uEnv.txt and Kernel 4.1 Device Overlays

Hello All,

I was attempting to configure uEnv.txt to enable the new Kernel 4.1 device overlays, using debian-8.3-console-armhf-2016-02-11. I mistakenly though that I had to rename /bbb-uEnv.txt to /uEnv.txt and make the changes there. Well, it turns out that it’s /boot/uEnv.txt that you need to edit (in the /boot directory, not the root). The one under /boot has friendly, commented-out blocks that you can use to do things like disable HDMI, or enable a device overlay. I just though I’d share my silly mistake so that others don’t repeat it and waste time.

For those who are not yet familiar with the new device overlays, check out the readme.md at https://github.com/RobertCNelson/bb.org-overlays. The new Debian images also come with a bunch of revised “canned” device overlay *.dtbo files that are ready to use. They are listed here.

Hope this helps someone,
Emile Cormier

Yes, that is because . . .

/uEnv.txt is the “real” uboot envoirnment file. You do not want to edit this file unless you know absolutely what you’re doing. Really though, this file is not meant to be edited.

/boot/uEnv.txt is the second stage environment file, from which the first stage file loads various variables for various configuration options. Editing stuff in this file should not keep the board from booting. But it is possible to configure this file in a way that will leave the board unable to find it’s proper kernel version.