--- user/start/tools.rst | 32 ++++++++++++++++++++++++++++++++ 1 file changed, 32 insertions(+)
diff --git a/user/start/tools.rst b/user/start/tools.rst index c3f039b..c1cd141 100644 --- a/user/start/tools.rst +++ b/user/start/tools.rst @@ -76,3 +76,35 @@ source code used. Add ``--verbose`` to the GCC command for the the verbose version details. + +Need for RTEMS-Specific Cross-Compiler +--------------------------------------------------------- + +New users are often confused as to why they cannot use their distribution's +cross-compiler for their target on rtems, e.g., the riscv64-linux-gnu or the +arm-none-eabi-gcc on RTEMS. Below mentioned are some of the reasons for using +the RTEMS cross-compiler. + +* ``Correct configuration of Newlib -`` + Newlib is a C standard library implementation intended for use on embedded + systems. Most of the POSIX and libc support for RTEMS is derived from + Newlib. The RTEMS cross-compiler configures Newlib correctly for RTEMS. + +* ``Threading in GCC support libraries -`` + Several threading packages in GCC such as Go threads (libgo), OpenMP + (libgomp), and OpenACC need to be customized according to RTEMS. This is + done by the RTEMS specific cross-compiler. + +* ``Provide preprocessor define __rtems__ -`` + The ``__rtems__`` preprocessor define is used to provide conditional code + compilation in source files that are shared with other projects e.g. in + Newlib or imported code from FreeBSD. + +* ``Multilib variants to match the BSP -`` + RTEMS configures GCC to create separate runtime libraries for each + supported instruction set, floating point unit, vector unit, word size + (e.g. 32-bit and 64-bit), endianness, ABI, processor errata workarounds, + and so on in the architecture. These libraries are termed as :ref:`Multilib + <TargetArchitectures>` variants. Multilib variants to match the BSP are set + by selecting a specific set of machine options using the RTEMS + cross-compiler. -- 2.17.1 _______________________________________________ devel mailing list devel@rtems.org http://lists.rtems.org/mailman/listinfo/devel
