How to install GSI on the Fairphone 5?



Everything is in the title.
I don’t like the stock OS shipped with the Fairphone 5. Google included, no customization, missing essential options for me I have on other system like LineageOS (tile of USB tethering, prevent screen from wake up when connecting/disconnecting charge cable etc.)

While waiting for official alternative system, I want to install a GSI (RisingOS or crDroid) to make the work.
Already tested them through DSU Sideloader and worked great.

But all GSI come as a system.img file, while the Fairphone 5 use the new super format (one file for system, vendor etc.)

All my attempt to install the GSI resulted in… nothing. The phone still boot on the stock OS.

What is the procedure to install GSIs on Fairphone 5?

Thank you in advance.

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Found the answer by myself.

For people who want to try the adventure, you need to restart the phone in fastbootd mode, not fastboot.
Then you can flash independant system.img partitions.


I had to look up “GSI”:

A generic system image (GSI) is a system image with adjusted configurations for Android devices. It’s considered a pure Android implementation with unmodified Android Open Source Project (AOSP) code that any Android device running Android 9 or higher can run successfully.

Sounds interesting. @SpringsTS did it work?

Would it work as a daily driver?
Is there a more comprehensive guideline somewhere?
What are the pros / cons compared to using one the typical custom roms?

Would it work as a daily driver?

If you can give up on some features yes.

What are the pros / cons compared to using one the typical custom roms?

Very quickly…

  • A lot of systems exists in GSI format (my favorites being crDroid, AncientOS and SparkOS)
  • Enjoy alternative OS features that you won’t find in stock OS (Smart Pixels for example)


  • Device-specific features may not work.
  • On FP5, 5G network doesn’t work (only up to 4G/LTE), neither Adaptative Brightness (you can only set the brightness manually)
  • Possible heavier battery drain and performance loss (noticed it on my old FP3, not on the FP5)

Is there a more comprehensive guideline somewhere?

As it was difficult for me to find the correct actions to do, I may add a guide here if you want. Just know that I’m not an expert and, as you’ll see everywhere, before doing anything, backup your data.


Interesting, will def play around with this tonight.

Guide would be nice to work out how to get it setup, if you add the usual

* Disclaimer 
* I am not responsible for bricked devices, dead SD cards, thermonuclear war, 
* or you getting fired because the alarm app failed. Please do some research 
* if you have any concerns about features included in this ROM
* before flashing it! YOU are choosing to make these modifications, and if
* you blame me in any way for what happens to your device, I will laugh at you.
* BOOM! goes the dynamite

It should be enough of a warning :slight_smile:

Got 5G working, had this issue with a phone ages ago and the same solution fixed it.

Go to the dialer and type “*#*#4636#*#*” and it should bring up a “Testing” menu, select “Phone Information”.
In there you should see “Set Prefered Network Type”, depending on where you are is what you need to use, for me in the UK “NR/LTE/GSM/WCDMA” worked for me to get 5G

Not all custom roms have this (I tested this on rising os), but there are otherways to get that menu.

NOTE: In rising os after making this change, the normal “preferred network type” still only gives an option for 4g, even though its clearly using 5g (speed + icon in status bar), I’m not sure if a reboot would solve this but as I’m using dsu sideloader I can’t reboot to test this

Never tried GSI’s before tonight, always used custom roms, been suprised how easy its been to test em, just gotta figure out how to properly install them now :blush:


Yes, I tested a lot of GSI through DSU Sideloader too, it’s a really good tool to try other OSes without wiping all data.

Thanks for the tip, I will check it next time I reinstall a custom OS!

If you use DSU Sideloader, I assume that you already have unlocked bootloader, disabled vb_meta verification etc.

In theory:

  1. Backup your data
  2. Boot to flashbootd from ADB:
    adb reboot fastboot (or adb reboot bootloader, I always forgot which one is the good one)
  3. Flash you GSI img file as system.img:
    fastboot flash system path-of-your-gsi-image.img
  4. Reboot into recovery (through on-screen menu)
  5. Wipe user data (aka. Factory reset), through on-screen menu
  6. Restart and enjoy

In practice, you may encounter errors if the GSI file is bigger than the stock system.img size. A workaround is to remove the “product” partitions, usually not used by GSIs, to free some space.
In fastbootd mode, execute the following:

fastboot delete-logical-partition product_a
fastboot delete-logical-partition product_b

Of course, this means that if you want to go back to stock OS, you’ll have to fully reinstall FairphoneOS, as provided by the Fairphone support.


Has anyone ever tried to install GSI Build like (Andy Jan´s Lineage)???

Moved your question here

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