EDIT: TWRP 3.4.0 has just been released and with its release FP3 is now officially supported:
https://twrp.me/fairphone/fairphone3.html
Unofficial releases for bug-fixes or feature tests may still pop up now and then on my github.
You can now find TWRP for the Fairphone 3 at my github:
You can boot into twrp using fastboot boot <twrp.img>
I have also included a twrp-installer zip-file that can be used to install TWRP to your device.
If you get a message, that your phone is corrupted and will shut down after 30 seconds,
you need to press the power button and the boot will continue.
You can reset the message using
adb reboot "dm-verity enforcing"
If fastboot boot
fails, it is likely, because your current slot is marked as unbootable.
To reset the retry-counter, you need to set it active again using fastboot.
fastboot getvar current-slot
fastboot --set-active=<slot>
Note: When flashing full stock images, that include sbl1 or aboot, make sure both slots have a working fastboot before flashing.
And never flash both slots without first testing on one.
Thanks to @basxto for entrusting me to use his FP3 for development
Thanks to @z3ntu for his initial work on the kernel and for testing.
Thanks to @corvuscorax and @pigpig for their further investigation
Thanks to @michlx for confirming the location of UART
Thanks to @Claymore1297 for relaying my messages
Full stock installable ZIPs available here:
Full dump of 105 for flashing via fastboot is available here:
Fairphone_FP3_8901.2.A.0105.20191217_12171325_user_release-keys_dump.zip
(8c0475eae9bae8c7ea2f09aae42d3e35)