mono.rst

Mono(tm) Binary Kernel Support for Linux

To configure Linux to automatically execute Mono-based .NET binaries (in the form of .exe files) without the need to use the mono CLR wrapper, you can use the BINFMT_MISC kernel support.

This will allow you to execute Mono-based .NET binaries just like any other program after you have done the following:

1. You MUST FIRST install the Mono CLR support, either by downloading a binary package, a source tarball or by installing from Git. Binary packages for several distributions can be found at:

   https://www.mono-project.com/download/

   Instructions for compiling Mono can be found at:

   https://www.mono-project.com/docs/compiling-mono/linux/

   Once the Mono CLR support has been installed, just check that /usr/bin/mono (which could be located elsewhere, for example /usr/local/bin/mono) is working.

2. You have to compile BINFMT_MISC either as a module or into the kernel (CONFIG_BINFMT_MISC) and set it up properly. If you choose to compile it as a module, you will have to insert it manually with modprobe/insmod, as kmod cannot be easily supported with binfmt_misc. Read the file binfmt_misc.txt in this directory to know more about the configuration process.

3. Add the following entries to /etc/rc.local or similar script to be run at system startup:

   # Insert BINFMT_MISC module into the kernel
   if [ ! -e /proc/sys/fs/binfmt_misc/register ]; then
       /sbin/modprobe binfmt_misc
       # Some distributions, like Fedora Core, perform
       # the following command automatically when the
       # binfmt_misc module is loaded into the kernel
       # or during normal boot up (systemd-based systems).
       # Thus, it is possible that the following line
       # is not needed at all.
       mount -t binfmt_misc none /proc/sys/fs/binfmt_misc
   fi
   
   # Register support for .NET CLR binaries
   if [ -e /proc/sys/fs/binfmt_misc/register ]; then
       # Replace /usr/bin/mono with the correct pathname to
       # the Mono CLR runtime (usually /usr/local/bin/mono
       # when compiling from sources or CVS).
       echo ':CLR:M::MZ::/usr/bin/mono:' > /proc/sys/fs/binfmt_misc/register
   else
       echo "No binfmt_misc support"
       exit 1
   fi

4. Check that .exe binaries can be ran without the need of a wrapper script, simply by launching the .exe file directly from a command prompt, for example:

   /usr/bin/xsd.exe
   

   Note

   If this fails with a permission denied error, check that the .exe file has execute permissions.