There is a LineageOS-specific recovery image in the download folder.
Ok, but for “normal” installation of the LOS I don’t need the recovery, right?
There’s no official LOS for FP4, and also no recovery and no official twrp, too
@Aaanze sorry it’s me again -.-
With your guide here I successfully rooted my phone 
But now I am confused. Next I want to install the build from mmustermann.
Do I need to follow the entire steps here or hook in at step 7?. I am still confused why mmustermann uploads a “normal” file and a recovery file. When do I use what?
Or do I completely misunderstood and the boot.img should be the LOS.img from mmustermann? So I “simply” root with this file?
Hi there ! Now I’m the one confused xD
The post you’re refering to is about installing Google Pay on a rooted device, not about rooting. But I suspect you just linked the wrong post.
Anyway:
-
I think you there’s a misunderstanding as to the purpose of rooting: rooting is not required to flash a rom build, it is an optionnal step that one can do afterwards to gain more control, but it is not in any way required if you have no use of it.
-
The build you’re refering to is signed, which means it probably can’t be flashed as an update of your current system even if you’re alread running LOS.
So you’re going to need to follow all steps indeed.
As for the role of the files:
-
the recovery.img is needed to provide your system the ability to sideload (ie upload, read, extract and install) a custom rom, which would normally not be possible with the one provided by the oginal system.
-
the boot.img contains - among others - the kernel of the system, it is already embedded in a full rom file like the one provided by mmustermann.
However when used as an independant file, it can be “patched” with magisk and reflashed on top of the system to gain root capabilitie. Again, totally optionnal.
In “short” you only need to follow the steps 1 to 5 with mmustermann rom file instead of mine. You will lose all data in the process.
Afterwards, if you want to root your device, you can follow the next steps, but you’re going to need the boot.img file specific to mmustermann’s rom in order to do so.
I hope this clarifies xD
1 Like
Hi @Aaanze,
thanks for the quick reply. Then I mistook it 
- Yes I want to root and I understand it is not required
- So what I need to do now is:
- Reboot to bootloader with adb reboot bootloader
- Flash Lineage recovery: fastboot flash recovery mmustermann_recovery.img
- Reboot to recovery.
- In recovery: wipe data / Factory Reset - there’s no way back to FPOS (for now) after this
- Still in recovery: Apply Update → ADB Sideload → Install from ADB and run:
adb sideload mmustermann.zip - I don’t need GApps
- a. Install Magisk apk on your device
b. Extract thepayload.binfrom mmustermann.img using payload-dumper-go to
$ ./payload-dumper-go path/to/payload.bin(Linux)
c. From the created folder extract the boot.img and copy to your phone
d. Patch the boot.img with Magisk on your phone and copy back the create magisk_boot.img to your computer
e. Runadb reboot bootloader
f. Runfastboot boot /path/to/magisk_boot.img(Do not flash that boot.img!!!)
g. Open Magisk and run direct installation
h. Reboot out of Magisk suggestion
3 Likes
For 7a I would advise to use the boot.img from mmustermann’s rom.
You got it right otherwise !
1 Like
If you just want to become root, you can enable root debugging in the developer options (it’s a userdebug build). You can then use adb root and adb shell to access the root shell.
1 Like
@Aaanze @mmustermann thanks both.
Interesting. But that is the “same” root state that I need to install AdAway for example or other root-requiring apps?
→ So, if I decide to use “root debugging” I would run steps 1-5 only and then activate root as described in the settings?
I edited accordingly, so the workflow is right.
In step 5. it tells me that the
Signature verification failed. Install anyway?
Yes or no?
In terminal it says:
E: failed to verify whole-file signature
Yes this is an expected behaviour, you can proceed anyway.
You might as well receive an error message that literally says that nothing went wrong 
Just ignore it.
2 Likes
Many thanks for the extreme quick reply.
But that is also true that this happens at:
adb sideload lineage-19.1-20220511-UNOFFICIAL-FP4.zip
serving: ‘lineage-19.1-20220511-UNOFFICIAL-FP4.zip’ (~47%)
Yes it is, no worries.
If you check the message it says something crazy like “error failed to read command: success”
1 Like
Hmm no 
E: failed to verify whole-file signature
Update package verification took 41.2s (result 1)
E: Signature verification failed
E:error 21
Still expected and fine?
Hmm that’s weird. Did you boot on LOS recovery ? It seems like you used stock recovery.
1 Like
But that is the “same” root state that I need to install AdAway for example or other root-requiring apps?
No, it just drops you in a root shell. Apps can’t use it. If you want your apps to get root access you have to install SuperSU or Magisk. I’ve never done that, so I can’t help you on that. I’m not even sure if the root access will persist after updates, because the update should overwrite the boot.img again. But try it out and let us know!
E: failed to verify whole-file signature
Update package verification took 41.2s (result 1)
E: Signature verification failed
E:error 21
This indeed looks like you used a different recovery. You should not get a verification failure if you used the one I uploaded.
fastboot boot lineage-recovery-19.1-20220511-UNOFFICIAL-FP4.img
1 Like
Hey both,
-
no, I used the recovery from mmustermann (now I also understand why there is a recover) and I have dobe the steps till no. 5 as I posted. And yes, it looks like the one on your image. before each retry, I wiped again.
-
@mmustermann now you suggest to boot instead of flashing?
In general, I will not be able to update the next LOS version from mmustermann like this? Still I have a running instance. Maybe I can use it for some month and hopefully there will be an official release in the mean time…
What else can I do?
So if you ignore the wrong signature and say yes to “install anyway?”, did you try to boot to the normal system afterwards? Does LOS work or does it hang in a bootloop?
If it ends in a bootloop, please check a few things:
- Ensure that the files you downloaded have not been corrupted. Do so by checking if the sha256 hashes match.
- Are you absolutely sure that you use the 20220511 recovery for sideloading? It didn’t complain about the wrong signature for me.
Doesn’t matter as long as it worked and you booted or flashed the 20220511 recovery.
You will be able to sideload the next update. You might just loose your root access after the update, because the update usually overwrites the boot partition. So any modifications you do to the boot partition might get lost and you probably have to patch the boot.img again to reinstall Magisk.
Many thanks. Yes it is running fine (so far) and it booted normally.
One last question: The rooting process will wipe my data?
PS: If one of you guys ever visit Hamburg - ping me, now I owe you a dinner + drinks for this support!
3 Likes