Hello all, many thx to R2D2 and hirnsushi for the nice guide and support. After some trouble with the drivers on windows and the usb connectivity at ubuntu i finally made it. 3.7.2 works very well right now. THX!
I checked on gitlab.com for newer updated and found the version 3.7.3 did anyone already flashed this version?
That version has only been released for the Pixel 6a for now, have a look at the checklist 
in that issue.
Might still be some time till this reaches the FP4 
Oh and welcome to the community 
Did the Calyx install script also overwrite the recovery?
At least there is one step executed during the installation (I saved it when I installed 3.7.2):
...
extracting recovery.img (96 MB) to disk... took 0.326s
archive does not contain 'recovery.sig'
Sending 'recovery' (98304 KB) OKAY [ 3.703s]
Writing 'recovery' OKAY [ 0.254s]
...
Now I was looking for a way to flash a zip (in my case it just contains an app, which should be installed as system app - background is a test with a camera installed as system app - see here).
So I have a flashable zip and was looking for a way to install it. Normally there were options in recovery (probably I remember TWRP) to install such a zip directly or to start adb sideload and flash it on that way.
First thing which confused me was the way of accessing the recovery (I donât remember that I booted into recovery with my FP4 before, so I cannot tell if it always looked like that):
I assume in there
I can use âApply update from ADBâ to sideload a zip?
Or is there any other recommended way to do this?
e.g.:
Flashing random .zips usually isnât a feature in any of the modern recoveries, those were the good 'ol TWRP days 
. But even if it was, I would strongly advise against using it, you will break OTA-updates.
Donât modify /system directly, create a Magisk module.
Thanks for the quick reply. So I will repeat what I learned recently (about how to create a Magisk module). 
A post was split to a new topic: Magisk module for (system-)camera apps
Thats the standard AOSP recovery I think, at least its the standard FPOS recovery (FP2+FP3)âŚ
Yes, this could be. When I researched about it, it felt like that it exists and behaves that way for a long time already and over several Android versions. Looks like I always used TRWP or Lineage Recovery over the years with my FP2 (got it end of 2016) and I never had the pleasure of using ASOP recovery.
Here are my five cents on installing CalyxOS on FP4:
After a few hours of sweating blood, I managed to install CalyxOS with a locked bootloader.
I followed the instructions listed on the top of this thread with the following modifications>
fastbood flash unlock_critical first as mentioned in the CalyxOS install instructions (which included an additional reboot, clicking through setup and re-enabling USB debugging and OEM unlock).Everything went as described (including the Cannot load Android system. error that can be resolved with the factory reset.
After successfully booting into CalyxOS, I found I was hit by this issue. 
In short: you cannot enable OEM unlocking through the OS (above shown option is greyed out,not 100% clear why), but the command fastboot flashing get_unlock_ability returns get_unlock_ability=0. 
Attempting to lock the bootloader in that state seems to brick your phone!
Since I wanted to have the security of a locked bootloader I went through the cumbersome procedure described in this post, which involved using Magisk to patch boot.img, boot that with fastboot and using the command
adb shell su -c 'resetprop ro.boot.flash.locked 1'
after which I was able to enable OEM unlocking again and got me get_unlock_ability=1.
After this I was confident enough to relock the bootloader using fastboot flashing lock.
My prayer were answered and after another factory reset, the bootloader was locked and I have now CalyxOS with a locked bootloader. 
Thanks everyone in this (and other) threads (especially @hirnsushi and @R2D2) for their help and tips on installing CalyxOS!
Iâm really glad this worked for you 
Could you please check what state fastboot flashing get_unlock_ability is in, now that you went through the whole process 
If it got reset to 0 again, consider yourself luckyâŚ
When I check now, I get get_unlock_ability: 0 but I have not activated OEM unlocking at the moment, so I guess thatâs expected? 
But you didnât deactivate yourself, right?!
Otherwise, I think it should stay enabled.
If you follow the thread with those instructions just a bit further, youâll notice we very quickly discovered that it would just reset to 0 again. Thatâs why I havenât recommended that method again after that.
You got lucky, you had the right conditions on your phone (likely down to the patch level being the same or newer than what you had before), but if you didnât, Iâm pretty sure you would have bricked your device.
In addition to what @hirnsushi wrote, this statement/warning is IMO wrong!
That state does not always lead to a bricked phone. It rather can cause a bricked phone if something goes wrong while locking the phone (mainly because as said above you downgrade the patch level) because then youâre no longer able to unlock it again.
Could you enable it or is it greyed out?
I can enable it now. I guess that allows me to re-open the bootloader if I ever decide to switch to another OS.
Once you lock the bootloader the option isnât greyed out anymore, itâs only greyed out while the bootloader is unlocked.
Thatâs why tricking the system, via Magisk, into thinking the bootloader is locked makes that switch toggleable again.
It does, but keep an eye on get_unlock_ability and donât install any ROM with an older patch level.
Your device is affected by this bug, be careful not to brick it.
And I would flip the OEM Unlocking switch to ON, otherwise, if something happens to your system, you wonât be able to fix it by unlocking the bootloader. Have a look at this post for a nice comparison of the different states.
who can tell me something about this or write, because I am in the directory and have unpacked it. It was a big one and after I unpacked it there was another one in the directory. I then extracted them again from the directory?? /home/carrabelloy/Downloads/FP4-calyxos/FP4-sp2a.220505.002# ./flash_
all.sh
. bash: ./flash_
all.sh
.: Datei oder Verzeichnis nicht gefunden
No need to unpack the second zip within the first one. When you unpack the first one there is flash_all.sh; the second zip is handled by the script.
Little add regarding the question:
Maybe just directly filter the issues to the releases label and additionally check (within the issue) if it is available for the FP4 (if it is ticked in the list) as @hirnsushi described it.
â CalyxOS issues filtered to lable_name âReleasesâ
If available for the FP4 â take the build number in the related issue (table at the top of each release issue) and swap it into the link like @hirnsushi described it. If it is still in beta state or already stable you should check the details of the issue. Availability of a factory image (so if your manual created link leads to something) is a good indicator, that it is stable , as well.
Iâm having the strangest issue with this install. I followed it to the letter (using 3.7.2 instead of OPâs original version) without problems until steps 8/9 (when you flash the extracted FP4 update.)
Prior to starting the installation, I downloaded 3.7.2, extracted it, and changed directory via Powershell to the folder with the extracted files.
The FP4 files flashed successfully, but the device then rebooted into FPOS as if nothing had happened!
Just to confirm, I have :
I initially flashed without using fastboot flashing unlock_critical and received those same error messages as OP on some of the files. But after the phone rebooted to FPOS the first time, I enabled unlock_critical and reflashed. Same result.
I also tried flashing the files with both Windows Powershell and Cmd Prompt. Same result.
What am I doing wrong? Like most of us installing CalyxOs, I was a little worried that I might brick the phone. I never would have imagined this outcome.
Hopefully Iâve just made a silly mistake. But I need a gut check here. 
