Version 5 (modified by Bobfishtank, on Aug 3, 2009 at 1:28:08 PM) (diff)

added info on GMP and MPFR error messages


The primary source of information about building and configuring RTEMS is always the Getting Started manual for the RTEMS version you are using (see This section contains answers to some frequently asked questions.

Required Tools

  • Which tools are required to build RTEMS?
  • Do I need autoconf and automake to build RTEMS?
  • Do I need a native gcc on my host?
  • Can I use a non-gcc cross-toolchain?
  • Where to get autoconf automake ld gcc etc.?
  • Building the Tool RPM packages?

Issues when building RTEMS

  • When running ./configure weird thing start to happen
  • When running bootstrap weird thing start to happen
  • configure xxx cannot create executables
  • Why can I not build RTEMS inside of the source tree?
  • Which environment variables to set?
  • Compiler /Assembler /Linker report errors
  • How to set up $PATH?
  • Can I build RTEMS Canadian Cross?
  • Building RTEMS is slow
  • Building my pre-4.5.x BSPs does not work anymore

Get rest from build45.t in FAQ and continue.

Issue relating to Debuging and Building

  • Does building with `make VARIANT=DEBUG' cause RTEMS_DEBUG to get defined?


  • How do I cause RTEMS_DEBUG to get defined

In newer snapshots it's --enable-rtems-debug. In older versions you had to define it inside the target-opts section in your BSP's <BSP>.cfg.

  • What exactly does VARIANT=debug do?

Builds with less optimisation

  • What does RTEMS_DEBUG do?

Enables debug checks inside the RTEMS kernel, including memory heap walking.

  • What do errors referring to GMP and MPFR mean?

This usually indicates that the GCC port you are using to build the RTEMS gcc is missing the libraries GMP and MPFR. You must obtain and build GMP and MPFR. Then, use the (for example) --with-mpfr-lib=path_to_mpfr option when running configure.

Building Under Cygwin

BuildingUnderCygwin? documents obtaining the latest pre-4.7 release (RTEMS- snapshot), installing an appropriate tool set, building RTEMS, and installing Insight/GDB. This procedure was tested using a Xilinx ml403 development board, which contains a Virtex-4 FX12 device with its embedded PowerPC.