Raspberry Pi Kernel Compilation

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Software & Distributions:

Software - an overview.

Distributions - operating systems and development environments for the Raspberry Pi.

Kernel Compilation - advice on compiling a kernel.

Performance - measures of the Raspberry Pi's performance.

Programming - programming languages that might be used on the Raspberry Pi.


Raspberry PI kernel compilation

You can compile the kernel on the board itself, but because of the limited resources it will take a lot of time. Alternatively you can crosscompile the kernel on another machine running Linux, Windows or OS X.

Compiling on the Raspberry pi itself

TODO: write the rest of this section.

Cross compiling on a foreign machine

Ubuntu Linux

getting the compiler

On Ubuntu Oneiric getting the arm cross compiler can be as easy as:

sudo apt-get install gcc-4.6-arm-linux-gnueabi
sudo apt-get install git   #jhauser14905 -- might as well state the obvious, you need git installed!

(TODO: Is this the right one? More packages required? I did this a while ago! TODO: Other distributions?)

getting the sources

create a directory where you can work on the raspberry pi software. I called mine "raspberrypi". Then clone the git repository.

mkdir raspberrypi
cd raspberrypi 
git clone https://github.com/raspberrypi/linux.git
cd linux

jhauser14905: on 2012-01-28, with all package updates applied, i had to add the following symlink in order to get the make commands to work. otherwise they would error out

sudo ln -s  /usr/bin/arm-linux-gnueabi-gcc-4.6 /usr/bin/arm-linux-gnueabi-gcc

compiling

Next you have to configure the kernel:

cp arch/arm/configs/bcmrpi_cutdown_defconfig .config
make ARCH=arm CROSS_COMPILE=/usr/bin/arm-linux-gnueabi- oldconfig

Then building the kernel:

make ARCH=arm CROSS_COMPILE=/usr/bin/arm-linux-gnueabi- -k

You can use the "-j" flag to improve compilation time. If you have a dual core machine you can use "-j 3", for a quad core machine you can use "-j 6", and so on.

If you get the error messages that arm-linux-gnueabi-gcc cannot be found when running make, run the following command:

sudo ln -s /usr/bin/arm-linux-gnueabi-gcc-4.6 /usr/bin/arm-linux-gnueabi-gcc

this creates a symbolic link to the 4.6 gcc binary

Gentoo Linux

getting the compiler

Build the cross toolchain:

crossdev -v -t arm-unknown-linux-gnueabi

This command will most certainly fail on your machine. What you have to do to make it work, is to adjust the cross tools versions with the "--b", "--g", "--k" and "--l" flags. For the exact usage refer to the crossdev manpage. A good starting point for figuring out the right versions are those which are stable for the arm architecture.

getting the sources

create a directory where you can work on the raspberry pi software. I called mine "raspberrypi". Then clone the git repository.

mkdir raspberrypi
cd raspberrypi 
git clone https://github.com/raspberrypi/linux.git
cd linux

compiling

Next you have to configure the kernel:

cp arch/arm/configs/bcmrpi_cutdown_defconfig .config
make ARCH=arm CROSS_COMPILE=/usr/bin/arm-linux-gnueabi- oldconfig

Then building the kernel:

make ARCH=arm CROSS_COMPILE=/usr/bin/arm-linux-gnueabi- -k

You can use the "-j" flag to improve compilation time. If you have a dual core machine you can use "-j 3", for a quad core machine you can use "-j 6", and so on.

Windows

TODO

OS X

TODO