Mount eMMC after booting from SD card

[User 11436]

Does anyone know whether it's possible to boot Debian from an SD card on the Pinebook Pro, then insert the eMMC card and mount it? I briefly tried, but had no success.

A while back I messed up uboot on the Manjaro installation on my eMMC card. Afterwards, the Pinebook Pro wouldn't boot from eMMC, or from any other Linux distribution on an SD card if the eMMC was attached. If I remove the eMMC, which I currently have, I can boot from the SD card, but if I re-attach the eMMC card after boot I can't work out how to make the system mount it.

I've ordered a eMMC-to-USB adapter from Pine64, but I was wondering whether there was any other way of mounting the eMMC on an already booted Pinebook Pro.

[tophneal]

You can, but it involved having the back plate off. There might be another way to do this, but what you'd want to do is :

Insert your bootable SD in the PBP.

Open the lid and lay they palm rest down on a surface, with the lid hanging off the edge. (recommended to avoid flexing/breaking plastics.)

With the emmc switch off, turn on the PBP.

When you see the power LED activate (uboot from the SD has started) turn the emmc switch to ON. You should have a few seconds from turning on to do this.

The PBP should now boot using the SD, with the emmc initialized by uboot. From there, let it boot up and do the maintenance you need.

[User 11436]

You can, but it involved having the back plate off. There might be another way to do this, but  what you'd want to do is :

Insert your bootable SD in the PBP.

Open the lid and lay they palm rest down on a surface, with the lid hanging off the edge. (recommended to avoid flexing/breaking plastics.)

With the emmc switch off, turn on the PBP.

When you see the power LED activate (uboot from the SD has started) turn the emmc switch to ON. You should have a few seconds from turning on to do this.

The PBP should now boot using the SD, with the emmc initialized by uboot. From there, let it boot up and do the maintenance you need.

Thanks for your help.

I managed to boot into my SD with the eMMC visible. Unfortunately, I wasn't able to undo whatever it was I did to uboot on the eMMC, so I'm reinstalling Manjaro.

[lxn]

An alternative to turning the switch at the right time is to take your time, insert the eMMc when the system has booted, turn the switch on and run the following as root:

echo 'fe330000.sdhci' | tee /sys/bus/platform/drivers/sdhci-arasan/unbind
echo 'fe330000.sdhci' | tee /sys/bus/platform/drivers/sdhci-arasan/bind