I will assume this is a CC6UL running Digi Embedded Yocto. In Digi Embedded Yocto, the recovery process is a bit different than the Android one, but we provide a binary and an API to make it easy. By default, if you setup the module using the install script, everything should be ready and configured to work out of the box. In the case of MTD partition updates or flash-erase actions, you will have to reconfigure the update partition to make it available again. To do that just follow these steps:
1. Boot Digi Embedded Yocto
2. Issue the following command:
root@ccimx6ulsbc:~# recovery-reboot -w -T 1
Where "-w" means to format and create the update partition and "-T 1" means to delay 1 second.
3. After 1 second the device should reboot into recovery mode and execute the requested action:
. . .
******************************************
* Warning: Booting into recovery mode... *
******************************************
. . .
[RECOVERY] Starting recovery...
[RECOVERY] Wipe 'update' partition requested
[RECOVERY] Partition 'update' successfully erased!
reboot: Restarting system
. . .
4. In the next boot the update partition should be already available to use from normal boot and recovery boot:
root@ccimx6ulsbc:~# mount
ubi1_0 on / type ubifs (rw,relatime)
devtmpfs on /dev type devtmpfs (rw,relatime,size=90288k,nr_inodes=22572,mode=755)
proc on /proc type proc (rw,relatime)
sysfs on /sys type sysfs (rw,relatime)
debugfs on /sys/kernel/debug type debugfs (rw,relatime)
tmpfs on /run type tmpfs (rw,nosuid,nodev,mode=755)
tmpfs on /var/volatile type tmpfs (rw,relatime)
ubi2:update on /mnt/update type ubifs (rw,relatime)
devpts on /dev/pts type devpts (rw,relatime,gid=5,mode=620,ptmxmode=000)
According to your comment, the update process has problems to wipe the update partition because it can't find the volume called 'update':
ERROR: Could not mount 'update' partition, volume not found I can't remember if this was a critical error. It may be, if you try to update from that partition, that is, if you are supposed to have a UBIFS in that partition and the *.swu file in it. If you put the *.swu file in a microSD card or a USB stick, that error shouldn't be critical.
I'm more concerned about the other error:
Cannot parse config file '/etc/fw_env.config': Invalid argument
I don't understand why you changed this file. This is telling Linux where is the U-Boot environment located and should not be changed unless the same change is done in U-Boot but there should be no good reason to change the location of the environment. A user would normally want to change the rest of the partitions but not the U-Boot one and the environment one unless you know what you are doing.