[Kernel][D850|1|2|5/F400/LS990/VS985]Unified Kernel Source repository/compilation - G3 Android Development

Just for developers!
Hey guys and girls,
I fixed and uploaded the stock kernel source for the G3 to my github which other developers can use as base for their kernels or just take it as it is to build their roms, currently the source for the D855, D851, D850, D852, VS985, F400 and LS990 are merged.
As said, it's just the fixed stock source for now!
There is for sure still the bootloader lock problem, but anyways, when this is fixed (which is hopefully soon) this may be helpful for some and it may can speed up things a bit.
There may be some additional things coming, but for now, that's it.
Have fun.
Repository
https://github.com/tectas/android_kernel_lge_msm8974ac
Changelog
14.08.2014
include/asm-generic: Change per_cpu_offset to take last element of array instead of returning 0 if out of bounds
firmware: Fix to compile prebuild firmware only once
13.08.2014
kernel: quick fix
Fix -Warray-bounds warnings
Makefile: reenable -Wframe-larger-than
Makefile: ifeq y instead of ifdef at CONFIG_CC_OPTIMIZE_SPEED and CONFIG_CC_OPTIMZE_DEFAULT
init/Kconfig: Removed CC_OPTIMIZE_SIZE (default now) and added CC_OPTIMIZE_SPEED and CC_OPTIMIZE_DEFAULT
arch/sh/lib|arch/title:Changes for CC_OPTIMIZE_SPEED and CC_OPTIMIZE_DEFAULT
12.08.2014
arch/arm/mach-msm|fs|ipc|kernel|mm: fix uninitialized warnings
arch/arm/configs: CONFIG_FRAME_WARN added, CONFIG_CC_OPTIMIZE_SPEED disabled
Makefile: Options for -O3, -O2 and -Os added
Makefile: Disabled warnigs for array-bounds and uninitialized
Makefile: linaro build optimizations
Makefile: started to add flags for -O3 linaro builds
net: bluetooth: linaro fix
drivers: cpufreq: Fixes for linaro at interactive governor
11.08.2014
Fix Compiling Firmware
Cleanup of generated files
Reset of CONFIG_NF_CONNTRACK_SIP to default value
dtsi fix for VS985
Changes for D852
Changes for VS985
Changed CONFIG_NF_CONNTRACK_SIP to default value
Changes for F400
...
Full list of commits can be found here
Currently supported devices
D855
D851
D850
LS990
F400
VS985
D852
Bugs
You tell me
Toolchain
Currently just the default android toolchain is officially supported, but it should work with others fine as well, if not, just tell me and i will fix it for the given toolchain.
Credits
@KAsp3rd
@HolyAngel

---

How to compile
Preperation
Check out aosp source and switch to it's directory (https://source.android.com/source/downloading.html)
In the terminal:
Code:
mkdir -p kernel/lge/msm8974ac
cd kernel/lge/msm8974ac
git clone https://github.com/tectas/android_kernel_lge_msm8974ac.git -b kitkat .
Compilation
All Variants
Code:
export PATH=$PATH:tools/lz4demo
D855
Code:
make ARCH=arm CROSS_COMPILE=../../../prebuilts/gcc/linux-x86/arm/arm-eabi-4.7/bin/arm-eabi- g3-global_com-perf_defconfig zImage-dtb -j4
D851
Code:
make ARCH=arm CROSS_COMPILE=../../../prebuilts/gcc/linux-x86/arm/arm-eabi-4.7/bin/arm-eabi- g3-tmo_us-perf_defconfig zImage-dtb -j4
D850
Code:
make ARCH=arm CROSS_COMPILE=../../../prebuilts/gcc/linux-x86/arm/arm-eabi-4.7/bin/arm-eabi- g3-att-perf_defconfig zImage-dtb -j4
LS990
Code:
make ARCH=arm CROSS_COMPILE=../../../prebuilts/gcc/linux-x86/arm/arm-eabi-4.7/bin/arm-eabi- g3-spr_us-perf_defconfig zImage-dtb -j4
F400
Code:
make ARCH=arm CROSS_COMPILE=../../../prebuilts/gcc/linux-x86/arm/arm-eabi-4.7/bin/arm-eabi- g3-lgu-perf_defconfig zImage-dtb -j4
VS985
Code:
make ARCH=arm CROSS_COMPILE=../../../prebuilts/gcc/linux-x86/arm/arm-eabi-4.7/bin/arm-eabi- g3-vzw-perf_defconfig zImage-dtb -j4
D852
Code:
make ARCH=arm CROSS_COMPILE=../../../prebuilts/gcc/linux-x86/arm/arm-eabi-4.7/bin/arm-eabi- g3-bell-perf_defconfig zImage-dtb -j4
Wait till it compiled
The resulting dtb zImage can be found at arch/arm/boot and is named zImage-dtb
Any suggestions for improvement? Feel free to comment

---

Now we just need a device config for D855 and let the CM game begin
BTW the bootloader may not be the biggest issue, the flashing of the rom may be able to be done using the tethered TWRP that was released.

---

sooti said:
Now we just need a device config for D855 and let the CM game begin
BTW the bootloader may not be the biggest issue, the flashing of the rom may be able to be done using the tethered TWRP that was released.
Click to expand...
Click to collapse
The flashing of the rom, yes, the boot.img is the problem i guess (and without proper kernel and ramdisk no aosp rom will work). It can be flashed as well, but if it doesn't match the stock one, the bootloader throws a security exception when you try to boot from it. At least that's what I faced, when i tried to boot up TWRP which I directly flashed to my device instead of temporarly booting it, so, I guess it's the same with the kernel.

---

Tectas said:
The flashing of the rom, yes, the boot.img is the problem i guess (and without proper kernel and ramdisk no aosp rom will work). It can be flashed as well, but if it doesn't match the stock one, the bootloader throws a security exception when you try to boot from it. At least that's what I faced, when i tried to flash TWRP directly to my device instead of just temporarly booting it, so, I guess it's the same with the kernel.
Click to expand...
Click to collapse
This is true, I work with LG and they sent the company I work for a tool that loads code into the bootloader allowing unsigned code to run (we need it since we run vitual environments), I wonder if this tool is only for the LG device we test it on (can't tell you the model) or can be used on any device,
it allows fastboot to write code to kernel + bootloader, something that always fails with the default tot without this app.
I will test it on my g3, hope it doesn't brick it, if it doesn't on one hand this may be the key to unlock and develop ROMs, on the other hand since the software is company property that could get me fired, I won't be able to release it to everyone, maybe if I understand how it works, if it works at all on the g3, I can develop my own tool, but this is all wishful thinking.
EDIT: the special file that is loaded into the app (you choose a file, I think it overides bootloader security chain certificate), just causes the app to crash on the G3, so no luck there unless I get this file from LG (we are not working on the G3 at this time in my company), so no hope with that, but there is a way obviously since this app without root is able to bypass bootloader (it shows a warning about security on the bootloader after)

---

sooti said:
This is true, I work with LG and they sent the company I work for a tool that loads code into the bootloader allowing unsigned code to run (we need it since we run vitual environments), I wonder if this tool is only for the LG device we test it on (can't tell you the model) or can be used on any device,
it allows fastboot to write code to kernel + bootloader, something that always fails with the default tot without this app.
I will test it on my g3, hope it doesn't brick it, if it doesn't on one hand this may be the key to unlock and develop ROMs, on the other hand since the software is company property that could get me fired, I won't be able to release it to everyone, maybe if I understand how it works, if it works at all on the g3, I can develop my own tool, but this is all wishful thinking.
Click to expand...
Click to collapse
Well, then good luck, if you need someone to test, I happily will
I wanted to get my device unlocked through jtag in a shop (but unfortunately I haven't found one owning a board in my city yet), with it, it shouldn't be the problem and in theory it should be possible to flash those images at least with dd afterwards on to other d855 when I pull them from my device. With comparing the locked and unlocked bootloader images through a hexeditor it may could even be possible to find an unlock for other variants, but that's all theory for now as well.

---

Tectas said:
Well, then good luck, if you need someone to test, I happily will
I wanted to get my device unlocked through jtag in a shop (but unfortunately I haven't found one owning a board in my city yet), with it, it shouldn't be the problem and in theory it should be possible to flash those images at least with dd afterwards on to other d855 when I pull them from my device. With comparing the locked and unlocked bootloader images through a hexeditor it may could even be possible to find an unlock for other variants, but that's all theory for now as well.
Click to expand...
Click to collapse
I don't think a jtag will unlock the bootloader as it is not a hard lock, its a security check that runs at boot, you'd need a bootloader image that bypasses the security check, flashing an unlocked bootlader is not the problem, its getting one that is the problem.
jtag is only useful in hard bricks of a device where the bootloader is bad. i could be wrong though.

---

sooti said:
I don't think a jtag will unlock the bootloader as it is not a hard lock, its a security check that runs at boot, you'd need a bootloader image that bypasses the security check, flashing an unlocked bootlader is not the problem, its getting one that is the problem.
jtag is only useful in hard bricks of a device where the bootloader is bad. i could be wrong though.
Click to expand...
Click to collapse
Sure it's "just" a security check, but there should be a flag at the bootloader indicating if it should be used or not (at least any watchdog I know of can be turned off in some way and this is basically just a watchdog), with jtag you're able to access the bootloader as you would with a serial port and you can get and set the variables of the bootloader, so when you find the fitting flag you should be able to turn it off, but as said, that's just theory for now.
Sent from my LG-D855

---

Just as notification, i've changed the repository name to reflect what i'm trying to achive with it.
I'm also working on including the other variants at the repository, D851 is allready added, but not finished yet, i've already updated the guide with the commands to compile for the d851.

---

Hey,
I'm searching for testers for the merges I've done and the proper fictionality on other variants than the d855 I own myself (for now d850, d851 and LS990).
If you want to participate please check by at the related thread ( http://forum.xda-developers.com/showthread.php?t=2840790 ) and leave a comment
Sent from my LG-D855

---

Dose this work for d8511??

---

jpeps3 said:
Dose this work for d8511??
Click to expand...
Click to collapse
If you're talking about the d851, yes, it's supported.
Sent from my LG-D855

---

Tectas said:
The op
Click to expand...
Click to collapse
can't we make a cm kernel like the lg g2 (kitkat bootloader)kernel, I mean just build a cm kernel on top af the stock one so that the security doesn't get triggered nevermind lg has caved in they are releasing an bootloader unlock soon
http://forum.xda-developers.com/showpost.php?p=54691624&postcount=1

---

suljo94 said:
can't we make a cm kernel like the lg g2 (kitkat bootloader)kernel, I mean just build a cm kernel on top af the stock one so that the security doesn't get triggered nevermind lg has caved in they are releasing an bootloader unlock soon
http://forum.xda-developers.com/showpost.php?p=54691624&postcount=1
Click to expand...
Click to collapse
Can't tell, I must confess, but can take a look at it. For now it is still possible to use custom kernels, when you boot it through fastboot, what for sure is far from being optimal, but at least something.
Hopefully lg won't wait too long till the unlock is released.
Sent from my LG-D855

---

Stock kernal for d851 please
---------- Post added at 11:50 PM ---------- Previous post was at 10:55 PM ----------
Can please. Add fast charger

---

This looks freaken awesome ?

---

I have a question....
If I have a D855P model (Telcel Mexico) and I actually have tested TWRP for D855, rom SphinX G3 Neo V2.0 for D855 both of them with success and my stock build.prop says
ro.build.id=KVT49L
ro.product.model=LG-D855
ro.product.brand=lge
ro.product.name=g3_global_com
ro.product.device=g3
ro.product.board=MSM8974
ro.product.cpu.abi=armeabi-v7a
ro.product.cpu.abi2=armeabi
ro.board.platform=msm8974
ro.build.description=g3_global_com-user 4.4.2 KVT49L 1401998873 release-keys
ro.build.fingerprint=lge/g3_global_com/g3:4.4.2/KVT49L/1401998873:user/release-keys
Click to expand...
Click to collapse
Does it mean that I can flash the custom D855 kernels when available??

---

badtzo said:
I have a question....
If I have a D855P model (Telcel Mexico) and I actually have tested TWRP for D855, rom SphinX G3 Neo V2.0 for D855 both of them with success and my stock build.prop says
Does it mean that I can flash the custom D855 kernels when available??
Click to expand...
Click to collapse
Yes, you can
Sent from my LG-D855

---

Hey Tectas how hard would it be to enable over clocking and underclocking on the d851 since it has an unlocked bootloader?

---

helikido said:
Hey Tectas how hard would it be to enable over clocking and underclocking on the d851 since it has an unlocked bootloader?
Click to expand...
Click to collapse
Not really that hard, but it got nothing to do with the bootloader, that's just a kernel thing, because of the unlocked bootloader you're just able to successfully flash and use a custom kernel permanently and not just temporarily over fastboot (if you try it at a locked bootloader it won't boot).
Sent from my LG-D855