Develop Bugs

Extracting kernel config from I9000XXJP3

Dear all,
Did anyone succeed extracting kernel configuration from I9000XXJP3? Kernel version is 2.6.32.9, the vermagic is "2.6.32.9 mod_unload ARMv7"
extract-ikconfig doesn't work on it.
I succeeded extracting a zImage gzipped payload, but it seems not to contain any configuration in it (see attached).
/proc/config.gz doesn't exist, Samsung open source package (downloaded from Samsung open source site) contains only Android 2.1 Eclair or previous versions.
My target is to build tun.ko and, eventually, ext3/ext4 modules to make them working in Samsung Galaxy S I9000 with rooted I9000XXJP3.
Any idea?

Without froyo source code or a good Samsung Kernel (es. for himem capable) I think is impossible to play good with theses beta roms.
Ciao

Any news? I need tun.ko for jp3 too..

I have tried to compile the 2.6.32.9 kernel editing the .config in 2.6.9, the module tun.ko is accepted by the device, but I get a kernel panic!

redsh said:
I have tried to compile the 2.6.32.9 kernel editing the .config in 2.6.9, the module tun.ko is accepted by the device, but I get a kernel panic!
Click to expand...
Click to collapse
Did you use the stock linux kernel? Or the common from android.kernel.org?
I'm trying the same thing actually. Isn't there any default config for the processor that might work? I tried with the config from .29 but when loading the module it says wrong format.

try to build 2.6.32 with the 2.6.29 config ("yes" all missing stuff)
turn on your galaxy, adb push the tun.ko
try to load it, it will say "missing symbols" blabla
find the config options that match those symbols, enable them, recompile, try again

Great to see some people who are hacking the kernel! Keep it up!
But I'm afraid it is not going to be as easy as dropping aries_rev03_defconfig as .config in a 2.6.32 kernel tree and doing 'make oldconfig'. That's because many of Samsung's changes have not been included in the newer mainline kernel versions yet.
Samsung added quite a lot of low-level board support for their dev boards (and for the SGS, of course), did some customization and added a few drivers which you will need to forward-port to the newer kernel.
Please have a look at this thread, in which I've started a breakdown of the Samsung patches against Android Eclair's 2.6.29 kernel.
The best course of action I think is to git clone Android's kernel from AOSP, checkout the android-2.6.29 branch, apply Samsung's patches to that, then attempt to rebase your tree to a newer kernel version. (Note, you may want to start with small steps, to get a feel for what you're up against )
Note that there probably will be lots of merge conflicts which you need to resolve, and after dealing with all those, you also have to make sure that everything else that's merged still works as expected, but at least that will show you the amount of work involved. You will basically be doing all the work that Samsung is doing right now for their kernel for FroYo. It will be interesting to follow their progress on the mailing lists and on IRC.

bilboa1 said:
try to build 2.6.32 with the 2.6.29 config ("yes" all missing stuff)
turn on your galaxy, adb push the tun.ko
try to load it, it will say "missing symbols" blabla
find the config options that match those symbols, enable them, recompile, try again
Click to expand...
Click to collapse
Thats exactly what I did, but I got wrong module format... which is a fatal error. I need to invest further in the used config... maybe i did not pick up the right one properly..

miki4242 said:
Great to see some people who are hacking the kernel! Keep it up!
But I'm afraid it is not going to be as easy as dropping aries_rev03_defconfig as .config in a 2.6.32 kernel tree and doing 'make oldconfig'. That's because many of Samsung's changes have not been included in the newer mainline kernel versions yet.
Samsung added quite a lot of low-level board support for their dev boards (and for the SGS, of course), did some customization and added a few drivers which you will need to forward-port to the newer kernel.
Please have a look at this thread, in which I've started a breakdown of the Samsung patches against Android Eclair's 2.6.29 kernel.
The best course of action I think is to git clone Android's kernel from AOSP, checkout the android-2.6.29 branch, apply Samsung's patches to that, then attempt to rebase your tree to a newer kernel version. (Note, you may want to start with small steps, to get a feel for what you're up against )
Note that there probably will be lots of merge conflicts which you need to resolve, and after dealing with all those, you also have to make sure that everything else that's merged still works as expected, but at least that will show you the amount of work involved. You will basically be doing all the work that Samsung is doing right now for their kernel for FroYo. It will be interesting to follow their progress on the mailing lists and on IRC.
Click to expand...
Click to collapse
Yes that would be a lot of work. Maybe its better to just wait until they release the kernel from froyo. I read that they release their opensource stuff rather fast. But just for adding a module like ext4 I don't think you need those patches, because imho they didn't touch the fs of the kernel. We just need an adaquate kernel config and adding modules should be possible.

Phlogiston said:
Thats exactly what I did, but I got wrong module format... which is a fatal error. I need to invest further in the used config... maybe i did not pick up the right one properly..
Click to expand...
Click to collapse
Make sure you're using the same kernel version number and build number, because samsung kernels do not have the option to load incorrect module versions

Yes i've set the subversion as well but without the patches from samsung its impossible it seems. We need to wait and hope that they release the froyo kernel sources soon....

bilboa1 said:
Make sure you're using the same kernel version number and build number, because samsung kernels do not have the option to load incorrect module versions
Click to expand...
Click to collapse
Are you sure they set CONFIG_MODVERSIONS? It's off in the downloadable sources.
Just compare the output of `modinfo -F vermagic <yourmodule>` to `modinfo -F vermagic <modulewhichloads>` or to /proc/version .

did this get solved yet? I google'd for the tun.ko file for my i9000 using jp3 but nothing yet... if you have a proper one for the MoDaCo version here please attach it! ~

I think I saw someone's post with tun.ko for FroYo beta somewhere in these forums, I mean i9000 Android Dev. One of the guys here has found a way to compile kernel for jp* here. I am sure.

I actually found it attached somewhere in the forum and it was 1,5447 mb big I think it was... but it still didn't work for me so I presumed the kernel or something must have been wrong.

[Q]2.3 drivers when source released

So my question is when the 2.3 source code is released will we as evo users be able to compile it using current drivers that we have from 2.2 or is it going to be like 2.2 where it took a month or 2 to get the camera and other stuff working
Simplified do the drivers have to be re-written or will current ones work on 2.3
Mainly wondering as would be nice to have working gingerbread a few days after source released vs weeks/months
Sent from my PC36100 using XDA App

Android uses the Linux kernel. Drivers for the Linux kernel are called "kernel modules" and their files end in .ko (kernel object). Usually they have to be updated for every kernel release e.g. for 2.6.28, 2.6.35, etc to keep up with the kernel APIs.
In some ways Android is just "user space" meaning that it could run theoretically on any kernel. However there are some specific Android kernel requirements that the details are unclear on to me.
Cyanogen has a 2.6.35 and 2.6.36 kernel running, and Gingerbread will use 2.6.35. So things "should" work already. However there's no way to be sure until the actual source code is available.

[REF] Source code: Unified git repo for GT-I9000 Gingerbread kernel source

Here we go
Common gingerbread-samsung git branch for all of us
This branch contains the fixed Gingerbread source (compiling and working) everyone of us may use as reference git repository.
Fixed in this source:
- all cleaned up gitignores
- missing FSR in Makefile
Take also a look at the updated README.txt that will explain you how to compile and get it working with modules
Also: makes sure you disable, in .config:
[*] Automatically append version information to the version string in menuconfig or CONFIG_LOCALVERSION_AUTO in .config
It will help each developer to exchange patches easily because of the common starting point.
bilboa1 said:
What supercurio means, is that he's offering to have a common GIT repository for the official Samsung kernel of the GT-I9000 (and similar phones).
The GIT tree would contain only Samsung drops and possible other upstream fixes/changes (the kernel being loosely based on the Nexus S kernel, there's at least Samsung and Google as different upstream), as well as bug fixes. No new features etc except maybe Voodoo.
The advantage of that is that the ones not using GIT yet could fork it and make their own kernel variation on a STABLE base. They could also issue pull requests for fixes they made, which would profit everyone. That's the open-source spirit and way of doing things efficiently by the way.
Note that the current GIT already contains fixes for compiling and using Samsung's GB sources with Samsung's firmwares (and binary modules).
I certainly support this idea.
Click to expand...
Click to collapse
How you can fork this repository:
- clone it via github directly
or, if you prefer keeping only this gingerbread branch directly, on your dev computer:
Code:
git clone git://github.com/project-voodoo/linux_gt-i9000.git -b gingerbread-samsung
cd linux_gt-i9000
git remote rm origin
git remote add origin git://your-new-remote-repository.git
git remote add common git://github.com/project-voodoo/linux_gt-i9000.git
This way, for people re-using Vodooo sound for example, it will be as easy as:
Code:
git fetch common
git merge gingerbread-voodoo-sound
If you have more idea of collaboration like that, express yourself
FAQ:
Q: Bleh! I hate this Kernel/ directory.
A: Yes, this was the case for the original commits but now it's a standard Linux repository with everything on its root.
But it didn't worked as expected, so I had to make the change, sorry for the inconvenience to the early adopters.
Q: What happens when Samsung update their source code tarballs
A: I'll update the common git repository accordingly (hopefully fast enough for you)
On your side, all you'll need to do will is.
Code:
git fetch common
− or git fetch git://github.com/project-voodoo/linux_gt-i9000.git
git merge gingerbread-samsung
Say good bye to messy tarballs!
PS: if you're looking to initramfs, take a shot at https://github.com/project-voodoo/samsung_initramfs − contribution welcome.

Good idea, I second that, it will be easier

wrong link
Github reads http://project-voodo.org/

What supercurio means, is that he's offering to have a common GIT repository for the official Samsung kernel of the GT-I9000 (and similar phones).
The GIT tree would contain only Samsung drops and possible other upstream fixes/changes (the kernel being loosely based on the Nexus S kernel, there's at least Samsung and Google as different upstream), as well as bug fixes. No new features etc except maybe Voodoo.
The advantage of that is that the ones not using GIT yet could fork it and make their own kernel variation on a STABLE base. They could also issue pull requests for fixes they made, which would profit everyone. That's the open-source spirit and way of doing things efficiently by the way.
Note that the current GIT already contains fixes for compiling and using Samsung's GB sources with Samsung's firmwares (and binary modules).
Forking in git hub is VERY VERY easy btw.
I certainly support this idea.

Awesome! - I also support this idea

United Galaxy S Developers
Nice idea! Perfect spirit of open source

I hope good things come out og this.

Great move Supercurio - once again !

Simply awesome men

Will the github include the multitouch fix(SGS only using two fingers rather than multiple fingers) that affects Google Maps rotation?

pikachu01 said:
Will the github include the multitouch fix(SGS only using two fingers rather than multiple fingers) that affects Google Maps rotation?
Click to expand...
Click to collapse
The gingerbread-samsung branch promoted here will only contain Samsung kernel sources and won't interfere with other developers modifications.
Only exception is if this source is broken and needs something to work, like nikademus's patch: https://github.com/project-voodoo/linux_gt-i9000/commit/6c8f989f58999770d23236bb172c3a4e1c80586b

It seems that JVK and JVB was pulled from Kies because of an update problem. Looks like we're going to have new ROMs to play with in a week or two (maybe less)
Edit: What about the SSL fix (http://forum.xda-developers.com/showthread.php?t=1040005)

Great, good idea. That's how community development should work!

zorxd said:
Great, good idea. That's how community development should work!
Click to expand...
Click to collapse
Agreed! Thanks for getting things started Supercurio! Now I have to start making a Vibrant branch.

Any chance this code will boot with preempt enabled? Does the MTD driver work with the OneNAND partitions like the NS code does? I'd kind of like to get away from FSR/RFS and such....
Still cloning...

ttabbal said:
Any chance this code will boot with preempt enabled? Does the MTD driver work with the OneNAND partitions like the NS code does? I'd kind of like to get away from FSR/RFS and such....
Still cloning...
Click to expand...
Click to collapse
The code has many similarities with Nexus S one (build from it IMO) and is preempt too

Just a note, I had to edit the Makefile to set the crosscompile variable to the right path
Question: is the generated zImage flashable through ODIN? Don't we need to add the initramfs?

supercurio said:
The code has many similarities with Nexus S one (build from it IMO) and is preempt too
Click to expand...
Click to collapse
Excellent! I just did a defconfig to check it out and saw the preempt in there.. Nice to see Samsung fixing things up a little. Now I need to get a GB ROM to install so I can try to boot.
Thanks again. I'll send a pull request when I have a Vibrant branch ready. Going for minimal modifications, fix touch button mapping and such. People can add whatever they want after that. Now I need to learn the new code tree... wheee! Hopefully the basics are the same, getting the changes into an i9k froyo kernel is pretty easy.

zorxd said:
Just a note, I had to edit the Makefile to set the crosscompile variable to the right path
Question: is the generated zImage flashable through ODIN? Don't we need to add the initramfs?
Click to expand...
Click to collapse
You will need an initramfs... anyone have a default one we can start with for 2.3?
zImage will have to be in a TAR file to flash with Odin. Heimdall can flash a bare zImage, as can the SGS Kernel Flasher tool for Android.
Oh... think I saw a setting in "make menuconfig" for the cross-compiler prefix. Might be able to avoid Makefile mods....

Sorry for the newb question, but how do we generate the initramfs? I guess we could take the one from stock JVB. But how do we extract it and how do we combine our compiled kernel with it?
On a side note, I noticed that CFQ is the default scheduler. Isn't it better to use No-op for flash memory?

[PATCH] Kexec-hardboot patch

In this post, I would like to explain what kexec-hardboot patch is.
@kernel developers: I would like to ask you to merge this patch to your kernels, because it is essential part of MultiROM - it allows me to boot any kernel without changing the boot partition. I realize that it is no small request, but the patch is not big, touches relatively stable parts of kernel and should not cause any problems. Thank you.
What is kexec?
It is syscall of Linux kernel, which allows you to boot another Linux kernel without restarting the device - "Linux boots itself". The functionality is equivalent to fastboot -c *cmdline* boot zImage initrd.img, but without PC and fastboot. It is fairly known thing, so more info at wikipedia and man kexec.
Standard kexec call unfortunatelly does not work on Nexus 4. It freezes somewhere, and it is very difficult to find out where - probably some of the drivers are not shut down/re-initialized properly, it is a commong thing among Android devices, which is why kexec-hardboot was made.
What is the difference between normal and hardboot exec?
Kexec-hardboot patch adds a real device restart to that process, so that all the drivers can be properly reinitialized. It stores new kernel to RAM, reboots the device as usual, and kernel from boot partition immediately jumps to the one which was stored to RAM before reboot.
Unlike grouper's kexec-hardboot patch, this one only requires the host kernel to be patched. This is one of the improvements I made, and I think it is pretty significant.
To sumarize the process:
kexec --load-hardboot.... is called and kernel it loaded into RAM.
kexec -e is called. Special info is written to memory (to area which is not overwritten on reboot) and the device is rebooted.
After reboot, very early in the boot process, kernel checks if that special info is present in RAM and if so, it loads new kernel from RAM and jumps to it.
Kexecd' kernel starts and boots.
For more info, read the original thread.
Patches:
Kernel patch: https://gist.github.com/Tasssadar/7833796, 4.4 AOSP kernel repo
This is the kernel patch. Only the host kernel needs to be patched.
Related CONFIG options:
CONFIG_KEXEC=y
CONFIG_KEXEC_HARDBOOT=y
CONFIG_PROC_DEVICETREE=y
CONFIG_ATAGS_PROC=n # This one is turned on automatically, but it is not needed, so you can disable it.
All these options must be enabled.​
Userspace kexec binary: https://github.com/Tasssadar/kexec-tools
I had to change some things in kexec userspace binary because of some kernel bugs, complete description is in that repository. You can get statically built binary at https://github.com/Tasssadar/multirom/blob/master/install_zip/prebuilt-installer/multirom/kexec​
Usage:
Once you have the kernel patches and kexec userspace binary in place, just run following command to boot into new kernel:
Code:
kexec --load-hardboot zImage --initrd=initrd.img --mem-min=0x20000000 --command-line="$(cat /proc/cmdline)" --dtb
kexec -e
Note the command line parameter - cmdline from bootloader is not added automatically, you have to put it there by yourself.
Authors:
This patch was made by Mike Kasick for Samsung Epic 4G. Since that, it was ported to several devices, one of them is Asus Transformer TF201 - I used patch from TF201 and modified it a bit (basically just changed few SoC specific constants). People at #ubuntu-arm helped me out with that, thanks.
For hammerhead, I've improved the patch a bit - only the host needs to be patched now and I've added support for DTB.

Merged, thanks again for the awesome work @Tasssadar!

Good deal.My day is getting better.

@show-p1984 would love to see this in bricked kernel too! ?

@neobuddy89 did you see this?
Sent from Nexus 5 on Slimkat

thanks for the hard work.. thats awesome.

AndroidSlave said:
@neobuddy89 did you see this?
Sent from Nexus 5 on Slimkat
Click to expand...
Click to collapse
Yeah, I saw this.

neobuddy89 said:
Yeah, I saw this.
Click to expand...
Click to collapse
I asked that 6 months ago
Sent from my Nexus 5 using Tapatalk

awesome work bro...
much needed..

AndroidSlave said:
I asked that 6 months ago
Sent from my Nexus 5 using Tapatalk
Click to expand...
Click to collapse
Yeah, I know and I saw that days back..
Enough of OT. :fingers-crossed:

Help with applying the patch
Okay so I have my aosp kernel made. I have my working directory too. Can you just guide me on how do I apply this partch to it?

Is it possible to add that patch from a on the fly flashable zip ?

@Anoopnk since the patch is for the kernel(zImage) its not possible to patch it like that. Or you have to compile the kernel or you need to ask your kernel dev friendly or he can include it in his kernel.

Hello, first I'd like to apologize for dredging up an old thread. Second, I am attempting to build a CM13+kali+kexec compatible kernel, with extra wifi drivers as the base kernel doesnt support my wifi card. Based on that goal, I have a multi-part question for the OP, or anyone else with the know-how to assist me in my quest.
1)Is there a source available for your kernel_kexec_hammerhead_cm13-01-2c39db662.zip listed on the multirom page for nexus 5? I'm attempting to build a new kernel, for kali+CM13+multirom, and your android_kernel_google_msm git only has branches going up to CM12. It would be far easier for me to start with a 'clean' CM13+kexec source then trying to patch myself as per question #2
2) I've attempted to patch a plain old hammerhead_defconfig from CM13 git, however I believe I am doing so wrong. I have managed to compile kexec-tools and aquired the hammerhead 3.4.x patch. Now am I supposed to patch my produced zImage-dtb AFTER build, running the patch from the kexec-tools folder and against the zImage-dtb? Is it something like 'KEXEC.patch -p1 < zimage-dtb'
Any clarification on the use of the kexec-tools patch, or simply a link to github source of a 'clean' CM13 kernel with the kexec patch already applied, would be incredibly helpfull on my journey down the rabbit hole
~EDIT~
Ok so I've managed to figure out the patch and feel like a dumbass. For anyone else looking to get into kernel dev, and wanting to use the kexec patch, heres the basics:
1- run patch within your kernel source directory
2-ensure that the config settings in OP are set (I had to add them to my source by hand as they werent there)
3-when zipping up your kernel, add the sbin and lib/kexec-tools folders from the kexec-tools source build, and be sure your updater-script / updater-binary is set to move these folders into /sbin and /lib respectively.
4-Flash and enjoy Kexec! (check with multirom manager)

[KERNEL][OREO] [SM-T830/T835] [2019-11-21] Modesty 1.0.0 [Linux 4.4.202] [ARK4]

Modesty - a modest custom kernel for the Samsung Tab S4
Modesty aims to provide a mildly appealing and reasonable alternative to the stock 4.4.78 kernel that comes with The Tab S4. In its pursuit of being both mildly appealing and reasonable, it will eschew features that could compromise device stability, whilst gleefully embracing low-risk, self-contained enhancements. In other words, your lowest expectation should be that this kernel will be at least as stable as the stock kernel.
Since there are currently no other custom kernel projects supporting the Tab S4, there isn't really any previous device-specific work to build on. Development of this kernel is therefore likely to be slow and steady.
"Why is this kernel called Modesty? That's crap! Why not Wolverine, Intrepid or Jupiter?"
Because it's just a operating-system kernel, not a turbo-charged supercar or a mission into outer space. Even as operating-system kernels go, this one is pretty dull. Besides, I'm a weary curmudgeon in his fifties, not a teenager.
This project has the modest aim of modestly enhancing the pleasure you derive from your Tab S4 and is therefore modestly named Modesty.
Key characteristics
Supports both the wi-fi only (T830) and wi-fi/LTE (T835) models.
Forked from Samsung's pristine kernel source code (Linux 4.4.78 for ARGH firmware at time of launch).
Regular merging of the upstream Linux kernel's linux-4.4.y branch (4.4.161 at time of public launch).
Regular merging of Samsung's updates to its modified kernel source as they are made available.
Includes @savoca's KCAL advanced colour/gamma control driver.
Includes @flar2's sound control driver to manage headphone and microphone gain.
Disables a huge amount of tracing and logging features inexplicably left enabled by Samsung in the stock release kernel. These debugging features have no place outside engineering builds.
Packed into a boot.img (boot image) taken directly from Samsung's latest stock firmware and kept as close to the original as possible. No obscure boot-time kernel configuration is stashed away here, and no changes are made to any other part of the file system at either install time or run time.
Provides a fully automated installer, with the option of interactive installation to allow manual selection of features and the ability to automatically root the device with Magisk in the post-installation phase.
Includes WireGuard VPN support (version 0.0.20180818 at the time of public launch), which will be updated as available.
Includes @Lord Boeffla's generic kernel wakelock blocker. The conservative default block-list is: qcom_rx_wakelock and NETLINK.
Utilises Westwood+ TCP congestion algorithm by default.
Includes Veno TCP congestion algorithm.
SELinux operates in enforcing mode and cannot be dynamically switched to permissive mode.
FAQ
Q. Is this kernel still actively developed?
A. No. The final ianmacd release was v1.0.0 on 21st November 2019 and no-one else has picked up maintenance of the project.​
Q. Will this kernel also run on Android 9.0 (Pie) devices?
A. No. Modesty targets Android 8.1 (Oreo) and there was never an intention to update it for 9.0 (Pie).​
Q. Can I overclock or underclock the CPU using this kernel?
A. No.​
Q. How does interactive installation mode work?
A. If the ZIP file name contains the string _interactive or a dot-file called .modesty_interactive is present in the root of the external SD card, interactive installation mode is triggered. Please note that this mode overrides any selections implied by the archive name or the presence of dot-files on the file-system.
In interactive mode, you will be asked whether to root the device afterwards with Magisk. Selections are made using the Volume buttons. Just follow the on-screen prompts.​
Q. Can I safely block wakelock X?
A. Perhaps. However, unless you know what a particular wakelock does and are certain that it is causing an actual problem on your device, I suggest you leave it alone.​
Q. Why is this kernel labelled beta? Is it safe to use? And who are you, anyway? Can you be trusted?
A. My T830 has been running this kernel every day since I first rooted it, and I can therefore personally vouch for its stability on this model.
A couple of users have reported Modesty running well on the T835. Initially, it was reported that the kernel did not boot on this model, but after trying several test kernels, the user in question discovered that his machine had a non-standard firmware installation. Once this situation was remedied, Modesty booted and worked as designed.
As the person who built the kernel, I know exactly what's in it, and therefore the only risk I'm exposing myself to when I run it is that of my own incompetence. That's not true for you, however, and you should exercise due caution and at least pause for a moment to consider what you are installing, and the far-reaching powers you are about to grant this unaudited code over your device. Although I link to the source code below, you have only my word for it that this bears any resemblance to the kernel actually provided in the installer.
There are likely to be many iterations of this kernel before it sees a 1.0 release. Features may be added or removed along the way, although there is no clear roadmap at this point in time. Development will go where the needs of the users take it.
Please see the Installation section below for an important note regarding the use of this kernel in combination with stock (i.e. unmodified) Samsung firmware.​
Q. Can I safely root this kernel?
A. Of course. What use would it be if you couldn't? I recommend Magisk for the task. It has a few minor issues, but as a project is very much alive, something that cannot be said about its peers. Magisk has arguably now established itself as the de facto root solution for Android devices.
It just so happens that I also produce my own builds of Magisk, which you are welcome to use. These are release builds (as opposed to debugging builds), produced from my own fork of @topjohnwu's original source, often augmented with patches. You can use anyone's builds, though.
Again, these builds work for me on various Samsung devices, but they are unofficial and you should approach them with fitting caution.​
Q. Can I install Magisk at the same time as Modesty?
A. Yes. The Modesty installer allows you to automatically root your device with Magisk following installation of Modesty..
To make use of this facility, either rename the Modesty zip file to contain the string _magisk or create a file called .modesty_magisk in either the root of your external SD card or in the standard Download directory of the internal SD card. Alternatively, you can utilise interactive installation mode. See above for details.
If any of these trigger conditions is met, the installer will look in the standard internal Download directory as well as in ./Magisk (if present) on the external SD card (if present) for a suitable Magisk zip file to install. Preference is given to versioned files matching the glob Magisk-v*, in which case the latest according to lexical sort order will be used. If none is found, the installer then looks for unversioned release builds (e.g. official Canary channel release builds) called magisk-release.zip in the same locations, selecting the one with the most recent timestamp. If none is found, the installer will then try to find unversioned debug builds (e.g. official Canary channel debug builds) called magisk-debug.zip, again picking the one with the most recent timestamp. Finally, the installer falls back to looking for the most recent file called Magisk.zip or magisk.zip. If still no files have been found by this stage, chaining of Magisk is abandoned.
For example:
Code:
star2lte:/ $ ls -l /storage/0000-0000/.modesty_magisk
-rwxrwx--x 1 root sdcard_rw 0 2018-09-15 14:31 /storage/0000-0000/.modesty_magisk
star2lte:/ $ ls /storage/0000-0000/Magisk/Magisk-* | tail -n 3
/storage/0000-0000/Magisk/Magisk-v17.2-2018091001-ianmacd.zip
/storage/0000-0000/Magisk/Magisk-v17.2-2018091201-ianmacd.zip
/storage/0000-0000/Magisk/Magisk-v17.2-2018091501-ianmacd.zip
When you flash the Modesty archive in TWRP, the most recent version of Magisk that could be found will now be used to automatically root your kernel, i.e. Magisk-v17.2-2018091501-ianmacd.zip in this example.​
Q. Why doesn't Modesty have its own Telegram group?
A. Because my experience of Android-themed Telegram groups is that they invariably degenerate into seething cesspits of rudeness, ignorance, superstition and — on a good day — pseudo-science. I don't wish to police such a den of iniquity. Of course, it's a free world (or so I still like to kid myself), so you are at liberty to create your own Telegram group for Modesty if you wish. Just please don't invite me to it.​
Building
Building the kernel from source is beyond the scope of this document. If you want to build this kernel from scratch, for example to change its configuration, start with this handy reference tailored to building kernels for Android.
Download
See posting #2 in this thread for links to the latest and all previous versions.
Known Issues
Bluetooth HID (input) devices do not work.
Versions 0.99.11 to 0.99.22 contained a bug that caused Bluetooth HID (input) devices, such as mice, keyboards and gamepads, not to function. They could be paired with the tablet, but their input was not recognised. This bug was finally traced and fixed in 0.99.23.​
Installation
Make a back-up of your existing boot partition using the custom recovery environment provided by TWRP. If your device doesn't yet have TWRP, you will need to install it first. Then, use it to flash the Modesty ZIP file. The boot image will automatically be installed in the boot partition of your device.
If your device has unmodified Samsung firmware, you will encounter problems with Bluetooth (namely delayed initialisation and forgotten pairings) after installing this or any other custom kernel. To remedy this, you will need to patch your system with modified libsecure_storage.so libraries. Some custom kernel installers actually install these without telling you, overwriting your system libraries and transparently circumventing the problem before you can run into it. This approach necessarily modifies your device's file-system, however, and that may not be what you want. At the very least, the user should be made aware what is happening to his device.
For this reason, I have instead prepared a companion Magisk module that achieves the same goal without modifying the file-system. This will allow you to run a custom kernel (not just this one, but any custom kernel) on pristine stock firmware without any Bluetooth issues. The module can be found in the official Magisk module repository, accessible from Magisk Manager on your tablet. If you install this Magisk module, you may wish to also disable the secure_storage_daemon by editing /system/etc/init/secure_storage_daemon.rc (change start to stop), as it no longer serves a purpose.
In a similar vein, you may encounter authentication errors when connecting to wireless networks after installing this or any other custom kernel. This problem is not serious and easily remedied by re-entering your passphrase for the networks you use.
Finally, if SecurityLogAgent notifies you that unauthorised actions have been detected, do not be alarmed. This is a normal consequence of having installed a custom kernel. You may wish to disable SecurityLogAgent to avoid being repeatedly notified..
Whilst the above issues are the only ones you can expect to encounter when running this kernel vs. the stock Samsung kernel, they may sound like more trouble than they're worth. In that case, you might be happier just sticking to Samsung's stock kernel. The company supplies a perfectly good kernel straight from the factory.
Configuration
You are encouraged to use either @morogoku's excellent MTweaks (a modified version of Kernel Aduitor) or @flar2's EX Kernel Manager to manage the features provided by this kernel.
Source code
Modesty's GitHub repository.
References
A useful guide to CPU governors, I/O schedulers (and more).
For more information on the some of the individual schedulers included in this kernel, you can also look under Documentation/block in the kernel source.
The WireGuard user guide, control app, home page and source code.
Credits
Thank you to everyone in the Linux kernel universe for getting us this far. Within the Android development community, I am grateful to the following people for their time-saving contributions:
@osm0sis for Android Image Kitchen, which has saved me a huge amount of work in packing and unpacking boot images.
An honorary mention must go to @Chainfire, the extent of whose benefaction to the Android community is still not fully understood or appreciated in some quarters.

Change log
v1.0.0 (final ianmacd release) (2019-11-21)
Kernel proclaimed stable. Version number incremented. No code changes since v0.99.49.
v0.99.49 (2019-11-16)
Updated to Linux 4.4.202.
v0.99.48 (2019-11-13)
Updated to Linux 4.4.201.
v0.99.47 (2019-11-11)
Updated to Linux 4.4.200.
v0.99.46 (2019-11-06)
Updated to Linux 4.4.199.
v0.99.45 (2019-10-31)
Updated to Linux 4.4.198.
v0.99.44 (2019-10-19)
Updated to Linux 4.4.197.
v0.99.43 (2019-10-08)
Updated to Linux 4.4.196.
v0.99.42 (2019-10-07)
Updated to Linux 4.4.195.
v0.99.41 (2019-09-22)
Updated to Linux 4.4.194.
v0.99.40 (2019-09-16)
Updated to Linux 4.4.193.
v0.99.39 (2019-09-11)
Updated to Linux 4.4.192.
Fixes unavailability of external SD card in Modesty 0.99.38.
v0.99.38 (2019-09-08) Release withdrawn (External SD card unavailable)
Updated to Linux 4.4.191.
v0.99.37 (2019-08-26)
Updated to Linux 4.4.190.
v0.99.36 (2019-08-12)
Updated to Linux 4.4.189.
v0.99.35 (2019-08-07)
Updated to Linux 4.4.188.
v0.99.34 (2019-08-05)
Updated to Linux 4.4.187.
v0.99.33 (2019-07-23)
Updated to Linux 4.4.186.
v0.99.32 (2019-07-12)
Updated to Linux 4.4.185.
v0.99.31 (2019-06-28)
Updated to Linux 4.4.184.
v0.99.30 (2019-06-22)
Updated to Linux 4.4.183.
v0.99.29 (2019-06-18)
Updated to Linux 4.4.182.
v0.99.28 (2019-06-12)
Updated to Linux 4.4.181.
v0.99.27 (2019-05-17)
Updated to Linux 4.4.180.
v0.99.26 (2019-04-28)
Updated to Linux 4.4.179.
v0.99.25 (2019-04-07)
Updated to Linux 4.4.178.
v0.99.24 (2019-03-26)
Updated to Linux 4.4.177.
Build only the latest revision of the DTB.
v0.99.23 (2019-03-02)
Fixed bug, introduced in v0.99.11, that caused input from Bluetooth HID devices, such as keyboards, mice and gamepads to be ignored.
v0.99.22 (2019-02-23)
Updated to Linux 4.4.176.
v0.99.21 (2019-02-20)
Updated to Linux 4.4.175.
v0.99.20 (2019-02-11)
Updated to Linux 4.4.174.
v0.99.19 (2019-02-08)
Updated to Linux 4.4.173.
v0.99.18 (2019-01-26)
Updated to Linux 4.4.172.
v0.99.17 (2019-01-17)
Updated to Linux 4.4.171.
v0.99.16 (2019-01-13)
Updated to Linux 4.4.170.
v0.99.15 (2018-12-30)
Rebased on ARK4 kernel source code and boot images.
v0.99.14 (2018-12-23)
Updated to Linux 4.4.169.
Merged four more UPSTREAM commits from android-4.4 kernel branch.
v0.99.13 (2018-12-13)
Updated to Linux 4.4.167.
Merged selected BACKPORT and UPSTREAM commits from android-4.4 kernel branch.
v0.99.12 (2018-12-05)
Updated to Linux 4.4.166.
Realtek USB Ethernet driver upgraded from v2.08.0 to v2.10.00.
v0.99.11 (2018-11-29)
Updated to Linux 4.4.165.
KCAL advanced colour/gamma control driver optimisation.
Added @flar2's sound control driver for controlling headphone and microphone gain. (Configure with MTweaks or EX Kernel Manager).
v0.99.10 (2018-11-21)
Updated to Linux 4.4.164.
Added KCAL advanced colour/gamma control driver. (Configure with MTweaks or EX Kernel Manager).
Lots of tracing and debug logging disabled, further reducing kernel size.
CONFIG_DISPLAY_USE_INFO
CONFIG_SEC_DISPLAYPORT_LOGGER
CONFIG_FB_MSM_MDSS_XLOG_DEBUG
CONFIG_SEC_FILE_LEAK_DEBUG
CONFIG_SEC_DEBUG_USER
CONFIG_SEC_DEBUG_SUMMARY
CONFIG_SCSI_UFSHCD_CMD_LOGGING
CONFIG_MSM_SMEM_LOGGING
CONFIG_PROFILING
CONFIG_DEBUG_INFO
CONFIG_SCHED_DEBUG
CONFIG_SEC_PM_DEBUG
CONFIG_CORESIGHT
Built as monolithic kernel (i.e. without CONFIG_MODULES).
Built as relocatable code (CONFIG_RELOCATABLE_KERNEL).
Assembler symbols stripped (CONFIG_STRIP_ASM_SYMS set).
Embedded kernel config (reported via /proc/config.gz) now falsely reports stock settings to allow disabling of superfluous kernel features that otherwise cause grave Android System warning on boot.
v0.99.9 (2018-11-13)
Rebased on ARJ3 kernel source code and boot images.
v0.99.8 (2018-11-10)
Updated to Linux 4.4.163.
More than 100 fixes applied from upstream AOSP android-4.4 and android 4.4-o branches.
Lots of tracing and debug logging disabled:
CONFIG_IPC_LOGGING (debug logging for IPC drivers)
CONFIG_QCOM_RTB (register tracing)
CONFIG_TRACER_PKT (for tracing IPC protocols)
CONFIG_FTRACE (kernel tracing infrastructure)
CONFIG_CPU_FREQ_SWITCH_PROFILER (CPU frequency switch profiler)
CONFIG_TRACING_EVENTS_GPIO (traces GPIO subsystem)
Fixes to allow kernel to build when above logging and tracing options are disabled.
v0.99.7 (2018-10-30)
Rebased on ARH5 kernel source code.
Reworked the v4l2 fix that restores liboemcrypto-dependent apps to working state.
v0.99.6 (2018-10-28)
v4l2 fixes to restore liboemcrypto-dependent apps to working state.
v0.99.5 (2018-10-21)
Updated to Linux 4.4.162.
v0.99.4 (2018-10-19)
Initial public release, based on Linux 4.4.161.
v0.99.3
Internal build, based on Linux 4.4.160.
v0.99.2
Internal build, based on Linux 4.4.159.
v0.99.1
Initial internal build, based on Linux 4.4.78.

It begins! Awesome to finally see a custom kernel for the Tab S4.

I want to test for you once I can get root back

ianmacd said:
Change log
v0.99.4 (2018-10-19)
Initial public release, based on Linux 4.4.161. Caution: This kernel remains completely untested on the T835.
v0.99.3
Internal build, based on Linux 4.4.160.
v0.99.2
Internal build, based on Linux 4.4.159.
v0.99.1
Initial internal build, based on Linux 4.4.78.
Click to expand...
Click to collapse
Flashed on T835 device doesnt even get past the Boot (custom device) screen is there a way to get logs without using a computer?
Sent from my Samsung SM-G950F using XDA Labs

dr460nf1r3 said:
Flashed on T835 device doesnt even get past the Boot (custom device) screen is there a way to get logs without using a computer?
Click to expand...
Click to collapse
I'll look into it this evening. I'm just about to get off a plane.
Were there any errors when installing? Was your device properly detected as a T835?
Sent from my SM-G965F using XDA Labs

ianmacd said:
I'll look into it this evening. I'm just about to get off a plane.
Were there any errors when installing? Was your device properly detected as a T835?
Click to expand...
Click to collapse
Installing just fine, correctly detected as well.
Sent from my Samsung SM-G950F using XDA Labs

dr460nf1r3 said:
Installing just fine, correctly detected as well.
Click to expand...
Click to collapse
I've gone through the ramdisk of the T835's boot image with a fine-tooth comb and can find nothing untoward. I also verified that I properly removed the dm-verity flag from the T835's device tree.
There are actually very few source code differences between the T830 and T835. Both can be built from a single tree. The only differences lie in the kernel config file and the device tree, but I am building with the default T835 configuration, and with the proper device tree for that device.
Let's try at least ruling out my installer code. Please image-flash this new boot image[/i] to your device and tell me if it boot-loops. If it does, my installer isn't the problem, because it's only used for a ZIP flash. I've already checked the installer code and can't see any bugs, so I don't think the issue lies there.
Can you also please tell me which version of the firmware your device is running? Possibly there's an issue there, too. Samsung has so far released the source to the ARGH kernel only. This seems to work fine on my ARH5 firmware, but it's uncertain whether it would still work on something based on ARI*, and I've seen that a couple of countries do now have ARI firmware available. Mind you, even if it wasn't compatible, it should still get as far as booting.
Anyway, please test that boot image and let me know your firmware version.

While I soldier on with the issues afflicting the T835 build, can anyone else verify the T830 build as working for them?
Don't be shy; I'm running it on my own device, so I'm certain that build boots.

ianmacd said:
While I soldier on with the issues afflicting the T835 build, can anyone else verify the T830 build as working for them?
Don't be shy; I'm running it on my own device, so I'm certain that build boots.
Click to expand...
Click to collapse
Sorry for the noob question if i flash this kernal on my SM-T835 will i lose DEX ? Sorry i'm not quite understanding what KERNEL does ? Thanks in advance!

N1NJATH3ORY said:
Sorry for the noob question if i flash this kernal on my SM-T835 will i lose DEX ? Sorry i'm not quite understanding what KERNEL does?
Click to expand...
Click to collapse
When the kernel is working as intended, you won't lose DeX, but it currently isn't even booting on the T835.
Only those who are able to assist in debugging the current boot failure should install the T835 build at this time.
The T830 build, on the other hand, is rock solid for me, and I encourage anyone who is capable of recovering from an unexpected bootloop to try it out.

Version 0.99.5 released.
This release updates the kernel to the latest upstream Linux.
T830 owners, install at will. T835 owners, beware: The previous release has been reported unbootable on this model, and this release is likely to be similarly afflicted. Investigations are ongoing. Until this issue is resolved, the whole project has been downgraded to alpha status.
Change log
Updated to Linux 4.4.162. Caution: This release is likely to cause a bootloop on the T835.

ianmacd said:
I've gone through the ramdisk of the T835's boot image with a fine-tooth comb and can find nothing untoward. I also verified that I properly removed the dm-verity flag from the T835's device tree.
There are actually very few source code differences between the T830 and T835. Both can be built from a single tree. The only differences lie in the kernel config file and the device tree, but I am building with the default T835 configuration, and with the proper device tree for that device.
Let's try at least ruling out my installer code. Please image-flash this new boot image[/i] to your device and tell me if it boot-loops. If it does, my installer isn't the problem, because it's only used for a ZIP flash. I've already checked the installer code and can't see any bugs, so I don't think the issue lies there.
Can you also please tell me which version of the firmware your device is running? Possibly there's an issue there, too. Samsung has so far released the source to the ARGH kernel only. This seems to work fine on my ARH5 firmware, but it's uncertain whether it would still work on something based on ARI*, and I've seen that a couple of countries do now have ARI firmware available. Mind you, even if it wasn't compatible, it should still get as far as booting.
Anyway, please test that boot image and let me know your firmware version.
Click to expand...
Click to collapse
Firmware Version ist arh5 and after flashing your img the device still constantly reboots on the start screen and doesnt even get to the boot Screen
Sent from my Samsung SM-G950F using XDA Labs

dr460nf1r3 said:
Firmware Version ist arh5 and after flashing your img the device still constantly reboots on the start screen and doesnt even get to the boot Screen
Click to expand...
Click to collapse
Thanks. That absolves the installer of any wrongdoing, at least.
Something is fundamentally wrong with the kernel for the T835.
The boot image is taken from stock firmware, and modified just enough to allow a custom kernel to boot. I very much doubt the problem lies there. A virtually identical image works for the T830.
The kernel config used is the one supplied by Samsung. The only modifications made to it are the same ones I made to the T830's.
I think my next step will be to produce a kernel built without downstreaming the 4.4.y Linux branch, so back to 4.4.78. If that works, it will indicate that an error affecting only the T835 was introduced during all of my merging of the upstream kernel.
I'll post again when I've built the kernel, which won't be for a few hours, as I'm on holiday at the moment.
Sent from my SM-G965F using XDA Labs

ianmacd said:
I think my next step will be to produce a kernel built without downstreaming the 4.4.y Linux branch, so back to 4.4.78. If that works, it will indicate that an error affecting only the T835 was introduced during all of my merging of the upstream kernel.
Click to expand...
Click to collapse
OK, @dr460nf1r3, please try this new T835 build.
This is rewound to 4.4.78, with just a few extra cherry-picked commits to enable it to build cleanly and boot without triggering dm-verity.
In other words, this kernel should be 99% identical to the one that shipped with the machine. This assumes that the source as supplied by Samsung was actually used to build the stock kernel.. They have been known to publish sources that don't match what's on the machine.

ianmacd said:
OK, @dr460nf1r3, please try this new T835 build.
This is rewound to 4.4.78, with just a few extra cherry-picked commits to enable it to build cleanly and boot without triggering dm-verity.
In other words, this kernel should be 99% identical to the one that shipped with the machine. This assumes that the source as supplied by Samsung was actually used to build the stock kernel.. They have been known to publish sources that don't match what's on the machine.
Click to expand...
Click to collapse
Thanks, flashing now will report back in a few minutes
Sent from my Samsung SM-G950F using XDA Labs
---------- Post added at 05:44 PM ---------- Previous post was at 05:17 PM ----------
ianmacd said:
OK, @dr460nf1r3, please try this new T835 build.
This is rewound to 4.4.78, with just a few extra cherry-picked commits to enable it to build cleanly and boot without triggering dm-verity.
In other words, this kernel should be 99% identical to the one that shipped with the machine. This assumes that the source as supplied by Samsung was actually used to build the stock kernel.. They have been known to publish sources that don't match what's on the machine.
Click to expand...
Click to collapse
Did not work still the same issue.. flashed via twrp to boot partition. Noob question, the boot backup i got is 64mb while your kernel hardly has 25.. whats going on here?
Sent from my Samsung SM-G950F using XDA Labs

dr460nf1r3 said:
Did not work still the same issue.. flashed via twrp to boot partition.
Click to expand...
Click to collapse
Well, that's disappointing. I was hoping that it was my screw-up, rather than Samsung's, but at this point almost everything I've done has been backed out and it still won't boot.
Noob question, the boot backup i got is 64mb while your kernel hardly has 25.. whats going on here?
Click to expand...
Click to collapse
Good question.
Your back-up is of the entire partition, including the area with no data on it, so you're getting a file the same size as the partition itself. My boot image contains just the data segment, so it's smaller.
If you pull the stock boot image from the AP file of Samsung's firmware, you'll see that it's a very similar size to mine (slightly smaller, actually):
Code:
$ unzip -p T835XXU1ARH5_T835OXM1ARH5_PHN.zip AP_T835XXU1ARH5_CL14008523_QB19263559_REV00_user_low_ship_MULTI_CERT_meta.tar.md5| tar xf - -O boot.img.\*lz4 | lz4 -dc > boot.img
$ ls -l boot.img
-rw-rw-r--. 1 ianmacd ianmacd 23593232 Oct 21 22:01 boot.img
$ file boot.img
boot.img: Android bootimg, kernel (0x8000), ramdisk (0x2000000), page size: 4096, cmdline (console=null androidboot.hardware=qcom user_debug=31 msm_rtb.filter=0x37 ehci-hcd.park=3 lpm_le)
So, what now?
I'll see which other minor changes I can back out, in an effort to arrive at a kernel built from source that is as close to stock as possible. If you're wondering Why doesn't he just build from pristine sources?, the answer is: Because Samsung's source code won't even build out of the box. Many of the kernel header files are simply not in the expected locations. Alas, this is a fairly common problem with Samsung's kernel source code releases.
I suspect the solution to this problem may actually lie in changes that have yet to be made, rather than changes made that need to be reverted. In other words, the T835 may require some kernel modifications or configuration that the T830 doesn't. Theoretically, a kernel compiled from Samsung's pristine sources should just work, but that's starting to look unlikely now.
I'm hoping that I can enable/disable a few further options in the kernel config, rebuild and produce a kernel that works for you. If, however, the problem is that the source itself is faulty, we may have to wait for a future release by Samsung to give us something that compiles into a working kernel.
But I don't intend to throw in the towel on the T835 just yet. There are still a few more things we can try.

ianmacd said:
Well, that's disappointing. I was hoping that it was my screw-up, rather than Samsung's, but at this point almost everything I've done has been backed out and it still won't boot.
Good question.
Your back-up is of the entire partition, including the area with no data on it, so you're getting a file the same size as the partition itself. My boot image contains just the data segment, so it's smaller.
If you pull the stock boot image from the AP file of Samsung's firmware, you'll see that it's a very similar size to mine (slightly smaller, actually):
So, what now?
I'll see which other minor changes I can back out, in an effort to arrive at a kernel built from source that is as close to stock as possible. If you're wondering Why doesn't he just build from pristine sources?, the answer is: Because Samsung's source code won't even build out of the box. Many of the kernel header files are simply not in the expected locations. Alas, this is a fairly common problem with Samsung's kernel source code releases.
I suspect the solution to this problem may actually lie in changes that have yet to be made, rather than changes made that need to be reverted. In other words, the T835 may require some kernel modifications or configuration that the T830 doesn't. Theoretically, a kernel compiled from Samsung's pristine sources should just work, but that's starting to look unlikely now.
I'm hoping that I can enable/disable a few further options in the kernel config, rebuild and produce a kernel that works for you. If, however, the problem is that the source itself is faulty, we may have to wait for a future release by Samsung to give us something that compiles into a working kernel.
But I don't intend to throw in the towel on the T835 just yet. There are still a few more things we can try.
Click to expand...
Click to collapse
Thanks for explaining everything for me. Id like to help you were i can but i dont have a computer by my hands right now for the next time
Sent from my gts4llte using XDA Labs

dr460nf1r3 said:
Thanks for explaining everything for me. Id like to help you were i can but i dont have a computer by my hands right now for the next time
Click to expand...
Click to collapse
Here's a new build to try. This one reverts the last few changes I originally made to the T835's kernel configuration before building. This is as close to stock as possible, whilst still being able to build.
If this doesn't boot, it pretty much means that Samsung has supplied code for the T835 that simply will not compile into a working kernel. At that point, we'll probably have to wait for updated sources. I already have a request pending with Samsung for the release of the BRI sources.
Just to be clear, the current status quo as I understand it is that the Samsung logo never starts to be written from left to right. You never get past the static screen with the device name and the word Custom. Is that correct?

ianmacd said:
Here's a new build to try. This one reverts the last few changes I originally made to the T835's kernel configuration before building. This is as close to stock as possible, whilst still being able to build.
If this doesn't boot, it pretty much means that Samsung has supplied code for the T835 that simply will not compile into a working kernel. At that point, we'll probably have to wait for updated sources. I already have a request pending with Samsung for the release of the BRI sources.
Just to be clear, the current status quo as I understand it is that the Samsung logo never starts to be written from left to right. You never get past the static screen with the device name and the word Custom. Is that correct?
Click to expand...
Click to collapse
Im sorry to tell you but this doesnt boot either in fact it doesnt even reboot the static screen. Your right about the current status quo sadly.
Sent from my Samsung SM-G950F using XDA Labs