[solved] can't boot Chromebook from USB / sdcard

[altreact]

After installing Arch Linux ARM on the internal flash memory (mmcblk0) of my Samsung Series 3 Chromebook, I lost the ability to boot from the USB ports and the SDcard slot.

After some searching, I found out how to do so.

pacman -S vboot-utils

crossystem dev_boot_USB=1 dev_boot_signed_only=0

Then, you can boot from USB / sdcard slot again! Woohoo!

I'm thinking that this solution may work for any Chromebook (ARM, x86) after installing an alternate operating system on the internal storage.

I hope this helps you, and that you don't have Togo through the headaches that I have gone through while trying to resolve this issue.