[Solved] SD Card strange boot behaviour

[carlosqueso]

I have a pinebook pro running the Manjaro KDE default install everything is working fine. I'm very pleased with the device. I had ordered an additional eMMC of 128GB to replace the 64GB eMMC with. So I installed an other OS, Manjaro I3 SD card image, on a micro SD card I owned (samsung micro sd hc card of 32 GB read and write speeds not known..) and I am experiencing some weird boot issues.

Here are the scenario's:
- If I shutdown the pinebook pro insert the SD Card and power it on, I get the orange light, turning green, but the device won't boot from the SD-card.
- If I boot from the eMMC, insert the SD Card, mount the boot partition of the SD-card and restart the device, it boots without any issues from the SD-card.

Now if I want to replace the eMMC with the 128GB one I am not able to boot from the SD-card as it won't boot from a 'cold' start.

Might this be an issue with the SD-card being to slow? or is this some other problem? I've done the above two scenario's many times over and over again and it always succeeds when first booting up from eMMC, inserting the SD Card, mounting the boot partition of the SD-card and reboot.

Try mounting your SD card boot partition, and editing the extlinux/extlinux.conf file for the SD card to add two dots before each slash as in this post: https://forum.manjaro.org/t/arm-stable-update-2020-04-02-kde-plasma-5-18-4-xorg-server-1-20-8-plasma-mobile-uboots-and-kernels/133266/2 

I know it's not supposed to be required on a fresh image, but it solved it for me when I was in your exact scenario.