[Q] kernel developing/tweaking - Thunderbolt Q&A, Help & Troubleshooting

Just wondering what pre-requisites were required. Are all of you Kernel devs actual programmers. What languages and any other skills would be required to understand what is going on.
Adrynalyne's guide is awesome and I was actually able to produce something usable , by following the directions, but understanding for example the Make command line we had to use, ARCH=arm, etc ????? have no idea what that line actually means, but would like to.
I have multiple certs, network+, active directory etc, and learned it all on my own so im not worried about understanding, just looking to be pointed in the right direction so as not to waste time learning languages or whatever that would not be relative.
Thanks again for any info.

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Make calls the makefile and follows instructions contained within.
J # tells gcc compiler how many threads to use. 1 thread per core. Rule is # of cores +1. This can increase compile speed tremendously.
ARCH specifies the CPU architecture.
Examples are ARM, x86, and x86-64.
The rest tells gcc to compile using the toolchain which allows gcc to compile for the specified architecture.
Sent from my ADR6400L using XDA App

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adrynalyne said:
Make calls the makefile and follows instructions contained within.
J # tells gcc compiler how many threads to use. 1 thread per core. Rule is # of cores +1. This can increase compile speed tremendously.
ARCH specifies the CPU architecture.
Examples are ARM, x86, and x86-64.
The rest tells gcc to compile using the toolchain which allows gcc to compile for the specified architecture.
Sent from my ADR6400L using XDA App
Click to expand...
Click to collapse
As always, thank you!

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Anyone else have any words of advice on the topic question.
Thanks again.

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you dont necessarily need to be a super coder. for example here is a common thing all the n1 kernel devs do to boost the audio in the nexus one in the arch/arm.audio.c file and board-mahimahi.audio.c file.
STOCK
PHP:
[Q6_HW_HANDSET] = {
.min_gain = -2000,
.max_gain = 0,
},
[Q6_HW_HEADSET] = {
.min_gain = -2000,
.max_gain = 0,
},
[Q6_HW_SPEAKER] = {
.min_gain = -1500,
.max_gain = 0,
},
[Q6_HW_TTY] = {
.min_gain = -2000,
.max_gain = 0,
},
[Q6_HW_BT_SCO] = {
.min_gain = -2000,
.max_gain = 0,
},
[Q6_HW_BT_A2DP] = {
.min_gain = -2000,
.max_gain = 0,
},
and the new values to "boost" volume
PHP:
[Q6_HW_HANDSET] = {
.min_gain = -1500,
.max_gain = 1100,
},
[Q6_HW_HEADSET] = {
.min_gain = -1500,
.max_gain = 1100,
},
[Q6_HW_SPEAKER] = {
.min_gain = -2000,
.max_gain = 800,
},
[Q6_HW_TTY] = {
.min_gain = -1500,
.max_gain = 1100,
},
[Q6_HW_BT_SCO] = {
.min_gain = -2000,
.max_gain = 800,
},
[Q6_HW_BT_A2DP] = {
.min_gain = -2000,
.max_gain = 800,
},
that's standard for any kernel released for that device, and its pretty easy to do. i've pulled the source and compiled my own kernel many times, but i am not a good coder at all, just a few classes in college. i managed to make changes to the battery driver and get it incorporated into the cyan repo, so i definitely think you should look into it. there is nothing more rewarding then contributing back to the community.
also take a look at the cyanogen kernel, and follow the daily commits and see the type of changes made. some will be bug fixes, but you can go way back in time and see major edits as well.
go here to the kernel:
https://github.com/CyanogenMod/cm-kernel
then click COMMITS on the top. then each commit, click on the description text and it will show you the old vs new code. it will show you what the original code was, and what that commit replaced that code with. its very insightful for something like this.
it also is a good way to see what is happening with your favorite ROMs, you just have to find the repo for the ROM of your choice. cheers.

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RogerPodacter said:
you dont necessarily need to be a super coder. for example here is a common thing all the n1 kernel devs do to boost the audio in the nexus one in the arch/arm.audio.c file and board-mahimahi.audio.c file.
STOCK
PHP:
[Q6_HW_HANDSET] = {
.min_gain = -2000,
.max_gain = 0,
},
[Q6_HW_HEADSET] = {
.min_gain = -2000,
.max_gain = 0,
},
[Q6_HW_SPEAKER] = {
.min_gain = -1500,
.max_gain = 0,
},
[Q6_HW_TTY] = {
.min_gain = -2000,
.max_gain = 0,
},
[Q6_HW_BT_SCO] = {
.min_gain = -2000,
.max_gain = 0,
},
[Q6_HW_BT_A2DP] = {
.min_gain = -2000,
.max_gain = 0,
},
and the new values to "boost" volume
PHP:
[Q6_HW_HANDSET] = {
.min_gain = -1500,
.max_gain = 1100,
},
[Q6_HW_HEADSET] = {
.min_gain = -1500,
.max_gain = 1100,
},
[Q6_HW_SPEAKER] = {
.min_gain = -2000,
.max_gain = 800,
},
[Q6_HW_TTY] = {
.min_gain = -1500,
.max_gain = 1100,
},
[Q6_HW_BT_SCO] = {
.min_gain = -2000,
.max_gain = 800,
},
[Q6_HW_BT_A2DP] = {
.min_gain = -2000,
.max_gain = 800,
},
that's standard for any kernel released for that device, and its pretty easy to do. i've pulled the source and compiled my own kernel many times, but i am not a good coder at all, just a few classes in college. i managed to make changes to the battery driver and get it incorporated into the cyan repo, so i definitely think you should look into it. there is nothing more rewarding then contributing back to the community.
also take a look at the cyanogen kernel, and follow the daily commits and see the type of changes made. some will be bug fixes, but you can go way back in time and see major edits as well.
go here to the kernel:
https://github.com/CyanogenMod/cm-kernel
then click COMMITS on the top. then each commit, click on the description text and it will show you the old vs new code. it will show you what the original code was, and what that commit replaced that code with. its very insightful for something like this.
it also is a good way to see what is happening with your favorite ROMs, you just have to find the repo for the ROM of your choice. cheers.
Click to expand...
Click to collapse
Very helpful and a great place to start, much appreciated, its funny posted this example in particular as i have been looking around on how to change the max possible volume of my phone, again thanks.
Its funny looking around the directories of the kernel source theres a sound subdirectory, which I have been looking for the above tweaks, but its not where I expected to find it.
Seems alot of stuff is in the Arch, Arm directories, what is the signifigance?

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also cant find those particular battery tweaks in the mecha kernel. any idea where that code is in the mecha kernel.

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happimeal said:
also cant find those particular battery tweaks in the mecha kernel. any idea where that code is in the mecha kernel.
Click to expand...
Click to collapse
here is the enhanced battery driver i did:
https://github.com/CyanogenMod/cm-k...a76d7a3bb91ec3#drivers/power/ds2784_battery.c
it looks a little overwhelming. but it literally took my months of research, compiling my own test kernel, before i finally got those couple hunder lines added and working. prior to that i had no experience except c++ class from college, and used google to learn and learn some more.
the driver is in drivers/power/ds2784_battery.c and the additions start at line 401 if you want to see the whole thing:
https://github.com/CyanogenMod/cm-k...a76d7a3bb91ec3/drivers/power/ds2784_battery.c
it was a great feeling once it was all done. check my sig for the link to the app we made too, which actually interacts with the enhanced driver and changes battery register addresses etc.
here's my repo for just the app (java code is what android apps are written in. the kernel is linux/c++). go into the SRC folder is where all the main stuff is.
http://github.com/R0gerP0dacter/BatteryCalibrator
Edit: actually I originally made a detailed commented driver version for someone who wasn't familiar with the project to follow the work. This would be helpful for you.
http://github.com/R0gerP0dacter/n1batcal/blob/master/ds2784_battery.c

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Thank you very much for all this info.
Anybody have any idea where the sound/volume data is.

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the audio will likely be in that same arch/arm folder. i'd go to the HTC developer site and download the kernel source code, since it has been released already. look thru and you should be able to find it.