Hi guys,
I'd like to tinker around a bit with the tiamat or other kernels for the Xoom
are the following steps enough to get it working ?
- clone the repo
- adjust toolchain paths (or create an external script that does it)
- make stingray_defconfig
- make -j2
- test-boot the zImage via fastboot
- if it's successful copy over the kernel-modules & flash the kernel via fastboot
how about an initramfs ?
have I forgotten anything ?
Many thanks in advance for your help !
edit:
slowly understanding how all this works,
still might need some help
I think that will get you started. I'm not an expert, but when I'm tinkering with kernels I pull the proc config strait from the device after flashing the kernel I want to modify. That way I know that the default config is correct. For example, if I wanted to modify the kernel running on an EOS nightly, after cloning the repo I would flash the EOS nightly ROM containing the kernel I want to modify. Then run the following commands to pull the kernel config from the kernel running on my device:
Code:
adb pull /proc/config.gz .
gunzip config.gz
mv config .config
The .config then goes in the root of the kernel source directory. That may do exactly the same thing as the "make defconfig" you mentioned but I just prefer to trust the defaults from the ROM and not the repo.
Related
This is a basic kernel build guide, to help those that keep coming into IRC asking for help.
If you follow this, you should have a working kernel that will work with ext4 or RFS.
NOTE::I wrote this at 1am, when Im kinda falling asleep, so there might be errors. Please let me know, and Ill fix it up
What you need:
A Linux system, with about 2gb free (This is written for 32bit systems, 64bit will need a compatible toolchain)
Development libraries
The kernel source
An ARM toolchain
An initramfs from an existing kernel
Downloads
EB13 source - search for D700 under mobile phone
Code Sourcery 2009q3 ARM toolchain
Daemon's Ext4/RFS Initramfs
Steps:
Set up the build environment
The first thing you need to do is set up the build environment.
For Ubuntu or other Debian-based system, you need the build-essential package and libncurses.
You can install this by running this command:
Code:
sudo apt-get install build-essential libncurses5-dev
If your not running Ubuntu/Debian, the packages are gcc, g++, libc-dev, and make.
Next, your going to need a directory for all your kernel build. You can't have spaces in any folder name. Im going to use /home/tortel/build/ for the rest of this guide.
Now you need to extract the kernel source to your directory. In the Samsung source file, its SPH-D700_kernel.tar
Next, extract the ARM toolchain into your build directory.
Last, extract your initramfs into the directory.
After this, your build directory should contain 4 things:
Code:
arm-2009q3/
eb13init/
Kernel/
build.sh
For this guide, Im not going to use the build.sh. If you want to, you'll need to configure that yourself.
Configure your kernel
Now the fun begins.
You need to edit the Kernel/Makefile file, and change line 184 to match where your toolchain is. My line 184:
Code:
CROSS_COMPILE ?= /home/tortel/build/arm2009q3/bin/arm-none-linux-gnueabi-
Now you need to configure the kernel.
The kernel configuration file is called .config, which is hidden by default (Ctrl+H shows hidden files in GNOME). You need to set lines 81-91, so it uses your initramfs. My lines:
Code:
CONFIG_BLK_DEV_INITRD=y
CONFIG_INITRAMFS_SOURCE="/home/tortel/kernel/eb13init/"
CONFIG_INITRAMFS_ROOT_UID=0
CONFIG_INITRAMFS_ROOT_GID=0
CONFIG_RD_GZIP=y
CONFIG_RD_BZIP2=y
CONFIG_RD_LZMA=y
# CONFIG_INITRAMFS_COMPRESSION_NONE is not set
CONFIG_INITRAMFS_COMPRESSION_GZIP=y
# CONFIG_INITRAMFS_COMPRESSION_BZIP2 is not set
# CONFIG_INITRAMFS_COMPRESSION_LZMA is not set
This will build your initramfs into the kernel image.
Now, your set to build.
Build the kernel
This is the easy part. Open a terminal, cd to build/Kernel and run make.
The commands:
Code:
cd build/Kernel/
make
If you have more than one core, you should add -j {1+ # of CPU cores} to make so it finishes faster. It only takes about 5min on my 2ghz C2D laptop.
Make it flashable!
Congrats, its built!
The file you want is Kernel/arch/arm/boot/zImage in your kernel source directory. After make finishes, run:
Code:
cp arch/arm/boot/zImage ..
This copies your kernel image file into your main build directory. Now, you need to put it into a flashable zip. To make it easy, here. Just throw the zImage into the root of that zip, put it on your SD card, and flash it.
Might want later
Advanced config stuff to come
Might want this too
Thank you for this, I'm glad too see this and others who have contributed great guides like this.
sent from "The Other Woman"
I was one of those people who kept bothering lol. I learned how to compile a kernal in two day though, now im on my way making a OC/UV Voodoo color kernal (coming soon) :]
Thanks alot
globalninja said:
I was one of those people who kept bothering lol. I learned how to compile a kernal in two day though, now im on my way making a OC/UV Voodoo color kernal (coming soon) :]
Thanks alot
Click to expand...
Click to collapse
what should I look into for making the changes necessary for an overclocking kernel?
Thanks for this helpful thread, and I had a question previously, that someone pm'ed me for. OP, please remove this reply if you feel inclined to. I had a question about the initramfs because my computer was having problems loading the page for the link.
Hey guys, kindof a noob to this.
How can I get an initramfs for DI18? Ideally, I could just use the one in the stock ROM unmodified, but I have no idea how to obtain it.
I figured it out! Used the scripts here to extract it from zImage:
http://forum.xda-developers.com/showthread.php?t=901152
I'm trying to get a kernel config file '.config' from an existing kernel....
Besides
Code:
cat /proc/config.gz
and the script.
Code:
extract-ikconfig
is there any other way to get the configuration of a kernel?
(e.g: If an OEM leaves '.config' out of their kernel source.)
Thanks!
I only ask because the config.gz doesn't exist on the device, and extract-ikconfig says
Code:
extract-ikconfig: cannot find kernel config
Which I googled and some results said that it could be because of the compression method, but I even used the 'patched' version from the later 2.6.X kernels. So I doubt its the compression method used in the kernel.
+1
I have this problem with the kernels shipped by my manufacturer. Is there a repository anywhere of known good configs that can be used for reference?
Hi my name is ashy and I need some help regarding building a kernel from source for an ongoing project called H1droid here: h**p://samsungi8320.freeforums.org/portal.php
Basically I am just getting into this kind of stuff and at best Iam a hacker and a modder not a developer, so Linux is pretty new to me. However I learn fast and have a good grasp on what's what.
I am trying to build the Kernel for this project from this source h**p://samsungi8320.freeforums.org/onenand-mtd-multiboot-recovery-cm7-2rc1-t765.html
These sources were created originally by R3D4 who doesn't come to our fourms any more, so I am here to ask for help.
In a nut shell I am trying to build the kernel from R3D4's sources. I have Ubuntu, the tool chains, cloned the source and have managed to build the kernel. The problem is that the kernel requires to be in uImage format with built in ramdisk, however for the life of me I can't figure out how to create the valid boot.img..
I have pulled the config file from the device to use as the default .config, and haven't changed anything in menuconfig when compiling.
I have tried flashing the resulting image to the device, but it doesn't boot at all. It seems that there is no ramdisk to boot a rootfs.
I notice in .config it expects an initramfs to be in a specified directory, however my problem is I have no idea how to create the initramfs to build into the kernel when compiling.
This is probably something easy, but I have searched and searched and can't figure it out, so I am asking here for someone who has the knowledge if they can guide me in the right direction as to how to build the initramfs into the kernel and then compile it as a boot.img to flash via recovery.
I appreciate any and all help.
Thanks, ashy
Please help!
Update: I have managed to compile the kernel with built in initramfs, however the phone still doesn't boot.
Can anybody help here I'm stumped. Iam using Ubuntu 11.10 in VMware and these are the steps I have taken:
1. Clone sources as in first post
2. copy initramfs files into directory specified in config file: CONFIG_INITRAMFS_SOURCE="../out/target/product/nowplus/root"
2. Open terminal in Kernel directory
3. use command: make ARCH=arm nowplus_defconfig (this is the config file from the phone)
4. start the build of the kernel: make ARCH=arm CROSS_COMPILE=/home/user/cm7/arm-2012.03/bin/arm-none-eabi- uImage
During the compile there are warnings regarding unused variables or something, but believe these are normal. However at the end of the build modpost reports: WARNING: modpost: Found 2 section mismatch(es).
Is this significant?
Could really do with some help here, I am new at this stuff and getting really frustrated as I've been at it for 2 weeks now. I have searched and searched the whole internet for an answer.
ashyx said:
Update: I have managed to compile the kernel with built in initramfs, however the phone still doesn't boot.
Can anybody help here I'm stumped. Iam using Ubuntu 11.10 in VMware and these are the steps I have taken:
1. Clone sources as in first post
2. copy initramfs files into directory specified in config file: CONFIG_INITRAMFS_SOURCE="../out/target/product/nowplus/root"
2. Open terminal in Kernel directory
3. use command: make ARCH=arm nowplus_defconfig (this is the config file from the phone)
4. start the build of the kernel: make ARCH=arm CROSS_COMPILE=/home/user/cm7/arm-2012.03/bin/arm-none-eabi- uImage
During the compile there are warnings regarding unused variables or something, but believe these are normal. However at the end of the build modpost reports: WARNING: modpost: Found 2 section mismatch(es).
Is this significant?
Could really do with some help here, I am new at this stuff and getting really frustrated as I've been at it for 2 weeks now. I have searched and searched the whole internet for an answer.
Click to expand...
Click to collapse
Ok have managed to make a little progress, it seems the rootfs is loading as it boots up to a screen with blue A N D R O I D text and then changes to a flashing cursor in the top left of the screen. I guess this means the kernel isn't booting.
Still looking for pointers out there on this, can nobody give me a hint or a way to debug this problem?
ashyx said:
Ok have managed to make a little progress, it seems the rootfs is loading as it boots up to a screen with blue A N D R O I D text and then changes to a flashing cursor in the top left of the screen. I guess this means the kernel isn't booting.
Still looking for pointers out there on this, can nobody give me a hint or a way to debug this problem?
Click to expand...
Click to collapse
Hey, like you i'm an user which enjoy to experiment stuff with linux, so, i want just thank you to share your experience, it helped me
I spent entirely too much time on this, so I'll post my boot.img and my findings here in case it's useful to anyone else in the future.
Paladin ROMs:
This page and this thread have working links to CWM and Superuser zips.
This page has a link to an ICS 4.0.3 ROM running Linux 3.0.8. I installed this ROM, but was disappointed with the kernel's feature set. Important options like CONFIG_IP_NF_TARGET_REJECT and CONFIG_IP_NF_TARGET_LOG were disabled.
This page has a custom ROM by "pinkflozd". I wasn't able to find this image in the wild. It may have a newer kernel (3.0.23?) but AFAICT it doesn't have the Netfilter changes I needed either.
Custom kernel build:
I stumbled across this kernel and used it as a baseline. Then I enabled:
Various missing Netfilter features (e.g. LOG and REJECT targets)
CONFIG_TUN
CONFIG_CIFS
The process looks like:
Install CWM
Find the .zip file for the ROM you want to use, e.g. the ICS 4.0.3 link above
Install that ROM and make sure the stock kernel works
Create a new boot.img with the desired options enabled
Flash the new boot.img with CWM
Basic steps to create the new boot.img:
Code:
git clone -b paladin-3.0.8 git://github.com/cernekee/linux
cd linux
git submodule init
git submodule update
cd paladin
cp /path/to/boot.img orig.img
make NDK=/opt/android-ndk-r9b
# if desired, edit kernel code or .config, and rerun "make"
The scripts under linux/paladin/ will extract the ramdisk from orig.img, then create a new boot.img based on your kernel source tree. For more details on the kernel build, see paladin/README .
Kernel installation:
To flash the new image, reboot into CWM, then:
Code:
adb push boot.img /tmp/
adb shell "dd if=/tmp/boot.img bs=1048576 seek=3 count=8 of=/dev/block/mmcblk0 ; sync"
# hit the reset button again
Other random findings:
I did not have any luck with the "z4root" app, although ro.secure=0 on this ROM so "adb shell" always gives you a root shell. It did take some work to find Superuser/su binaries that worked on MIPS.
Enabling Netfilter's conntrack option seemed to cause dhd.ko to become unstable, possibly because it affected binary compatibility with existing kernel modules. So I left it alone.
This ROM is missing native iptables/ip6tables binaries, so AFWall needs to be set to use the builtin copies. The latest AFWall betas do ship with MIPS binaries now (the purpose of this exercise was to test them).
Checking the box to enable IPv6 crashes AFWall instantly. Need to investigate this.
AFWall's inbound connection option probably will not work, due to the lack of conntrack in the kernel.
This ROM appears to be missing some Java libraries needed for ICS+ VpnService apps to work.
NDK r9b is the first NDK release with support for the "MXU" SIMD instructions supported by the Ingenic JZ4770 chip. Prior to this, most people used Ingenic's special toolchain to build the kernel.
To forcibly boot into CWM, hold down VOL+ while pressing the reset button.
I've only recently after lot of struggle compiled my first kernel. While the information is still fresh in my mind, I want to share all the problems I encountered and what to do if you are in the same situation.
This guide is mainly for Linux users since that is what I am familiar with.
I've used this amazing guide to learn the basics. If you haven't yet, read it first.
Errors from scripts/gcc-wrapper.py
Open the file and change the first line from
Code:
#! /usr/bin/env python
to
Code:
#! /usr/bin/env python2
Kernel won't compile
* Did you forget to set and export the variables ARCH and CROSS_COMPILE?
* Do you have the right .config file present?
Try extracting the .config file from the original boot kernel and use it instead
* Are you sure you are in the correct branch?
Run git branch inside kernel's source code to verify that
* Are you using a very recent or very old version of the compiler? Some old kernels for example would only compile with gcc-4 but not gcc-7 or 8. Most kernels - at the time of writing - won't compile with gcc-8
Kernel compiles fine but won't boot
* Are you using wrong kernel configuration (.config) ?
* Try different compiler or different compiler version.
I've tried to compile my current with Android's prebuild gcc 4 compiler and it wouldn't boot, switched to gcc 7 and it booted perfectly fine.
Kernel starts but system crashes somewhere during boot
You can enable adb during boot so that you can see what causes the error.
Find this file in your extracted boot image ramdisk/default.prop
Set or update the following values
Code:
ro.adb.secure=0
ro.secure=0
persist.sys.usb.config=adb
Then you can do adb shell logcat or adb shell dmesg to see what is going on
My phone won't boot after flashing my new kernel, how do I boot to recovery?
First of all, you shouldn't have! You should test your new kernel without flashing it using fastboot.
Simply reboot to bootloader then run the command
Code:
fastboot boot /path/to/my/new-image
So what can I do now? Try to reach bootloader screen. the method differs from device to device but it involve pushing certain physical phone buttons while turning on the phone.
Once you are in the bootloader screen, you can do adb fastboot /path/to/twrp-recovery.img or even path to original boot image if you kept a backup.
ramast_ said:
I've only recently after lot of struggle compiled my first kernel. While the information is still fresh in my mind, I want to share all the problems I encountered and what to do if you are in the same situation.
This guide is mainly for Linux users since that is what I am familiar with.
I've used this amazing guide to learn the basics. If you haven't yet, read it first.
Errors from scripts/gcc-wrapper.py
Open the file and change the first line from
Code:
#! /usr/bin/env python
to
Code:
#! /usr/bin/env python2
Kernel won't compile
* Did you forget to set and export the variables ARCH and CROSS_COMPILE?
* Do you have the right .config file present?
Try extracting the .config file from the original boot kernel and use it instead
* Are you sure you are in the correct branch?
Run git branch inside kernel's source code to verify that
* Are you using a very recent or very old version of the compiler? Some old kernels for example would only compile with gcc-4 but not gcc-7 or 8. Most kernels - at the time of writing - won't compile with gcc-8
Kernel compiles fine but won't boot
* Are you using wrong kernel configuration (.config) ?
* Try different compiler or different compiler version.
I've tried to compile my current with Android's prebuild gcc 4 compiler and it wouldn't boot, switched to gcc 7 and it booted perfectly fine.
Kernel starts but system crashes somewhere during boot
You can enable adb during boot so that you can see what causes the error.
Find this file in your extracted boot image ramdisk/default.prop
Set or update the following values
Code:
ro.adb.secure=0
ro.secure=0
persist.sys.usb.config=adb
Then you can do adb shell logcat or adb shell dmesg to see what is going on
My phone won't boot after flashing my new kernel, how do I boot to recovery?
First of all, you shouldn't have! You should test your new kernel without flashing it using fastboot.
Simply reboot to bootloader then run the command
Code:
fastboot boot /path/to/my/new-image
So what can I do now? Try to reach bootloader screen. the method differs from device to device but it involve pushing certain physical phone buttons while turning on the phone.
Once you are in the bootloader screen, you can do adb fastboot /path/to/twrp-recovery.img or even path to original boot image if you kept a backup.
Click to expand...
Click to collapse
good job!
Do you have any general tutorials on kernel optimization?
wangyiling said:
good job!
Do you have any general tutorials on kernel optimization?
Click to expand...
Click to collapse
I am afraid not, sorry. I am just a beginner
@ramast_
The information you provided has solved pretty much all of the problems I was having. We need more content like this. Everything I find about kernel building explains things like you're a Linux expert, where as your post is much more layman friendly. I can't thank you enough for this.
Quick question; which version of Linux do you use?
You are very welcome, happy someone found it useful.
By Linux version I suppose you mean Linux distro (distribution).
I use Gentoo which is certainly not for beginners.
I'd suggest Ubuntu for beginners. Not because it's the best but because it has a very big community and you are more likely to find help when facing any problem.
This article explain how to cross compile arm code (how to compile code so that it can run on an arm device). Should get you started.
Best of luck
Spaceminer said:
@ramast_ I can't thank you enough for this.
Quick question; which version of Linux do you use?
Click to expand...
Click to collapse
ramast_ said:
You are very welcome, happy someone found it useful.
By Linux version I suppose you mean Linux distro (distribution).
I use Gentoo which is certainly not for beginners.
I'd suggest Ubuntu for beginners. Not because it's the best but because it has a very big community and you are more likely to find help when facing any problem.
This article explain how to cross compile arm code (how to compile code so that it can run on an arm device). Should get you started.
Best of luck
Click to expand...
Click to collapse
Thanks again. Distro is what I meant. I was thinking I should use Ubuntu, but I wanted to see what you had to say about it.