A couple days ago I installed e/OS 2.9 (security patch: 2025-03-01) on my Fairphone 4 using this guide: Install /e/OS on a Fairphone FP4 - “FP4”. In the guide it says:
“If you try installing a version of /e/OS based on a security patch that is older than the one on your device, you will brick your device.”
I don’t know which security patch I had before installing e/OS. Is there any way to find this out? Will I brick my phone when I lock the bootloader?
Hello @ByeGoogle, welcome to /e/ forum.
not sure now that you have overwrite the FairphoneOS, but have a look in
→ settings → about the phone → android version 14 → android security update
What do you see ?
relocking is not always a good idea
A discussion about bootloader locking/unlocking… AKA I want to relock my bootloader, should I?
The date is stored in an index deep within the device but I cannot tell you how to read it.
Which of the Different Build Types did you install ? Only official may be locked. If you installed community it should not be locked.
Looking for clues for previous SPL, did you update the phone since it was delivered ? Was this long ago ? Did you keep a note of date when you updated ? If you did you might check the SPL of relevant / latest FairphoneOS release.
As @piero suggested, I will leave the bootloader unlocked. Next time I will note the current security patch level before installing e/OS.