First post here, and please excuse me if the matter is common knowledge, I dug in many threads on kany forums without finding any clarity.
My question revolves around the TWRP installation files for Fairphone 3.
On the TWRP website (Fairphone 3) are given 2 files, a twrp-installer-…zip and a matching version of a twrp- …img, and from the instruction given it is not clear to me are both files used concomitantly during the installation (Windows ), or not.
The TWRP instruction reads:
“…Download the correct image file and copy the file into the same folder as your platform-tools as well as device’s storage. Rename the image to twrp.img.”
Since the file needs to be renamed to .img I assume it is the original installer.zip - the other file is already with .img extension.
The entire instruction afterwards refers to this downloaded and renamed file.
What then is the the purpose of the matching .img file? Is it used at all? The TWRP installation instruction doesn’t even mention it.
Or am I missing something and misinterpreting the instruction?
If the original twrp…img file is ised to boot and from there to install TWRP what is then the purpose of the installer.zip?
I am trying to clarify the above for myself before attempting installation in view of how fraught with risks it could be.
Although this doesn’t answer your question directly, someone please correct me if I’m wrong or misunderstood something:
The FP3 doesn’t have a recovery partition since it is an A/B device. I assume you may know this but I’m just clarifying it in-case.
The TWRP website suggests not flashing the installer zip, and only booting the img temporarily using fastboot
WARNING: If you accidently flash TWRP to your device using fastboot instead of temporarily booting the image, you will need to download the latest factory image for your device and reflash the boot image.
The Fairphone support article is a little less subtle in its warning
Fairphone does not support the use of the TWRP (Team Win Recovery Project), as it might cause malfunctioning.
If you need our assistance after installing such software, you will have to restore your device to its original state. If not, we will consider it as out of warranty.
However, I am not sure your interpretation of the TWRP instructions is correct. What they specifically advice in not to flash the twrp file directly from fastboot - as was done on the old type devices.
Instead the instruction is unequivocal that (1) one should boot the image, and (2) to flash the permanent installation from within that image.
Here is the text:
" Temporary boot the downloaded image using the following command:
fastboot boot twrp.img
Preferred Installation Method: Once booted, navigate to the Advanced > Flash Current TWRP option. This will install the TWRP image you just booted permanently to the device.
Alternate Installation Method: Once booted, navigate to the Advanced > Install Recovery Ramdisk option. This will ask you to select the image you want to install TWRP from. Select the TWRP image you just downloaded and copied into device storage. Proceed to install this image."
The matter was resolved very quickly as somebody from the TWRP team was very kind to reply to my query. Here is what he/ she wrote:
“Hello, the img file is for the initial installation of TWRP to your phone. The zip file will allow you to install an updated version of TWRP from the Install function in TWRP.”
Therefore to summarise for if somebody in doubt like me reads this post:
Use the original image file (renamed to twrp.img as per the instructions) to boot temporarily into it.
From the booted twrp install the same file permanently.
Reboot into newly installed TWRP Recovery and install the twrp…zip file.
In case of Fairphone OS, installing TWRP instead of just temporarily booting it will break OTA updating because the OTA updater requires and checks for unaltered partitions while installing TWRP will have altered the boot partition (because there’s no dedicated recovery partition).
In case of /e/OS, OTA updates will restore the /e/OS recovery to the boot partition.
The emphasis here should be on the twrp. part, not on the img file extension.
The user is asked to rename e.g. twrp-3.6.0_9-0-FP3.img to twrp.img, so that the instructions can simply continue to refer to twrp.img instead of needing to be updated everytime the current image file name changes over time.
As users of TWRP from non-A/B devices are used to flashing the TWRP image to a partition to install it, I think the warning only tells them to notfastboot flash boot twrp.img (kind of intuitively) instead of fastboot boot twrp.img, else they would need to reflash a working boot partition image.
Magisk has a module to keep the TWRP installation after update, it is just a few simple steps to follow before executing the actual update hence updates are not my worry.