I did the “git clone -devicetree link-” already in the folder for the specific files; but wdym?

Ohh

And you can use higher compression algorithm if your bootloader supports

Oh

Remember when they used to be 8MB?

I have a rooted (with Magisk) Samsung Galaxy S20 Ultra 5G (G988B) device with TWRP installed in recovery partition.

Stock kernel version: 4.19.187-20291612
Build number: G988BXXU5CTKG

My purpose is to have a custom kernel which is identical to stock kernel except for configs for ftrace and kgdb (can be changed in defconfig before compilation)

Steps I’ve performed to flash a custom kernel for the given device:
1) Downloaded Linux Kernel for the given device from https://opensource.samsung.com/ SM-G988B_RR_Opensource.zip according to the above mentioned build number
2) Used https://github.com/kdrag0n/proton-clang toolchain to build the kernel
3) Used Android Image Kitchen to generate a new boot.img in the following way:
* Extracted boot.img from the device via dd utility (100% correct, I’ve reflashed the extracted image for the sake of validation and had no problems)
* ./unpacking.sh original_boot.img
* Replaced original_boot.img-kernel file in /split_img directory with custom_kernel_root_dir/arch/arm64/boot/Image
* ./repacking.sh
* Got image-new.img which must contain a bootable custom kernel
4) Rebooted into TWRP and flashed the image-new.img in Boot and then rebooted into System

After that, the device is stuck (NOT bootloop!) in warning screen (device logo name and warning about an unlocked bootloader warranty void) forever. Luckily, I am able to reboot to TWRP and reflash the previous boot.img in order unbrick the device and be able to boot into the rooted device again.

During unpacking and repacking it seems that the original and the custom boot.img files have the same values for kernel base, offset and other values.

So what’s the problem? Can toolchain be problematic/unsuitable even though I was able to compile the kernel with it?

No idea how is android kitchen but you can try use mkbootimg/unpackbootimg and create image with it

aarch64-elf-ld: unrecognised emulation mode: aarch64linux
Supported emulations: aarch64elf aarch64elf32 aarch64elf32b aarch64elfb armelf armelfb
make[2]: *** [../arch/arm64/kernel/vdso/Makefile:49: arch/arm64/kernel/vdso/vdso.so.dbg] Error 1
make[1]: *** [arch/arm64/Makefile:272: vdso_prepare] Error 2

Make clean && make mrpropper

Probavly your kernel source was dirty
I was happened with me too

Tell folder paths

i did the “git clone -devicetree link-” already in the folder for the specific files; but wdym?

Oh okay, got it, lemme try

dw, i’m searching like on xda forum or github

I know one guy you can bother
Come pm

The same result – after flashing a new boot.img the device is stuck at boot

Have you tried using anykernel3 to flash the kernel?

Anykernel3 can deal with hard part (boot offset, ramdisk?, etc), the same as mkbootimg, but in an automate way

Yes. Unfortunately, the same result 😒

F

Tried disabling verification inside vbmeta?