Install e/os on Fairphone 4


I want to install e/os 1.0 on my Fairphone 4, but I don’t know which version I must install. Must I install the 1.0 stable version or the 1.0 dev version ? I would like to install the 1.0 stable version (the same as the system available by the Murena company on their smartphone). Some people told me about recovery image but the 1.0 stable version don’t have the recovery image, so what about it ?

If I have questions about the installation guide, can I post them here ?

Note: If you have installed e/os on Fairphone 4, can you help me ?

Thanks in advance.

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for type of version you can see Different Build Types


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You don’t install it from recovery but via fastboot.
Just follow the instructions you find here:

Yes, sure.

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ok, I’ve got questions about the installation guide.

First of all, 3 versions are offered in the download section for the Fairphone 4: /E /Recovery for Dev Build, /E /OS Build: R Dev (Security Patch: 2022-04-05) and /E /OS Build: R Stable (Security Patch: 2022-04-05). In the guide, they indicate to recover all the files and images in the Download section. Ok, but what version I install on my device? If I don’t want to have problems, I install the stable version? This is the first important point.

Afterwards, I must unlock the bootloader. I understood that I have to do this on my smartphone.

First, I want to know why I must enable and connect to wifi.

Second, in the point eight, I must reboot again into the bootloader. So, can I use the command: ‘adb reboot bootloader’ ,or, must I turn off the Fairphone 4 and Press and hold the Volume Down button ? The point eight is not clear.

Finally, after installing e/os, I must locking the bootloader before rebooting. Ok, but can I rebooting the system without locking the bootloader to see if e/os is launched and if it is good then locking the bootloader ?

If you have advice, suggestions, I’m interested.

Note: I’ve check the security patch level of my device (default) and it is less that the e/os security patch level, so can I install e/os without problem and can I lock the bootloader without problem after installing e/os ? I don’t know what is the security patch level for e/os 1.0.


No one can guarantee “no problems”. But problems are less likely with the stable which offers updates later (so others have tested the version already).

You type in the unlock command on the computer connected via USB (step 6) and then you confirm it on the phone display (step 7).

If not connected to the internet you can’t use the “enable OEM unlock” function (step 4).

If you don’t do anything the phone will reboot into the (factory reset) OS. Then “turn off the Fairphone 4 and Press and hold the Volume Down button” as you mentioned. Or you may keep pressed Vol Down just when the phone reboots so you’ll reach the bootloader directly (this way is just faster).

Yes, I’d strongly recommend that. It’s good to know if system works before relocking the bootloader and if “OEM unlock” is still “enabled” (so in case anything goes wrong with relocking the device it’s not bricked…).



@ff2u: Thank you for these explanations.

I have two more questions:

  1. In the zip file for e/os 1.0 stable rom, there are 3 files who are not used in the command lines to flash the rom (see the installation guide): dtb.img, ramdisk.img, ramdisk-recovery.img. why these files are not present in the installation guide for flashing ? Must these file be flashing too when we want to install e/os stable version ?

  2. After installing e/os and locking again the bootloader. Can we disable the oem unlocking option in the phone or is there a risk to do so ?


I assume those images are just created during the build. They might be used on other devices.
But I’ve flashed a lot of /e/OS versions and all have worked well without flashing these images.
Apart from that I doubt very much that especially the ramdisk images are of any need for flashing. Based on the nature of a ramdisk the content is of no use directly after starting a device.

The answer can be found on Fairphone forum.

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Ok, thanks for your reply.

Hi, I also got a Fairphone 4 and wish to install /e/OS on it.

Installation guide is well explained and I don’t expect to encounter any issue as I already did flash custom ROMs on a few devices.

My question is: The stable version doesn’t seem to get any recovery, so how will OTA updates run without /e/ recovery nor TWRP?

Will the native Fairphone recovery be able to manage /e/ OTA upgrades?

Thank you very much for enlightening me…

Recovery isn’t involved. The necessary partitions get flashed directly to the unused OS slot of two OS slots, then the slot in use gets simply swapped with a reboot, data stays the same, see


Thank you very much, this is a very usefull information.

This convinced me to get the stable version.

Thanks a lot! :+1: