Embedded Cross-Compilation Template

This is a generic, cross-platform template to use for embedded systems development.

CMake Configuration

Toolchain Files

The toolchain files allow cmake to find the cross-compilation toolchains for specific architectures. To this end, the relevant toochain is added to the corresponding CMAKE_TOOLCHAIN_FILE section in CMakePresets.json, e.g.:

"CMAKE_TOOLCHAIN_FILE": {
    "type": "FILEPATH",
    "value": "toolchain-arm-none-eabi-gcc.cmake"
}

The following variables are defined in all toolchain files:

• TARGET_TRIPLET: The triplet describing the CPU, Operating System, and ABI of the target system.
• TOOLCHAIN_COMPILER: The full path to the cross-compiler.
• TOOLCHAIN_PREFIX: The prefixed directory where to find the bin, include, lib, and other directories relevant for compiling to the target system.
• CMAKE_C_COMPILER: The C compiler to use for cross compiling to the target.
• CMAKE_CXX_COMPILER: The C++ compiler to use for cross compiling to the target.
• CMAKE_ASM_COMPILER: The assembler to use for the target CPU.
• CMAKE_OBJCOPY: The object copy tool to use for the target.
• CMAKE_OBJDUMP: The object dump tool to use for the target.
• CMAKE_RANLIB: The randomising tool for static libraries.
• CMAKE_READELF: The readelf tool for target object files.
• CMAKE_SIZE_UTIL: The object copy tool to use for the target.
• CMAKE_STRIP: The strip tool to use for target objects.

toolchain-arm-none-eabi-gcc.cmake

This file defines the gcc cross-compilation toolchain for cross-compiling to ARM embedded platforms.

In addition to the common toolchain variables, this file defines the following variables:

• ARM_EABI_BINUTILS_PATH: The path to the binutils for this toolchain.
• ARM_EABI_TOOLCHAIN_DIR: The path to the binaries for this toolchain.

Examples

Here is an example invocation using the arm-none-eabi-gcc toolchain:

Pre-requisites:

• Ensure that you have the arm-none-eabi-gcc toolchain
• Ensure that you have cmake installed

These can be installed on Ubuntu with:

sudo apt install gcc-arm-none-eabi cmake

Build:

cmake --preset arm-none-eabi-gcc-debug -DPROJECTS=EmptyTemplate -DBOARDS=nucleo_f207zg
cmake --build --preset arm-none-eabi-gcc-debug

Replace EmptyTemplate with your project (in one of the projects subdirectories such as bare_metal, or use an absolute path). Ensure that your project folder contains a project.cmake file with the source files and include directories defined. Replace nucleo_f207zg with your board (in one of the boards subdirectories such as STM).

NOTE: Ensure that this is invoked from the root directory of this repository, not inside the project directory.