No detection of Emmc module in Ubuntu Stretch


#1

HI All,

I have flashed Ubuntu Stretch Image on SD card, a system is working fine, able to update and upgrade it but I could not see emmc detected in it.

Could anyone please tell me about the emmc support in this release included or not?

Thanks,


#2

Hi,

So you flash the stretch image on SD card and also have the eMMC module mounted on board? For ROCK Pi 4 default 4.4 kernel, the eMMC is alway /dev/mmcblk1 and the uSD card is always /dev/mmcblk0.


#3

Hi Jack,

My bad, It was just connection issue.
I could see both emmc and SD detected in system.


#4

as you said, default boot device is SD card?


#5

If you have SD card and eMMC module with both bootable image on it, SD card will boot first. There are some details but to be short, it is so.


#6

is there a way to ajust boot device order like PC bios?


#7

Arm doesn’t work the same way as x86 does. I.e. there is no BIOS. Order how to boot is hardcoded in very small amount of memory that’s installed almost inside chip itself. There a few possibilities, i.e. rewrite this piece of memory, but this could lead to brick or use USB otg mode to set boot manually, but that’s all