On linux, you should be able to issue “fastboot oem allow-flashing” command if you only made it through the “fastboot flashing unlock_critical” step and then run the flash_fp5_factory.command with all the checks commented out. The main program starts at line 365 and I commented out the integrity_check and is_unlocked and was able to run the script and get Fairphone OS back on the phone. (THIS IS DANGEROUS - YOU ARE REMOVING THE SAFETY CHECKS FROM THE INSTALL FILE)
That being said, I wanted e/OS on the Fairphone 5 with a locked bootloader, so I started over, installed Fairphone OS (Android 13) and then laid down Murena e/OS 2.7 for Android 13. (I had this combination installed previously on this Fairphone 5 so I know it works, I still had the same install files and the security patch levels are all ok) I commented out the “reboot_device” at the end of the flash_FP5_factory.sh install script in the eOS image (IMG-e-2.7-t-20250111460957-official-FP5) since the instructions say to issue the “fastboot flashing lock_critical” BEFORE the phone reboots.
prod:~/Downloads/eOS/IMG-e-2.7-t-20250111460957-official-FP5$ fastboot flashing lock_critical
OKAY [ 0.027s]
Finished. Total time: 0.027s
I get the screen on the phone with the warning that locking the bootloader will erase all data. I accept and the phone reboots. Next, upon reboot I go through all the steps to set up the phone so I can enable USB debugging and connect the phone via USB. (The same one I’ve used for this multiple times.)
Back out to a command prompt and check the device status:
prod:~/Downloads/eOS/IMG-e-2.7-t-20250111460957-official-FP5$ fastboot oem device-info
(bootloader) Verity mode: true
(bootloader) Device unlocked: true
(bootloader) Device critical unlocked: false
(bootloader) Charger screen enabled: true
OKAY [ 0.001s]
Finished. Total time: 0.001s
Good, looks like I’m halfway there…critical is locked now I just have to issue the second lock command and I’m all good, my bootloader is locked and my data is secure, right?
bpp@prod:~/Downloads/eOS/IMG-e-2.7-t-20250111460957-official-FP5$ fastboot flashing lock
OKAY [ 0.027s]
Finished. Total time: 0.027s
The phone reboots and I get the message, “Your device is corrupt. It can’t be trusted and will not boot”.
Now when I issue the “fastboot oem allow-flashing” command, I get the following response…
prod:~/Downloads/FPOS/FP5-TT4H-factory$ fastboot oem allow-flashing
FAILED (remote: ‘unknown command’)
fastboot: error: Command failed
bpp@prod:~/Downloads/FPOS/FP5-TT4H-factory$
And the fastboot version…
prod:~/Downloads/eOS/IMG-e-2.7-t-20250111460957-official-FP5$ fastboot --version
fastboot version 34.0.4-debian
Installed as /usr/lib/android-sdk/platform-tools/fastboot
It appears I might not be able to get around the bricking this time. Any thoughts? I followed the locking procedure and yet it still bricked the device. Also of note, I was never able to get into fastboot mode using the buttons on the device - I alwasy had to issue the “adb reboot bootloader” or “fastboot reboot bootloader” command.