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

[Peng Fan <b51431@freescale.com>]

Hi Stefano,

On Tue, Dec 15, 2015 at 03:58:47PM +0100, Stefano Babic wrote:
>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).

Thanks for comments. How about the following way:

Add the weak function in imx-common/cpu.c:
__weak int board_mmc_get_env_devno(int devno)
{
	return CONFIG_SYS_MMC_ENV_DEV;
}

Add add in arch/arm/cpu/armv7/mx6/soc.c
int mmc_get_env_devno(void)
{
	devno = [ check src smbr1 ]

	return board_mmc_get_env_devno(devno)
}
For i.MX7, it's different, and need to fix it in arch/arm/cpu/armv7/mx7/soc.c

And final in board file,implement
int board_mmc_get_env_devno(int devno)
{	
   following is example for different boot slot used by different boards:
	sd1/sd2/sd3, return devno;
	sd2/sd3, return devno - 1;
	sd3/sd4, return devno - 2;
	sd1/sd4, if (devno == 3) return devno - 2; return devno
}

Thanks,
Peng.
>
>>  
>>  #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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