Xenomai

Xenomai is a free software project focused on building a real-time framework for the Linux platform.

External Documentation

• Xenomai Web Site

• Official Instructions for Building Xenomai Debian Packages

Installation Notes

Ubuntu 18.04

Download xenomai-3.1.tar.bz2 from:

https://xenomai.org/downloads/xenomai/stable/

and extract the archive:

mkdir ~/xeno-builds/4.19.94-cip18-xenomai-3.1
cd  ~/xeno-builds/4.19.94-cip18-xenomai-3.1
tar -xvf xenomai-3.1.tar.bz2

Alternatively, check out the desired Xenomai version from git:

mkdir ~/xeno-builds/4.19.94-cip18-xenomai-3.1
cd  ~/xeno-builds/4.19.94-cip18-xenomai-3.1
GIT_SSL_NO_VERIFY=1 git clone git://git.xenomai.org/xenomai-3.git
cd xenomai-3
git checkout stable/v3.0.x

Install the required packages for building the userspace library (once):

sudo apt-get install devscripts debhelper dh-kpatches findutils

Build and install the Xenomai userspace library packages:

cd ~/xeno-builds/4.19.94-cip18-xenomai-3.1/xenomai-3.1
DEBEMAIL="your@email" DEBFULLNAME="Your Name" debchange -v 3.1 Release 3.1
debuild -uc -us
cd ..
sudo dpkg -i libxenomai-dev_3.1_amd64.deb  \
             libxenomai1_3.1_amd64.deb  \
             xenomai-kernel-source_3.1_all.deb  \
             xenomai-runtime_3.1_amd64.deb

Install the required packages for building the kernel (once):

sudo apt-get install kernel-package libncurses-dev fakeroot zlib1g-dev bison flex libssl-dev

Download the CIP long-term support kernel from:

https://git.kernel.org/pub/scm/linux/kernel/git/cip/linux-cip.git/tag/?h=v4.19.94-cip18

and extract the archive:

tar -xvf linux-cip-4.19.94-cip18.tar.gz

Alternatively, download the linux kernel source from the mainline tree:

https://mirrors.edge.kernel.org/pub/linux/kernel/v4.x/linux-4.9.38.tar.xz

and extract the archive:

tar -xvf linux-4.19.84.tar.xz

Download a matching ipipe patch from here:

https://xenomai.org/downloads/ipipe/v4.x/x86/ (e.g. ipipe-core-4.19.94-cip18-x86-10.patch)

Apply the ipipe patch and set up the Xenomai cobalt kernel support:

cd linux-cip-4.19.94-cip18
/usr/src/xenomai-kernel-source/scripts/prepare-kernel.sh \
  --arch=x86 --linux=. --adeos=../ipipe-core-4.19.94-cip18-x86-10.patch \
  --outpatch=../xenomai-kernel.patch
patch -p1 < ../xenomai-kernel.patch
cd ..

Start with the kernel configuration from the standard Ubuntu kernel:

cd linux-cip-4.19.94-cip18
cp /boot/config-4.15.0-70-generic .config
make olddefconfig
make menuconfig

Note that if you import the config from a previously built xenomai/ipipe-patched kernel instead of the “standard” Ubuntu kernel config mentioned above, the configuration options below should already be selected.

Adjust the following kernel configuration options:

4.4.199-cip39, 4.19.94-cip18 Config

 General Setup
   Local version: -xenomai-3.1
 Processor type and features
   Multi-core scheduler support
     CPU core priorities scheduler support -> [n] (on newer kernels)
 Memory Management Options (or Processor type and features on older kernels)
   Transparent Hugepage Support -> [n]
   Allow for memory compaction -> [n]
   Contiguous Memory Allocator -> [n]
   Page migration -> [n]
 Power management and ACPI options
   CPU Frequency scaling
     CPU Frequency scaling -> [n]
   ACPI Support
     Processor -> [n]
   CPU Idle
     CPU idle PM support -> [n]
 Device Drivers
   Input device support
     Miscellaneous devices
       PC Speaker support -> [n]
   Character devices
     Serial Drivers
       8250/16550 and compatible serial support -> [m]
   Microsoft Hyper-V guest support -> [n]
   Staging drivers -> [n]
 Kernel hacking
   KGDB -> [n]
 Xenomai/cobalt
   Core features
     Shared interrupts -> [y]
   Drivers
     Serial Drivers
       16550A UART driver -> [m]
         Hardware access mode
           Any access mode -> [y]
       PCI board support -> [y]
     RTnet
       RTnet, TCP/IP socket interface -> [m]
         Protocol Stack
           Real-Time IPv4
             TCP support -> [m]
           RTmac Layer
             NoMAC discipline for RTmac -> [m]
       Drivers
         New Intel(R) PRO/1000 (Gigabit) -> [m]
       Add-Ons
         Real-Time Capturing Support -> [m]
         IP protocol proxy for Linux -> [m]
           Enable ARP handling via protocol proxy -> [y]
     Real-time IPC drivers
       RTIPC protocol family -> [y]
     UDD support
       User-space device driver framework -> [m]

Save the kernel configuration to .config and exit the configuration tool.

Build the debian (Ubuntu) kernel packages:

time make -j `getconf _NPROCESSORS_ONLN` deb-pkg

Install the kernel packages:

cd ..
sudo dpkg -i linux-image-4.19.94-cip18-xenomai-3.1_4.19.94-cip18-xenomai-3.1-1_amd64.deb linux-headers-4.19.94-cip18-xenomai-3.1_4.19.94-cip18-xenomai-3.1-1_amd64.deb

RHEL 8

First of all, make sure that you are set up to build RPM packages by creating a few required directories:

mkdir -p ~/rpmbuild/BUILD
mkdir -p ~/rpmbuild/BUILDROOT
mkdir -p ~/rpmbuild/RPMS
mkdir -p ~/rpmbuild/SOURCES
mkdir -p ~/rpmbuild/SPECS
mkdir -p ~/rpmbuild/SRPMCS
mkdir -p ~/rpmbuild/tmp

and an ~/.rpmmacros file containing:

%packager Firstname Lastname
%_topdir /home/username/rpmbuild
%_tmppath /home/username/rpmbuild/tmp

Now create a file named xenomai3.spec in ~/rpmbuild/SPECS/ containing:

%define _unpackaged_files_terminate_build 0

Summary: Xenomai real-time system
Name: xenomai
Version: 3.1.3
Release: 1
License: GNU GPL
Group: Development/Tools
Source: xenomai-3.1.3.tar.gz
URL: http://www.xenomai.org
Buildroot: %{_tmppath}/%{name}-%{version}-root

%description
Xenomai user-space installation.  Requires a Xenomai patched kernel.

%prep
%setup -q

%build
./scripts/bootstrap
./configure --prefix=/usr --sysconfdir=/etc --includedir=/usr/include/xenomai
make -j8

%install
[ "$RPM_BUILD_ROOT" != "/" ] && rm -rf $RPM_BUILD_ROOT
make DESTDIR=$RPM_BUILD_ROOT install

%clean
[ "${RPM_BUILD_ROOT}" != "/" ] && rm -rf ${RPM_BUILD_ROOT}

%post
if ! getent group xenomai >/dev/null; then
    groupadd --system xenomai || true
fi
grubby --update-kernel=/boot/vmlinuz-$(uname -r) --args=\"xenomai.allowed_group=$(getent group xenomai | cut --delimiter ':' --fields 3)\"

%files
%defattr(-,root, root)
%dir /usr/include/xenomai
%dir /usr/lib/xenomai
/usr/bin/*
/usr/demo/*
/usr/include/xenomai/*
/usr/lib/cobalt.wrappers
/usr/lib/dynlist.ld
/usr/lib/lib*
/usr/lib/modechk.wrappers
/usr/lib/xenomai/*
/usr/sbin/*
/etc/udev/rules.d/00-rtnet.rules
/etc/udev/rules.d/rtdm.rules
/etc/rtnet.conf
/etc/tdma.conf

and download the associated source tarball (e.g. xenomai-3.1.3.tar.gz) from https://xenomai.org/downloads/xenomai/stable/ into ~/rpmbuild/SOURCES.

Now you should be able to build an RPM file containing the Xenomai user-space support like this:

rpmbuild -ba ~/rpmbuild/SPECS/xenomai3.spec

If all goes well, an RPM file will be generated in ~/rpmbuild/RPMS that can be installed like this:

sudo rpm -i RPMS/x86_64/xenomai-3.1.3-1.x86_64.rpm

Building a Linux kernel with Xenomai support on RHEL 8 is very similar to the process outlined above for Ubuntu 18.04, so most of those instructions are applicable here.

The kernel config file from Ubuntu 18.04 (i.e. /boot/config-4.15.0-70-generic) should also be a suitable starting point for building a kernel under RHEL 8. If you want to use the kernel config file from RHEL 8 instead (i.e. /boot/config-4.18.0-425.3.1.el8.x86_64), you may need to disable guest OS support (in menuconfig) to eliminate some warnings about PARAVIRT dependencies when running the “make olddefconfig” command.

You will also want to build an RPM package instead of a Debian/Ubuntu package, so the make command will look like this instead:

time make -j `getconf _NPROCESSORS_ONLN` binrpm-pkg

If all goes well, this command will generate an RPM package for the new kernel under ~/rpmbuild/RPMS that can be installed using rpm -i.

If you have trouble building RPMs, you can build and install everything manually (instead of from RPM packages), but uninstalling may get messy:

make -j 8
sudo make modules_install -j 8
sudo make install -j 8
sudo update-grub

Kernel Boot Parameters

The following kernel boot parameters may (or may not) be useful:

drm_kms_helper.poll=0
nouveau.noaccel=1
pci=routeirq
xenomai.allowed_group=997
acpi_irq_nobalance
noirqbalance
nmi_watchdog=0
nosoftlockup
nosmap
nohalt
mce=ignore_ce
idle=poll
intel_idle.max_cstate=0
processor.max_cstate=0
intel.max_cstate=0
processor_idle.max_cstate=0

Note that kernel boot parameters can be set by adding them to the GRUB_CMDLINE_LINUX_DEFAULT string in /etc/default/grub and then running sudo update-grub.