Windows-Native and Linux/macOS-Hosted GNU Toolchain for Windows Arm64 (MinGW/Cygwin) targets

Windows-native and Linux/macOS-hosted GNU Toolchain for Windows Arm64, targeting MinGW (aarch64-w64-mingw32) and Cygwin (aarch64-pc-cygwin), built on hosts such as (aarch64-w64-mingw32, x86_64-pc-linux-gnu, aarch64-pc-linux-gnu, arm64-apple-darwin* or others). It is a work in progress, with ongoing efforts to upstream the necessary changes to the corresponding repositories. The resulting toolchain produces binaries that can be run on Windows Arm64. The scripts are actively tested on the default Ubuntu 22.04 GitHub Actions runners and Ubuntu 22.04 in WSL.

Known Issues

aarch64-w64-mingw32 target has reached sufficient quality to build itself natively and pass tests for many packages. aarch64-pc-cygwin target is not yet ready for real-world use. Problems and missing parts are listed in the issues. Please report all issues, including those specific to Binutils/GCC/MinGW/Cygwin.

Building the Native GNU Toolchain for Windows Arm64

To build the native compiler, cross-compilation on Linux/macOS host is still needed. Once built, the toolchain can be moved to a Windows host to build required packages natively.

1. Clone the repository:

   git clone https://github.com/eukarpov/gnu-toolchain-windows-arm64.git

2. Navigate to the root repository folder:

   cd gnu-toolchain-windows-arm64

3. Run the build script:

   ./build.sh --native-toolchain

Building the Cross-Toolchain

To build the cross-toolchain and install it into a ~/install/toolchains/<host name>/aarch64-w64-mingw32-msvcrt folder, run the build script:

./build.sh

The toolchain uses the aarch64-w64-mingw32 target by default. The PLATFORM variable should be specified to change the target to aarch64-pc-cygwin.

PLATFORM=pc-cygwin ./build.sh

To install the toolchain into a different folder TOOLCHAIN_PATH environment variable should be used:

TOOLCHAIN_PATH=/opt/aarch64-w64-mingw32 ./build.sh

To skip the dependencies bootstrapping process and fetching source code repositories for consecutive builds RUN_BOOTSTRAP and UPDATE_SOURCES environment variables should be used:

RUN_BOOTSTRAP=0 UPDATE_SOURCES=0 ./build.sh

The build script does multiple things:

• Installs the dependency Ubuntu packages.
• Clones several dependency source code repositories:
  • modified binutils from eukarpov/binutils-windows-arm64,
  • modified GCC from eukarpov/gcc-windows-arm64,
  • modified MinGW from eukarpov/mingw-windows-arm64.
  • modified Cygwin from eukarpov/cygwin-windows-arm64.
• Bootstraps the binutils and GCC sources with gmp, mpfr, isl, etc. dependencies.
• Builds and installs binutils, stage 1 GCC, MinGW runtimes, GCC with libgcc, and then the entire MinGW.

Using the Cross-Compiler

After building the toolchain, to build a simple C source code file run:

export PATH="~/install/toolchains/<host name>/aarch64-w64-mingw32-msvcrt/bin:$PATH"
aarch64-w64-mingw32-gcc hello.c -o hello.exe

To build a set of basic AArch64-specific tests:

.github/scripts/tests/build.sh

The test script requires a working CMake executable in the environment and will place the resulting binaries into the tests/build/bin folder.

Installing Build Dependencies

The main build script installs its dependencies automatically when the RUN_BOOTSTRAP=1 environment variable is defined, which is the default. To see what will be installed refer to .github/scripts/install-dependencies.sh.

Testing the Toolchain

The toolchain is tested with the GCC test suite and against four example projects builds (OpenSSL, FFmpeg, OpenBLAS, libjpeg-turbo) and their testing suites.

As of 2024/08/09 the toolchain has reached the following level of quality with the GCC testing targeting armv8-a without optional extensions such as SVE:

Metric	Count
Expected passes	573324
Unexpected failures	12118
Unexpected successes	172
Expected failures	4528
Unresolved testcases	7363
Unsupported tests	10774
DejaGnu errors	0
Total	608279
Reliability rate	96%