Cannot lock the bootloader FP4

[Dan-sol]

Hallo!

So I installed 1.17-s eos on my Fairphone 4 Nov 23, and misunderstood the antirollback warnings. So I installed an os based on an android security patch from october on a phone with patch from november.

Everything went smoothly until I performed the fastboot flashing lock operation. That sent me into an eternal loop where I always ended up in the bootloader. So thought that I had bricked my phone. Fortunately I could get my phone to work by running fastboot flashing unlock.

But, this meant that I have a rooted phone. This has quite a few disadvantages, especially being unable to install aps because some apps simply wont install when the phone is rooted. There is of course also the added risk of having a phone that is less protected to intruders…

I have now waited quite a while and have now upgraded to 1.19-t. And assumed that this would dove the issue, but exactly thw same thing happened even though it now 1.19 t should be based on a security patch from december… I have a few questions related to this.

1. Did i brick my phone after all, is that why it doesn’ work?

2. Would a complete factory restore at least fix the issue. So that can get an unrooted phone

3. Is this because eos doesn’t really work with eos, at least not completely?

4. Could I get out of this somehow, and stil have eos on my phone. Or do I need to chicken out and get move back to fairphone os?

Otherwise I am really happy with eos, so would be a shame…

Regain your privacy! Adopt /e/OS the unGoogled mobile OS and online services

[ff2u]

@Dan-sol

Did i brick my phone after all, is that why it doesn’ work?

No, that’s not the reason (although I also can’t give you the reason why locking after installing 1.19-t did work neither).

@Dan-sol

Would a complete factory restore at least fix the issue. So that can get an unrooted phone

No, this won’t change anything. Locking the bootloader does a factory reset anyway.
Unlocking the bootloader is not rooting the phone. So relocking it does not help to “unroot” the phone.

@Dan-sol

Is this because eos doesn’t really work with eos, at least not completely?

No.

@Dan-sol

Could I get out of this somehow, and stil have eos on my phone. Or do I need to chicken out and get move back to fairphone os?

You might still wait until 1.20-t is out. This might happen soon…?!

Anyway - I’d very much recommend to always check the OEM unlocking flag before trying to lock the bootloader. Here you were lucky and OEM was (still) enabled, so

@Dan-sol

Fortunately I could get my phone to work by running fastboot flashing unlock.

In case OEM unlocking flag is disabled and you unsuccessfully lock the bootloader you’ll hard brick the device!

An imho helpful post with a security consideration of locking the bootloader in relation to the OEM unlocking flag can be found here: https://forum.fairphone.com/t/is-there-any-benefit-to-disabling-the-option-oem-unlocking-again/83703/6?u=volker