Booting Solidrun ClearFog Base from eMMC

General Discussions
1

Hi Mirzak,

I wasn’t able to get this to run on the eMMC or when booting from USB on ClearFog Base. I have been able to boot the Debian image successfully from the eMMC. Have you tested the images produced and have been able to boot? I should also say I didn’t modify the recipes other than activating hosted mender and putting in my token.

2

Hi @henzigen,

No this was never tested using eMMC as I did not have an eMMC module when I did this integration. This has only been tested using SD as boot medium. I should probably have put a note on this in the tutorial.

With that said it might work with eMMC, if you add the following in e.g local.conf:

 MENDER_STORAGE_DEVICE = "/dev/mmcblk1"

As I assume mmcblk0is the SD card.

3

Thanks for the quick reply. The eMMC is actually mmcblk0 if you order the eMMC version and the sdcard slot is disabled. It’s one or the other.

So I followed the guide here but instead replacing the debian image with the image built with yocto. The eMMC has two boot partitions, and a data partition. The guide provides a u-boot-mmc to dd onto boot partition 0 and then set the eMMC to boot from there. When I did that, it failed to boot but interestingly enough it did have some messages regarding mender-setup not being defined. I also tried to set the eMMC to boot directly from the data partition because I see that /dev/mmcblk0 ends up having 4 partitions (boot, data, primary, secondary) but that fails completely. No boot messages at all. I was thinking of dd’ing the /dev/mmcblk0p1 onto the eMMC boot parition 0. Do you think that would work?

4

This probably means that you did not get the correct U-boot binary flashed as it is trying to execute the following,

But it wont be that easy and this probably requires some additional integration work. If i recall correctly, they have different U-boot configuration depending on where you will load it from, so you need to adjust this,

Also the sdimg can not have an embedded U-boot for eMMC so you would need to manually write it after you have flashed the sdimg, and this is the command according to Solidrun docs that you execute on a running system to flash U-boot,

  echo 0 | sudo tee /sys/block/mmcblk0boot0/force_ro
  sudo dd if=u-boot-spl-mmc.kwb of=/dev/mmcblk0boot0 conv=sync
1 Like
5

Mirzak, you’re amazing. That did it. I added UBOOT_BINARY = “u-boot-spl-mmc.kwb” and ran bitbake. It produced “u-boot-spl-mmc.kwb”. I flashed that to boot 0 parition of eMMC and it worked perfectly. The device popped up on my hosted mender. Thank you so much for your help.

1 Like
6

Glad it worked out for you.