Switching from CalyxOS on FP4

Installation Help
1

Hi. I want to switch to iode from Calyx for my FP4. Currently the bootloader is locked. I want to lock the bootloader after installation again if possible but I also know of some risks concerning the update status so I have some questions concerning the installation:

  1. Which update status has iode at the moment? I can not find any documentation about it. Calyx is on
    platform: 01.06.2025
    kernel: 05.06.2025
    vendor: 05.03.2025
    firmware: 05.03.2025

  2. Do I need to switch to FP OS before switching or does it work directly? I read one post in the forum that it worked directly but want to know your thought if the step in between might be worth it. Then I should compare the updates with FP OS (July 2025) with iode I guess. Or does the lower android version on FP OS also play a role?

Thank you very much in advance.

2

I am not the most authoritative, but my understand is that the iodéOS 6.6 builds (released late July) incorporate at least the June security patches, but maybe the July patches as well (it depends a bit on when upstream releases them in relation to our build cycle).

So I don’t think there will be an issue with installing, but best to not incorporate the July FP patches before you install iodéOS I think.

Note that our “full installation method” (either using the graphical iodéOS installer or using the flash-all.sh from the downloaded full device fastboot.zip image) will fully re-format all partitions, so I don’t think there is a need for going back to stock FP first.

This said, there have been some users installing on a Pixel 8 Pro and Pixel 6a quite recently that have had some oddities lately that at least one reported going back to stock rom then install iodéOS gave better results with. One of these may be coming from Calyx.

3

Hi. I just made the move from CalyxOS on FP5. To play safe, I reinstalled Fairphone stock Android with version 14; iodeOS is android 15. I wanted to make sure I start from an old security patch.
Installation went smoothly. I have not relocked the boot loader though.

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4

For anybody reading it:
I successfully switched to iodeOS with a locked bootloader.

I first installed the original FPOS but the Version TP2U with the security level from June. Then I locked critical and used the iode installer. The installation has the security patch of July so I locked the bootloader completely again. No bootloop. Everything works.

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5

Glad to know the installation went smoothly!. Please mark you post as the “solution”

6

Hi to everybody,

I’m on a Fairphone 5 with Calyx security patch level 06.2025 and I’m also thinking about changing to IodeOS. I might also take the detour over Stock in between. Whats the current security patch level of the installation file of a Fairphone 5? I just want to make sure to not brick the phone but still get a locked bootloader.

Is there any way to find out the security patch level of the installation files from public available sources?

7

For iodé 6.6 for the FP5 you can find a stable branch in our repo for it (or follow the v6-staging branch for leading edge development):

I am pretty sure what happens is that the upstream LineageOS source tree is sync’d to our repos, then any necessary adjustments are made on our side, then we build. So as a rule of thumb the security patch versions would match what is in LineageOS a few days (at most) before our builds.

If you look at that repo above, you can see the commit history here:

From that history, I see that one of the more recent upstream commits has this title: FP5: Update to FP5.UT2Q.B.125.20250605 with the actual code showing a security patch applied with the date 2025-06-05.

8

I successfully switched from Calyx to IodeOS on my Fairphone 5. I first tried to go straight from Calyx to IodeOS but that didn’t work. After the installation every reboot went straight to the bootloader. I got it working by installing the original FPOS in between. Like J00N1, I went to FPOS, locked critical and then ran the Iode-Installer. The current IodeOS on my FP5 has the bootloader locked and everything is working as expected. I also have a debian laptop. So I had to upgrade to Debian Trixie (13) in order to run the iode installer first.

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