Bare Metal ARM Cortex-M GDC Cross Compiler

Introduction

These instructions will describe how to build a bare metal ARM Cortex-M (arm-none-eabi) GDC cross compiler for a Linux host. All scripts were tested on an Arch Linux 64 host. If you encounter any problems while following these instructions, you may be able to get help at the D.GNU forum. If you can improve these instructions, please do so by making an account on this wiki and authoring changes.

A C library will not be built as this toolchain is intended for building all software in D. The D Runtime and Phobos (the D standard library) also will not be built as those libraries have not yet been ported to the ARM Cortex-M platform. However, this toolchain should give one the tools needed to do so.

As an alternative to these instructions, you may be able to use the pre-built ARM binaries at http://gdcproject.org/downloads. All ARM GCC compilers can generate code for all ARM variants (the hard-float compiler can generate soft-float code and the soft-float compiler can generate hard-float code as well) as long as the appropriate platform compiler flags are used. The difference between the compilers are the bundled libraries (e.g. the bundled libgcc may not be compatible with the thumb targets).

These instructions will use GCC 4.9.2 and the corresponding GDC branch from the GDC source code repository.

WARNING: The scripts in these instructions will create and remove several intermediate folders, so it is best if they are executed from within an empty folder to prevent removing or overwriting existing files and folders.

Specifying a target and installation folder

export TARGET=arm-none-eabi
export PREFIX={installation directory}

Replace {installation directory} with the absolute path to the folder the toolchain should be installed in.

GNU Binutils

For information on what GNU Binutils is and what features of the toolchain it provides see their website here.

# Delete existing binutils source archive and download a new one
#-------------------------------------------------------------------
export BINUTILS_NAME=binutils-2.25
export BINUTILS_SOURCE_ARCHIVE=$BINUTILS_NAME.tar.bz2
rm -f $BINUTILS_SOURCE_ARCHIVE
rm -rf $BINUTILS_NAME
wget http://ftpmirror.gnu.org/binutils/$BINUTILS_SOURCE_ARCHIVE

# Extract binutils
#-------------------------------------------------------------------
tar xjfv $BINUTILS_SOURCE_ARCHIVE

# Create binutils build directory
#-------------------------------------------------------------------
export BINUTILS_BUILD_DIR=binutils-build
rm -rf $BINUTILS_BUILD_DIR
mkdir $BINUTILS_BUILD_DIR

# Configure and build binutils
#-------------------------------------------------------------------
cd $BINUTILS_BUILD_DIR
../$BINUTILS_NAME/configure \
  --target=$TARGET   \
  --prefix=$PREFIX   \
  --disable-nls      \
  --disable-multilib \
  --with-gnu-as      \
  --with-gnu-ld      \
  --disable-libssp   
make -j4 all
make install
cd ..

Download GDC

# Download GDC
#-------------------------------------------------------------------
rm -rf gdc
mkdir gdc
git clone https://github.com/D-Programming-GDC/GDC.git gdc
cd gdc
git checkout gdc-4.9
cd ..

Download GCC

# Delete existing GCC source archive and download a new one
#-------------------------------------------------------------------
export GCC_MIRROR=http://ftpmirror.gnu.org/gcc
export GCC_NAME=gcc-4.9.2
export GCC_SOURCE_ARCHIVE=$GCC_NAME.tar.bz2
rm -f $GCC_SOURCE_ARCHIVE
rm -rf $GCC_NAME
wget $GCC_MIRROR/$GCC_NAME/$GCC_SOURCE_ARCHIVE

# Extract GCC
#-------------------------------------------------------------------
tar xjfv $GCC_SOURCE_ARCHIVE

You may wish to use an alternate GCC mirror.

Add GDC to GCC

# Add GDC to GCC
#-------------------------------------------------------------------
cd gdc
./setup-gcc.sh ../$GCC_NAME
cd ..

Build GCC

# Create GCC build directory
#-------------------------------------------------------------------
export GCC_BUILD_DIR=gcc-build
rm -rf $GCC_BUILD_DIR
mkdir $GCC_BUILD_DIR

# Configure and build GCC
#-------------------------------------------------------------------
cd $GCC_BUILD_DIR
../$GCC_NAME/configure --target=$TARGET --prefix=$PREFIX \
  --enable-languages=d     \
  --disable-bootstrap      \
  --disable-libssp         \
  --disable-libgomp        \
  --disable-libmudflap     \
  --disable-multilib       \
  --disable-libphobos      \
  --disable-decimal-float  \
  --disable-libffi         \
  --disable-libmudflap     \
  --disable-libquadmath    \
  --disable-libssp         \
  --disable-libstdcxx-pch  \
  --disable-nls            \
  --disable-shared         \
  --disable-threads        \
  --disable-tls            \
  --with-gnu-as            \
  --with-gnu-ld            \
  --with-cpu={your_cpu}    \
  --with-tune={your_cpu}   \
  --with-mode=thumb        \
  --without-headers
make -j4 all-gcc
make -j4 all-target-libgcc

Adjust --with-cpu and --with-tune with your CPU variant (e.g. cortex-m3, cortex-m4, etc..).

--disable-libphobos disables the D Runtime and Phobos (the D standard library) as these have not yet been ported to the ARM Cortex-M platform.

make all-gcc and make all-target-libgcc are used instead of make in order to limit the build to just the necessary components.

Documentation on the various configure options can be found in GCC's documentation here

Install the toolchain

make install-gcc
make install-target-libgcc
cd ..

Testing the toolchain

The toolchain can be tested with the minimal semihosted "Hello World!" program documented here.

To get a list of compiler options specific to the target of your cross-compiler, use the command arm-none-eabi-gdc --target-help

Additional Information

These instructions were modeled after the instructions and build scripts at GNU Tools for ARM Embedded Processors. The GCC cross compiler instructions on OSDev.org were also quite helpful.

See also

• GDC
• GDC Cross Compiler