[U-Boot] [PATCH 1/5] common: env_mmc: support loading env from different cards

[Stefano Babic <sbabic@denx.de>]

Hi Peng,

On 15/12/2015 09:26, Peng Fan wrote:
> Some boards support booting from different SD card slots.
> For example, mx6dpsabresd board supports booting from SD2,
> SD3, EMMC4, using different boot switch. And the index
> numbers are SD2(0), SD3(1), EMMC4(2).
> But CONFIG_SYS_MMC_ENV_DEV is hardcoded to 1(for SD3), so when
> booting from SD2(using 0), uboot complains "MMC: no card present",
> since there is no card in SD3 slot.
> 
> This patch introduces a weak function which still returns
> CONFIG_SYS_MMC_ENV_DEV to avoid break other boards. Then
> different boards can implement mmc_get_env_devno to read
> env from the correct sd/emmc.
> 
> Signed-off-by: Peng Fan <Peng.Fan@freescale.com>
> Cc: Stefano Babic <sbabic@denx.de>
> Cc: Simon Glass <sjg@chromium.org>
> Cc: Tim Harvey <tharvey@gateworks.com>
> Cc: Hans de Goede <hdegoede@redhat.com>
> ---
>  common/env_mmc.c | 22 ++++++++++++++--------
>  1 file changed, 14 insertions(+), 8 deletions(-)
> 
> diff --git a/common/env_mmc.c b/common/env_mmc.c
> index 9639822..d2e2a40 100644
> --- a/common/env_mmc.c
> +++ b/common/env_mmc.c
> @@ -63,6 +63,11 @@ int env_init(void)
>  	return 0;
>  }
>  
> +__weak uint mmc_get_env_devno(void)
> +{
> +	return CONFIG_SYS_MMC_ENV_DEV;
> +}
> +
>  #ifdef CONFIG_SYS_MMC_ENV_PART
>  __weak uint mmc_get_env_part(struct mmc *mmc)
>  {
> @@ -72,7 +77,7 @@ __weak uint mmc_get_env_part(struct mmc *mmc)
>  static int mmc_set_env_part(struct mmc *mmc)
>  {
>  	uint part = mmc_get_env_part(mmc);
> -	int dev = CONFIG_SYS_MMC_ENV_DEV;
> +	int dev = mmc_get_env_devno();
>  	int ret = 0;

mmc_get_env_devno() is moved inside the board file. Anyway, for i.MX6
this means to check in the SRC register to get which is the boot device.
Your board functions differ just for the number they return, depending
how many controllers are initialized.

The check routine can be factorized and moved to imx-common. The devnum
could then be extracted from a table (maybe usdhc_cfg present in all
boards).

>  
>  #ifdef CONFIG_SPL_BUILD
> @@ -108,7 +113,7 @@ static const char *init_mmc_for_env(struct mmc *mmc)
>  static void fini_mmc_for_env(struct mmc *mmc)
>  {
>  #ifdef CONFIG_SYS_MMC_ENV_PART
> -	int dev = CONFIG_SYS_MMC_ENV_DEV;
> +	int dev = mmc_get_env_devno();
>  
>  #ifdef CONFIG_SPL_BUILD
>  	dev = 0;
> @@ -127,7 +132,7 @@ static inline int write_env(struct mmc *mmc, unsigned long size,
>  	blk_start	= ALIGN(offset, mmc->write_bl_len) / mmc->write_bl_len;
>  	blk_cnt		= ALIGN(size, mmc->write_bl_len) / mmc->write_bl_len;
>  
> -	n = mmc->block_dev.block_write(CONFIG_SYS_MMC_ENV_DEV, blk_start,
> +	n = mmc->block_dev.block_write(mmc_get_env_devno(), blk_start,
>  					blk_cnt, (u_char *)buffer);
>  
>  	return (n == blk_cnt) ? 0 : -1;
> @@ -140,7 +145,8 @@ static unsigned char env_flags;
>  int saveenv(void)
>  {
>  	ALLOC_CACHE_ALIGN_BUFFER(env_t, env_new, 1);
> -	struct mmc *mmc = find_mmc_device(CONFIG_SYS_MMC_ENV_DEV);
> +	int mmc_env_devno = mmc_get_env_devno();
> +	struct mmc *mmc = find_mmc_device(mmc_env_devno);
>  	u32	offset;
>  	int	ret, copy = 0;
>  	const char *errmsg;
> @@ -168,7 +174,7 @@ int saveenv(void)
>  	}
>  
>  	printf("Writing to %sMMC(%d)... ", copy ? "redundant " : "",
> -	       CONFIG_SYS_MMC_ENV_DEV);
> +	       mmc_env_devno);
>  	if (write_env(mmc, CONFIG_ENV_SIZE, offset, (u_char *)env_new)) {
>  		puts("failed\n");
>  		ret = 1;
> @@ -192,7 +198,7 @@ static inline int read_env(struct mmc *mmc, unsigned long size,
>  			   unsigned long offset, const void *buffer)
>  {
>  	uint blk_start, blk_cnt, n;
> -	int dev = CONFIG_SYS_MMC_ENV_DEV;
> +	int dev = mmc_get_env_devno();
>  
>  #ifdef CONFIG_SPL_BUILD
>  	dev = 0;
> @@ -216,7 +222,7 @@ void env_relocate_spec(void)
>  	int crc1_ok = 0, crc2_ok = 0;
>  	env_t *ep;
>  	int ret;
> -	int dev = CONFIG_SYS_MMC_ENV_DEV;
> +	int dev = mmc_get_env_devno();
>  	const char *errmsg = NULL;
>  
>  	ALLOC_CACHE_ALIGN_BUFFER(env_t, tmp_env1, 1);
> @@ -302,7 +308,7 @@ void env_relocate_spec(void)
>  	struct mmc *mmc;
>  	u32 offset;
>  	int ret;
> -	int dev = CONFIG_SYS_MMC_ENV_DEV;
> +	int dev = mmc_get_env_devno();
>  	const char *errmsg;
>  
>  #ifdef CONFIG_SPL_BUILD
> 

Best regards,
Stefano Babic

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