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root@raspberrypi:/opt/raspberrypi/xenomai-2.6.1/examples/native# make
gcc -I/usr/xenomai/include -D_GNU_SOURCE -D_REENTRANT -D__XENO__ -lnative -L/usr/xenomai/lib -lxenomai -lpthread -lrt -Xlinker -rpath -Xlinker /usr/xenomai/lib trivial-periodic.c -o trivial-periodic
gcc -I/usr/xenomai/include -D_GNU_SOURCE -D_REENTRANT -D__XENO__ -lnative -L/usr/xenomai/lib -lxenomai -lpthread -lrt -Xlinker -rpath -Xlinker /usr/xenomai/lib sigdebug.c -o sigdebug
gcc -I/usr/xenomai/include -D_GNU_SOURCE -D_REENTRANT -D__XENO__ rtprint.c -lnative -L/usr/xenomai/lib -lxenomai -lpthread -lrt -Xlinker -rpath -Xlinker /usr/xenomai/lib -o rtprint... read more

After you prepared the kernel for xenomai you can install the user space tools

• Run the configure script of xenomai
  ./configure --
• Build xenomai tools
  make
• Install the build tools
  make install
• Run the latency test script of xenomai
  
root@raspberrypi:/opt/raspberrypi/xenomai-2.6.1# /usr/xenomai/bin/latency -T 25
== Sampling period: 1000 us
== Test mode: periodic user-mode task
== All results in microseconds
warming up...
RTT| 00:00:01 (periodic user-mode task, 1000 us period, priority 99)
RTH|----lat min|----lat avg|----lat max|-overrun|---msw|---lat best|--lat worst
RTD| -4.000| -1.000| 26.000| 0| 0| -4.000| 26.000
RTD| -4.000| 0.000| 27.000| 0| 0| -4.000| 27.000
RTD| -4.000| 0.000| 25.000| 0| 0| -4.000| 27.000
RTD| -4.000| -1.000| 27.000| 0| 0| -4.000| 27.000
RTD| -4.000| -1.000| 28.000| 0| 0| -4.000| 28.000
RTD| -4.000| -1.000| 24.000| 0| 0| -4.000| 28.000
RTD| -4.000| 0.000| 27.000| 0| 0| -4.000| 28.000
RTD| -5.000| -1.000| 29.000| 0| 0| -5.000| 29.000
RTD| -4.000| -1.000| 26.000| 0| 0| -5.000| 29.000
RTD| -6.000| -1.000| 30.000| 0| 0| -6.000| 30.000
RTD| -4.000| 0.000| 29.000| 0| 0| -6.000| 30.000
RTD| -4.000| 0.000| 28.000| 0| 0| -6.000| 30.000
RTD| -4.000| 0.000| 30.000| 0| 0| -6.000| 30.000
RTD| -4.000| -1.000| 25.000| 0| 0| -6.000| 30.000
RTD| -4.000| -1.000| 25.000| 0| 0| -6.000| 30.000
RTD| -4.000| -1.000| 28.000| 0| 0| -6.000| 30.000
RTD| -4.000| 0.000| 27.000| 0| 0| -6.000| 30.000
RTD| -4.000| -1.000| 22.000| 0| 0| -6.000| 30.000
RTD| -4.000| -1.000| 27.000| 0| 0| -6.000| 30.000
RTD| -4.000| 0.000| 29.000| 0| 0| -6.000| 30.000
RTD| -4.000| -1.000| 26.000| 0| 0| -6.000| 30.000
RTT| 00:00:22 (periodic user-mode task, 1000 us period, priority 99)
RTH|----lat min|----lat avg|----lat max|-overrun|---msw|---lat best|--lat worst
RTD| -5.000| -1.000| 32.000| 0| 0| -6.000| 32.000
RTD| -4.000| -1.000| 33.000| 0| 0| -6.000| 33.000
RTD| -5.000| 0.000| 27.000| 0| 0| -6.000| 33.000
---|-----------|-----------|-----------|--------|------|-------------------------
RTS| -6.000| 0.000| 33.000| 0| 0| 00:00:25/00:00:25
... read more

1. Log in into your Raspberry PI.
2. Install module-init-tools:
   apt-get install module-init-tools
3. Download the Raspberry PI Linux Kernel 3.2.21 via git
   git clone --branche=rpi-3.2.21 --depth 1 git://github.com/bootc/linux.git
4. Download xenomai 2.6.1
   wget http://download.gna.org/xenomai/stable/xenomai-2.6.1.tar.bz2
5. Download and apply the raspberry PI Xenomai Patch
   http://www.cim.mcgill.ca/~ian/rpi-linux-3.2.21-xenomai-2.6.1.patch
6. Copy your current Linux Configuration into your Linux-Kernel-Source-Tree
   zcat /proc/config.gz > /path/to/kerneltree/.config
7. Comment out some stuff in your Kernel.config, which are good for reducing the latency
   # CONFIG_NO_HZ
   # CONFIG_CC_STACKPROTECTOR
   # XENO_OPT_STATS
   Select via make menuconfig:
   Go to: "Kernel Features -> Preemption Model" and set "Preemptible Kernel (Low-Latency Desktop)"
8. Patch the kernel with the rpi-linux-3.2.21-xenomai-2.6.1.patch
   patch -p1 ...
9. Apply the xenomai 2.6.1 Patch
   $xenomai_root/scripts/prepare-kernel.sh --arch=arm \
   --adeos=$xenomai_root/ksrc/arch/arm/patches/ipipe-core-3.2.21-arm-1.patch \
   --linux=$linux_tree
10. Compile the kernel and the kernel modules (higher priorities with nice could make the compiler process faster)
    nice -n -10 make && nice -n -10 make modules
11. Make a copy of your old kernel, if the system will not boot you can maybe replace it if you replace the file on the SD Card:
    cp /boot/kernel.img /boot/kernel.old
12. Copy the Kernel Image into /boot
    cp arch/arm/boot/Image /boot/kernel.img
13. Install the kernel modules
    make ARCH=arm modules_install INSTALL_MOD_PATH=/
14. Add a group "udevd" for xenomai
    groupadd xenomai
15. Reboot and hope that it works... read more