iodéOS coming from /e/OSI have the last release on /e/OS released on 27 april 2026. I tried to install last iodéOS fastboot build but when I locked bootloader I had the alert “device corrupted”. I installed back /e/OS and everything went fine. I understand it’s because it’s because /e/OS build is newer so I can’t go back and install earlier builds. Is there a newer (beta ?) builds I can install using fastoot ?
If you don’t lock the bootloader one can install an older version and use the os.
Hello @oblako, Welcome to this Fairphone users forum.
what matter is the “Android Security Update” at time of the unlock,
if you unlocked the bootloader with e-3.7-a15 and “2026.04.01” ASU/SPL, you can install whatever version you want if you wait for an update to relock the bootloader with a newer “Android Security Update”.
after relocking the bootloader, DO NOT DISABLE “allow OEM unlock” in Developer Options to keep ability to unlock in the future
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Thank you a lot !
so you suggest I install iodé OS and not lock the bootloader until next Android Securilty Update. Am I not more exposed with a unlocked bootloader ? I have already seen IodéOS doeesn’t need flash lock_critical. Isnt’it more vulnerable ?
only if an attacker have your device in his hand…
you also can wait for the iodé update to switch OS.
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OK Thank you ! I see
I guess you can do that but if I understood it correctly, you’ll loose all your data because relocking erases the data. That means reinstalling all the apps and settings after relocking.
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I’m not sure to understand: as you mentionned, this settings allows the bootloader to be unlocked. However it does not formally unlock it, it only allows to unlock it. So even if this setting is enabled but the bootloader is still locked, it won’t prevent a soft brick if an OS with an older SPL is installed. Is that correct? If so, then what is the actual benefit of leaving that setting enabled?
if the bootloader is locked, installing an OS with an older SPL is not possible.
benefit is to not be stuck with a locked bootloader in case android refuse to boot…
Bootloader Lock – The AXP.OS Project
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Sure ! this is a problem but I am now used to it 
Fairphone Iodé user here. I would recommend different approach when switching ROM’s.
First install back the official Fairphone OS. It can be downloaded here and there is a guide as well. This will ensure you have the latest firmware (very important). Then install IodéOS, but make sure that the latest security patch on Iodé is the same or newer than the one you had on the Fairphone OS (it will most likely be the same). Then you can re-lock your bootloader immediately with no issues. If you don’t do the firmware update you risk issues like this - you won’t be able to do phone calls for example.
Isn’t e/OS also updating the firmware (on devices with official support e.g FP6)?
it is a safe advise..
because iodéOS as like as /e/OS include firmware parts relating to its own android level.
that may means upgrading or downgrading regarding current / latest Fairphone Gogol OS version