Database Develop

Kernel Confusion

Hi,
http://wiki.cyanogenmod.com/wiki/Sa...te_Guide#Installing_the_ClockworkMod_Recovery mentions a "hardcore's kernel". What kind of kernel is that? Is it the actual system kernel used by the ROM one is installing afterwards or is it just some sort of boot kernel for the recovery application?
It also mentions hardcore's even though the kernel logo during booting refers to Semaphore.

No one?

neroux said:
Hi,
http://wiki.cyanogenmod.com/wiki/Sa...te_Guide#Installing_the_ClockworkMod_Recovery mentions a "hardcore's kernel". What kind of kernel is that? Is it the actual system kernel used by the ROM one is installing afterwards or is it just some sort of boot kernel for the recovery application?
It also mentions hardcore's even though the kernel logo during booting refers to Semaphore.
Click to expand...
Click to collapse
It is not the Stock kernel, it is a customized kernel which can be used for the custom ROM installation via ClockworkMod_Recovery.
thanks.

Thanks forupeople but that was not exactly the question. I would like to know whether the mentioned kernel is the actual kernel on which a ROM then is running on or whether all ROMs come with their own kernel and this is something else.

Really no one?

neroux said:
Hi,
http://wiki.cyanogenmod.com/wiki/Sa...te_Guide#Installing_the_ClockworkMod_Recovery mentions a "hardcore's kernel". What kind of kernel is that? Is it the actual system kernel used by the ROM one is installing afterwards or is it just some sort of boot kernel for the recovery application?
It also mentions hardcore's even though the kernel logo during booting refers to Semaphore.
Click to expand...
Click to collapse
All ROM's have kernels included in their package, without it your phone wont be able to boot..In this case Hardcore ( its actually a speedmod kernel, maybe tweaked by Hardcore) is being used to give you CWM recovery on Stock ROM's which do not have CWM recovery but only 2e recovery., after you flash CM, its removed and the new kernel from your update, is used
Instead of Odin, CWM recovery is used for ICS and JB installation

xsenman said:
All ROM's have kernels included in their package, without it your phone wont be able to boot..In this case Hardcore ( its actually a speedmod kernel, maybe tweaked by Hardcore) is being used to give you CWM recovery on Stock ROM's which do not have CWM recovery but only 2e recovery., after you flash CM, its removed and the new kernel from your update, is used
Instead of Odin, CWM recovery is used for ICS and JB installation
Click to expand...
Click to collapse
Thanks. I have to admit I am not really very familiar with the boot process, however I was under the assumption that CWM is just a replacement for the stock's basic boot/recover loader and both do not need an actual Android kernel as they both come before it in the boot order.

neroux said:
Thanks. I have to admit I am not really very familiar with the boot process, however I was under the assumption that CWM is just a replacement for the stock's basic boot/recover loader and both do not need an actual Android kernel as they both come before it in the boot order.
Click to expand...
Click to collapse
To make it simple.
Boot loaders are generally locked, hence needs to be rooted (unlocked), in oder to add CWM to it.
Custom kernels or kernels that are customized, do this function of rooting (unlocking the boot loader) as well as adding the CWM (customized recovery features) to the boot loader.
Only customized kernels will work with custom ROMS.
Hence when you flash a custom kernel on top of a stock ROM/with stock kernel, it is replaced and gives the added features (that stock kernel lacks) that is needed for flashing Custom ROMS
The reason being Gingerbread stock kernels will not work for ICS ROMs..hence must be replaced and this is vital for phones operations, since one main function of kernel is to control the hardware.

Why should we flash the boot file when flashing a custom rom?

I have been using Samsung for a long time and so this process seems weird. All we use to do there was just put the custom ROM and GAAPS and flash it via recovery and wipe phone. But when i was going through a lot of forums here..i see that the OP has asked people to flash the boot file using command prompt and then flash the ROM. Is this process really required even if we have the dual recovery installed?

If the updater script in the .zip does not have the correct commands to install the boot.img itself it has to be manually flashed.
Untill recently this was always the case, it was not possible to flash a kernel using recovery, it had to be done via fastboot.
I think this is probably a hangover from then, but now it can be done in recovery.
Also, if you have just unlocked, but do not have recovery installed the quickest way to get recovery is to flash the boot.img using fastboot, then flash the update.zip.
If you already have recovery, just flash the update.zip and the boot.img will be flashed.
This is only for roms int he original development section, as they require a custom kernel, roms in the development section will work on the stock kernel, so there is no need to flash a boot.img at all

Actually you need to flash different kernels for different roms... Like Stock-based(Sony) Roms can be either run on Stock Kernel(Sony) or Stock-Based Custom Kernel(like DooMKerneL). while AOSP Roms(like CM11) should be run on AOSP-based Custom Kernels(like Pimped Kernel).
You can flash custom Kernels only if you have unlocked your bootloader. if you have recovery on locked bootloader, then you can flash only Stock-based roms because they dont need a different kernel becoz they run on Sony Kernel itself. If you have a unlocked bootloader you can flash custom kernel, Then you can use both Stock-based Roms or AOSP-based Roms by flashing respective kernels.
If you already have Custom rom installed and changing to another Custom rom, Then if you are changing from (Stock-Based Rom to another Stock-Based Rom) or (AOSP-based Rom to another AOSP-based Rom) then you need not flash the kernel again, you can just wipe all partitions and install the new Custom rom over it. But if you are Cross flashing from (Stock-Based Rom to AOSP-Based Rom) or (AOSP-based Rom to Stock-based Rom), Then you should flash respective kernel, wipe partitions and install the rom over it.
if you dont know, whether the rom is Stock-based or AOSP-based, it will be mentioned in the OP of each Thread.Usually Roms that are available for a wide range of devices across OEMs are AOSP. Roms like CM, AOKP, PAC, Carbon, etc. are all AOSP roms.
Hope it helped.

[Q] Can I flash the stock kernel on a CM ROM?

Can I flash the stock kernel on a CM ROM? Notably the latest stock kernel on CM11+.

The answer appears to be no unless maybe its patched. I restored a stock kernel over a CM11 TWRP restore and the screen just turned off after the boot logo.

Question about kernels

If I flashed a rom that has a different kernel and then went back to a rom that has a stock kernel do I not have a stock kernel anymore?
I went from Poprocks to texodus then back to poprocks.

If the new rom you flashed included the stock kernel, then that's the kernel you have now. Kernels don't survive a rom flash, they get overwritten by whatever kernel is included in the rom.

Thanks

base kernel??

I flashed **** kernel and now I have issues with aosp roms. Is there a way to go back to base? Its very annoying not being able to use PE

Kernel is actually in boot.img so whichever rom you were using just flash it's boot.img back and it will work