Come, listen to the story of our (Mac) people.
If you follow https://source.android.com, you can certainly build Android on OSX with relative ease. But, this only uses a prebuilt kernel. If you want to actually modify the kernel you will need this guide, which will get you about 80% there and then drop you off in the middle of broken builds-ville.
Prerequisites and Limitations
This guide assumes you already have the Android SDK installed and checked out the source for AOSP with repo. Follow the official Android guide and complete a normal Android build to make sure everything is working. If you haven’t already unlocked and rooted a phone this guide will probably just confuse you and possibly break your phone permanently.
Overview
For those new to the kernel build process, an overview of what we are about to do would be helpful. Context is great when starting something new so you aren’t just blindly copy/pasting commands.
There are many git repositories controlled by repo. Repo is a android specific meta repository of the many hundreds of git repositories that make up AOSP. There are two git repositories that we care about now, the kernel binary repository and kernel source repository. Typically, doing repo sync should automatically download the binary kernel repository for you. However, the kernel source must be downloaded manually. When you do a AOSP normal build, it just uses this pre-built kernel, this is why you can build AOSP on OSX without the kernel building headache we are about to deal with.
You will notice a lot of references to weird codenames like hammerhead and msm. Phones have codenames, and Nexus phones are typically named after sea creatures. The Nexus 5 is hammerhead and the Nexus 6 is shamu for example. See the table here for the locations of Nexus and some other kernels. Finding kernels for non Nexus devices can be it’s own adventure, you will have to track those down on the manufacturer website or a community site like http://www.xda-developers.com/.
The first thing we will do is examine the prebuilt binary kernel repo included in AOSP for our device. We will check that repo to figure out the commit hash of the kernel source repo that was used to build it.
Then, we will download the kernel source repository. We can then check out the proper commit from the last step.
You will need to verify that you have a cross-compiling toolchain from darwin to your phone’s architecture (usually arm). AOSP comes with one, so generally, you should be good to go.
Then you will build. Since we are on OSX, it will fail due to library issues. We will overcome these issues.
Next, you will need to package your kernel into a flashable boot image. The files generated by the kernel build consist of only the kernel. The initial ramdisk, the tiny in memory disk image that contains some basic drivers and executables to get things started, need to be packaged with the kernel in a very specific manner for the hardware on your phone. Because we have the AOSP repo, this is a breeze.
Finally, you will boot the image to test it, and finally flash it to make it persistent. At that point, welcome to level 0 of android kernel hacking.
Examine the Prebuilt
We will start close to the official kernel build guide, but for the Nexus 5 instead of a HiKey. It will also be from the perspective of already having the AOSP repo checked out. The official guide assumes you have not, and need to check out the kernel repo separately.
Assume your AOSP repo root is assigned to an environment variable, $AOSP. The first thing you must do, is check the pre-built kernel binary directory for your device and use git to determine the last commit from the kernel source repository which we will visit soon. Of course, if your intention is to use a different kernel as a starting point, then you are probably way over my head.
The directory with the prebuilt binary kernel is in this form<AOSP_ROOT>/device/<vendor>/<name>-kernel and should already be checked out if you did a repo sync. Name here is the codename for the device, hammerhead for the Nexus 5.
Code:
cd $AOSP/device/lge/hammerhead-kernel
git log --max-count=1
So, now you might see a commit message with something similar to:
commit 7b209ca7ce7bf98e6344c96c4ca172d6fa553549
Code:
...
Linux version 3.4.0-g0e4eb55 ([email protected])
(gcc version 4.8 (GCC) ) #1 SMP PREEMPT
...
All you need from this is the short commit hash in the message, minus the “g”. It is not the commit hash of the current commit in this repo! It is the actual commit message which contains the commit hash from the kernel source repo. In this case, 0e4eb55. Record this somewhere, we will use it a hot second. We are done with the pre-built binary.
On to the Source
Alright, now, time to get the kernel source. Refer to the device table for the proper repo. Check it out! By the way, msm stands for Qualcomm’s MSM, or Mobile Station Modem SoC.
Code:
cd $AOSP
git clone https://android.googlesource.com/kernel/msm.git
Now, before we get started, we need to have a cross compile capable gcc toolchain. Fortunately, this is available for OSX. It should already be in $AOSP/prebuilts/gcc/darwin-x86/arm/arm-eabi-4.8. This is different than the guide, which has an older version arm-eabi-4.6. So check the contents of your prebuilt/gcc/darwin-x86/arm directory. Now, you may see an arm-linux-androideabi-x.x directory in there too, but I did not use that. I believe this is for userspace, not kernel compilation.
Anyway, check your path, and if you don’t have the toolchain, do this to add it to the path and check if it was successful:
Code:
export PATH=$AOSP/prebuilts/gcc/darwin-x86/arm/arm-eabi-4.8/bin:$PATH
arm-eabi-gcc -v
You should see GCC spit out a bunch of text and list its version at the end.
And Then They Just Stopped Caring
At this point the writers of the guide probably got to a point where **** gets real and just hoped that no one would actually try this. Remember that commit they asked us to record, well, they just vaguely reference that you should use it but it’s not clear how you are supposed to use it. Furthermore, if you on OSX you are about to learn a few things about the differences between linux and darwin.
Time to Build
Alright, according to the official guide, we should be ready to go. It tells us to run something like (probably won’t work, don’t actually run this yet):
Code:
$ export ARCH=arm
$ export CROSS_COMPILE=arm-eabi
$ cd msm
$ git checkout -b android-msm-hammerhead-3.4-marshmallow-mr2 origin/android-msm-marshmallow-3.4-mr2
$ make hammerhead_defconfig
$ make
Wait, what about that commit? How did they know to checkout out android-msm-hammerhead-3.4-marshmallow-mr2? Well you can look at the git log and figure out which branch or tag you should use by educated guessing, but, nevermind that. Just use the hash from before:
Code:
git co 0e4eb55
Alright, now let’s actually try a build. In case you are wondering, this sets the target architecture to arm, which is the proper one for the Nexus 5 and most android phones. It sets the prefix for the cross compile toolchain. This is just the text prefix that will be used in front of things like gcc. In other words, all the toolchain tools will be invoked with something like arm-eabi-gcc. Then, we load up a the pre-existing kernel build configuration for the hammerhead, which loads the configuration file into a .config file in the current directory. Finally, we make, actually building the kernel, and then…
Code:
cd msm
export ARCH=arm
export CROSS_COMPILE=arm-eabi
make hammerhead_defconfig
make
You will probably have a sad face. You probably got something about elf.h missing:
Code:
... elf.h was not found ...
Off the Rails
Suddenly, OSX doesn’t seem like such a great choice! I almost capitulated after trying some advice on StackOverflow and other forums and not having success.
But there is a way! First, let’s get a nice package managed libelf. Get homebrew if you don’t have it already:
Code:
brew install libelf
Now, we have elf. I thought that this may have been as easy as just symlinking the gelf.h file from the brew libelf to /usr/local/include/elf.h, but not so fast. As I learned here, there are a whole bunch of architecture declarations missing in libelf that we need to compile… the android kernel? I’m not actually 100% sure why these are needed, would appreciate any kernel hackers who could explain why.
Anyway, we can leave the “why” for later, but the “how” is that we need a shim file that includes the gelf.h file from libelf and adds the extra declarations. Now this might also not be the most UNIX-y way to do this, so let me know if there is a better way.
Code:
cat <<EOT >> /usr/local/include/elf.h
#include "../opt/libelf/include/libelf/gelf.h"
#define R_386_NONE 0
#define R_386_32 1
#define R_386_PC32 2
#define R_ARM_NONE 0
#define R_ARM_PC24 1
#define R_ARM_ABS32 2
#define R_MIPS_NONE 0
#define R_MIPS_16 1
#define R_MIPS_32 2
#define R_MIPS_REL32 3
#define R_MIPS_26 4
#define R_MIPS_HI16 5
#define R_MIPS_LO16 6
#define R_IA64_IMM64 0x23 /* symbol + addend, mov imm64 */
#define R_PPC_ADDR32 1 /* 32bit absolute address */
#define R_PPC64_ADDR64 38 /* doubleword64 S + A */
#define R_SH_DIR32 1
#define R_SPARC_64 32 /* Direct 64 bit */
#define R_X86_64_64 1 /* Direct 64 bit */
#define R_390_32 4 /* Direct 32 bit. */
#define R_390_64 22 /* Direct 64 bit. */
#define R_MIPS_64 18
EOT
Fantastic. Now in theory, your build should probably work for certain kernel versions and phones. So give it a shot! I include the ARCH and CROSS_COMPILE values here in case you didn’t export them as variables already, feel free to omit them if already defined. The -j8 just parallelizes your build over more cores for better performance, I have 8 virtual cores, use somewhere between 1–2 times the number of cores your have.
Code:
make -j8 ARCH=arm CROSS_COMPILE=arm-eabi-
If you happen to be using a Nexus 5, on the current kernel *-mr2 and have an up to date perl, you may have an error with timeconst.pl. It appears to be a linux kernel bug that is fixed in later version of the kernel. Here is a simple patch to fix that:
Code:
diff --git a/kernel/timeconst.pl b/kernel/timeconst.pl
index eb51d76..0461239 100644
--- a/kernel/timeconst.pl
+++ b/kernel/timeconst.pl
@@ -370,7 +370,7 @@ if ($hz eq '--can') {
}
@val = @{$canned_values{$hz}};
- if (!defined(@val)) {
+ if ([email protected]) {
@val = compute_values($hz);
}
output($hz, @val);
Alright, try to build again and you should have a successful build!
And then… Silence
Right, so now how do you actually get this on your phone? It has produced a bunch of files. These cannot be flashed to your phone. We need a full boot.img file that has the proper structure and incantations of the kernel and the initial ramdisk.
There are a lot of guides out there that go through pulling apart an existing boot.img to use as a basis for re-making the boot image. But, you have AOSP checked out already, don’t bother with that noise, the make system already has a target that builds the boot image!
Code:
export TARGET_PREBUILT_KERNEL=$AOSP/msm/arch/arm/boot/zImage-dtb
cd $AOSP
make bootimage
Now, just hold tight, it looks like it is about to rebuild the entire Android system again, which is a terrific way to waste several hours of your life, but it will not, it will just package the kernel in a boot.img that you can boot or flash.
Boots
Now, finally, you get to test your kernel. Here are two ways to get your new boot image running on your phone, but for a new kernel, you really should only boot from it without flashing. This means that the new kernel is resident in memory but not stored. Which is great if you produce some boot looping turd because it will just fall back to the old working kernel on restart.
Code:
adb reboot bootloader
fastboot boot $AOSP/out/target/product/hammerhead/boot.img
Your phone will restart and hopefully, if you check the “About Phone” menu in the System Options, you should see your [email protected] listed.
If everything seems healthy, then you can do:
Code:
adb reboot bootloader
fastboot flash boot $AOSP/out/target/product/hammerhead/boot.img
There you go! A brand new homemade kernel. I hope someone can benefit from this, because, I really did not want to have to host another vm on my machine. I would appreciate any feedback!
I've been experimenting with this and successfully built. I also made a guide on it that helps build the kernel 100%
https://forum.xda-developers.com/an.../tutorial-reference-building-android-t3856676
Related
This thread aims to be a comprehensive guide to building and packaging kernels for US Variant Samsung Galaxy SIIIs
In my opinion, a kernel is a great way to get into building things for your device and its pretty easy to do too.
Intro
What is a kernel?
http://en.wikipedia.org/wiki/Kernel_(computing)
This guide is for US SGSIII's (d2att,d2cri,d2mtr,d2spr,d2tmo,d2usc,d2vzw,others?)
It may be possible to adapt this to other devices, but I am not responsible for anything that happens should you try to do this.
This guide assumes you have a general knowledge of the Linux operating system. If you've never used it, you might consider playing around
with it for awhile before attempting this guide.
Click to expand...
Click to collapse
Prerequisites
On all devices you must be rooted, on Verizon SGS3 (d2vzw) you must also have the unlocked (VRALE6) bootloader installed.
This is not the thread for figuring out how to do this. You can use the forum's search function to figure out how to do this on your device.
You'll need a computer or a virtual machine running ubuntu. You may be able to figure out how to get this working on other distributions,
but since ubuntu is generally the most accepted distribution to use for building android things, I'll stick to using that here.
At the time of this writing, I'm using ubuntu 12.10, 64-bit.
You'll need to install some packages on your ubuntu machine:
Code:
sudo apt-get install build-essential git zip unzip
On 64-bit you'll also need some multilib and 32-bit compatibility packages:
Code:
sudo apt-get install gcc-multilib g++-multilib lib32z1-dev
Click to expand...
Click to collapse
Setting up the Build Environment
Next, you'll need a toolchain which is used to actually build the kernel. You may download one of these:
GCC 4.4.3: Download || Mirror
GCC 4.6: Download || Mirror
GCC 4.7: Download || Mirror
If you aren't sure, go for 4.4.3 or 4.6.
4.7 requires some code changes to work. The original kernel developer may or may not have made these changes.
Here is what I needed to do in order for 4.7 to build, boot and have wifi work:
https://github.com/invisiblek/linux-msm-d2/commit/f8d7199d37cfbfa1bcb6b4bcae3fc15ae71fbdea
https://github.com/invisiblek/linux-msm-d2/commit/ea58076501e5874db7b934c215c4dae81ddfd0a6
The toolchains are also available in the android NDK.
*** There are many toolchains out there, some of you may know of the Linaro toolchain which is aimed to optimize your binary even further ***
*** If you choose to use a different toolchain, that is fine. Keep in mind that you may run into issues depending on the toolchain you use ***
You can check what your currently running kernel was built with by issuing these commands:
Code:
adb root
adb shell cat /proc/version
It should return something like:
Linux version 3.4.0-cyanogenmod-gc4f332c-00230-g93fb4aa-dirty ([email protected]) (gcc version 4.7 (GCC) ) #134 SMP PREEMPT Thu Feb 28 00:22:41 CST 2013
Click to expand...
Click to collapse
This shows my particular kernel here was built with GCC 4.7
You can use wget to download one of the links from above, in this instance we'll download version 4.4.3 from the first link:
Code:
wget http://invisiblek.org/arm-eabi-4.4.3.tar.bz2
Extract this to somewhere you will remember, probably your home directory.
Code:
mkdir arm-eabi-4.4.3
tar -xf arm-eabi-4.4.3.tar.bz2 -C arm-eabi-4.4.3/
Click to expand...
Click to collapse
Obtaining Source
Find someone's source to use as a base. This can be a source archive from Samsung, a kernel tree from CyanogenMod, or any other developer around that makes kernels for your device.
TIMEOUT
This is a good spot to stop and take note that the Linux kernel is licensed under the GNU General Public License (GPL): http://www.gnu.org/licenses/gpl-2.0.html
What does this mean you ask? It means that if you plan to share your kernel with the community (if it's good, please do so!) then you MUST share your
source code as well. I am not liable for what you choose to do once you start building kernels, but know this: if you share your kernel and do not
provide source code for it, you will get warnings from XDA for a determined amount of time, after that you may have your threads closed, deleted and
possibly your user account terminated. This is extremely important!
Also, you may run into more problems than just XDA. There are organizations out there that do take action if you consistently refuse to comply with the GPL.
I recommend you read this: http://www.gnu.org/licenses/gpl-2.0.html so that you are familiar with what legalities you are getting yourself into.
The main thing to remember is to share your source code if you decide to share your built kernel.
Click to expand...
Click to collapse
In this instance, we will use CyanogenMod's kernel source for the US Galaxy S3's. You may browse the source code here:
https://github.com/CyanogenMod/android_kernel_samsung_d2
You'll notice that the branch there is cm-10.1
This is the default branch of this repository on github. This means that if you intend to build this branch, you'll need to use it on CM version 10.1. Most
likely it will not function on another version.
To obtain the source code:
Code:
git clone https://github.com/CyanogenMod/android_kernel_samsung_d2
This will take a little while, be patient.
When done, you'll have a directory called android_kernel_samsung_d2, cd into this directory.
Code:
cd android_kernel_samsung_d2
Next, you'll need to set up a couple environment variables. These tell the system two things:
1. What CPU architecture to build for, in this case arm
2. Where to find the toolchain we downloaded earlier, so that the system can cross compile for arm
Code:
export ARCH=arm
export CROSS_COMPILE=~/arm-eabi-4.4.3/bin/arm-eabi-
You'll need to set these variables on each new session. You can modify your Makefile in the root of your kernel tree in order to have these set permanently.
Click to expand...
Click to collapse
Building
At this point you can make any changes to the source code that you want. If this is your first time, I recommend not making any changes and make sure you have a
sane build environment before adding any complications.
When you build a kernel, you need to choose a defconfig. This is a specialized configuration file, specifically tailored for your device.
CyanogenMod names their defconfigs for their devices like so: cyanogen_<device>_defconfig and they are located in arch/arm/configs/
Code:
ls arch/arm/configs/cyanogen*
In this example, we will build for d2vzw.
Set up your tree to build for the d2vzw:
Code:
make cyanogen_d2vzw_defconfig
(do this in your kernel's root directory, in this example it was android_kernel_samsung_d2/ )
Now you are ready to build:
First, determine how many cpu's your computer has. You'll use this number to determine how many jobs the compiler command will use. The more jobs you can use, the more
cpu threads the compile will take advantage of, thus you'll get faster builds. If you don't know, just assume you'll use the number 2. We'll use 2 as an example here.
Code:
make -j2
Where 2 is the number of CPU cores your build system has.
And now we wait...until it's done compiling...
You'll know it successfully compiled when you have this line when it stops:
Kernel: arch/arm/boot/zImage is ready
Click to expand...
Click to collapse
PROTIP:
If it stops somewhere other than "zImage is ready" then you had build errors. Try running the 'make' command with no options after it. This will run the compile on a single thread
and will cause it to stop compiling as soon as it hits an error. When you run it on multiple threads, it definitely goes much faster, but if an error occurs, the console doesn't stop
until it finishes all of its threads. Causing you to have to scroll up and search around for an error
Click to expand...
Click to collapse
Now, assuming the build completed successfully, you have two things you are concerned with: A zImage (the kernel binary itself) and your kernel modules, which get built based
on what was configured in your defconfig.
You'll find your zImage at: arch/arm/boot/zImage
Code:
ls arch/arm/boot/zImage
The modules are scattered all over the place, depending on where the source existed that they were compiled from. We can easily search for them using this command:
Code:
find . -name "*.ko"
If both of the previous commands completed, you are now ready to package your kernel up for testing.
Move up a directory before continuing.
Code:
cd ..
Click to expand...
Click to collapse
Packaging
You may know of an awesome developer by the name of koush.
Well, once upon a time, koush created a rather simple zip, called AnyKernel, that would flash a kernel on a device, regardless of what ramdisk the kernel has on it.
I've taken his zip and modified it for d2 devices and to work with the newer recoveries out there.
This has a script in it that will dump your current boot.img (kernel+ramdisk), unpack it, replace the kernel, repack it and flash it.
It'll also copy any modules to the proper directory (/system/lib/modules) and set permissions appropriately.
You can get a zip here: Download || Mirror
(You can get it here as well: https://github.com/invisiblek/AnyKernel )
(Everyone is invited to use this zip, it'll probably make your life easier to not have to worry about the ramdisk. Enjoy!)
IMPORTANT
This AnyKernel package is for US variations of the Galaxy S3.
NOT the international (I9300) or any other device.
There are checks in the updater-script that will ensure you are running a d2 device before it does anything.
If you were to remove these checks, and not modify the partition that it flashes to later, you could end up with a brick.
If you intend to adapt this package for another device (please, do this! its a very handy script!), make sure you know it well, or ask someone to help you determine your device's
partition scheme before using it.
The risk here is due to the fact that the script doesn't know your device's partition scheme. It is configured specifically for the d2 devices. Flashing it on something else, who's boot
partition is somewhere else, might cause a bad flash to the bootloader partition (bad bad news if this happens).
Just be careful if you want to use this on another device. You won't run into problems if you use this on a d2 device.
EDIT: I made modifications that should make this less likely, but please, if you intend to use this on a different device (which is completely fine!) make sure you configure
the scripts to flash to the proper partitions.
Click to expand...
Click to collapse
Download and extract one of the above, we'll again use the first link for this example:
Code:
wget http://invisiblek.org/AnyKernel_samsung-d2.zip
unzip AnyKernel_samsung-d2.zip -d AnyKernel/
Now we'll copy our newly compiled zImage (still referring to the same kernel directory we used above, your repo might be called something different)
Code:
cp android_kernel_samsung_d2/arch/arm/boot/zImage AnyKernel/kernel/
cp `find android_kernel_samsung_d2 -name "*.ko"` AnyKernel/modules/
Finally we are ready to zip this up and test out flashing it.
Code:
cd AnyKernel
zip ../MyAwesomeKernel.zip -r *
cd ..
You'll now have a file named MyAwesomeKernel.zip which you should be able to flash via custom recovery (TWRP or CWM)
Click to expand...
Click to collapse
Extra Credit/Protips
Learn to use git. It's very powerful and great way to store your code.
Learn to use adb. It's an invaluable tool for any android developer.
Touchwiz and AOSP-based kernels are different. This means you cannot take CyanogenMod's source, build a kernel and expect it to work on a Touchwiz-based ROM.
Build a ROM next: http://wiki.cyanogenmod.org/w/Build_for_d2vzw
Crackflash your own stuff!
ALWAYS NANDROID!
Click to expand...
Click to collapse
Source code for all of my projects can be found here: http://github.com/invisiblek
FAQ
Q: How do I update my source tree to the latest that is available from where I downloaded it?
A: This can be handy if, for instance, you are building a CyanogenMod kernel and they added some patches, after you downloaded the source, that you want to include in your next build. You'll want to cd to your kernel tree and issue a git pull:
Code:
cd android_kernel_samsung_d2
git pull
You may then continue with the building instructions.
This may, however, have other problems if you've made changes to files. You might run into conflicts. I won't cover fixing any of this here, its not in the scope of this thread.
Q: I'm using X as a kernel base, but Y has a patch that I really like. How do I get it in my kernel easily?
A: I'll let you check Google for this answer, but I'll give you a hint use: git cherry-pick
Nice tutorial bro! Always good to learn something new everyday
Really is a good thread,thanks
This guide would have made things too easy for me.
Too easy, indeed. haha
Great job, invisiblek! AnyKernel is the beez neez.
Ok so this is a noob question but I gotta ask anyway lol. Ok so I cloned the kernel source, I made my edits, now how do I push all this to my github?
I already have a github account, I already made a new repo for the kernel. Here's a link to my github if you need it...
https://github.com/ghicks12/d2vzw_kernel.git
spc_hicks09 said:
Ok so this is a noob question but I gotta ask anyway lol. Ok so I cloned the kernel source, I made my edits, now how do I push all this to my github?
I already have a github account, I already made a new repo for the kernel. Here's a link to my github if you need it...
https://github.com/ghicks12/d2vzw_kernel.git
Click to expand...
Click to collapse
git remote add origin git_location_you_created_on_github.git
git push -u origin somebranch
The -u is for first time run only, you can just git push afterwards.
Sent from my SCH-I535
GideonX said:
git remote add origin git_location_you_created_on_github.git
git push -u origin somebranch
The -u is for first time run only, you can just git push afterwards.
Sent from my SCH-I535
Click to expand...
Click to collapse
Thanks! When I run
Code:
git remote add origin https://github.com/ghicks12/d2vzw_kernel.git
I get this back:
Code:
fatal: remote origin already exists.
I'm editing a CM based kernel, not sure if that matters or not?
That just means you added the remote already. Just issue the push command then.
Sent from my SCH-I535
Why is this happening? I don't know what i did wrong
[email protected]:~/cm$ make VARIANT_DEFCONFIG=cyanogen_d2att_defconfig
scripts/kconfig/conf --silentoldconfig Kconfig
drivers/media/video/msm/Kconfig:123:warning: choice value used outside its choice group
drivers/media/video/msm/Kconfig:128:warning: choice value used outside its choice group
***
*** Configuration file ".config" not found!
***
*** Please run some configurator (e.g. "make oldconfig" or
*** "make menuconfig" or "make xconfig").
***
make[2]: *** [silentoldconfig] Error 1
make[1]: *** [silentoldconfig] Error 2
make: *** No rule to make target `include/config/auto.conf', needed by `include/config/kernel.release'. Stop.
[email protected]:~/cm$
Hey. I'm having some problems with some GIT terminology and procedures. I'm a .NET developer and I use TFS and SVN on a daily basis. Forgive me if this is complete off basis from what you'd do with GIT.
What I want to do is merge one branch into another branch. In other words I want to take the latest kernel source from my favorite dev and merge in the latest from cyanogen's 4.3 d2 branch. Is this a rebase thing? It doesn't seem like cherrypicking to me.
I have successfully compiled kernel and made modules.I inserted zImage and modules inside any kernel updater,flashed via TWRP.When reboot stuck in odin and it says could not do normal boot.
Hi Folks
I wasn't sure where this should belong but as it is a bit of an Hack this forum is probably the most appropriate
Introduction
This short tutorial will show you how to patch the Android Build System to allow you to cross-compile Android AOSP host tools ( adb, fastboot etc ) for OSX using a linux based machine. This is something Google said was impossible or at the very least unsupported.
Assumptions
You have a linux based machine and working copy of the AOSP source tree.
You can/have successfully compile(d) a full Android Release from this tree.
A basic idea of how the Android Build System works is beneficial.
Getting Started
I've set-up a git repository which contains a binary copy of the OSX SDK 10.6 and the apple-darwin10-gcc cross compiler. So first things first. open a terminal and set the root of the AOSP sources tree to the current directory.
STAGE 1: Copy the OSX SDK
Step 1.
Clone the repo with the SDK and toolchain
Code:
git clone https://github.com/trevd/android_platform_build2.git build2
Step 2.
Create /Developer directory at your filesystem root, this is a known location for the SDKs
Code:
sudo mkdir /Developer
sudo chown $USER.$USER /Developer
Step 3.
Copy and unpack the SDK package
Code:
cp build2/osxsdks10.6.tar.gz /Developer
cd /Developer
tar -zxvf osxsdks10.6.tar.gz
rm osxsdks10.6.tar.gz
cd - # back to aosp root
STAGE 2 : Swapping the Toolchain
This is where the fun begins :laugh:
The Android Build system has the majority of the infrastructure in place already to build for OSX, the only problem is that you need OSX to build for OSX. However we can remedy that with a couple of dirty hacks :laugh:.
The prebuilts/gcc/darwin-x86 directory contains a toolchain compatible with osx ( mach-o binaries ). We are going to swap this for a linux compatible ( elf ) executables.
Step 4:
Copy and unpack the elf compatible darwin cross toolchain
Code:
cp build2/i686-apple-darwin-4.2.1.tar.gz prebuilts/gcc/linux-x86/host
cd prebuilts/gcc/linux-x86/host
tar -zxvf i686-apple-darwin-4.2.1.tar.gz
cd - # back to aosp root
Step 5:
Remove the mach-o binaries and symlink the elf binaries in it's place
Code:
cd prebuilts/gcc
rm -rf darwin-x86
ln -s linux-x86 darwin-x86
cd - # back to aosp root
Step 6:
We also need to replace the mach-o version of the ccache executable which live in the prebuilt/misc directory
Code:
cd prebuilts/misc
rm -rf darwin-x86
ln -s linux-x86 darwin-x86
cd - # back to aosp root
STAGE 3: Patching the build system .mk files
We need to patch a couple of files in the build directory namely the build/core/combo/HOST_darwin-x86.mk the main crux of this is swapping the ar tool for libtool so static libraries can be created without error.
Code:
patch -p1 < build2/build.patch
If the patch has been applied successfully you should see the following
Code:
patching file system/core/adb/Android.mk
patching file build/core/combo/HOST_darwin-x86.mk
patching file build/core/combo/select.mk
patching file build/core/envsetup.mk
patching file build/envsetup.sh
You are now ready to cross compile!! :good: ..... well not quite, but nearly.... here's why!
The Android Build System will attempt to build both the Target and Host files for most modules so I'd advise using a lunch option which already has a full target built for it or alternatively you can build the generic sdk using the following commands at the AOSP source tree root.
Code:
. build/envsetup.sh
lunch sdk-eng
make sdk
This will stop target dependency errors occurring when you build individual modules.
NOW we're ready to cross compile.
STAGE 4: Building Modules
At present module build is very much a piecemeal process. To build adb for example we need to build the dependencies first. This is not too onerous as most host modules have very few dependencies.
Building adb
adb has dependencies on the following libraries
Code:
external/zlib
external/openssl
system/core/liblog
system/core/libcutils
system/core/libzipfile
I've found the easiest way to compile the dependencies is to navigate to each directory in turn an use to "mm" build system command to compile the individual module. the commands I run to compile adb are as follows.
From AOSP Source Root
Code:
cd external/zlib
USE_DARWIN=true mm -j8
cd ../openssl
USE_DARWIN=true mm -j8
croot # go back to the AOSP root
cd system/core/liblog
USE_DARWIN=true mm -j8
cd ../libcutils
USE_DARWIN=true mm -j8
cd ../libzipfile/
USE_DARWIN=true mm -j8
cd ../adb
USE_DARWIN=true mm -j8
All being well you should now have and adb binary located at out/host/darwin-x86/bin/adb. running the file command on this binary should produce the following output
Code:
adb: Mach-O executable i386
Conclusion
Although this method is a little rough and ready, it should produce the desired results if you need to cross compile for OSX. The eventual goal would be to compile a full OSX Android SDK on linux in a similar manner to the way the windows-sdk is currently compiled. This requires more investigation as compiling the windows sdk on linux employs a little bit of trickery on the part of the build system.
Final Notes and FAQs:
Why can't I just type make <module> from the root?
Doing this triggers building of additional modules such as LLVM and clang which are to deployed out/host/darwin-x86/bin the build system then attempts to use binary later on. These are obviously built for the Mach-o architecture and as such are incompatible with the linux. This results in a build error which can and would be resolved by the above mentioned trickery ( see conclusion )
I use OSX binaries (along with Windows and my native Linux) in one of my projects. Thanks, I have always relied on finding compiled binaries elsewhere. Lack of an OSX aapt held up an update at one point.
One of those things that you don't really use until you need it, but I will try to remember to give it a shot. I don't have any doubt that it works.
mateorod said:
I use OSX binaries (along with Windows and my native Linux) in one of my projects. Thanks, I have always relied on finding compiled binaries elsewhere. Lack of an OSX aapt held up an update at one point.
One of those things that you don't really use until you need it, but I will try to remember to give it a shot. I don't have any doubt that it works.
Click to expand...
Click to collapse
Thanks. Yes this really is an edge case. Hopefully It will help some folks out.
Regarding aapt in particular.... It's perfectly possible to build aapt, however, we need to do some slight of hand with the clang and clang++ executables as libpng on which aapt depends uses these 2 binaries as part of it's build process.
Here's the build list and the clang trick if you want to try it some time.
Code:
build/libs/host
external/expat
external/zlib
system/core/liblog
system/core/libcutils
mkdir out/host/darwin-x86/bin
cp out/host/linux-x86/bin/clang out/host/darwin-x86/bin
cp out/host/linux-x86/bin/clang++ out/host/darwin-x86/bin
external/libpng
frameworks/base/libs/androidfw
frameworks/native/libs/utils
frameworks/base/tools/aapt
I started off with a clean out/host/darwin-x86 directory so I didn't miss any dependencies.
like I mentioned the clang "swap out" is something the make win_sdk option does automatically so with it a little more research I should be able to get the mac build to do the same but you'll have to "fill yer boots" with the ghetto method for now
For reference here's a link to the sdk building instructions http://tools.android.com/build which describes how to cross compile the windows sdk on linux ( in case anyone was wondering what the hell i'm on about)
My use case has come up
I will be cross-compiling for OSX today...specifically with aapt in mind. I will report back, but I fully expect it to work as described.
mateorod said:
My use case has come up
I will be cross-compiling for OSX today...specifically with aapt in mind. I will report back, but I fully expect it to work as described.
Click to expand...
Click to collapse
Cheers Man!
Hopefully no bitrot has crept in since april and now. I know I've changed my OS version since to Lubuntu 13.04, not like the OS version really matters any.
mateorod said:
but I fully expect it to work as described.
Click to expand...
Click to collapse
Then you Sir, are either Drunk or a Fool! LOL Keep expectations Quantum and only decided when the result is observed a'la Schrodinger Cat
okay...So I was trying to compile SlimRom (so as to get an OSX aapt binary with the SlimRom changes) and things did not necessarily go as planned. There were enough changes to the SlimRom android_build that your build/build.patch does not apply cleanly. I spent some time and tried to modify the patch so that it would work for both SlimRom, AOSP and probably others, but each android_build repo has some differences in surrounding the HOST_AR line, so commenting that just was not portable between flavors. Not cool.
Anyway, turns out that this method does not quite work out of the box for non-AOSP versions (not that you claimed that it did). I got some unfamiliar errors related to (I believe) some OSX toolchains. But in both times I tried this, I actually had to pretty immediately swap out of that flavor and so I was unable to do much debugging. (I keep all the flavors I build {CM, AOKP, SlimRom, PAC, PA, OpenPDroid, etc, etc, etc} all layered in one android/system/jellybean directory. It saves a ton of space, but only allows me to do one thing at a time.)
So the only feedback I have is nothing...I even formatted my hard drive in-between and forgot to put up a paste, so the errors are currently lost to history.
Things that I noticed, for better or worse
You recommend putting the SDKs in the root dir. I believe the documentation is recommending the Developer be placed in home (as per the SDK/ADT bundle docs).
You might want a
Code:
mv android_platform_build2 build2
line. I normally wouldn't bother, but it looks like you are trying to post a line-by-line guide.
I would put the recommendation that a full build be available to the out folder (or a built generic sdk) right at the top, since it is a preliminary step. I had to revert my handwritten changes, then build, then reapply the changes and rebuild since I thought it needed a clean out dir.
Did you have any trouble with git reverting the toolchain swap? On two separate machines, I had to go so far as to delete .repo/projects/prebuilts/gcc/* and prebuilts/gcc/darwin-x86/arm/arm-eabi-4.6. It kept complaining of that the project in the .repo folder was a bad match. No amount of git trickery (which I am not terrible at) let me back out more easily.
I am willing to try again...but I have some other small things to attend to first. It is an admirable hack you have here sir. I will return to it soon and report back once more.
mateorod said:
okay...So I was trying to compile SlimRom (so as to get an OSX aapt binary with the SlimRom changes) and things did not necessarily go as planned. There were enough changes to the SlimRom android_build that your build/build.patch does not apply cleanly. I spent some time and tried to modify the patch so that it would work for both SlimRom, AOSP and probably others, but each android_build repo has some differences in surrounding the HOST_AR line, so commenting that just was not portable between flavors. Not cool.
Anyway, turns out that this method does not quite work out of the box for non-AOSP versions (not that you claimed that it did). I got some unfamiliar errors related to (I believe) some OSX toolchains. But in both times I tried this, I actually had to pretty immediately swap out of that flavor and so I was unable to do much debugging. (I keep all the flavors I build {CM, AOKP, SlimRom, PAC, PA, OpenPDroid, etc, etc, etc} all layered in one android/system/jellybean directory. It saves a ton of space, but only allows me to do one thing at a time.)
So the only feedback I have is nothing...I even formatted my hard drive in-between and forgot to put up a paste, so the errors are currently lost to history.
Things that I noticed, for better or worse
You recommend putting the SDKs in the root dir. I believe the documentation is recommending the Developer be placed in home (as per the SDK/ADT bundle docs).
You might want a
Code:
mv android_platform_build2 build2
line. I normally wouldn't bother, but it looks like you are trying to post a line-by-line guide.
I would put the recommendation that a full build be available to the out folder (or a built generic sdk) right at the top, since it is a preliminary step. I had to revert my handwritten changes, then build, then reapply the changes and rebuild since I thought it needed a clean out dir.
Did you have any trouble with git reverting the toolchain swap? On two separate machines, I had to go so far as to delete .repo/projects/prebuilts/gcc/* and prebuilts/gcc/darwin-x86/arm/arm-eabi-4.6. It kept complaining of that the project in the .repo folder was a bad match. No amount of git trickery (which I am not terrible at) let me back out more easily.
I am willing to try again...but I have some other small things to attend to first. It is an admirable hack you have here sir. I will return to it soon and report back once more.
Click to expand...
Click to collapse
Hi
Thanks for this, It sounds like you've suffered an exercise in frustration there. I wasn't aware that "SlimRom" had a different aapt ( just out of general ignorance and not having paid any attention )
SDK - My Tree last time I used this was /Developer directory in the root - I think It comes from what the toolchain is expecting, I just gave it what it wants
mv android_platform_build2 build2 - Yep I did mean that it's the git clone line which wants changing
Code:
git clone https://github.com/trevd/android_platform_build2.git build2
SDK Recommendation - I shall move that to the top, even though it is already in there, It should probably be highlighted better and possible it's own "Stage"
Reverting the toolchain - Ahh , It appears I work slightly different from most in this respect. I have a general mistrust of SCM's ( I lost too much code on too many different SCM's, Probably through my own inability to use them correctly but ) what I do to revert to change is
Code:
cd prebuilts/gcc/darwin-x86/host/
rm -rf i686-apple-darwin-4.2.1
repo sync i686-apple-darwin-4.2.1
You can do this "trick" on any project in the source tree it's only on rare occasions where I screwed up badly that I have to delete anything in .repo/projects but I also have my distro in their own individual directories with there own full git trees, which is a massive waste of space and has a ton of redundancy due to the AOSP repositories being mirror by every single one but switching between them is a lot easier
If SlimRom's changes are localized to aapt, I'd be more inclined to drop it into the AOSP build and try that... If you have a link to slimrom's frameworks/base repository I'll grab it and try it myself.
On a final note there's a "full version" of the HOST_darwin make file in the build2/core/combo directory the changes to envsetup.mk and select.mk are minimal and can easily be applied manually. You don't need to patch the adb makefile if your not building it.
Again Thanks for the feedback
Introduction
Hello everyone, I will be going over how to compile a kernel from beginning to end!
Prerequisites:
A Linux environment (preferably 64-bit)
Knowledge of how to navigate the command line
Common sense
A learning spirit, there will be no spoonfeeding here
What this guide will cover:
Downloading the source
Downloading a cross compiler
Building the kernel
Flashing the kernel
What this guide will NOT cover:
Setting up a build environment (plenty of existing Linux installation guides)
Adding features to the kernel (plenty of git cherry-picking guides)
I know this has been done before but on a cursory search, I have not seen a guide that was recently updated at all.
1. Downloading the source
If you have a custom kernel you want to build, move along after cloning the kernel using the git clone command below.
If you are compiling your stock kernel, it is ultimately up to you to know where to get your kernel source from but here are some common places:
Google: https://android.googlesource.com/kernel/msm/ (pick your architecture and look at the branches)
LG: http://opensource.lge.com/index
Samsung: http://opensource.samsung.com/reception.do
HTC: https://www.htcdev.com/devcenter/downloads
OnePlus: https://github.com/OnePlusOSS
Motorola: https://github.com/MotorolaMobilityLLC
Sony: https://github.com/sonyxperiadev/kernel
To download the kernel, you can either use git clone or download the tarball and extract it:
Code:
git clone -b <branch_to_checkout> <url> <desired_folder_name>
OR
tar -xvf <filename>
For example, if I wanted to grab the latest Nexus 6P from Google above:
Code:
git clone -b android-msm-angler-3.10-nougat-mr2 https://android.googlesource.com/kernel/msm/ angler
This will clone the kernel/msm repo into an angler folder and checkout the android-msm-angler-3.10-nougat-mr2 automatically.
I can try and help you locate your source if necessary.
2. Downloading a cross compiler
Since most Android devices are ARM based, we need a compiler that is targeting ARM devices. A host (or native) compiler will not work unless you are compiling on another ARM device.
You can either compile one yourself if you know how (crosstool-NG is a great tool for this) or download a prebuilt one. Luckily Google provides a high quality toolchain for this, in both an arm (32-bit) and arm64 (64-bit). It's up to you to know the architecture of your device. Typically speaking, most devices in the past two-three years are 64-bit.
Another popular toolchain is UberTC, which can be found here: https://bitbucket.org/matthewdalex/. Most kernels will need patches for anything higher than 4.9 and while I don't mind assisting with finding them, you should compile with Google's toolchain first.
Once you have decided, clone the toolchain:
Code:
git clone <url>
3. Compile the kernel
1. Point the Makefile to your compiler (run this from within the toolchain folder!!)
Code:
export CROSS_COMPILE=$(pwd)/bin/<toolchain_prefix>-
Example:
Code:
export CROSS_COMPILE=$(pwd)/bin/aarch64-linux-android-
NOTE #1: For kernels that can be compiled with Clang (like the Pixel 2), see this guide. I will support it here if there are any questions.
NOTE #2: Pixel and Pixel 2 users, you will need to follow these steps as well if compiling for Android Pie.
2. Tell the Makefile the architecture of the device
Code:
export ARCH=<arch> && export SUBARCH=<arch>
Example:
Code:
export ARCH=arm64 && export SUBARCH=arm64
3. Locate your proper defconfig
Navigate to the arch/<arch>/configs folder within the kernel source (e.g. arch/arm64/configs) and locate your device's or custom kernel developer's proper config file. For example, it will often be in the form of <codename>_defconfig or <kernel_name>_defconfig. Generic Qualcomm configs may be used as well (msm-perf_defconfig, msmcortex-perf_defconfig). When in doubt, ask here if you are confused. A defconfig tells the compiler what options to add to the kernel.
4. Build the kernel
Code:
make clean
make mrproper
make <defconfig_name>
make -j$(nproc --all)
If those commands succeed, you will have an Image, Image-dtb, Image.gz, or Image.gz-dtb file at the end.
If it failed, as was pointed out to me by @flar2 while making a complete idiot of myself, you may need to specify an output directory while making new CAF based kernels, like so:
Code:
mkdir -p out
make O=out clean
make O=out mrproper
make O=out <defconfig_name>
make O=out -j$(nproc --all)
If after that something is still broken, you may need to fix some headers or other issues. If it is a custom kernel, bring it up with your developer.
If it's an OEM, it's up to you to try and fix it, which we can assist with.
4. Flash the kernel
Assuming you were able to compile the kernel successfully, you now need to flash it! I will be covering two different ways to flash a compiled kernel: unpacking and repacking the boot image by hand using Android Image Kitchen or AnyKernel2, both by the brilliant @osm0sis. If there are any per-device nuances, please let me know and I'll add them here! Additionally, this section can vary drastically by device, you may need to consult developers of your device for assistance if necessary.
Android Image Kitchen
Pull your device's boot image from the latest image available for your device (whether it be a ROM or stock)
Download the latest Android Image Kitchen from this thread.
Run the following with the boot image:
Code:
unpackimg.sh <image_name>.img
Locate the zImage file and replace it with your kernel image (rename it to what came out of the boot image)
Run the following to repack:
Code:
repackimg.sh
Flash the new boot image with fastboot or TWRP!
AnyKernel2
Download the latest AnyKernel2 zip: https://github.com/osm0sis/AnyKernel2/archive/master.zip
Apply this patch to clean out all of the demo files:
Code:
wget https://github.com/nathanchance/AnyKernel2/commit/addb6ea860aab14f0ef684f6956d17418f95f29a.diff
patch -p1 < addb6ea860aab14f0ef684f6956d17418f95f29a.diff
rm addb6ea860aab14f0ef684f6956d17418f95f29a.diff
Place your kernel image in the root of the file.
Open the anykernel.sh file and modify the following values:
kernel.string: your kernel name
device.name#: List all of your device's codenames (from the /system/build.prop: ro.product.device, ro.build.product)
block: Your boot image's path in your fstab. The fstab can be opened from the root of your device and it will look something like this:
https://android.googlesource.com/device/huawei/angler/+/master/fstab.angler
The first column is the value you want to set block to.
After that, zip up the kernel and flash it!
Code:
zip -r9 kernel.zip * -x README.md kernel.zip
Tips and tricks
1. Remove GCC wrapper
A lot of kernels from CAF include a Python script that will essentially turn on -Werror, causing your build to error at the most benign stuff. This is necessary with higher GCC versions as there are a lot more warnings.
Here is the diff of what you need to change in the Makefile:
Code:
diff --git a/Makefile b/Makefile
index 1aaa760f255f..bfccd5594630 100644
--- a/Makefile
+++ b/Makefile
@@ -326,7 +326,7 @@ include $(srctree)/scripts/Kbuild.include
AS = $(CROSS_COMPILE)as
LD = $(CROSS_COMPILE)ld
-REAL_CC = $(CROSS_COMPILE)gcc
+CC = $(CROSS_COMPILE)gcc
CPP = $(CC) -E
AR = $(CROSS_COMPILE)ar
NM = $(CROSS_COMPILE)nm
@@ -340,10 +340,6 @@ DEPMOD = /sbin/depmod
PERL = perl
CHECK = sparse
-# Use the wrapper for the compiler. This wrapper scans for new
-# warnings and causes the build to stop upon encountering them.
-CC = $(srctree)/scripts/gcc-wrapper.py $(REAL_CC)
-
CHECKFLAGS := -D__linux__ -Dlinux -D__STDC__ -Dunix -D__unix__ \
-Wbitwise -Wno-return-void $(CF)
CFLAGS_MODULE =
2. Using a higher level GCC toolchain
Using a higher GCC toolchain (5.x, 6.x, 7.x or even 8.x) will require you to nuke the GCC wrapper script as above and use a unified GCC header file (pick the following if you have an include/linux/compiler-gcc#.h file):
3.4/3.10: https://git.kernel.org/pub/scm/linu...h?id=a4a4f1cd733fe5b345db4e8cc19bb8868d562a8a
3.18: https://git.kernel.org/pub/scm/linu...h?id=677fa15cd6d5b0843e7b9c58409f67d656b1ec2f
You may get a lot of warnings but they are not entirely necessary to fix.
3. Adding upstream Linux to kernel source
Once you have gotten familiar with git and the compilation process, you should consider upstreaming your kernel. This will allow you to stay on top of CVE and bug fixes by staying up to date with the latest work of the Linux kernel developers.
Receiving help
I am happy to answer anything that I touched on in this guide. I may point you to another thread if it's better suited but I don't mind off topic (within reason) within the thread. I also want this to be a collaborative effort; other developers, if you have something to add, correct, or improve upon, please let me know!
I am particular in how people ask for help. I do NOT respond to posts asking for a hand out ("How do I fix this?", "Please fix this!", etc.). I only respond to posts with clear logs and steps that you have tried. Basically, show me that you have read this guide and have a specific issue. I am not here to hold your hand through this, this is a developers' forum.
You're on fire with this kernel stuff
Sent from my LEX727 using XDA Labs
Nice and clear introduction on how to build a kernel. This small how-to was so simple, I can keep it in my head! Awesome!
A really helpful guide much needed around for upcoming developers. This is the perfect guide for them. Nice work ?
Sent from my ONE A2003 using Tapatalk
The guys a Feckn Champ.
Thanks a lot!!.
Thanks @The Flash
Enviado desde mi Nexus 6 mediante Tapatalk
The Flash said:
Introduction
I am happy to answer anything that I touched on in this guide. I may point you to another thread if it's better suited but I don't mind off topic (within reason) within the thread. I also want this to be a collaborative effort; other developers, if you have something to add, correct, or improve upon, please let me know!
I am particular in how people ask for help. I do NOT respond to posts asking for a hand out ("How do I fix this?", "Please fix this!", etc.). I only respond to posts with clear logs and steps that you have tried. Basically, show me that you have read this guide and have a specific issue. I am not here to hold your hand through this, this is a developers' forum.
Click to expand...
Click to collapse
On a scale of 1-10 how much Off-Topic is allowed ? :highfive::laugh::silly:
Nice guide :good: :highfive: ..
I have been using ./build_kernel.sh to compile kernels as was suggested by another guide and I'm wondering if there's any pros or cons doing it that way as opposed to using the make defconfig way.
They seem to be working ok but this is the second guide on xda that suggest the way you're doing it and I'm definitely open to change if this way is better. Any thoughts on the two methods would be much appreciated. I also would like to say thanks for these new guides as finding kernel dev info for newbies is very scarce and mostly outdated. I really look forward to seeing this thread take off. :good:
kevintm78 said:
I have been using ./build_kernel.sh to compile kernels as was suggested by another guide and I'm wondering if there's any pros or cons doing it that way as opposed to using the make defconfig way.
They seem to be working ok but this is the second guide on xda that suggest the way you're doing it and I'm definitely open to change if this way is better. Any thoughts on the two methods would be much appreciated. I also would like to say thanks for these new guides as finding kernel dev info for newbies is very scarce and mostly outdated. I really look forward to seeing this thread take off. :good:
Click to expand...
Click to collapse
Well this build_kernel.sh script is most likely doing just this. I personally use a script to compile and package my kernel, I would never do the "manual" way like this once you know how.
I have updated the OP with a note about compiling newer CAF releases (3.18 and 4.4 to my knowledge). As was pointed out by @flar2 while I was making an idiot of myself accusing him of violating the GPL (for which I truly do apologize), you may need to specify an output directory (by adding an O= flag). This is actually done automatically when a ROM compiles a kernel inline so you will only run into this while compiling standalone.
I have added it to my script here if you want an idea of how to add it to yours.
So here i'am what should i do to fix the initramfs problem?
I tried "chmod -R a+x kernel" but i still get the same problem.
AhmAdDev99 said:
So here i'am what should i do to fix the initramfs problem?
I tried "chmod -R a+x kernel" but i still get the same problem.
Click to expand...
Click to collapse
Why aren't you compiling in your home folder?
The Flash said:
Why aren't you compiling in your home folder?
Click to expand...
Click to collapse
Moved both kernel source and gcc to /home but still the same problem
AhmAdDev99 said:
Moved both kernel source and gcc to /home but still the same problem
Click to expand...
Click to collapse
Have you tried the bit about specifying an out folder?
The Flash said:
Have you tried the bit about specifying an out folder?
Click to expand...
Click to collapse
Yes , And this is exactly what i get
GEN /Kernel/android_kernel_samsung_t1-android-4.4/out/Makefile
scripts/kconfig/conf --silentoldconfig Kconfig
GEN /Kernel/android_kernel_samsung_t1-android-4.4/out/Makefile
CHK include/linux/version.h
UPD include/linux/version.h
CHK include/generated/utsrelease.h
UPD include/generated/utsrelease.h
Using /Kernel/android_kernel_samsung_t1-android-4.4 as source for kernel
HOSTCC scripts/genksyms/genksyms.o
Generating include/generated/mach-types.h
CC kernel/bounds.s
GEN include/generated/bounds.h
CC arch/arm/kernel/asm-offsets.s
SHIPPED scripts/genksyms/lex.c
SHIPPED scripts/genksyms/parse.h
SHIPPED scripts/genksyms/keywords.c
SHIPPED scripts/genksyms/parse.c
HOSTCC scripts/genksyms/lex.o
CC scripts/mod/empty.o
HOSTCC scripts/mod/mk_elfconfig
GEN include/generated/asm-offsets.h
CALL /Kernel/android_kernel_samsung_t1-android-4.4/scripts/checksyscalls.sh
HOSTCC scripts/genksyms/parse.o
HOSTCC scripts/selinux/genheaders/genheaders
MKELF scripts/mod/elfconfig.h
HOSTCC scripts/mod/file2alias.o
HOSTCC scripts/selinux/mdp/mdp
HOSTCC scripts/mod/modpost.o
HOSTCC scripts/kallsyms
HOSTLD scripts/genksyms/genksyms
HOSTCC scripts/conmakehash
HOSTCC scripts/recordmcount
HOSTCC scripts/mod/sumversion.o
HOSTLD scripts/mod/modpost
CHK include/generated/compile.h
CC init/main.o
HOSTCC usr/gen_init_cpio
CC arch/arm/vfp/vfpmodule.o
UPD include/generated/compile.h
CC init/do_mounts.o
GEN usr/initramfs_data.cpio
File ../../ramdisk.cpio could not be opened for reading
line 32
File ../../ramdisk-recovery.cpio could not be opened for reading
line 33
/Kernel/android_kernel_samsung_t1-android-4.4/usr/Makefile:67: recipe for target 'usr/initramfs_data.cpio' failed
make[2]: *** [usr/initramfs_data.cpio] Error 255
/Kernel/android_kernel_samsung_t1-android-4.4/Makefile:945: recipe for target 'usr' failed
make[1]: *** [usr] Error 2
make[1]: *** Waiting for unfinished jobs....
AS arch/arm/vfp/entry.o
AS arch/arm/vfp/vfphw.o
CC arch/arm/vfp/vfpsingle.o
CC arch/arm/vfp/vfpdouble.o
CC init/do_mounts_rd.o
CC init/do_mounts_initrd.o
CC init/initramfs.o
CC init/calibrate.o
CC init/version.o
LD arch/arm/vfp/vfp.o
LD arch/arm/vfp/built-in.o
LD init/mounts.o
LD init/built-in.o
Makefile:130: recipe for target 'sub-make' failed
make: *** [sub-make] Error 2
I've been working a little more on my Pixel XL kernel. Question...
I do:
Code:
make clean && make mrproper
make marlin_defconfig
make menuconfig
I go through several options, save, and exit. But when I do "git status", it thinks nothing has changed? I'm not sure if that's true, or if it just doesn't track whatever files were modified by menuconfig (of which I have no idea which ones they are).
chevycam94 said:
I've been working a little more on my Pixel XL kernel. Question...
I do:
Code:
make clean && make mrproper
make marlin_defconfig
make menuconfig
I go through several options, save, and exit. But when I do "git status", it thinks nothing has changed? I'm not sure if that's true, or if it just doesn't track whatever files were modified by menuconfig (of which I have no idea which ones they are).
Click to expand...
Click to collapse
I'm sorry I forgot to reply to your message, I looked at it then left my computer. make menuconfig saves the changes to the .config file in the kernel source. You need to copy that file to your arch/arm64/configs/<defconfig_name>.
The Flash said:
I'm sorry I forgot to reply to your message, I looked at it then left my computer. make menuconfig saves the changes to the .config file in the kernel source. You need to copy that file to your arch/arm64/configs/<defconfig_name>.
Click to expand...
Click to collapse
No problem. I'm not in a huge rush. It builds, and runs better than any kernel I have tried yet. Not joking.
So you're saying I need to copy the contents of the .config file INTO the "marlin_defconfig" file? Just append those lines to the end of the file?
Also, did I mention my little headache with my 9 "section_mismatch" errors? Doesn't seem to affect anything, but on this same build VM, I can build any other kernel source without any issues at all. So strange.
chevycam94 said:
No problem. I'm not in a huge rush. It builds, and runs better than any kernel I have tried yet. Not joking.
So you're saying I need to copy the contents of the .config file INTO the "marlin_defconfig" file? Just append those lines to the end of the file?
Also, did I mention my little headache with my 9 "section_mismatch" errors? Doesn't seem to affect anything, but on this same build VM, I can build any other kernel source without any issues at all. So strange.
Click to expand...
Click to collapse
You should just be able to copy the whole file (cp .config arch/arm64/configs/marlin_defconfig).
You could run a git bisect on your kernel source and see if there is a commit causing those mismatch errors. Very rarely is that a result of a toolchain or environment configuration.
Hi..Sir Flash,
I want to ask a question for ARM Device. ( Nexus 6 )
This is right method for ARM?
example:
- - - - -
export CROSS_COMPILE=${HOME}/Kernel/Toolchain/bin/arm-eabi-
export ARCH=arm && export SUBARCH=arm
make clean && make mrproper
make shamu_defconfig
make -j$(nproc --all)
- - - - -
I want to know this about.
If this method is wronged, Please teach me Sir.
Thanks.
•••
Sent from my Google Nexus 5X using XDA Labs
What is ?
Android is the open-source operating system used for smartphones. Full Freedom for people using it
What is Source Code?
Android is an open-source software stack created for a wide array of devices with different form factors. The primary purposes of are to create an open software platform available for carriers, OEMs, and to make their innovative ideas a reality and to introduce a successful, real-world product that improves the mobile experience for users.The result is a full, production-quality consumer product with source code open for customization and porting.
So basically Allows to customize the things you like and make new things without any Restrictions. Cool isn’t it?
What is ROM ?
The ROM is the operating system. This is the User interface (Sense UI in HTC phones) and the file system for maintaining contacts etc. It is composed of a Linux kernel and various add-ons to achieve specific functionality.
What does a Rom Contain ?
Basically a Rom Contains following main things :
· Kernel
· Bootloader
· Recovery
· Radio
· Framework
· Apps
· core
· -runtime,Etc
Some Basics About Above Terms
Kernel :
A kernel is critical component of the and all operating systems. It can be seen as a sort of bridge between the applications and the actual hardware of a device. devices use the Linux kernel, but it's not the exact same kernel other Linux-based operating systems use. There's a lot of specific code built in, and Google's kernel maintainers have their work cut out for them. OEMs have to contribute as well, because they need to develop hardware drivers for the parts they're using for the kernel version they're using. This is why it takes a while for independent and hackers to port new versions to older devices and get everything working. Drivers written to work with the Gingerbread kernel on a phone won't necessarily work with the Ice Cream Sandwich kernel. And that's important, because one of the kernel's main functions is to control the hardware. It's a whole lot of source code, with more options while building it than you can imagine, but in the end it's just the intermediary between the hardware and the software. So basically if any instruction is given to mobile it first gives the command to kernel for the particular task execution.
Bootloader :
The bootloader is code that is executed before any Operating System starts to run. Bootloaders basically package the instructions to boot operating system kernel and most of them also have their own debugging or modification environment. Think of the bootloader as a security checkpoint for all those partitions. Because if you’re able to swap out what’s on those partitions, you’re able to break things if you don’t know what you’re doing. So basically it commands the kernel of your device to Boot the Device properly without any issues. So careful with bootloader since it can mess things very badly.
Recovery :
Recovery is defined in simple terms as a source of backup. Whenever your phone firmware is corrupted, the recovery does the job in helping you to restore or repair your faulty or buggy firmware into working condition. It is also used for flashing the Rom’s , kernel and many more things.
Radio
The lowest part of software layer is the radio: this is the very first thing that runs, just before the bootloader. It control all wireless communication like GSM Antenna, GPS etc.
What you’ll need
A relatively recent 64-bit computer (Linux, OS X, or Windows)(Virtual Machine will work as well) with a reasonable amount of RAM and about 100 GB of free storage (more if you enable ccache or build for multiple devices). The less RAM you have, the longer the build will take (aim for 8 GB or more). Using SSDs results in considerably faster build times than traditional hard drives.
A decent internet connection & reliable electricity
Some familiarity with basic operation and terminology. It would help if you’ve installed custom roms on other devices and are familiar with recovery. It may also be useful to know some basic command line concepts such as cd for “change directory”, the concept of directory hierarchies, that in Linux they are separated by /, etc.
Install the SDK
If you haven’t previously installed adb and fastboot, you can download them from Google. Extract it running:
Code:
unzip platform-tools-latest-linux.zip -d ~
Now you have to add adb and fastboot to your PATH. Open ~/.profile and add the following:
Code:
# add SDK platform tools to path
if [ -d "$HOME/platform-tools" ] ; then
PATH="$HOME/platform-tools:$PATH"
fi
Then, run source ~/.profile to update yur environment.
Install the build packages
Several packages are needed to build LineageOS. You can install these using your distribution’s package manager.
To build LineageOS, you’ll need:
bc bison build-essential curl flex g++-multilib gcc-multilib git gnupg gperf imagemagick lib32ncurses5-dev lib32readline-dev lib32z1-dev libesd0-dev liblz4-tool libncurses5-dev libsdl1.2-dev libssl-dev libwxgtk3.0-dev libxml2 libxml2-utils lzop pngcrush rsync schedtool squashfs-tools xsltproc zip zlib1g-dev
For Ubuntu versions older than 16.04 (xenial), substitute:
libwxgtk3.0-dev → libwxgtk2.8-dev
Java
Different versions of LineageOS require different JDK (Java Development Kit) versions.
LineageOS 14.1: OpenJDK 1.8 (install openjdk-8-jdk)
LineageOS 11.0-13.0: OpenJDK 1.7 (install openjdk-7-jdk)*
https://askubuntu.com/questions/761127/how-do-i-install-openjdk-7-on-ubuntu-16-04-or-higher
Create the directories
You’ll need to set up some directories in your build environment.
To create them:
Code:
mkdir -p ~/bin
mkdir -p ~//lineage
Install the repo command
Enter the following to download the repo binary and make it executable (runnable):
Code:
curl [url]https://storage.googleapis.com/git-repo-downloads/repo[/url] > ~/bin/repo
chmod a+x ~/bin/repo
Put the ~/bin directory in your path of execution
In recent versions of Ubuntu, ~/bin should already be in your PATH. You can check this by opening ~/.profile with a text editor and verifying the following code exists (add it if it is missing):
Code:
# set PATH so it includes user's private bin if it exists
if [ -d "$HOME/bin" ] ; then
PATH="$HOME/bin:$PATH"
fi
Then, run source ~/.profile to update your environment.
Initialize the LineageOS source repository
Code:
cd ~//lineage
repo init -u [url]https://github.com/LineageOS/.git[/url] -b lineage-15.1
Download the source code
Code:
repo sync -c -f --force-sync --no-clone-bundle --no-tags --optimized-fetch --prune
Prepare the device-specific code
Code:
git clone [url]https://github.com/TheScarastic/android_device_xiaomi_msm8953-common[/url] -b lineage-15.1 device/xiaomi/msm8953
git clone [url]https://github.com/TheScarastic/android_device_xiaomi_tissot[/url] -b lineage-15.1 device/xiaomi/tissot
git clone [url]https://github.com/TheScarastic/proprietary_vendor_xiaomi[/url] -b lineage-15.1 vendor/xiaomi
git clone [url]https://github.com/Tissot-Development/android_kernel_xiaomi_tissot[/url] -b 8.1 kernel/xiaomi/msm8953
Turn on caching to speed up build
Code:
export CCACHE_DIR=./.ccache
ccache -C
export USE_CCACHE=1
export CCACHE_COMPRESS=1
prebuilts/misc/linux-x86/ccache/ccache -M 50G
Configure jack
Jack is the new Java compiler used when building LineageOS 14.1. It is known to run out of memory - a simple fix is to run this command:
Code:
export _JACK_VM_ARGS="-Dfile.encoding=UTF-8 -XX:+TieredCompilation -Xmx4G"
Make Clean Build
Code:
make clean
Initialize the build command
Code:
source build/envsetup.sh
Start Build
Code:
croot
brunch tissot
For More info:
https://source..com/source/requirements
https://wiki.lineageos.org/devices/cheeseburger/build
Thanks bro..
DGEEEK said:
Thanks bro..
Click to expand...
Click to collapse
Thany you for this guide! Will try this!
saski4711 said:
Thany you for this guide! Will try this!
Click to expand...
Click to collapse
:good:
Thanks for guide, btw what's the size of source code ?
prabhjot-singh said:
Thanks for guide, btw what's the size of source code ?
Click to expand...
Click to collapse
Around 20-25GB I think
Followed the above steps to the letter but I get an error right at the beginning:
Code:
ninja: error: 'kernel/xiaomi/msm8953/arch/arm64/configs/lineage_tissot_defconfig', needed by '/home/rossi/android/lineage/out/target/product/tissot/obj/KERNEL_OBJ/.config', missing and no known rule to make it
build/core/ninja.mk:151: recipe for target 'ninja_wrapper' failed
make: *** [ninja_wrapper] Error 1
make: Leaving directory '/home/rossi/android/lineage'
Current git broken? Any idea?
saski4711 said:
Followed the above steps to the letter but I get an error right at the beginning:
Code:
ninja: error: 'kernel/xiaomi/msm8953/arch/arm64/configs/lineage_tissot_defconfig', needed by '/home/rossi/android/lineage/out/target/product/tissot/obj/KERNEL_OBJ/.config', missing and no known rule to make it
build/core/ninja.mk:151: recipe for target 'ninja_wrapper' failed
make: *** [ninja_wrapper] Error 1
make: Leaving directory '/home/rossi/android/lineage'
Current git broken? Any idea?
Click to expand...
Click to collapse
Hello,
Don't use that kernel, as actually don't work properly in Xiaomi Mi A1. This error is caused because the file "lineage_tissot_defconfig" it's not named like that, exactly it's name is "tissot_defconfig", for your first build with lineage I recommend you to use the following sources, because are adapt for Lineage. Don't forget to use superuser privileges to compile, it avoids a lot of possible errors with normal user.
Device tree
Vendor
Kernel
Give thanks to user @ghpranav for sources :good:
Regards
black_arashi said:
Hello,
Don't use that kernel, as actually don't work properly in Xiaomi Mi A1. This error is caused because the file "lineage_tissot_defconfig" it's not named like that, exactly it's name is "tissot_defconfig", for your first build with lineage I recommend you to use the following sources, because are adapt for Lineage. Don't forget to use superuser privileges to compile, it avoids a lot of possible errors with normal user.
Device tree
Vendor
Kernel
Give thanks to user @ghpranav for sources :good:
Regards
Click to expand...
Click to collapse
Thanks for the info. I'm now past the error. Will take some time though since I'm building on my laptop :cyclops:
saski4711 said:
Thanks for the info. I'm now past the error. Will take some time though since I'm building on my laptop :cyclops:
Click to expand...
Click to collapse
Between 3 to 5h in modern pc, probably you will need between 7 to 10h in a laptop, depends on Nº of Cores and RAM, anyway, good luck in your first compilation :good:
black_arashi said:
Between 3 to 5h in modern pc, probably you will need between 7 to 10h in a laptop, depends on Nº of Cores and RAM, anyway, good luck in your first compilation :good:
Click to expand...
Click to collapse
Thx m8. Still no error. Compiling over night on single core to avoid throttling / overheating. :highfive:
saski4711 said:
Thx m8. Still no error. Compiling over night on single core to avoid throttling / overheating. :highfive:
Click to expand...
Click to collapse
Probably you will se a lot of "warning" don't apologice, it's normal, these warning issues is being solved during the compilation. Some info just in case
saski4711 said:
Followed the above steps to the letter but I get an error right at the beginning:
Current git broken? Any idea?
Click to expand...
Click to collapse
Rename tissot_defconfig to lineage_tissot_defconfig in arch/arm64/configs
Nice share brotherr :good:
Keep mia1 like the sky full of stars, so many custom rom :highfive::laugh:
Sent from my Xiaomi Mi A1 using XDA Labs
-Rhoby|™-Bugs said:
Nice share brotherr :good:
Keep mia1 like the sky full of stars, so many custom rom :highfive::laugh:
Click to expand...
Click to collapse
Thanks
Hello and thanks for the guide.
I am trying to build Dirty Unicorns 7.1.2 for tissot. I have downloaded kernel, vendor and device and repo synced DU n7x branch. I have also downloaded device_qcom_sepolicy and changed some files in device/xiaomi/tissot folder in order for the build to start normally. After 1.30 minutes of building i get this error
Code:
ninja: error: '/home/manoskav/du-tissot/out/target/product/tissot/obj/STATIC_LIBRARIES/bootctrl.msm8953_intermediates/export_includes', needed by '/home/manoskav/du-tissot/out/target/product/tissot/obj/EXECUTABLES/update_engine_sideload_intermediates/import_includes', missing and no known rule to make it
make: *** [build/core/ninja.mk:167: ninja_wrapper] Error 1
Maybe should i try n7x-caf branch or n7x is ok for tissot? Can anyone help me with the building process?
Thanks in advance.
mparmpas122321 said:
Hello and thanks for the guide.
I am trying to build Dirty Unicorns 7.1.2 for tissot. I have downloaded kernel, vendor and device and repo synced DU n7x branch. I have also downloaded device_qcom_sepolicy and changed some files in device/xiaomi/tissot folder in order for the build to start normally. After 1.30 minutes of building i get this error
Maybe should i try n7x-caf branch or n7x is ok for tissot? Can anyone help me with the building process?
Thanks in advance.
Click to expand...
Click to collapse
Hmm but seriously it's tougher bro because its bootctrl it need more configuration
I tried building for Tissot but I'm having this issue.
[email protected]:~/dos$ . build/envsetup.sh
including device/generic/car/vendorsetup.sh
including device/generic/mini-emulator-arm64/vendorsetup.sh
including device/generic/mini-emulator-armv7-a-neon/vendorsetup.sh
including device/generic/mini-emulator-x86_64/vendorsetup.sh
including device/generic/mini-emulator-x86/vendorsetup.sh
including vendor/discovery/vendorsetup.sh
[email protected]:~/dos$ brunch tissot
including vendor/discovery/vendorsetup.sh
build/core/product_config.mk:236: *** Can not locate config makefile for product "tissot". Stop.
build/core/product_config.mk:236: *** Can not locate config makefile for product "tissot". Stop.
No such item in brunch menu. Try 'breakfast'
[email protected]:~/dos$
Click to expand...
Click to collapse
Can anyone please help me out?
black_arashi said:
Hello,
Don't use that kernel, as actually don't work properly in Xiaomi Mi A1. This error is caused because the file "lineage_tissot_defconfig" it's not named like that, exactly it's name is "tissot_defconfig", for your first build with lineage I recommend you to use the following sources, because are adapt for Lineage. Don't forget to use superuser privileges to compile, it avoids a lot of possible errors with normal user.
Device tree
Vendor
Kernel
Give thanks to user @ghpranav for sources :good:
Regards
Click to expand...
Click to collapse
@black_arashi
Oh so ghpranav's repo has LOS source added into it? If so is there any Android Stock for all these?
Thanks
About this guide
I have been building kernels for many machine types and have been fiddling around with custom android kernels for my own phone but to my great frustration the rules changed quite a lot for my new phone. It seems every kernel after 2017 is A LOT harder to build and needs quite some fiddling around te get it to boot. The documentation is terrible the least on the steps and all howtos are all outdated by now. This guide shares with you the secrets to build yourself a modern post 2017 kernel from source. I only own a op7 at this moment but I am pretty sure the rules apply to all devices.
So why do we need to build our own kernel? Well that's simple. I have scrolled through many custom kernels missing a simple module that I need. In my case binfmt. Perhaps you need a specific device driver compiled into your kernel or you want to hack in/patch in some special functions that are only needed by you. Or you love a certain kernel but need that one little adjustment in the configs that this kernel doesn’t have and so on.
Lets get through it step by step but I do assume you know something about Linux, you know how to use the terminal and that you have some knowledge on building binaries from source. Ready? Ok lets get started.
These steps are required to be followed to be successful:
1. Set up a building environment
2. Obtain the kernel source
3. Download the proper tool-chain
4. Adjust configuration files to match your needs
5. Build the actual kernel image
6. Backup your current boot.img!!!
7. Trow the image into a anykernel zip and flash it.
8. Close your eyes prey and run the kernel.
Prerequisites
You will need:
A fairly fast computer with lets say 4 gigs of RAM and a decent CPU.
A workable linux distribution that you can boot into (I prefer ubuntu bionic at this moment).
The kernel sources for your device.
ROOT!!
Lots of spare time.
A attitude that makes you unstoppable.
1. Setting up the building environment
Ok lets first open a terminal. You will need the terminal a lot. As a matter of fact it will be your friend through this guide so better get used to it. Assuming you are on a ubuntu like distribution lets fetch the important packages first
Code:
$sudo apt install build-essential bizon flex git
This command will install some of the prerequisites you need to do anything. More packages will need to be installed on the way but at least you will be able to type $make
Now lets create a working directory. Go into your home folder and create a working directory which will later on contain your kernel sources and tool chain.
Code:
$cd
$mkdir [COLOR="MediumTurquoise"]name-of-your-working-folder[/COLOR]
2. Obtain the kernel source
This one is tricky as my experience have learned me the kernel sources supplied by my own vendor are usually badly documented and contain a few bugs here and there resulting in either build errors or a unbootable kernel. So usually I grab a custom kernel that has minimal changes to the stock kernel and boots by only using a single kernel file without extra kernel modules attached. The custom kernels usually have the nasty building bugs flawed out and thus your chances for success are higher. I used the exkernel in my case and out of respect for the hard work of flang2 I bought the app that came along.
To get the sources google around and find the sources on for example git and click the download or clone button there and copy the link of the depository.
Then simply clone the depository to your working directory so after changing to your working directory type
Code:
$git clone link-you-just-copied
Git will now automatically clone the entire kernel source into the source sub-directory. You can change the name of this directory to make you life easier.
3. Download the proper tool-chain
This is where I lost many days and weeks of my life. Where do we find the proper tool-chain for our kernel?
You basically need 3 compilers
clang
GCC
device-tree-compiler
There are many versions of clang and GCC and you will need to find the one that matches your kernel and builds for your cpu architecture. I will assume in this guide that your CPU is aarch64 or arm64 (both names are used at the same time).
To obtain clang head over to the following address:
"https://android.googlesource.com/platform/prebuilts/clang/host/linux-x86/"
now in the tags and branches you can find the version of android you are looking for. If your kernel is for android 9 then use the android 9 tag. Click on it and then click tgz which will provide you with a huge tarball.
Create a folder in your working directory named toolchain en extract the contents of the tarball into the sub-folder clang.
You can try any subversion of clang there is but I recommend to simply peek into the build.config files located in the root of your kernel source directory which usually specify the exact subversion of clang used.
Time to get GCC which is easier since there is only one version right now.
Head over to
"https://android.googlesource.com/platform/prebuilts/gcc/linux-x86/arm/arm-linux-androideabi-4.9/"
and use the correct version here as well. In my case I picked the latest build. Then do the same as for clang but name the sub-folder GCC or whatever you please to do.
And then finally get yourself the device-tree-compiler
Head over to
"https://github.com/dgibson/dtc/tree/v1.4.4"
and clone this depository into ~/your-working-directory/toolchain/
and navigate to the subdir you cloned it into
then build by typing
Code:
$make
any missing package errors will need you to install them using
Code:
$sudo apt install missing-package-name
and do make again until the build completes.
If all went well your tool-chain and working directory will look like this:
Code:
/[COLOR="mediumturquoise"]current-working-dir[/COLOR]/[COLOR="mediumturquoise"]kernel-source-dir[/COLOR]/
|
/toolchain/
|
/clang/
/gcc/
/dtc/
4. Adjust configuration files to match your needs
Lets first grab the correct defconfig file and setup the build directory. This defconfig file contains the default kernel configuration parameters which you propably want to adjust.
Head over to ~/working-directory/kernel-source-dir/arch/arm64/configs/
see what you can find there. I found the elementalX_defconfig file which is the file I needed to build the Exkernel from scratch. If you are trying a stock kernel dive a little bit deeper into the vendor folder and see if you can find a good config file there.
Alternatively sometimes the config is hidden on your device itself. Have a look at
/proc/config.gz
the file inside the archive contains a valid defconfig for your device but beware your may need to open it with menuconfig first and save it again to make it workable for the compiler script.
Place the defconfig file you like to use into the configs folder.
(Skip the following step if your are going to build your kernel for the first time because we first want to see it work.)
Now head over to your kernel source dir and type the following command
Code:
$PATH="~/[COLOR="mediumturquoise"]working-dir[/COLOR]/toolchain/clang/[COLOR="mediumturquoise"]clang-r353983c[/COLOR]/bin:~/[COLOR="mediumturquoise"]working-dir[/COLOR]/toolchain/gcc/a[COLOR="mediumturquoise"]arch64-linux-android-4.9[/COLOR]/bin:${PATH}" \
make menuconfig O=out \
ARCH=arm64 \
CC=clang \
CLANG_TRIPLE=aarch64-linux-gnu- \
CROSS_COMPILE=aarch64-linux-android-
now remember to use the correct paths to your tool-chain. In this command I use clang-r353983c but you may use a different version. The same applies for linux-android-4.9.
I would like to thank Nathan Chance for supplying documentation on the clang tool-chain on his github.
If all well you will be presented with a menu in which you can adjust things. First open the defconfig file you wish to use and then save the file after you are done. Now REMEMBER! With this command the menuconfig will save your new file into the /kernel-source-dir/out folder.
(end of the skipped step)
Now it is time to prepare our kernel build using the following command (do this from your kernel source dir) and remember that this command will look in the /kernel-source-dir/arch/arm64/configs/ directory
$make O=out ARCH=arm64 name-of-your-defconfig
If all goes well you will see something like configuration written to .config
Everything is up and ready to go. Your hart will start pounding from this moment on
5. Build the actual kernel image
This is where things get complicated. I hope you have many years to live because this part consumes time, a lot of it.
type
Code:
$PATH="~/[COLOR="mediumturquoise"]working-dir[/COLOR]/toolchain/clang/[COLOR="mediumturquoise"]clang-r353983c[/COLOR]/bin:~/[COLOR="mediumturquoise"]working-dir[/COLOR]/toolchain/gcc/[COLOR="mediumturquoise"]aarch64-linux-android-4.9[/COLOR]/bin:${PATH}" \
make -j$(nproc --all) O=out \
ARCH=arm64 \
CC=clang \
DTC=~/[COLOR="mediumturquoise"]working-directory[/COLOR]/toolchain/dtc/dtc \
CLANG_TRIPLE=aarch64-linux-gnu- \
CROSS_COMPILE=aarch64-linux-android-
ready set GO!
This will depending on your machine take between forever and eternally. You will witness many warnings on the DTC build seems normal these days and a few warnings on the CC part. Most important is that no errors are thrown at you.
If all goes well you will see a normal exit status and you will have a “working” kernel image.
“Error?: Well that happens. Try a different build of clang check your command line. And if all that fails try to find out what is wrong in the source and that means digging through thousands of forum pages until you find out whats wrong. But using the google tools usually goes well.”
Almost there go and check
kernel-source-dir/out/arch/arm64/boot
and there should be a image-dtb or image.gz-dtb file depending on you settings.
That is your kernel image right there. The difference in size between image and image-dtb should not be huge. 10Megs in difference usually means your dtb is not good but trying is the only way to find out if it works.
6. Backup your current boot.img!!!
You know what to do here right? Do not skip this step unless you like bricked devices or want to reflash and lose your data and all that kind of stuff. Not sure what you are doing stop here or backup your entire device including system vendor etc.
7. Trow the image into a anykernel zip and flash it.
Ok something changed in the last few years. Unpacking repacking and booting using fastboot somehow gives me problems. Dm-verity errors and all kind of red screens. Signing the boot image results into new errors. Well this is how I did it.
Get yourself a anykernel zip file. I used the Exkernel.zip because it only contains a kernel image which I like. Open the zip in a good zip tool (I used ark) and replace the image-dtb file with the one you created. Place this new zip you created on a memory stick and then….
Flash it using twrp or any tool of choice.
8. Close your eyes prey and run the kernel.
Two things can happen.
1. Blank screen nothing happens. Only god can help you, repeat all the steps.
2. Your android starts booting. Start crying of joy
Check in your android if this is indeed the kernel you build. If so time to make some adjustments to your configs or happily enjoy your boosted phone.
Now please remember. If you plan to distribute your kernel that you do the correct steps of accrediting the original programmer and trow the source online. If you use a already custom kernel please respect the hard work of the maker and communicate your plans with him/her.