Hi,
I try to install Ubuntu Touch on my new FairPhone.
On this page https://devices.ubuntu-touch.io/device/fp4/ it says “Your device must be running the Fairphone OS version of Android 11”. My version of Android is 13 since today’s first power on and update.
So I tried to follow https://support.fairphone.com/hc/en-us/articles/18896094650513-Install-Fairphone-OS-manually to install Android 11.
Followed " Flashing with fastboot" because it “Can be used to downgrade to an older version (for example: Android 13 → Android 11).”
Following this steps, when I type adb devices, nothing appears on the phone but it’s listed in listed devices attached on command prompt.
When I type adb reboot bootloader, the phone restarts on a screen FastBoot mode with “device state - locked” with 4 choices above : START/Restart bootloader/Recovery mode/Power off.
If I type fastboot flashing unlock : waiting for any device.
I don’t understand if I am on the expected boot screen and need some help.
Fairphone 4.
Thanks !
Probably the same when you try fastboot devices, right?
What kind of OS is your PC/notebook running? Windows? Linux? Mac? …?
when I type fastboot devices after adb reboot bootloader :
c:\Users*\Desktop\platform-tools-latest-windows\platform-tools>adb devices
List of devices attached
ad****** device
c:\Users*\Desktop\platform-tools-latest-windows\platform-tools>adb reboot bootloader
c:\Users*\Desktop\platform-tools-latest-windows\platform-tools>fastboot devices
c:\Users*\Desktop\platform-tools-latest-windows\platform-tools>adb devices
List of devices attached
I’m on Windows 10 but I can run a usb stick with persistent Ubuntu if you think it’s easyer
I tried with an other USB cable data certified.
Is the screen below the normal screen ?
A thing I forgot to mention is when I "type adb devices and press Enter 
, I don’t see any pop-up on my Fairphone asking if I allow USB debugging on this computer. So I can’t tap Allow.
Thank you for your help.
Yes, that’s the correct screen where fastboot should work.
So you say that you apply this command while your phone is running in normal phone mode, you haven’t enabled usb debugging and it still shows a number when you apply this command?
The problem with fastboot sounds to me like a windows driver problem.
Have a look here for proposed solutions:
Hello,
thank you for the answer.
Precisely, when I type adb devices on normal mode, nothing appears under “List of devices attached”
Until I enable USB debugging on the FairPhone (this setting is curiously disabled after each restart of the phone, don’t know if it’s a normal behaviour…)
But typing this command after USB debugging enabled just shows me the SN of the FP and not "a pop-up on [my] Fairphone asking if [I] allow USB debugging on this computer. "
I installed 4 updates from Google and LeMedia this morning and I have exactly the same behaviour after restarting both devices PC and FP.
Thanks for your replies.
Regarding adb debugging that’s all normal except the missing pop-up. The latter might be related to the problem that fastboot is not yet working.
You might try out on a different USB port on your PC. Sounds strange but has been reported on the forum to have helped sometimes.
If not, you might try to not Linux from your stick and check there.
Thank you Volker. I completely forget to answer you were true.
The issue was the USB port (or driver) on the first laptop. On the second one, it works perfectly. I installed Ubuntu Touch.
I will now open a second question to go back to Android (or other OS) from Ubuntu.
Thanks a lot !