Trouble booting from EMMC

(azteca1998) #1


I’m having trouble making my bpi-r2 boot centos 7 lite from eMMC. As far as I know, the instructions for other boards are just doing:

# dd if=image.img of=/dev/emmc

with their respective image and device names. This, though, doesn’t seem to work on my board.

When I run that command, shut down (gracefully, and after a sync), remove the SD card and try to boot again, it doesn’t boot as if only thing the bpi-r2 could boot is the SD card. In my board, there’s a selector which has SD and EMMC labels, but it doesn’t seem to do anything either.

Has someone had a similar problem? If so, have you fixed it? And how?


(Frank W.) #2

have you changed your partition-config of emmc?

(Wolfgang) #3

Due to the way the MT7623 chip works, it will never be possible to have a single image that can be either copied to SD card or eMMC by simply using ‘dd’.

The MT7623 requires a preloader binary that is provided by Mediatek/Sinovoip. When using eMMC, this preloader is required to be in the eMMC’s protected boot partition.

Such a boot partition does not exist on SD cards, so the preloader is located at address 0x800 instead.

(azteca1998) #4

I’ve managed to boot from emmc by setting the partition mode to 0x48 (thanks frank-w).

As for the preloader binary, I’ve noticed that there is a partition (/dev/mmcblk1boot0 and /dev/mmcblk1boot1 I think), which is most likely to contain that binary.

Strangely enough, running dd on the root drive (/dev/mmcblk1) does not erase those partitions. That is probably why dd worked for me after setting the partition mode.