Database Develop

how to build kernel ramdisk

let me explain my problem, i've created a .ftf (kernel for xperia x8) and it is boot up but i missed some files inside the ramdisk, so now i need to repack my new ramdisk folder into ramdisk file and i don't know how to do that .

Read my guide on how to compile and put together a custom kernel for the X8: http://forum.xda-developers.com/showthread.php?t=1923240
The method (whatever it is) you are following is not correct for any Android phone.
Oops. I guess it isn't mentioned there.
Basically what you have to do is open up a Terminal in Ubuntu. Navigate to your ramdisk folder (the one that contains the init.rc, init.usb.rc etc.). Then issue this command:
Code:
find . | cpio -o -H newc | gzip > ../ramdisk
Grab the ramdisk from one directory above your ramdisk folder.
Sorry for the confusion.

sgt. meow said:
Read my guide on how to compile and put together a custom kernel for the X8: http://forum.xda-developers.com/showthread.php?t=1923240
The method (whatever it is) you are following is not correct for any Android phone.
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Click to collapse
i don't understund one thing, when i'm getting the ramdisk file? when compiling the rom?or the kernel?
i've compiled cm10.1 rom and i need to change the bootclasspath

You have to unpack a working kernel with DooMLorD's kernel.sin unpacker. You'll get the ramdisk. Then edit the BOOTCALSSPATH in init.rc.

sgt. meow said:
Read my guide on how to compile and put together a custom kernel for the X8: http://forum.xda-developers.com/showthread.php?t=1923240
The method (whatever it is) you are following is not correct for any Android phone.
Oops. I guess it isn't mentioned there.
Basically what you have to do is open up a Terminal in Ubuntu. Navigate to your ramdisk folder (the one that contains the init.rc, init.usb.rc etc.). Then issue this command:
Code:
find . | cpio -o -H newc | gzip > ../ramdisk
Grab the ramdisk from one directory above your ramdisk folder.
Sorry for the confusion.
Click to expand...
Click to collapse
when i run the i get this error
bash: ../ramdisk: Is a directory

Name the folder that has the ramdisk contents something like "XYZ" and put it in another folder named "ABC". Then issue this command.
So basically the structure would be:
/ABC/XYZ/* /*ramdisk contents have been denoted by * */
And after issuing the command grab the ramdisk from ABC folder.

sgt. meow said:
Name the folder that has the ramdisk contents something like "XYZ" and put it in another folder named "ABC". Then issue this command.
So basically the structure would be:
/ABC/XYZ/* /*ramdisk contents have been denoted by * */
And after issuing the command grab the ramdisk from ABC folder.
Click to expand...
Click to collapse
yeah thank you now it's working but i think something is missing , can you help me in developed kernel for cm10.1 ?
i already compiled the rom but now i'm struggling with the kernel part , i can send you all the files for the ramdisk and if you can put together a working kernel it will be great and i can move on and fix the problems with the rom itself

Look man. I can download the source and help you compile the kernel and the ramdisk. But as Daveee10 has said, even if you get it booting, there are tons of things that need to be backported (which is extremely hard) for it to work properly. So it's almost like choosing a route that you know will lead to a dead-end. But I'll help anyway.
PM me.

How do you unpack and repack boot.img?

NOTE: Unfortunately I've had to remove links from this post because I'm a new user. I'll add them back in once I have enough posts.
I've been trying to edit a file in boot.img from the CyanogenMod 12.1 (huashan) nightlies but I'm experiencing some issues finding the right tools/methods for the job.
Most scripts I've found expect an Android Magic number at the beginning of the file but this simply isn't there. It seems there is no header at all that matches the specification from bootimg.h (missing link) though I did discover the cmdline argument at the end of the file with a hex editor.
After searching and experimenting for hours I found a script here (missing link) which enabled me to extract the kernel and ramdisk images despite the missing header but now I don't know how to repack the files into a boot.img of the same structure.
I've tried the following but it results in a boot.img that is about 40% larger than the orginal (despite me only adding one line of code) and has an entirely different structure (with an Android Magic number, etc.).
Code:
mkbootimg --base 0x00200000 --pagesize 2048 --kernel boot.img-kernel.gz --ramdisk newramdisk.cpio.gz -o newboot.img
I found this resource (TWRP, missing link) which mentions that Xperia devices have special boot images (or something like that, I didn't understand all of it) - this might explain why the boot.img structure is so different - but I can't find any further documentation on this or instructions on how to deal with the format.
The Xperia devices have a recovery-in-boot arrangement. This means that the recovery is booted using the regular kernel / boot image in the device. Team Win has worked with the FreeXperia device maintainers to come up with a way to extract the ramdisk from the FOTAKernel partition and use the ramdisk from that partition instead of the recovery that is included in the boot image of your device. This means that if you install current CM nightlies and flash TWRP to the FOTAKernel partition, you will be able to use TWRP instead of the CWM or CM recovery that normally comes in a CM boot image. Other boot images including stock kernels can be repacked to include this extraction utility to allow you to use TWRP from the FOTAKernel partition. This setup allows you to choose what recovery you want to have installed and allows you to update your recovery more easily. Unfortunately this setup requires that the boot image that you have installed include the ramdisk extraction utility.
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Click to collapse
So now I'm at a loss at how to continue. I would much appreciate any pointers, ideas or help in general.

@infernalpostcard , hopefully this tool made by @Adrian DC will help you out.
https://github.com/AdrianDC/android_huashan_bootimg_editor

Raienryu said:
@infernalpostcard , hopefully this tool made by @Adrian DC will help you out.
https://github.com/AdrianDC/android_huashan_bootimg_editor
Click to expand...
Click to collapse
Thanks. This looks really promising. I'm trying it out now...
EDIT: It worked! This is exactly what I needed. Unfortunately what I was actually trying to achieve (apply a fix to break a boot-loop my phone gets in, due to an encrypted filesystem) didn't work so I'll have to come up with new ideas.

[SOLVED] Help building a custom kernel...

Whatever I do, my custom build kernels fail to boot. There's the ZUK logo very briefly, then device drops to bootloader screen. I'm out of ideas what I'm doing wrong, maybe someone here can give me a hint. :good:
I've tried with current AEX kernel git snapshot and also stock kernel sources. Building using the AEX_defconfig goes ok, I have Image.gz, replace it in previously extracted "stock" boot image and use mkbootimg.py to rebuild the new image. Offsets etc. are all correct (I think), like this: (from AEX)
Code:
kernel=kernel
ramdisk=ramdisk
page_size=4096
kernel_size=9101281
ramdisk_size=2671109
base_addr=0x80000000
kernel_offset=0x00008000
ramdisk_offset=0x01000000
tags_offset=0x00000100
cmd_line='androidboot.hardware=qcom ehci-hcd.park=3 lpm_levels.sleep_disabled=1 [email protected] buildvariant=userdebug'
board=""
format=gzip
But the damn new image won't boot, like described above. There has to be something (probably very stupid) I'm missing...
If I replace my own Image.gz with the originally extracted one and mkboot and so on, it's ok. So I guess it has something to do with my kernel build and/or environment. Are there any subsequent steps needed to do with the compiled kernel Image.gz? Or is it just my kernel config which is wrong? But I'm using the AEX defconfig (n7x-caf_z2_row_defconfig, to be exactly) so this should be fine, no?

Ok, I've got it. I had forgottten (=didn't know about at all) to append the device tree blob (arch\arm64\boot\dts\qcom\msm8996-v3-pmi8996-mtp.dtb) to kernel zImage... Simply cat'ing these together works!

Goodluck bro.

void23 said:
Ok, I've got it. I had forgottten (=didn't know about at all) to append the device tree blob (arch\arm64\boot\dts\qcom\msm8996-v3-pmi8996-mtp.dtb) to kernel zImage... Simply cat'ing these together works!
Click to expand...
Click to collapse
please explain .. what exactly i need to do with that file..

Samsung Galaxy Tab A 7.0 LTE (2016) SM-T285 Lineage OS complete build guide

For SM-T285 users that want to build Lineage OS for their own device I have posted a complete build guide here:
https://github.com/lineage-gtexslte/build_guide

jedld said:
For SM-T285 users that want to build Lineage OS for their own device I have posted a complete build guide here:
https://github.com/lineage-gtexslte/build_guide
Click to expand...
Click to collapse
Thanks for the ROM update!
I started from scratch and when I compiled, I got this error:
fixdep: error opening config file: ../../../../../../kernel/samsung/gtexslte/scripts/genksyms/parse.tab.c: No such file or directory
I have had this error before and had to copy the file from another folder, but I should not have to do this.
So, I copied the file to folder where it was missing.
New error:
target Prebuilt: am (/home/gcrutchr/taba/out/target/product/gtexslte/obj/EXECUTABLES/am_intermediates/am)
Symlink: /home/gcrutchr/taba/out/target/product/gtexslte/system/bin/app_process -> app_process32
clang++: error: unable to execute command: Aborted (core dumped)
clang++: error: linker command failed due to signal (use -v to see invocation)

gcrutchr said:
Thanks for the ROM update!
I started from scratch and when I compiled, I got this error:
fixdep: error opening config file: ../../../../../../kernel/samsung/gtexslte/scripts/genksyms/parse.tab.c: No such file or directory
I have had this error before and had to copy the file from another folder, but I should not have to do this.
So, I copied the file to folder where it was missing.
New error:
target Prebuilt: am (/home/gcrutchr/taba/out/target/product/gtexslte/obj/EXECUTABLES/am_intermediates/am)
Symlink: /home/gcrutchr/taba/out/target/product/gtexslte/system/bin/app_process -> app_process32
clang++: error: unable to execute command: Aborted (core dumped)
clang++: error: linker command failed due to signal (use -v to see invocation)
Click to expand...
Click to collapse
What's your gcc version? might need to use gcc 6

jedld said:
What's your gcc version? might need to use gcc 6
Click to expand...
Click to collapse
gcc version 8.1.1 20180712 (Red Hat 8.1.1-5) (GCC)

gcrutchr said:
gcc version 8.1.1 20180712 (Red Hat 8.1.1-5) (GCC)
Click to expand...
Click to collapse
later versions of gcc may not work with lineage 14.1, I had to downgrade mine, though for another project.
you can do:
Code:
sudo apt-get install gcc-6 g++-6 g++-6-multilib
sudo update-alternatives --install
inform me if this works and I'll update my guide. Might consider making a docker based build if issues like this happen often.

jedld said:
later versions of gcc may not work with lineage 14.1, I had to downgrade mine, though for another project.
you can do:
Code:
sudo apt-get install gcc-6 g++-6 g++-6-multilib
sudo update-alternatives --install
inform me if this works and I'll update my guide. Might consider making a docker based build if issues like this happen often.
Click to expand...
Click to collapse
Actually, I am on Fedora Linux (uses less resources) and have been using gcc 8xx for some time. I compile LineageOS 14.1 for Note 3 (ha3g) and the Note Pro 12.3 (v1a3g) and have no problems. But, I will investigate further.
Ok...so I had issues building the kernel...could not find some include files.
So...I decided to use build_kernel.sh script to to make boot.img. The resultant file is about 1.4 MB smaller, there is no init file in the ramdisk folder and the boot.img-ramdisk.cpio.gz in the split_img folder is about 1/2 the size of your recent boot.img file.
Not sure when to go from here.

Okay, so I followed the instructions - after upgrading Fedora to v29 - but, this time I used Docker. Had to make some script changes for Fedora, but got most everything installed. The "work" directory is empty. I was able to make a working system.img that installed with the built .zip file. The kernel would not boot - hung on the logo screen. I restored the 10/17 boot.img and the system booted up. Now, I will work on the boot.img file. I did notice this time that the boot.img file was about the same size as the 10/17 boot.img file I downloaded. So, that's an improvement. I just finished modifying the build_kernel.sh file. So, I installed the kernel I made and it still hung on the logo screen. So, back to square 1 regarding the kernel.

gcrutchr said:
Okay, so I followed the instructions - after upgrading Fedora to v29 - but, this time I used Docker. Had to make some script changes for Fedora, but got most everything installed. The "work" directory is empty. I was able to make a working system.img that installed with the built .zip file. The kernel would not boot - hung on the logo screen. I restored the 10/17 boot.img and the system booted up. Now, I will work on the boot.img file. I did notice this time that the boot.img file was about the same size as the 10/17 boot.img file I downloaded. So, that's an improvement. I just finished modifying the build_kernel.sh file. So, I installed the kernel I made and it still hung on the logo screen. So, back to square 1 regarding the kernel.
Click to expand...
Click to collapse
Were you able to obtain a logcat with the failed boot? Possible issue is that the external kernel modules did not get compiled

jedld said:
Were you able to obtain a logcat with the failed boot? Possible issue is that the external kernel modules did not get compiled
Click to expand...
Click to collapse
Actually, not sure how I got it to compile. Having problems with docker. Cannot run python or any other dev command. Stuck as root user. So am trying to learn about docker. I do not think I was in docker when it compiled. Will get back to you after I figure this whole mess out.
27 October 2018
After reading the Docker documentation and playing with Docker, I removed it from Fedora. It is just too complicated to use even though it sounds simple. After removing Docker, I did a make clean and a make mrproper in the kernel folder. I ran 'brunch gtexslte'. The compile completed after I copied mkbootimg to the out folder - for some reason it is not getting copied there during the make process. This time the boot.img was over 9mb. It still will not boot. I will get log files today. I will also check to make sure the system files work with the good boot.img.
Question how do I update the system folder to the latest builds of lineage 14.1?
Your repo xml file restricts the source to your repo.

Okay!
Fixed boot.img not booting.
If you unpack boot.img, the file 'boot.img-imgtype' has an invalid image type. In the file, it says 'AOSP-PXA'.
It should say 'AOSP'.
I do not know where this is getting added. I have done a grep and could not find it.
As a side note, I used the build_kernel.sh script to make the kernel.
Question: How do I apply the security updates without manually following the (-) (+) in the diff file?

I am now able to do a complete make and install using the generated .zip file.
Here are the steps:
1. Setup your environment - I am using Fedora, but these instructions will work for any flavor of linux
2. Make sure you have the linaro gcc toolchain (32-bit) installed, and you have modified kernel/samsung/gtexslte/build_kernel.sh
3. Run: build/envsetup.sh, then brunch gtexslte
4. If the brunch stops near the end, copy mkbootimg from system/core/mkbootimg to out/host/linux-x86/bin
......or you can write a shell script to copy the file, as I did, before starting the build
5. After the build completes, cd into kernel/samsung/gtexslte
6. Run make mrproper, to clean the kernel folders
7. Run build_kernel.sh
8. After the kernel (zImage) is built, you need to make the boot.img
9. @jedld has posted how to do this in his build instructions
10. Now that you have a boot.img, you need to modify it.
11. Unpack boot.img
12. In the file 'boot.img-imgtype' , you need to change 'AOSP-PXA' to 'AOSP' - without the quotes
13. Repack boot.img
14. Replace boot.img in the lineage*.zip file with the one you just modified
15. Copy the lineage*.zip to you Tab-A, reboot into recovery and install it.
Here is my script for copying the mkbootimg file into the out folder, BEFORE I run brunch gtexslte:
if [ ! -d "out/host" ]; then
mkdir out/host
mkdir out/host/linux-x86
mkdir out/host/linux-x86/bin
fi
cp system/core/mkbootimg/mkbootimg out/host/linux-x86/bin

@jedld
Update on normal kernel build:
The reason the boot.img - when building via brunch gtexslte - will not boot is a bad zImage. If I replace the zImage from a bootable boot.img, the bad boot.img will boot okay.
Now I need to figure out what the problem is.

you can get the incremental diffs from linux.org

jedld said:
you can get the incremental diffs from linux.org
Click to expand...
Click to collapse
Is this for kernel changes or security patches?

gcrutchr said:
Is this for kernel changes or security patches?
Click to expand...
Click to collapse
My mistake, I meant kernel.org not linux.org. The incremental diffs contain changes to the mainline kernel which can contain security fixes and/or bug fixes. This is different from android specific patches which google releases separately as kernel patches. The kernel started out from the stock sources provided by samsung on 5.1.1 and then I added google's N and Oreo patches on it (patches related to selinux and oreo binder enhancements). I also added incremental diffs from kernel.org, it started out at 3.10.58 and then I applied incremental diffs until I got to 3.10.107. Unfortunately 3.10 is EOL now, upgrading the kernel to the 4.10 series will take a lot of work.

The SM-T285 Lineage OS is excellent. Is it possible to get the FM radio working? I have tried everything but can't get it to work. I would appreciate your help.

akasarf said:
The SM-T285 Lineage OS is excellent. Is it possible to get the FM radio working? I have tried everything but can't get it to work. I would appreciate your help.
Click to expand...
Click to collapse
It's probably not implemented in the kernel.
Just downloaded Radio FM from PlayStore and installed it. It works!!

I meant if there is a working FM radio tuner app that works without the internet on Lineage
gcrutchr said:
It's probably not implemented in the kernel.
Just downloaded Radio FM from PlayStore and installed it. It works!!
Click to expand...
Click to collapse

Building/Flashing custom kernel to SM-G780F(Exynos) help

Obligatory first post on the forums here so hopefully this is the right place!
I have been lurking on the forums for the past month or so and have been working on building a custom kernel from source for the SM-G780F/DSC(Exynos) edition. I've built some kernels from source before so I have some experience there, but actually getting the kernel to flash and run on the device is a different story. I have built the kernel with the modifications that I wanted, fixed some flashing issues I was running into, finally got the boot.img to flash succefully to the device, rebooted the device and the phone just hangs at the Samsung logo. (See "Image from iOS.png").
Here is the steps that I did:
Unlock Bootloader on the device.USB Debugging on, OEM Unlocking enabled in dev settings/ OEM Lock: OFF(U) in DL mode.
Checked to make sure KG State is not Prenormal, it is in checking state.
Device is currently running stock G780FXXS7CUI5, so I download this version source from https://opensource.samsung.com/uploadSearch?searchValue=SM-G780F
Extract Kernel.tar.gz, update toolchain paths in the Makefile/build_kernel.sh, and I make some modifications to the defconfig file.
Code:
./build_kernel.sh
; Fix compiler errors/warnings as they appear. Rinse and repeat until the kernel is built.
Now that the kernel is built I pull the stock ROM that this device is currently running from Sammobile. https://www.sammobile.com/samsung/g.../SM-G780F/MID/download/G780FXXS7CUI5/1583411/
Extract the AP directory from the Sammobile ROM download.
Extract the boot.img.lz4 from the AP directory so I now have the uncompressed boot.img.
Copy over the the stock boot.img to my AIK directory. (AIK-Kinux-V3.8)
Code:
./unpackimg.sh boot.img
, cd into split_img, rm the stock boot.img-kernel
Move my custom kernel image to the AIK directory,
Code:
mv kernel_source/out/arch/arm64/boot/Image /AIK-Linux/split_img/boot.img-kernel
Run AIK repackimage.sh
Now I have a SM-G780G(Snapdragon edition) S20_FE with Magisk installed. So I copy over my image-new.img to this device and patch the image-new.img with Magisk
Move back the patched image to my linux enviroment. Rename my patched image boot.img.
Compress my boot img with
Code:
lz4 -B6 --content-size boot.img boot.img.lz4
.
Replace the stock boot.img.lz4 in my AP directory with my modded boot.img.lz4
Pull down a clean vbmeta.img from https://dl.google.com/developers/android/qt/images/gsi/vbmeta.img
Compress this image as well
Code:
lz4 -B6 --content-size vbmeta.img vbmeta.img.lz4
Replace the stock vbmeta.img.lz4 in the AP directory with my clean vbmeta.img.lz4 in the
So the contents of the AP directory currently is
Code:
22556009 Apr 7 12:57 boot.img.lz4
1155 Sep 23 2021 dqmdbg.img.lz4
219753 Sep 23 2021 dtbo.img.lz4
4096 Sep 23 2021 meta-data
1148 Sep 23 2021 metadata.img.lz4
2773 Sep 23 2021 misc.bin.lz4
35115127 Sep 23 2021 recovery.img.lz4
5457239441 Sep 23 2021 super.img.lz4
822394050 Sep 23 2021 userdata.img.lz4
2375 Apr 7 12:57 vbmeta.img.lz4
2812 Sep 23 2021 vbmeta_samsung.img.lz4
tarball all these files with
Code:
tar -cvf Modded_AP.tar *
Spin up latest version of ODIN
Place Custom AP into AP slot, Stock BL into BL slot, Stock CP into CP slot, and Stock HOME_CSC into CSC slot
Start Flashing.
Flashing is successful.
Device reboots, and hangs at the Samsung Galaxy S20FE Screen with the warning "I am not running samsungs official software."
A couple of questions I am asking myself is the stock vbmeta_samsung.img.lz4 necessary, as well as some of the other stock files? Is patching my boot.img with Magisk running on a different
device giving me issues? Am i missing a step somewhere or is there still extra steps I need to take to get a modded kernel running on this device. Any help would be greatly appreciated or if I need to provide any more insight please let me know! Thanks again!

you'd be extremely welcome in our little group
S20 FE Modding
Exynos AOSP: https://t.me/S20FE_Exy TurboUI: https://t.me/projectxs20fe Prime Kernel Snap: https:/t.mes20fesnapdragon Prime Kernel Exynos: https://t.me+vpzEK9kPMc41MmY9 Bandido Kernel https://t.me/bandidokernel Klimbo Kernel https://t.me/klimbokernel
t.me
there's also a kernel dev there from time to time who has built kernels for all versions FE completely blind, i.e. without being able to flash them himself. maybe we can get you two talking.

it sounds like you've added two kernels to your AP archive. as I understand it once you've built your kernel, compressed it to .lz4 you can just archive it inside a tar file and flash that alone (as long as it matches your firmware).

Hi there Buddy, so answering your questions- we dont need vbmeta everytime, we only use it once to flash twrp after which flashing vbmeta not necessary. Now yes patching boot.img with other device other than the one you are running causes problems here and device doesnt like to boot. As per the last kernel dev he just used our stock boot.img and compiled his changes. And we flash hi kernel like normal flash.
S20 FE Modding
Exynos AOSP: https://t.me/S20FE_Exy TurboUI: https://t.me/projectxs20fe Prime Kernel Snap: https:/t.mes20fesnapdragon Prime Kernel Exynos: https://t.me+vpzEK9kPMc41MmY9 Bandido Kernel https://t.me/bandidokernel Klimbo Kernel https://t.me/klimbokernel
t.me
You can even join this group, there are many people willing to help others.

Also i have been developing stock based roms for all the variants, so would be happy to test them once they get stable enough to boot.

Thanks for the responses everyone! I'll take my follow up questions to the group!

Hi. There are some kernel changes that is needed to be applied in order to successfully boot the custom kernel. I suggest you post the kernel source so I can review it. You don't need to place everything inside the AP. You can just archive the boot.img.lz4 as tar.
Also, a lot of your steps can be simplified by making a twrp-flashable zip instead. You can use my template here:
android_kernel_samsung_s20fe/AnyKernel3 at exynos · pascua28/android_kernel_samsung_s20fe
Custom kernel for Samsung S20 FE (Snapdragon and Exynos variants) - android_kernel_samsung_s20fe/AnyKernel3 at exynos · pascua28/android_kernel_samsung_s20fe
github.com
Just move the arch/arm64/boot/Image as zImage and you can zip the AnyKernel3 folder and there you have a twrp-flashable zip. It's a lot more convenient this way as people do not need to carry around their computers whenever they need to flash custom stuffs plus, it's more universal this way as they don't have to have a matching firmware version; it will just use the existing boot image, unpack it, replace the kernel, repack and then flash it back to the device.
If you have any questions, feel free to contact me on telegram (pascua14). I hope you succeed
Regards