Kernel for FP4 C0.87

Hello everyone.

I updated my phone to Version C 087. As Fairphone is unfortunately not kind enough to offer the lates kernel per download, I tried to extract it from the phone itself.

adb shell
dd if=/dev/block/by-name/boot_b of=/sdcard/boot_b.img

or

dd if=/dev/block/platform/soc/1d84000.ufshc/by-name/boot_b.img of=/sdcard/boot.img

did not help anymore. But this is also the first time, I am trying it on Android 13. So, there must have been changed something in Android 13, I guess.

On the internet I cannot find any hint on how to get the kernel, which is needed to reinstall after rooting and before updating to another version of the FP4.

So, was anybody sucessfull extracting the kernel or knows how this works?

For now, it seems, I am stuck on an unrooted phone…

PS: Here the error message I get when trying to extract Kernel _a (allthough my active Kernel is -b, so I should do it with _b, of course):

FP4:/ $ dd if=/dev/block/by-name/boot_a of=/sdcard/boot_a.img
dd: /dev/block/by-name/boot_a: Permission denied
0+0 records in
0+0 records out
0 bytes (0 B) copied, 0.000316 s, 0 B/s
1|FP4:/ $ 

So, it’s obviously a permission problem. Seems, that I am missing a setting, or so…(?)

Did you try with slot “_a”? Your commands should work in general.
This time I used the rooted C-079 kernel for the Magisk installation and that worked well.

My boot images are available for download here
http://download.el-hennig.de/

Please PM me for the login data

Okay,

with Lars’ help I finally managed to extract the boot.img (kernel) myself, again.

I had to make a few changes to the recipy to get it working on my Linux PC. That’s how I did it:

I created a folder like /folder

cd /folder

I downloaded the lineage recovery image here:
https://download.lineage.microg.org/FP4/

In my case it was the file
https://download.lineage.microg.org/FP4/lineage-20.0-20231201-microG-FP4-recovery.img

I renamed the file to lineage-recovery.img and moved it to /folder

Now it is important to know on which active slot I am:

adb reboot bootloader

I waited for the phone to have booted into bootloader.

fastboot getvar current-slot

I noted, if it is “_a” or “_b”. For me it was _b. Then

fastboot reboot

After the phone rebooted:

adb reboot bootloader 
fastboot boot lineage-recovery.img

Then, in recovery, I selected “Advanced” and enabled ADB.

On my PC:

adb shell
dd if=/dev/block/by-name/boot_b of=/sdcard/boot_b.img

If your current slot is _a :

dd if=/dev/block/by-name/boot_a of=/sdcard/boot_a.img

My slot is _b, so I continued:

exit
adb pull /sdcard/boot_b.img   
adb reboot

In the /folder directory I now have the boot image (kernel) of my current system.

Enjoy…

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