Trapped in fastboot mode with locked bootloader and corrupted custom ROM

I think hundreds of people use Custom ROM on the FP3 which is an A/B device with locked bootloader as well, and most people re-lock there bootloader. This has all been discussed over and over and over again the last days maybe you want to read the other threads first and search the forum for FP3 related topics

1 Like

I just want to verify if this issue is really something in the domain FP can solve :wink: If this is really not just a 3rd party issue, then I’ll just leave it there in that list. I remain a bit skeptical, but since someone mentioned FP hasn’t replied to this issue, I guess something must be up.

I understand what you said and still reading other topics will help you to exactly answer this question

Not sure what is difficult about extracting a ZIP folder and double click “flash_fp4_factory.bat” followed by a yes confirmation? Seems to be the exact same process as on the FP2 and that was really simple

That’s for sure not hard indeed, also not for Linux, it seems just to run Maybe this is a recent change? I came across a documentation page with a lot of manual steps. I’m a senior Linux systems architect and even I was like; whut? Good to see it has improved.

You can lock the bootloader on /e/, iode and CalyxOS (and stock FPOS of course) and all of them actually encourage you to do so, so yeah this is a real problem.
If something goes wrong when locking the bootloader and get_unlock_ability was somehow (no one has figured out how) reset to 0, the phone is bricked and can only be repaired by Fairphone.

Since this is a flag that should survive factory resets (and it survived the phone being flashed back to stock on my devices), I’d expect Fairphone to have knowledge about where it’s stored and what could be messing with it.

Even if this turns out not to be a Fairphone problem, some help for the community how to figure it out would be really appreciated. I’m pretty sure they don’t want unnecessary work for their support staff either…


I got my FP4 today and I’m facing the same problem. I cannot unlock anymore and the phone won’t boot either. Does anyone figured anything out yet?

Nope, if your phone is not booting, the bootloader is locked and you cannot unlock you are unfortunately out of luck.
If you boot into fastboot mode and connect your phone to your PC, what does fastboot flashing get_unlock_ability return? If it returns 0 you will have to send it to get it reflashed.

1 Like

Huh that’s a bummer, it returns 0 indeed. That’s kinda unlucky I was so hyped. Thanks for the quick reply though.

Your next steps are

  1. contact FP support
  2. send your device to the repair centre in France
  3. receive a quote of ~600€ (price of a new phone)
  4. complain to FP that the repair centre doesn’t do its job properly
  5. wait 5 days
  6. receive a new quote for 30€
  7. pay
  8. ???
  9. profit

Thanks for the detailed info. Wow that’s crazy. About what should I complain exactly :smiley: I already contacted the support. I hope it won’t be much more than the 30€ since I’m a student and I saved all my money up to even buy this phone…

Complain might be a tad strong, but Cordon repair has a track record of wanting to replace perfectly good phones. Don’t be scared if you receive a quote for a new phone, you wouldn’t be the first. Just ask FP support why they want to replace your phone and not just reflash a factory image, whoch they should be able to do.

If you want the complete history I’ll just link to my own thread, was a wild ride :slight_smile:

30€ seems to be the standard rate they charge to fix this kind of issue, that is also what they charged me :slight_smile:


Thank you very much for the detailed info and shame on me for making this happen in the first place. I just wanted to enjoy a smooth /e/ experience today. But things happen, at least there are great people like you out there… Thanks a lot <3


I managed to set get_unlock_ability back to 1 again (with an unlocked bootloader, don’t get your hopes up) by using Magisks resetprop

adb shell su -c 'resetprop ro.boot.flash.locked 1'

…and switching the OEM toggle in developer settings back to on.
Magisk for the rescue again :metal:

We should advise people to check fastboot flashing get_unlock_ability before locking the bootloader.
It’s a bit of a hassle having to set up Magisk just to reset that flag, but beats bricking the phone. Maybe there’s another way to fix this :thinking:


I mentioned that (already as we diskussed this the first time) as a a imortant step in my instruction to install iodé.

1 Like

Hi there, thank you all for your contributing to this thread!
We’ve been following it closely and your feedback has not gone unheard.

There is a new package for manual installation available for download here, it’s for build 107 - the latest at time of writing. The script now addresses an error that can be introduced by installing software manually. As long as you use the latest available package, you should not be getting stuck in Fastboot mode.

As always - in case of any issues, #contactsupport


Thank you very much for this!
Could you explain a bit more what the problem is? So that we understand it and the community also knows what to do in case of further problems?

I did a quick diff and here’s the most obvious change i could find:

echo "INFO: Deleting factory reset partition"
    ${FASTBOOT_BIN} erase frp

was changed to

echo "INFO: Deleting factory reset partition"
    flash_image_or_abort "${sn}" frp "${IMAGES_DIR}/frp_for_factory.img"
    flash_image_or_abort "${sn}" devinfo "${IMAGES_DIR}/devinfo_for_factory.img"

Those two images mentioned above have also been added to the included images.

Last but not least, the slot is now automatically changed to a:

echo "INFO: Activating partition slot A"
  fastboot --set-active=a

The rest seems to be mostly linting as far as I can tell :thinking:


Thanks for this!

Can confirm that for me the get_unlock_ability flag unexpectedly changed as well to 0, in my case when going from e/os to CalyxOS without having OEM-locked the phone at any point:

From stock to e/os

  • Fresh FP4
  • OEM unlock on untouched stock OS
  • bootloader unlock and unlock_critical
  • checking: get_unlock_ability=1
  • flashing e/os, worked fine
  • still get_unlock_ability=1
  • bootloader lock and lock_critical
  • still get_unlock_ability=1

From e/os to CalyxOS

  • bootloader unlock and unlock_critical
  • still get_unlock_ability=1
  • flashing CalyxOS
  • get_unlock_ability=0, OEM unlocking greyed out while bootloader is still unlocked (which I will not lock for now, of course, until I get that flag set back to 1)

So now, the big question is: how can this done easily?