how to change uEnv.txt from U boot interface ?

Hi all,

I made some changes on the uEnv.txt file from my computer , then I rebooted my beaglebone.
Now it starts the u-boot and writes “starting kernel” and it just hangs.
My system(ubuntu) can’t see the beaglebone anymore when I connect it using USB, so I can’t re-edit my uEnv.txt

So, is there anyway I can undo my edits on uEnv.txt ?? Can I do it from the U-Boot interface ?

Screenshot from 2016-09-14 02:51:05.png

Fist, you would get an sdcard, and flash an image to it.

Once you have that image on an sdcard, you boot as normal- with the sdcard inserted of course. Then:

login as: root
Debian GNU/Linux 8 Debian Image 2016-06-19
default username:password is [debian:temppwd]

root@beaglebone:~# lsblk
mmcblk0boot0 179:8 0 2M 1 disk
mmcblk0boot1 179:16 0 2M 1 disk
mmcblk0 179:0 0 3.7G 0 disk
`-mmcblk0p1 179:1 0 3.7G 0 part /

root@beaglebone:~# mkdir /media/rootfs

root@beaglebone:~# mount /dev/mmcblk0p1 /media/rootfs/

root@beaglebone:~# cd /media/rootfs/

root@beaglebone:/media/rootfs# nano boot/uEnv.txt

undo the changes you made. If you can not remember the changes you’ve made, it may be easier to just reflash the eMMC.

Hi Ahmed,

I write a bit later but it can help someone else.

If you have a backup of uEnv.txt - so than it is quick and simple.

First copy file content to RAM memory:

ext4load mmc 1 0x80000000 /boot/uEnv.txt_bck

Write content of file to new file:
ext4write mmc 1 0x80000000 /boot/uEnv.txt 2042 0

mmc 1 - it is my rootfs partition. Use the command mmc list to see the partition.

This is how I did it using a microSD card:!category-topic/beagleboard/b21LZKh8z2w

John Allwine
Principal Software Engineer