[HOW TO] Compile and Deploy a Kernel

[doomboss]

Once you guys get good at kernel building, you might want to try your hand at toolchain building, this is very hard, consider building a kernel a warm up.

to get info about your kernel, including the toolchain used to build the kernel.

adb shell

cat /proc/version

My current kernel displays.

root@android:/ # cat /proc/version
Linux version 3.1.10 (vampirefo@vampirefo-GA-MA78GM-US2H) (gcc version 4.7.3 20130102 (prerelease) (crosstool-NG hg+default-20f2459b97bf) ) #1 SMP PREEMPT Sun Feb 3 13:00:51 EST 2013

This is way more advanced than my knowledge about kernel... But it seems like you are using the Linaro Toolchain right? That is what i know so far, and i don't even know anything about the toolchain building I still have a lot to learn

 

[vampirefo.]

This is way more advanced than my knowledge about kernel... But it seems like you are using the Linaro Toolchain right? That is what i know so far, and i don't even know anything about the toolchain building I still have a lot to learn

Yes I am using Linaro Toolchain, You are doing fine, no need to rush, it's more important to learn what you are doing, then just doing it.

 

[doomboss]

I kind of get how to use Linaro ToolChain to complie the kernel, and i am still messing about with the kernel right now But i have a question: in order to modify cpu frequency or governor, i need to open up the code file from the kernel that i complied right? So for example, i see a bunch of file (I believe it is c code?) on my kernel folder, and there is a file name cpu.c. Do i just need to modify the code if i want to change the frequency? Sorry if this is confusing, and please point me at the right direction if i am totally going to the wrong side B)

It would be awesome if the code is actually written in C or C++, so that I can practice my programming skills hehe

 

[FloRider]

I kind of get how to use Linaro ToolChain to complie the kernel, and i am still messing about with the kernel right now But i have a question: in order to modify cpu frequency or governor, i need to open up the code file from the kernel that i complied right? So for example, i see a bunch of file (I believe it is c code?) on my kernel folder, and there is a file name cpu.c. Do i just need to modify the code if i want to change the frequency? Sorry if this is confusing, and please point me at the right direction if i am totally going to the wrong side B)

It would be awesome if the code is actually written in C or C++, so that I can practice my programming skills hehe

You've got the source. It's written in C. Don't bother with trying to write overclocking into the kernel unless you want to try integrating someone else's code into the A2109 code. It's not simple. Governors are a different matter. Those you can cut & paste in. That'd be a good place to start.

Sent from my IdeaTabA2109A using Tapatalk HD

 

[doomboss]

You've got the source. It's written in C. Don't bother with trying to write overclocking into the kernel unless you want to try integrating someone else's code into the A2109 code. It's not simple. Governors are a different matter. Those you can cut & paste in. That'd be a good place to start.

Sent from my IdeaTabA2109A using Tapatalk HD

Alright, time to apply what i learn at school to the kernel i will try to add more Governors on the kernel first before integrate other overclock code into the A2109 I am re-installing my Ubuntu right now since the system randomly freeze sometime and it is really making me mad... I was reading the code and then suddenly i couldn't move my mouse and everything was frozen

 

[doomboss]

Oh one more question: If i want to copy the Governor code from Nexus 7 kernel, how do i view the code??

 

[FloRider]

Oh one more question: If i want to copy the Governor code from Nexus 7 kernel, how do i view the code??

Open it in your editor of choice. I like Eclipse for C/C++. Oh, you're going to have to download the git repo and checkout the branch you want. I think XDA U has some good info on using git.

Sent from my HTC DNA using Tapatalk 2.

 

[doomboss]

Open it in your editor of choice. I like Eclipse for C/C++. Oh, you're going to have to download the git repo and checkout the branch you want. I think XDA U has some good info on using git.

Sent from my HTC DNA using Tapatalk 2.

I guess i need the kernel source for Nexus 7. Let me try to figure out what is git repo Thanks for your patience

Wait, actually i am confused now, I was going to ask where can i find those code. I downloaded a custom kernel on the Nexus 7 forum on XDA, but I don't know where i should start to look for those code since it is a zip file. I opened it and just don't know where those file is. Can you tell me which file i should look at?

 

[FloRider]

I guess i need the kernel source for Nexus 7. Let me try to figure out what is git repo Thanks for your patience

Wait, actually i am confused now, I was going to ask where can i find those code. I downloaded a custom kernel on the Nexus 7 forum on XDA, but I don't know where i should start to look for those code since it is a zip file. I opened it and just don't know where those file is. Can you tell me which file i should look at?

There will be a link on the page to the source. They have to publish it as part of the GPL. See this page as an example: [KERNEL][GPL][N7][30 JAN] franco.Kernel - r42 - xda-developers

 

[FloRider]

What you want is the Nexus 7 kernel source and a custom kernel. Run a file diff to see what they changed and why. Here's the Nexus 7 stock kernel: https://android.googlesource.com/device/asus/grouper/.
PS Eclipse is a good editor for this purpose.

 

[doomboss]

What you want is the Nexus 7 kernel source and a custom kernel. Run a file diff to see what they changed and why. Here's the Nexus 7 stock kernel: https://android.googlesource.com/device/asus/grouper/.
PS Eclipse is a good editor for this purpose.

Ok thank you! I will try to mess around with the kernel again during weekend
Oh i realized sometimes i ask some question but it is just me didn't see the answer on your post. So just say it in advance that if i ask something that you already answered before, then please don't mind
I will try to use the Eclipse. Alright thanks again

 

[FloRider]

My pleasure. I'm glad someone is interested in kernel development.

 

[doomboss]

Just a quick question: Does anyone use kernel-tool for the kernel development or modify?

Also, i think i have a clue of where the CPU frequency is. It is on the drivers folder of the source right?

 

[vampirefo.]

Just a quick question: Does anyone use kernel-tool for the kernel development or modify?

Also, i think i have a clue of where the CPU frequency is. It is on the drivers folder of the source right?

Never heard of kernel-tool, so I am pretty sure I don't use it.

 

[doomboss]

Never heard of kernel-tool, so I am pretty sure I don't use it.

But how about Android Kernel Kitchen??