Hello everybody,
I have the Stock kernel for my device and I downlaoded the Cm-Kernel. Is there a way to create a patch containing all the Kerneltweaks from Cm-Kernel for the Stockkernel. I know how to handle diff, but I don't know which files are changed and which I should leave like they are. Or if its easier to patch the device specific configurations to the CM-Kernel?
These are the folders both Kernels contain:
Code:
arch crypto include kernel net security
block Documentation init lib README sound
drivers ipc MAINTAINERS REPORTING-BUGS tools
COPYING firmware Kbuild Makefile samples usr
CREDITS fs Kconfig mm scripts virt
chaoskoch said:
Hello everybody,
I have the Stock kernel for my device and I downlaoded the Cm-Kernel. Is there a way to create a patch containing all the Kerneltweaks from Cm-Kernel for the Stockkernel. I know how to handle diff, but I don't know which files are changed and which I should leave like they are. Or if its easier to patch the device specific configurations to the CM-Kernel?
These are the folders both Kernels contain:
Code:
arch crypto include kernel net security
block Documentation init lib README sound
drivers ipc MAINTAINERS REPORTING-BUGS tools
COPYING firmware Kbuild Makefile samples usr
CREDITS fs Kconfig mm scripts virt
Click to expand...
Click to collapse
If you are going to be using all the cm kernel tweaks anyway, why not just use the cm-kernel? Maybe there is something I am missing.
lithid-cm said:
If you are going to be using all the cm kernel tweaks anyway, why not just use the cm-kernel? Maybe there is something I am missing.
Click to expand...
Click to collapse
But in the Kernel are some device specific information and drivers,
is there a way to get them all in the CM-Kernel?
Or aren't there any and I just need the .config-file?
In this post, I would like to explain what kexec-hardboot patch is and also bring it to light a bit more since until now, it was only burried in MultiROM thread.
@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 7. 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/6687647, 4.3 AOSP kernel repo, cm 10.2 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_ATAGS_PROC=y
All these options must be enabled.
Userspace kexec binary: View attachment kexec-tools.zip
That ZIP file contains kexec source, patches and README. It is from the original patch from Mike Kasick. It also contains precompiled, statically linked kexec binary, so you probably just want to use that.
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=0x85000000 --command-line="$(cat /proc/cmdline)"
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 flo, I've improved the patch a bit - only the host needs to be patched now and I also fixed a bug with /proc/atags not reading all tags.
The patch was updated with commit https://github.com/Tasssadar/androi...mmit/20f59235cf61694f8118b943e33aa382fc9ad494 in repositories and on gist.
The reason is that my initial ramdisk address was not compatible with all kernels, and changing it resulted in a problem to appear on CM kernel - it just crashes on kexec-hardboot call. AOSP kernel worked just fine after the change, but I applied the patch just to be sure. Sorry about this, I didn't expect the patch to change at all, but it happened :/ I really hope this is the last time.
@ayysir originaly made this change, thanks.
@Tasssadar I would like to port your kexec-hardboot patch on my device which has a Qualcomm MSM7225A chipset with a locked bootloader. How do I locate the memory addresses in adb shell to boot the kernel? Thanks. I'm currently using Fedora 64-bit on my computer.
Please Please help been smashing brains out on google trying to find this
Am trying to build various ROMs without selinux support, i noticed a while back in 4.1 there was a selinux build flag in one of the thousands .mk files in the android source tree, which seemed to be a global switch to enable selinux (modules i assume ).
With 4.3 and 4.4 selinux seems more integrated, is the SElinux env var still there ?,if not can i just build a NO SElinux kernel and remove the selinux components from the manifests ?
SElinux has considerable userland components, do i need to clean up the init to remove refs as well as remove the binaries ?
Any info and help would be greatly appreciated thanks
I've been building custom cm builds for about a year. With the transition to lollipop, with selinux being much more restrictive in enforcing mode, my init.d script no longer works. I need the script to be able to write to sysfs nodes. Can anyone help me out with writing a policy to allow init.d scripts write access to sysfs? I'm fairly knowledgeable, but I'm in the weeds with selinux.
Hi,
is there any Stockkernel for CM 12.1 Nightly available which is compiled as SELinux permissive or disabled, IsoRec enabled would be useful.
Disabling SELinux via the App "SELinuxModeChanger" requires a software reboot to enable some Xposed Modules to work, which is a long procedure (considering daily random reboots) and could be left out this way.
Nice to know: Will disabling SELinux enable init.d support? Looking forward to the Netflix fix.
Greetings,
F4R3