GSI ROMs for FP4 (WIP)

Hello there ^^

I’m asking myself whether there are any experiences with GSI ROMs for the Fairphone 4?
I switched from Fairphone OS to LineageOS 20 because of… features…

How to flash
  1. Get an up-to-date fastboot on your computer (fastboot —version should give version >= 29)
  2. Get vbmeta.img from
  3. Get A/B arm64 GSI
  4. From running Android, do adb reboot bootloader and select fastboot
  5. fastboot --disable-verity --disable-verification flash vbmeta vbmeta.img
  6. fastboot reboot fastboot
  7. fastboot flash system system-xxxx.img
    6bis. If fastboot tells you there isn’t enough place, do fastboot delete-logical-partition product, fastboot delete-logical-partition producta, fastboot delete-logical-partition productb and run the fastboot flash command again
  8. On your phone, the screen should have a button “go back to recovery”, select it, then select “factory reset / wipe data” (for clean flash)
  9. Reboot and enjoy
ROM Flash method Base ROM (what was before) Results
AncientOS v7.1 vanilla clean flash LineageOS 20 w/o Magisk :wavy_dash::watch:
AncientOS v7.1 vanilla dirty flash LineageOS 20 w/ BitGApps & Magisk :x:
crDroid GSI v9.9 dirty flash LineageOS 20 w/ BitGApps & Magisk :x:
crDroid GSI v9.9 clean flash LineageOS 20 w/o Magisk :wavy_dash: (Boots up but after unlocking the touchscreen stops responding)
SparkOS v13.7 dirty flash LineageOS 20 w/ BitGApps & Magisk :x:
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the search function might give answers


And the other one here? I mean, I could flash every day or week a new GSI ROM, but that’s just me…

Who knows, if someone else did that already like the idea of soldering a 2nd SIM card slot to the left solder pads and implement a small switch to switch between eSIM or 2nd physical SIM ^^

my GSI for FP3 could theoretically work on a FP4, or any other phone, because it’s a GSI

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Weird… I can’t edit my first post… meeh!

I’m currently experimenting with GSI ROMs and so far, I BELIEVE to understand how GSI works
(Please correct me, I didn’t read the technical stuff YET, I’m only talking about experiences!)

I’ve noticed that nowadays, there is a /vendor partition and there seems to be many hardware related stuff inside like drivers, config files and so on…

I have a tablet with /vendor which I had to modify to slim down the stock Android…

Now I’m abusing my old Sony XZ2C for testing and so far, every GSI works fine…
I’m thinking about to test soon how dirty flashing works out for people, who doesn’t want to config everything again although I would NEVER recommend doing this if you don’t use AOSP or LineageOS before (these ROMs are mostly used as a base for custom ROM and they are pretty bare…)

I also won’t test many GSI ROMs because I only have ONE main phone… I try to get hold of a FP4 for cheap for development purposes! But feel free to test some GSI ROMs and report your experiences :slight_smile:

Wish me luck!

Made it a wiki if you want to edit the first post still


@yvmuell Do you know, how I can resize the system partition? It need space for GApps installation :confused:

no I dont know, maybe this helps