IS_IN_FAT)
> +enum env_location env_get_location(enum env_operation op, int prio)
> +{
> +	switch (prio) {
> +	case 0:
> +		return ENVL_FAT;
> +
> +	case 1:
> +		return ENVL_MMC;

So even though the actual u-boot.bin for 64-bit boards is still somewhat
below the limit (~480KB), adding the ATF image (~32KB) pushes it over
the edge. So since v2017.11 u-boot.itb is already too big for the
traditional MMC env location.
So shall this "case 1:" be guarded by #ifndef CONFIG_ARM64, to not even
consider MMC for sunxi64 anymore?

Cheers,
Andre.

> +
> +	default:
> +		return ENVL_UNKNOWN;
> +	}
> +}
> +#endif
> +
>  /* add board specific code here */
>  int board_init(void)
>  {
>