The ARM Embedded Toolchain is a GNU licensed cross compiler for ARM CPU architectures, allowing you to compile C/C++ code into binaries which can execute on CPUs such as the Cortex-M line of microcontrollers.
When dealing with C/C++ embedded development, you have the choice of several compilers. Keil is probably the most well-known commercial brand in the embedded toolchain space. They have their own proprietary compiler and IDE which is quite popular for commercial applications (it's pricey and only runs on Windows).
We'll be focusing on the ARM toolchain, which is open source under a GNU license and free to use for all projects.
Visit the downloads page.
and download the .pkg file labeled with Mac OS X 64-bit Package (Signed and notarized).
Sidenote: Prior to the 9-2020-q2-update, a notarised installer for macOS was not available
which meant that macOS would display a security warning and refuse to run any tools unless
you explicitly grant permission in the Security & Privacy preferences pane, or run a CLI
command to whitelist all binaries in the toolchain folder.
Run the .pkg installer. cd /Applications/ARM and you should see the following
structure:
.
├── arm-none-eabi
│ ├── bin
│ ├── include
│ ├── lib
│ └── share
├── bin
│ ├── arm-none-eabi-addr2line
│ ├── arm-none-eabi-ar
│ ├── arm-none-eabi-as
│ ├── arm-none-eabi-c++
│ ├── arm-none-eabi-c++filt
│ ├── arm-none-eabi-cpp
│ ├── arm-none-eabi-elfedit
│ ├── arm-none-eabi-g++
│ ├── arm-none-eabi-gcc
│ ├── arm-none-eabi-gcc-9.3.1
│ ├── arm-none-eabi-gcc-ar
│ ├── arm-none-eabi-gcc-nm
│ ├── arm-none-eabi-gcc-ranlib
│ ├── arm-none-eabi-gcov
│ ├── arm-none-eabi-gcov-dump
│ ├── arm-none-eabi-gcov-tool
│ ├── arm-none-eabi-gdb
│ ├── arm-none-eabi-gdb-add-index
│ ├── arm-none-eabi-gdb-add-index-py
│ ├── arm-none-eabi-gdb-py
│ ├── arm-none-eabi-gprof
│ ├── arm-none-eabi-ld
│ ├── arm-none-eabi-ld.bfd
│ ├── arm-none-eabi-nm
│ ├── arm-none-eabi-objcopy
│ ├── arm-none-eabi-objdump
│ ├── arm-none-eabi-ranlib
│ ├── arm-none-eabi-readelf
│ ├── arm-none-eabi-size
│ ├── arm-none-eabi-strings
│ └── arm-none-eabi-strip
├── lib
│ ├── gcc
│ ├── libcc1.0.so
│ └── libcc1.so -> libcc1.0.so
└── share
├── doc
└── gcc-arm-none-eabi
Most third-party tools and IDEs will try and execute various binaries in the
./bin folder (e.g. the arm-none-eabi-g++ C++ compiler), so add that to your
PATH.
That's it! You should be able to run arm-none-eabi-g++ anywhere on your system
to execute the C++ cross compiler. Happy hacking!