static int do_mmc_bootmode(cmd_tbl_t *cmdtp, int flag,
int argc, char * const argv[])
{
struct mmc *mmc;
int ret = BOOTMODE_NORMAL;
u32 blk, cnt, n;
void *addr;
char original_part;
addr = (void *)malloc(512);
blk = BOOTMODE_BLK_NUM;
cnt = BOOTMODE_BLK_COUNT;
mmc = init_mmc_device(curr_device, false);
if (!mmc)
{
free(addr);
return CMD_RET_FAILURE;
}
/* Switch to the Boot 2 partition */
original_part = mmc->block_dev.hwpart;
blk_select_hwpart_devnum(IF_TYPE_MMC, curr_device, MMC_PART_BOOT2);
mmc_set_part_conf(mmc, 0, MMC_PART_BOOT2, 2);------------------------------------------切换到eMMC boot1分区。
n = blk_dread(mmc_get_blk_desc(mmc), blk, cnt, addr);----------------------------------读取一个block。
if(n != cnt)
{
free(addr);
return CMD_RET_FAILURE;
}
/* flush cache after read */
flush_cache((ulong)addr, cnt * 512); /* FIXME */
if(*(unsigned int *)addr == BOOTMODE_UPDATE_MAGIC)
{
ret = BOOTMODE_UPDATE;
}
else
{
ret = BOOTMODE_NORMAL;
}
#if 0
for(int i = 0; i < 512/16; i++)
printf("%08x %08x %08x %08x\n", *((int *)addr+i*4), *((int *)addr+i*4+1), *((int *)addr+i*4+2), *((int *)addr+i*4+3));
#endif
/* Switch to original partition. */
blk_select_hwpart_devnum(IF_TYPE_MMC, curr_device, original_part);----------------------切换到默认分区。
free(addr);
return ret;
}
至此可以在Linux和Uboot下对boot分区进行操作，进行bootloader烧写或者进行重要数据更新。
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