I've got this side project going where I've decided to try to modify the stock kernel for my GT-I9000M.
I'm a Gentoo linux user and have cross-compiled kernels for embedded systems with or without initramfs and modules successfully many times. Rather than just grab and flash the latest mod from the net I want to understand exactly how to create my own.
I already have access via a chroot to a working Gentoo install, however that runs in a sandbox inside android userland, which can be irritating to say the least. I'm already able to create binaries for armv7a on the phone itself, which is a time and power-consuming novelty.
I setup a development environment on my main computer and made sure I could create working binaries for the armv7a.
I backed up all the bml partitions on my phone.
Next, I made sure I could access Download Mode and experimented with Heimdall until I was satisfied I was able to recover from any bad kernel flashes.
I altered the first boot logo in param.lfs with dd, but that's a whole other story.
Next, I downloaded Samsung's source for Froyo and followed the instructions to create a zImage.
aries_eur_defconfig selects the FM radio module and the Samsung TV out driver which are broken. No problem, I figured I could check that out later so I disabled those options for now. it compiles! great! But it didn't boot. I turned to the internet for ways to solve the problem.
There was a lot of conflicting information. I ended up trying a lot of different approaches, modules, firmware, version info, kernel command lines, fbcon... well I messed around.
Some time later, I find myself happily booting with my own kernel. The bootloader displayed my custom logo in param.lfs, but fbcon didn't work and I got a stock samsung gt-i9000 logo before android booted up! The phone worked, wifi worked, bluetooth worked, it was awesome (for 2.6.32.9 that is )!
So, great! Except I got overconfident and cocky. I made a slew of changes trying to get fbcon to work and to top off the evening I overwrote my working zImage with a broken kernel (without a backup of my working custom zImage or .config). I still have backups otherwise of course and haven't lost the functionality of my phone in any way, but now I'm just irritated.
Anybody else working on compiling from source on the GT-I9000M?
I pressed ahead and tried to recreate the conditions that got me a working kernel and as of yet I've been unsuccessful Luckily I've got a kmsg from the kernel when it booted. I can see the kernel command line on the custom kernel that booted was simply "console=ttySAC2,115200" although I do recall trying different values for init= ... The default init in the sources is /linuxrc which doesn't exist in initramfs.
There are also settings for the kernel command line and version information in arch/arm/mach-s5pv210/include/mach/param.h
Is there a known good method to compile from Samsung's sources?
I unpacked a known good zImage, played with it's initramfs, repacked it and it boots just fine.
I've tried again with a fresh copy of the gt-i9000 froyo-samsung branch:
- unpack initramfs from a known good 2.6.32.9 kernel
- make clean
- make aries_eur_defconfig
- make menuconfig, add initramfs, remove Samsung TV driver and FM radio module
- make
the resulting vmlinux is: ELF 32-bit LSB executable, ARM, version 1 (SYSV), statically linked, not stripped (I know, it's zImage not vmlinux but I'm just doing sanity checks)
I have a custom logo in param.lfs which always displays on boot. A second logo is compiled into the kernel, and I do see a change in the logo when my kernel boots (it shows GT-I9000 instead of GT-I9000M after the first logo). This leads me to believe that the kernel is booting... but the phone powers off after booting.
I've tried the recommended changes to default.prop to use adb to obtain the kmsg of the new kernel. This has not worked however, which could mean that the kernel doesn't get as far as initramfs.
the kernel command line from the kmsg I have from the one time that a custom kernel of mine booted is simply: "console=ttySAC2,115200 loglevel=4" . There's no mention of init, which I think should be init=/init although aries_eur_defconfig seems to think that init=/linuxrc is appropriate (linuxrc doesn't exist?) Regardless, it doesn't seem to matter what I specify for init.
Which leaves proprietary Samsung kernel modules. If they can't load, this could explain everything I'm experiencing. It isn't clear what specific version the proprietary modules are expecting.
Maybe this will help somebody else. I've got it working now.
Attached is my working config.
Hi guys!
Someone requested a tutorial on how to build the kernel source code, so I thought I might as well do it I'll give you a bit more information too.
Maybe this will kick start kernel development a little bit too. Who knows.
Anyway:
1. Set up your build environment as per this guide by AOSP here: http://source.android.com/source/initializing.html
This guide will be primarily aimed at Ubuntu, but it should be easy enough to do on other Linux PCs. Ubuntu is highly recommended. And don't ask about Windows.
2. Download the toolchains: http://code.google.com/p/rohan-kernel-evita/downloads/detail?name=toolchains.tar.gz&can=2
I've hosted both GCC 4.4 and GCC 4.6 (prebuilt) on my Google Code page. These are for Linux.
Download the toolchain package here: http://code.google.com/p/rohan-kernel-evita/downloads/detail?name=toolchains.tar.gz&can=2
Then un-tar the archive and extract it to your home folder so that the path to the toolchain directories are ~/toolchain/whatever-one-you-want
3. At this point you can decide which kernel source you want to download. There are really two sources.
The first choice is getting it from HTC Dev directly. This is good if you want to build your kernel for a Sense 4 ICS ROM. If you want to build for AOSP/JB, then scroll down below all the following HTC stuff.
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To use HTC's source:
Go to HTCdev.com and make an account. Then download the source code for our device (I'd recommend the "One X" source under carrier "AT&T" version "2.20". Let the zip file download and extract it to your home folder (so the path is /home/user/evita-ics..../
To build HTC's source, run these commands:
Code:
cd ~/evita-ics-whatever_the_directory_is_named
export ARCH=arm
make elite_defconfig
Second command is saying what type of architecture we want (we are compiling for ARM processors, so we want ARM)
Third command is saying to make the default config for our device (whose hardware is codenamed "elite")
Then to build the actual kernel:
Code:
make -j# ARCH=arm CROSS_COMPILE=~/toolchain/arm-eabi-4.4.3/bin/arm-eabi-
In the command above, there is "-j#". Replace the "#" with the number of CPUs you have.
Ask me about it if you need help. That should be it! Let the build go and in a few minutes you should have a zImage file located at ~/evita-ics-..../arch/arm/boot. That is the actual kernel.
To test out the zImage (kernel), connect your device via fastboot mode and type:
Code:
fastboot boot /path/to/zImage
Combined with the ramdisk, thats what makes the boot.img file. Eventually if you want to distribute your kernel, you should use an installer that injects the zImage into the boot.img or combine the zImage with a ramdisk to make a boot.img. I can do a tutorial on that later on as well.
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To get the "other" source:
This source is based off of HTC's source and includes other devices as well in it (the One S and Evo 4G LTE). Its good if you want to build JB AOSP kernels.
To download this kernel source do this:
Code:
mkdir ~/kernel
cd ~/kernel
git clone https://github.com/CyanogenMod/android_kernel_htc_msm8960.git -b android-msm-evita-3.0
This version also includes a number of optimizations and odd bug fixes present in the HTC version.
To build this second source, run these commands:
Code:
cd ~/kernel/android_kernel_htc_msm8960
export ARCH=arm
make elite_defconfig
Second command is saying what type of architecture we want (we are compiling for ARM processors, so we want ARM)
Third command is saying to make the default config for our device (whose hardware is codenamed "elite")
Then to build the actual kernel:
Code:
make -j# ARCH=arm CROSS_COMPILE=~/toolchain/arm-linux-androideabi-4.6/bin/arm-eabi-
In the command above, there is "-j#". Replace the "#" with the number of CPUs you have.
Ask me about it if you need help. That should be it! Let the build go and in a few minutes you should have a zImage file located at ~/evita-ics-..../arch/arm/boot. That is the actual kernel.
To test out the zImage (kernel), connect your device via fastboot mode and type:
Code:
fastboot boot /path/to/zImage
Combined with the ramdisk, thats what makes the boot.img file. Eventually if you want to distribute your kernel, you should use an installer that injects the zImage into the boot.img or combine the zImage with a ramdisk to make a boot.img. I can do a tutorial on that later on as well.
-----------------------------------------------------------------------------
The second option is also a bit better as it uses the 4.6 toolchain instead of GCC 4.4. HTC's source doesn't work with GCC 4.6 so it can't be used without changes that the second source has.
If you have any questions, feel free to post here, message me on twitter (@rohanXm), chat me on IRC (#HTC-One-XL) or PM me!
If this helped you, please consider hitting the donation link under my username on the left. Donations are never required but always appreciated.
Instead of downloading cm10 the readme inclided with the HTC source has directions for getting a tool chain which will compile the source.
Sent from my HTC One X using Tapatalk 2
Perfect. Now I just have to read.
Sent from my HTC One XL bumping it
rohan32 said:
Code:
repo init -u git://github.com/CyanogenMod/android.git -b jb
Click to expand...
Click to collapse
FYI, It looks like the branch name has changed. When I changed "jb" to "jellybean" the repo init command worked.
Rohan. You are one bad MF'er
Sent from my twin turbo'ed OneXL rocking rezound beats
rohan32 said:
2. You can either try to find a standalone package of the precompiled toolchain, or you are going to need to download a ROMs source. I'd recommend downloading a ROMs source since I've never found a good toolchain that worked for me. If you find one that works, post below
For now we will download CM10 since that seems like the defacto standard.
Click to expand...
Click to collapse
I downloaded the 2.20.502.7 kernel source and when I extracted it there was a file named evita_readme.txt which gave another, possibly more "official", location for downloading a toolchain:
--Please follow below command to download the official android toolchain: (arm-eabi-4.4.3)
git clone https://android.googlesource.com/platform/prebuilt
Click to expand...
Click to collapse
I just performed a build with this toolchain but got this error when I attempted to load zImage via fastboot:
c:\>fastboot flash boot zImage
sending 'boot' (5140 KB)...
OKAY [ 1.044s]
writing 'boot'...
FAILED (remote: image error! (BootMagic check fail))
finished. total time: 1.077s
Click to expand...
Click to collapse
I'm not sure if this is caused by the toolchain or if I screwed something up. Have you ever seen this error before?
EDIT: Ok I see what I did incorrectly. The zImage needs to be "Combined with the ramdisk". You wouldn't know how to perform this operation... would you?
denversc said:
I downloaded the 2.20.502.7 kernel source and when I extracted it there was a file named evita_readme.txt which gave another, possibly more "official", location for downloading a toolchain:
I just performed a build with this toolchain but got this error when I attempted to load zImage via fastboot:
I'm not sure if this is caused by the toolchain or if I screwed something up. Have you ever seen this error before?
EDIT: Ok I see what I did incorrectly. The zImage needs to be "Combined with the ramdisk". You wouldn't know how to perform this operation... would you?
Click to expand...
Click to collapse
You are trying to flash a zImage
To my knowledge, only booting zImages work on this device. For the time being just boot the zImage (use fastboot boot zImage)
I will make a tutorial on how to combine the zImage created with a ramdisk to make a boot.img when I get the chance
denversc said:
FYI, It looks like the branch name has changed. When I changed "jb" to "jellybean" the repo init command worked.
Click to expand...
Click to collapse
Oops, my bad! That was a mistake. AOKP uses -jb and CM uses -jellybean so I got them switched fixed now
Out of any device I've seen more people actually interested in helping and learning to help then any other community. I've watched noobs become less noobish.. I've watched skizz learn how to make themes. Hell I've learned 10 fold what I knew before this phone myself.
That is beautiful, and now such an informed, helpful post such as this.
Have great Sunday you guys! I think I might give this a shot!
Sent from my One X
I'll streamline this process in a bit, so that you don't need to download CM10
Edit: cleaned up post, now I'm uploading just the toolchains. Its a tar.gz archive, around 150mb. Much better than downloading the entire CM10 source
rohan32 said:
You are trying to flash a zImage. To my knowledge, only booting zImages work on this device. For the time being just boot the zImage (use fastboot boot zImage)
Click to expand...
Click to collapse
Thanks for your response, rohan. You are absolutely right: I was incorrectly attempting to flash zImage straight to the boot partition, and the error produced by flashboot was justified. I have since successfully "tested out" my compiled zImage by flashing it via "fastboot boot zImage" and it worked like a charm! I ported the modifications from sbryan's Blackout BeastMode kernel and I am now able to OC to 2106 MHz and UC to 192 MHz. It's been running solid for the past few hours at least
Of course, the kernel reverts back to the one stored in the boot partition after a reboot, and I want my shiny new kernel to "stick". I've done a bit of research on this topic and found some information about combining my zImage with a ramdisk into a "real" boot.img but have not yet been successful in creating a boot.img which does not bootloop after flashing it.
For example, I found an article on xda called Basic Kernel Kitchen for Minor Kernel Tweaking which points to a "kitchen sink" tool for creating a boot.img from a zImage and a ramdisk. My problem is that I don't know where to get or how to make a ramdisk. So I tried using the ramdisk from the boot.img of the ROM that I am currently running (CleanROM 4.5 DE) but just got into a bootloop. I've since been doing some yard work today so haven't gotten back to investigating further.
I also found another program named abootimg which can also produce a boot.img from a zImage abd a ramdisk, but when I tried it an error message about my zImage being "too big" was produced.
If it's not obvious yet, I am kind of fumbling around in the dark as compiling and deploying custom kernels is completely new to me! But this post was the most valuable resource I've come across in getting to this point. Thanks so much for writing it! I eagerly await your next article about creating the boot.img
---------- Post added at 06:05 PM ---------- Previous post was at 05:50 PM ----------
rohan32 said:
cleaned up post
Click to expand...
Click to collapse
Thanks for cleaning up the post rohan. I have a few follow-up questions/comments:
missing toolchains link -- the post says "Download the toolchains:" but there is no link to download anything... did you forget to paste the link?
official toolchain -- That's great that you uploaded the toolschains to save tonnes of bandwidth. The CM10 source was taking a VERY long time for me to grab. However, I imagine some people (like me) would prefer to get the toolchain from an "official" source. In the "evita_readme.txt" file of the kernel sources downloaded from HTC dev it instructs one to use the official sources from "git clone https://android.googlesource.com/platform/prebuilt". This is the toolchain that I used and it successfully built the zImage.
ko files -- I noticed in the ZIP file for Blackout BeastMode, in additional to installing the zImage it also puts a bunch of "ko" (kernel modules I believe) into the /system partition (eg. qce40.ko). Should I also be deploying .ko files from my build to the device?
Thanks!
denversc said:
Thanks for your response, rohan. You are absolutely right: I was incorrectly attempting to flash zImage straight to the boot partition, and the error produced by flashboot was justified. I have since successfully "tested out" my compiled zImage by flashing it via "fastboot boot zImage" and it worked like a charm! I ported the modifications from sbryan's Blackout BeastMode kernel and I am now able to OC to 2106 MHz and UC to 192 MHz. It's been running solid for the past few hours at least
Of course, the kernel reverts back to the one stored in the boot partition after a reboot, and I want my shiny new kernel to "stick". I've done a bit of research on this topic and found some information about combining my zImage with a ramdisk into a "real" boot.img but have not yet been successful in creating a boot.img which does not bootloop after flashing it.
For example, I found an article on xda called Basic Kernel Kitchen for Minor Kernel Tweaking which points to a "kitchen sink" tool for creating a boot.img from a zImage and a ramdisk. My problem is that I don't know where to get or how to make a ramdisk. So I tried using the ramdisk from the boot.img of the ROM that I am currently running (CleanROM 4.5 DE) but just got into a bootloop. I've since been doing some yard work today so haven't gotten back to investigating further.
I also found another program named abootimg which can also produce a boot.img from a zImage abd a ramdisk, but when I tried it an error message about my zImage being "too big" was produced.
If it's not obvious yet, I am kind of fumbling around in the dark as compiling and deploying custom kernels is completely new to me! But this post was the most valuable resource I've come across in getting to this point. Thanks so much for writing it! I eagerly await your next article about creating the boot.img
---------- Post added at 06:05 PM ---------- Previous post was at 05:50 PM ----------
Thanks for cleaning up the post rohan. I have a few follow-up questions/comments:
missing toolchains link -- the post says "Download the toolchains:" but there is no link to download anything... did you forget to paste the link?
official toolchain -- That's great that you uploaded the toolschains to save tonnes of bandwidth. The CM10 source was taking a VERY long time for me to grab. However, I imagine some people (like me) would prefer to get the toolchain from an "official" source. In the "evita_readme.txt" file of the kernel sources downloaded from HTC dev it instructs one to use the official sources from "git clone https://android.googlesource.com/platform/prebuilt". This is the toolchain that I used and it successfully built the zImage.
ko files -- I noticed in the ZIP file for Blackout BeastMode, in additional to installing the zImage it also puts a bunch of "ko" (kernel modules I believe) into the /system partition (eg. qce40.ko). Should I also be deploying .ko files from my build to the device?
Thanks!
Click to expand...
Click to collapse
Hey!
Sorry, set it to upload then got distracted Link posted
The reason why your boot.imgs bootloop is because there is a special ramdisk address that needs to be set when combining the ramdisk with the zImage, and most kitchens don't support this. You also need to set the address after setting the base value.
I will post a guide on how to make it a real boot.img whenever I get the chance.
I'm telling you people, Rohan is a BOSS. Most helpful dev I know.
Sent from my HTC One XL using xda app-developers app
rohan32 said:
Hey!
Sorry, set it to upload then got distracted Link posted
The reason why your boot.imgs bootloop is because there is a special ramdisk address that needs to be set when combining the ramdisk with the zImage, and most kitchens don't support this. You also need to set the address after setting the base value.
I will post a guide on how to make it a real boot.img whenever I get the chance.
Click to expand...
Click to collapse
I have the zImage thanks to your tutorial, but I want to know how to create the kernel zip, whenever you have time will be amazing if you can post a guide, I'm really looking forward to that guide, because i haven't been able to locate a guide that works
Sent from my HTC One XL using xda premium
rohan32 said:
Hi guys!
Second command is saying what type of architecture we want (we are compiling for ARM processors, so we want ARM)
Third command is saying to make the default config for our device (whose hardware is codenamed "elite")
Then to build the actual kernel:
Code:
make -j# ARCH=arm CROSS_COMPILE=~/toolchain/arm-linux-androideabi-4.6/bin/arm-eabi-
Click to expand...
Click to collapse
This is the correct make for "other source" kernel.
Code:
make -j# ARCH=arm CROSS_COMPILE=~/toolchain/arm-linux-androideabi-4.6/bin/[COLOR="Red"]arm-linux-androideabi-[/COLOR]
Can you make a tutorial on how to insert governors into a kernel?
Compiling problem
Hey man,
Please help me I followed your article but when I try copile with:
make -j2 ARCH=arm CROSS_COMPILE=~/toolchain/arm-eabi-4.4.3/bin/arm-eabi
I got something like this:
/home/martin/toolchain/arm-eabi-4.4.3/bin/../lib/gcc/arm-eabi/4.4.3/../../../../arm-eabi/bin/as: error while loading shared libraries: libz.so.1: cannot open shared object file: No such file or directory
Thanks
UPDATE:
now its work
I went deeper and install lib32z1 with "sudo apt-get install lib32z1"... now its work
My device repositories are not available on github, But I got device tree and vendor blobs by making changes in similar device repo. That reference device's kernel's lineageos_defconfig is situated in htc msm8974 kernel repo. So how can I get lineageos_defconfig for my device, and which other my device related kernel files(.dtsi or any other) I have to push in htc msm8974 repo and get those files to make things ready for build?
Please help......
Hi,
I am a new beginner of android. I am trying to rebuild the kernel with profiling support for Samsung galaxy s2 (GT-i9100). After flashing my custom rom to my phone, my phone does not work.
This is how I do it:
1.Downloaded the image I9100XXLP6_I9100OXXLP3_OXX and flashed my galaxy s2 mobile using odin software. now my Galaxy s2 works fine with ICS build (kernel version - [email protected] #3, Ardroid version - 4.0.3).
2. Downloaded the samsung galaxy s2 source code GT-I9100_ICS_Opensource_Update8.zip from opensoure.samsung.com and cross compiler arm-eabi-4.4.3.
3. Use the initramfs from github (Since I am a new user of this forum, I can not post outside link here; I google with "arighi/initramfs-gt-i9100.git" and use the first link)
4. Through "make menuconfig" to enable the profiling support and configure the initramfs source path as specified at step 3.
5. After compiling, I can get the custom zImage of size about 8 MB
6. Then I use "tar -cvf mykernel.tar zImage" to generate my custom rom; and then flash it to my phone through odin.
7. Now my phone boots with a kernel panic upload mode screen and my phone doesn't work.
My question:
1. Does the initramfs cause the problem? If it is, where can I get the matched initramfs for the kernel source code?
2. Is there anything wrong in my above steps?
I would be very appreciated if someone could help me.
Thanks.
Hi,
I'm currently trying to build a kernel for my GT-P5110. I have a stock Android 4.2.2 which I downloaded from sammobile. I also downloaded the kernel from Samsung Open Source. I've use split_bootimg.pl to get the ramdisk from the boot.img and mkbootimg to make a boot.img from my zImage build successfully and the ramdisk. The problem is, when I flash my boot.img, I get stuck on the Samsung Galaxy Tab 2 logo even if I use the android_espresso10_omap4430_r02_user_defconfig which is suggested by Samsung.
Is there anyone able to sucessfully flash this kernel on his device?
Update: It seems like the defconfig file included in the Samsung Open Source contains some error.
If you want a working defconfig file use this one: http://forum.xda-developers.com/showpost.php?p=37685672&postcount=12
I have:
Downloaded the exact kernel version running on my device from an AOSP mirror (4.9.170) (https://github.com/aosp-mirror/kernel_common.git)
Downloaded the exact compiler used to compile the kernel from my device:
Ran `cat /proc/version`, which returns "Linaro GCC 5.3-2016.05", which I downloaded from https://releases.linaro.org/components/toolchain/binaries/5.3-2016.05/aarch64-linux-gnu/
Took the kernel configuration from `/proc/config.gz`, copied it to the kernel source directory `kernel_common` as `.config`
Ran `make ARCH=arm64 CROSS_COMPILE=xxx oldconfig`
What I'm seeing:
First, the downloaded kernel source for 4.9.170 seems to think that my `config` is incomplete, since it will prompt me to answer ~15 extra configuration questions.
Second, this old Linaro compiled doesn't appear to support `-fstack-protector-strong` despite it being explicitly enabled in the `/proc/config.gz` file. So I end up disabling it with `./scripts/config --disable CONFIG_CC_STACKPROTECTOR_STRONG`
Finally, after successfully compiling, I take `net/ipv4/tcp_westwood.ko`, just as a test module, and try to load it on my Android device, and it fails:
`insmod: failed to load tcp_westwood_5.ko: Exec format error`
And in dmesg output: `tcp_westwood: disagrees about version of symbol module_layout`
My questions:
Can I assume that the `/proc/config.gz` file is not the actual file used to compile the running kernel, considering it doesn't completely configure the 4.9.170 kernel?
Am I on the right path to getting a kernel module that my kernel will load?
Background information:
I'm hoping this isn't very relevant, but just to head off some questions
This is a T95 Android TV device running what appears to be, to this newbie's eyes, a very Frankenstein'd Android 10 install (See https://www.cnx-software.com/2020/0...-comes-with-mali-g31-gpu-supports-android-10/)
I can't find any official - or unofficial - source for this device, which is why I'm going to all the trouble above.
I really appreciate any help, thank you!