EMMC v5.0 cannot work on Android 4.4.3

wangvictor — Wed, 30 May 2018 08:03:44 GMT

Hi All,

I have a plan to use Kingston as my eMMC IC v5.0.

As I know that Android 4.4.3 can only support it up to 4.5.

After some googling, I realize I need to modify some code in uboot and kernel driver.

There are what I had done.

bootable/bootloader/uboot-imx/drivers/mmc/mmc.c
switch (ext_csd[EXT_CSD_REV]) {
case 1:
mmc->version = MMC_VERSION_4_1;
break;
case 2:
mmc->version = MMC_VERSION_4_2;
break;
case 3:
mmc->version = MMC_VERSION_4_3;
break;
case 5:
mmc->version = MMC_VERSION_4_41;
break;
case 6:
mmc->version = MMC_VERSION_4_5;
break;
+ case 7:
+ mmc->version = MMC_VERSION_5_0;
+ break;
}
bootable/bootloader/uboot-imx/include/mmc.h
#define MMC_VERSION_5_0 (MMC_VERSION_MMC | 0x500)
kernel_imx/drivers/mmc/core/mmc.c
card->ext_csd.rev = ext_csd[EXT_CSD_REV];
if (card->ext_csd.rev > 8) {//6
pr_err("%s: unrecognised EXT_CSD revision %d\n",
mmc_hostname(card->host), card->ext_csd.rev);
err = -EINVAL;
goto out;
}
After I rebuild my image for new modification, I burn it in to my board and boot it.
Unfortunately, it still cannot starting kernel as usual.

What else should I do ?
Did I miss any step?

Thanks in Advanced

Re: EMMC v5.0 cannot work on Android 4.4.3

joanxie — Fri, 01 Jun 2018 06:38:01 GMT

try to change check value of card->ext_csd.rev, change 6 to 7.