2.4. Install the Tool Suite¶
You have chosen an installation prefix, the BSP to build, the tool’s
architecure and prepared the source for the RSB in the previous sections. We
$HOME/quick-start/rtems/6 as the installation prefix, the
erc32 BSP and the SPARC architecture name of
sparc-rtems6, and unpacked
the RSB source in
The tool suite for RTEMS and the RTEMS sources are tightly coupled. For example, do not use a RTEMS version 6 tool suite with RTEMS version 4.11 or 5 sources and vice versa.
Build and install the tool suite:
cd $HOME/quick-start/src/rsb/rtems ../source-builder/sb-set-builder --prefix=$HOME/quick-start/rtems/6 6/rtems-sparc
This command should output something like this (omitted lines are denoted by …). The build host appears as part of the name of the package being built. The name you see may vary depending on the host you are using:
RTEMS Source Builder - Set Builder, 6 (5e449fb5c2cb) Build Set: 6/rtems-sparc ... config: tools/rtems-binutils-2.36.cfg package: sparc-rtems6-binutils-fbb9a7e-x86_64-linux-gnu-1 building: sparc-rtems6-binutils-fbb9a7e-x86_64-linux-gnu-1 sizes: sparc-rtems6-binutils-fbb9a7e-x86_64-linux-gnu-1: 716.015MB (installed: 163.538MB) cleaning: sparc-rtems6-binutils-fbb9a7e-x86_64-linux-gnu-1 reporting: tools/rtems-binutils-2.36.cfg -> sparc-rtems6-binutils-fbb9a7e-x86_64-linux-gnu-1.txt reporting: tools/rtems-binutils-2.36.cfg -> sparc-rtems6-binutils-fbb9a7e-x86_64-linux-gnu-1.xml config: tools/rtems-gcc-10-newlib-head.cfg package: sparc-rtems6-gcc-6051af8-newlib-d10d0d9-x86_64-linux-gnu-1 building: sparc-rtems6-gcc-6051af8-newlib-d10d0d9-x86_64-linux-gnu-1 .... Build Sizes: usage: 9.607GB total: 2.244GB (sources: 264.186MB, patches: 43.468KB, installed 1.986GB) installing: 6/rtems-sparc -> $HOME/quick-start/rtems/6 clean staging: 6/rtems-sparc Staging Size: 5.292MB Build Set: Time 1:01:48.019157
Once the build has successfully completed you can check if the cross C compiler works with the following command:
This command should output something like below. The version informtion helps
you to identify the exact sources used to build the cross compiler of your
RTEMS tool suite. In the output you see the version of RTEMS or the hash from
the RSB repository if you are building using a Git repository clone. The Newlib
hash is the version of Newlib in the RTEMS’s github
sourceware-mirror-newlib-cygwin repository. The
patches directories created by the RSB contain all the
source code used.
sparc-rtems6-gcc (GCC) 10.2.1 20210309 (RTEMS 6, RSB 5e449fb5c2cb6812a238f9f9764fd339cbbf05c2, Newlib d10d0d9) Copyright (C) 2020 Free Software Foundation, Inc. This is free software; see the source for copying conditions. There is NO warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
--verbose to the GCC command for the the verbose version details.
2.4.1. 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. 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__
__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 Multilib variants. Multilib variants to match the BSP are set by selecting a specific set of machine options using the RTEMS cross-compiler.