FP4 Root Access is possible, maybe a bit risky

I’ve been owning and rooting phones for more than 15 years now, never had any issue with warranty.
There’s always unrooting method, flag counter reset etc so I’m not worried about that.
I’m not asking advice on whether or not I should root, just asking about status :wink:

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Maybe, but as this is a discussion in a public forum, I guess it’s legit to post some warnings for not so experienced users.

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Of course that’s a fair point.

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After my FP1 died i bought an LG G6 which is flashed with HavocOS and is rooted. No Problem with google pay…

HavocOS might have some additional tweaks out of the box that hide the bootloader status and root account from Google Pay, I know some custom ROMs do that. im regular conditions though, unlocking the bootloader means that Google Pay will throw a fit unless you use something like MagiskHide and tinker a little bit.

Disclaimer: You do this at your own risk! I’ve been running my phone this way only for about an hour, this might still eat your data, make backups!

I managed to get Magisk working, here’s what you need:

  • Unlocked bootloader

  • adb & fastboot

  • Magisk app installed

  • Either the stock boot.img provided by Fairphone (check Settings → About phone → Build number for the version you need, just use the newest one if you are on a version not yet available)

  • Or, if running an OS other than stock, the boot.img that’s being shipped with your ROM.

Step-by-step:

  1. Patch the downloaded stock boot.img with Magisk

  2. Transfer / adb pull that patched boot.img to your PC

  3. Reboot to fastboot adb reboot bootloader and temporarily boot from the patched boot.img fastboot boot /path/to/patched_boot.img
    Do not flash that boot.img!!!

  4. Wait for the device to boot (took a bit longer than usual)

  5. Open the Magisk app (press Cancel when asked to perform Additional Setup), choose direct install and reboot

  6. Have fun

I tried to directly flash a patched stock boot.img, pulled boot_a and boot_b from the phone and patched those, but never could get Wi-Fi working (despite the hint in the developer docs). This way finally worked :metal:


Performing an OTA update with Magisk installed:

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Looks promising…I always root my mobiles in the past. How to get back to unrooted if things go wrong?

Depends upon what goes wrong for you

If things go wrong (but not too wrong, as @amound already said) and device still works then I think the uninstall function of Magisk app should do the trick (but also might fail and brick your phone - so use at your own risk!).

No risk, no fun

But i have enough fun in real life
I don’t need any more :wink:

which software version are you running? I’d love to do that, but I’m afraid I’ll end up flashing boot.img from a wrong version and mess things up.

also keep in mind that this method will require you to repeat those steps (patching boot.img, transferring to the phone, flashing through fastboot) after every software update.

Is a reinstall of the original ROM possible for example?

That’s true, but ok to reinstall it if already possible.

I’m running the most recent build. Unpacked the phone, tried stock Android for 5 min, unlocked the bootloader, updated to the most recent OTA and started tinkering :smirk:
The important part here is, I didn’t flash any boot.img. If you use $ fastboot boot boot.img your device boots the boot.img directly from RAM. So until you actually install Magisk in step 5 using your temporay root priviledges, a reboot brings you straight back to a unmodified phone.

There is an option in Magisk to patch the inactive partition after a OTA-Update. If you apply that before you reboot, that should probably work. Can’t say if it does, there haven’t been any updates and this is my first A/B partitioned device :man_shrugging:

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It’s an interesting option. I used an Samsung a71 partition a/b for the last 2 years. On that phone you had to install the patched boot.img.

I tried that first, but never managed to get WiFi working (see the last paragraph in Fairphone 4 Kernel Source Code Documentation).
Once full stock system images become available it’s of course way easier to patch that boot.img and flash it directly. (Or someone with actual knowledge about low level Android / kernel stuff tells us how to get WiFi working :smirk: )

Easier to wait for the original files to show up.

Hi there, I’m about to walk in your tracks soon, how’s been your device going so far ? Nothing to report ?

Edit: nevermind I went for it anyway, so far nothing to report, I’m a glad owner of a rooted fp4 and it’s wonderful. Thank you very much !
Small remark though, after booting on patched boot.img will take not “a bit longer” but “MUCH MUCH LONGER” than usual. So don’t worry :wink:

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So you have rooted since unlocking the bootloader, wow! nice job.

Without reading all the past posts, exactly what did you use to root?

Then I may change the title from a question to a ‘How to’ :slight_smile:

Thanks

Maybe you should read the posts before posting? See here:

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