Raspberry Pi Kernel Compilation

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Revision as of 01:47, 10 August 2012 by Stevenf (Talk | contribs) (Macports)

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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.

Overview

First, you are going to get and build the linux kernel and its modules using a suitable compiler (a "cross-compiler" if you aren't building it on the same hardware you will be running it on) and then you are going to create a kernel image from the uncompressed kernel (Image) to place on the sd, along with the modules you build alongside it.

From the Raspberry pi

Firmware

cd /opt
git clone --depth 1 git://github.com/raspberrypi/firmware.git
cd firmware/boot
cp arm128_start.elf arm192_start.elf arm224_start.elf bootcode.bin loader.bin start.elf /boot/
cd /opt
rm -r firmware

Kernel compilation

Debian pre-build

apt-get update
apt-get -y dist-upgrade
apt-get -y install git gcc make tmux

Arch Linux pre-build

pacman -Syu
pacman -S git gcc make tmux

Common

cd /opt
mkdir raspberrypi
cd raspberrypi
git clone --depth 1 git://github.com/raspberrypi/linux.git
cd linux
zcat /proc/config.gz > .config
#optional#make menuconfig
tmux new -s make
nice make; nice make modules
[Ctrl]+[B],[D]
############## … 5 hours later ...
tmux a -t m
[Ctrl]+[D]
cp arch/arm/boot/Image /boot/kernel.img
make ARCH=arm modules_install INSTALL_MOD_PATH=/
cd /opt
rm -r raspberrypi
shutdown -r now;

From a foreign machine

Firmware

cd /opt
git clone git://github.com/raspberrypi/firmware.git
cd firmware/boot
scp arm128_start.elf arm192_start.elf arm224_start.elf bootcode.bin loader.bin start.elf <user>@<host>:/boot/

After the first time:

cd /opt/firmware
git pull
cd boot
scp arm128_start.elf arm192_start.elf arm224_start.elf bootcode.bin loader.bin start.elf <user>@<host>:/boot/

Kernel compilation

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.

Ubunt

apt-get install git gcc-arm-linux-gnueabi make ncurses-dev
cd /opt
mkdir raspberrypi
cd raspberrypi 
git clone git://github.com/raspberrypi/linux.git
cd linux
cp arch/arm/configs/bcmrpi_cutdown_defconfig .config
make ARCH=arm CROSS_COMPILE=/usr/bin/arm-linux-gnueabi- oldconfig
#optional#make ARCH=arm CROSS_COMPILE=/usr/bin/arm-linux-gnueabi- menuconfig
make ARCH=arm CROSS_COMPILE=/usr/bin/arm-linux-gnueabi- -k

Gentoo Linux

crossdev -S -v -t arm-unknown-linux-gnueabi
mkdir raspberrypi
cd raspberrypi 
git clone git://github.com/raspberrypi/linux.git
cd linux
cp arch/arm/configs/bcmrpi_cutdown_defconfig .config
make ARCH=arm CROSS_COMPILE=/usr/bin/arm-linux-gnueabi- oldconfig
#optional#make ARCH=arm CROSS_COMPILE=/usr/bin/arm-linux-gnueabi- menuconfig
make ARCH=arm CROSS_COMPILE=/usr/bin/arm-linux-gnueabi- -k

crossdev should create a cross-toolchain using the latest stable versions of the required packages. If it fails, you can specify exact versions by removing the "-S" flag and adding the "--b", "--g", "--k" and "--l" flags.

On 2012-05-06, cross -S -v -A gnueabi arm works just fine

Arch Linux

pacman -S git
yaourt -S arm-linux-gnueabi-gcc
cd /opt
mkdir raspberrypi
cd raspberrypi 
git clone git://github.com/raspberrypi/linux.git
cd linux
cp arch/arm/configs/bcmrpi_cutdown_defconfig .config
make ARCH=arm CROSS_COMPILE=/usr/bin/arm-linux-gnueabi- oldconfig
#optional#make ARCH=arm CROSS_COMPILE=/usr/bin/arm-linux-gnueabi- menuconfig
make ARCH=arm CROSS_COMPILE=/usr/bin/arm-linux-gnueabi- -k

OS X

The Kernel source requires a case-sensitive filesystem. If you do not have a HFS+ Case-sensitive partition that can be used, create a disk image with the appropriate format. Ensure latest Xcode and command line tools are installed from Apple Developer Connection

Macports

Install macports

port install arm-none-eabi-gcc
port install arm-none-eabi-binutils
cd /opt
mkdir raspberrypi
cd raspberrypi 
git clone git://github.com/raspberrypi/linux.git
cd linux
cp arch/arm/configs/bcmrpi_cutdown_defconfig .config
make ARCH=arm CROSS_COMPILE=/opt/local/bin/arm-none-eabi- oldconfig
make ARCH=arm CROSS_COMPILE=/opt/local/bin/arm-none-eabi- -k

If you get an error message that elf.h is missing

sudo port install libelf && sudo ln -s /opt/local/include/libelf /usr/include/libelf

From opensource.apple.com, download and copy elf.h and elftypes.h to /usr/include

Edit elf.h and add

#define R_386_NONE        0
#define R_386_32          1
#define R_386_PC32        2
#define R_ARM_NONE        0
#define R_ARM_PC24        1
#define R_ARM_ABS32       2
#define R_MIPS_NONE       0
#define R_MIPS_16         1
#define R_MIPS_32         2
#define R_MIPS_REL32      3
#define R_MIPS_26         4
#define R_MIPS_HI16       5
#define R_MIPS_LO16       6

If you get a "SEGMENT_SIZE is undeclared" error open the Makefile and change the line:

NOSTDINC_FLAGS += -nostdinc -isystem $(shell $(CC) -print-file-name=include)

to

NOSTDINC_FLAGS += -nostdinc -isystem $(shell $(CC) -print-file-name=include) -Dlinux

Yagarto

Downoad and install an GNU ARM toolchain such as yagarto.

cd /opt
mkdir raspberrypi
cd raspberrypi 
git clone git://github.com/raspberrypi/linux.git
cd linux
cp arch/arm/configs/bcmrpi_cutdown_defconfig .config
make ARCH=arm CROSS_COMPILE=/path/to/yagarto/bin/arm-none-eabi- oldconfig
make ARCH=arm CROSS_COMPILE=/path/to/yagarto/bin/arm-none-eabi- -k

Transferring The Build

Then you have to transfer this img file to the /boot directory and install the compiled modules. Unfortunately the compiled modules are not in a single place, there are two options of installing them.

Boot your RaspberryPi and mount the linux directory over the network using sshfs:

cd /mnt
mkdir linux
sshfs <user>@<host>:<path/to/linux> linux
cd linux
make install
make modules_install

If you got "Permission denied" when doing cd linux, try:

sudo sh -c "cd linux ; make modules_install"

If that is not an option, you can also install the modules into a temporary folder:

mkdir /tmp/modules
make ARCH=arm modules_install INSTALL_MOD_PATH=/tmp/modules

Now you have to copy the contents of that directory to /lib/modules on the SD card.

scp linux/arch/arm/boot/Image <user>@<host>:/boot/kernel.img
scp -r /tmp/modules/* <user>@<host>://lib/modules/

Once you've done those two steps, you are ready to put the SD card in and try booting your new system!

References