Compiling Xenomai

Get Xenomai 2.6.1 sources

cd /opt/raspberrypi
git clone git://git.xenomai.org/xenomai-2.6.git
cd xenomai-2.6
git checkout v2.6.1

Follow the instructions

here

How to get the ARM_ARCH value from the compiler

${CROSS_COMPILE}-gcc -dM -x c -E /dev/null | grep ARCH

One additional patch

The latest compiler defines a different ARM_ARCH -- account for it:

diff --git a/include/asm-arm/features.h b/include/asm-arm/features.h
index 279f752..ecb23bf 100644
--- a/include/asm-arm/features.h
+++ b/include/asm-arm/features.h
@@ -61,7 +61,7 @@
 #define __LINUX_ARM_ARCH__ 5
 #endif /* armv5 */
 
-#if defined(__ARM_ARCH_6__) || defined(__ARM_ARCH_6K__)
+#if defined(__ARM_ARCH_6__) || defined(__ARM_ARCH_6K__) || defined(__ARM_ARCH_6ZK__)
 #define __LINUX_ARM_ARCH__ 6
 #endif /* armv6 */