Tero's Arduino Blog

Installing GNAT 4.7

Since we are building GNAT 4.7 using GNAT 4.6, everything should go smoothly.

Commands are following:

yum install mpfr-devel gmp-devel bison make autoconf automake libtool flex gcc-gnat
wget ftp://ftp.mirrorservice.org/sites/sourceware.org/pub/gcc/releases/gcc-4.7.0/gcc-4.7.0.tar.gz
tar zxf gcc-4.7.0.tar.gz
mkdir gcc-obj-470
cd gcc-obj-470
../gcc-4.7.0/configure --enable-languages=c,ada \
  --prefix=$HOME/programs/gnat470 --disable-multilib
make bootstrap
make install

When 'make install' finishes, you should have (native/normal) gnat 4.7 in $HOME/programs/gnat470 directory.

Installing avr-binutils

Binutils package provides tools like 'as', 'ld', and 'objcopy', which are necessary when gcc compiles something. Binutils for AVR can be installed in following way:

wget http://ftp.uni-kl.de/pub/gnu/binutils/binutils-2.20.1a.tar.bz2
tar jxf binutils-2.20.1a.tar.bz2
git clone git://avr-ada.git.sourceforge.net/gitroot/avr-ada/avr-ada
cd binutils-2.20.1
for a in ../avr-ada/patches/binutils/2.20.1/*.patch;
do
    patch -p0 < $a || fail "avr-binutils: patch $a"
done
cd ..
mkdir binutils-obj
cd binutils-obj
../binutils-2.20.1/configure --target=avr --program-prefix=avr- \
  --disable-shared --disable-nls --enable-commonbfdlib=no \
  --disable-werror --prefix=$HOME/programs/avrada
make
make install

The patching part is there, because AVR-Ada repository includes some patches with improve AVR support of binutils and it is a good idea to use the patches.

Installing avr-gcc with Ada support

Now we are ready to compile avr-gcc. Notice how we set the PATH environment variable that the gcc build process picks up our custom gnat 4.7.0. Also, our new avr-binutils tools need to be in PATH.

export PATH=$HOME/programs/gnat470/bin:$HOME/programs/avrada/bin:$PATH
mv gcc-4.7.0 gcc-4.7.0-native
git clone git://avr-ada.git.sourceforge.net/gitroot/avr-ada/avr-ada
tar zxf gcc-4.7.0.tar.gz
cd gcc-4.7.0
for a in ../avr-ada/patches/gcc/4.7.0/*.patch;do patch -p0 < $a;done
cd ..
mkdir avr-gcc-obj
cd avr-gcc-obj
../gcc-4.7.0/configure --target=avr --program-prefix=avr- \
            --disable-shared --disable-nls --disable-libssp \
            --with-system-zlib \
            --disable-libada \
            --enable-languages=ada,c,c++ --enable-cpp --with-dwarf2 \
            --enable-version-specific-runtime-libs \
            --prefix=$HOME/programs/avrada
sed -i -e 's/$(STAMP)/echo timestamp >/' ../gcc-4.7.0/gcc/config/avr/t-avr
make
make install

Steps explained

export PATH=$HOME/programs/gnat470/bin:$HOME/programs/avrada/bin:$PATH

Put gcc/gnat 4.7.0 to PATH. Also, put avr-binutils to PATH.

mv gcc-4.7.0 gcc-4.7.0-native

Move previous gcc-4.7.0 source directory out of the way.

git clone git://avr-ada.git.sourceforge.net/gitroot/avr-ada/avr-ada

Clone the official avr-gcc repository, which contains some avr-gcc specific patches. You need to do this only if you haven't cloned the repository in earlier steps.

tar zxf gcc-4.7.0.tar.gz

Extract gcc-4.7.0 sources (since you move the previous source directory), to have fresh untouched gcc-4.7.0 sources.

cd gcc-4.7.0
for a in ../avr-ada/patches/gcc/4.7.0/*.patch;do patch -p0 < $a;done
cd ..

Enter the gcc-4.7.0 source directory and apply AVR and AVR-Ada specific patches to gcc sources from the avr-ada repository.

mkdir avr-gcc-obj

Create a separate build directory for gcc object files.

cd avr-gcc-obj
../gcc-4.7.0/configure --target=avr --program-prefix=avr- \
            --disable-shared --disable-nls --disable-libssp \
            --with-system-zlib \
            --disable-libada \
            --enable-languages=ada,c,c++ --enable-cpp --with-dwarf2 \
            --enable-version-specific-runtime-libs \
            --prefix=$HOME/programs/avrada

Configure gcc to be cross-compiler with avr target. We disable a lot of unnecessary things, and enable three languages: Ada, C, and C++.

In addition, we disable libada (Ada runtime) compilation. This means that gnattools (avr-gnatmake, avr-gnatclean, etc.) will use Ada runtime from the host system. If the Ada runtime on the host system is from different version of gcc, then gnattools will not work.

sed -i -e 's/$(STAMP)/echo timestamp >/' ../gcc-4.7.0/gcc/config/avr/t-avr

This line fixes a little bug in gcc sources. STAMP variable is not defined in t-avr file and easiest work-around is to replace it with 'echo' command.

make

Compile the code.

make install

Install everything.

Installing avr-libc

AVR-Ada depends on avr-libc, so you need to build it also.

export PATH=$HOME/programs/avrada/bin:$PATH
wget http://download.savannah.gnu.org/releases/avr-libc/avr-libc-1.8.0.tar.bz2
tar jxf avr-libc-1.8.0.tar.bz2
cd avr-libc-1.8.0
./configure --host=avr --prefix=$HOME/programs/avrada
make
make install

Installing AVR-Ada

Finally, we are ready to install AVR-Ada. We will fetch the latest version from AVR-Ada git repository, since it contains many improvements over AVR-Ada 1.1.

export PATH=$HOME/programs/avrada/bin:$PATH
git clone git://avr-ada.git.sourceforge.net/gitroot/avr-ada/avr-ada
cd avr-ada
./configure
make
make install_rts
cd avr/avr_lib
sed -i -e 's/stamp-libs: $(thread_libs)/stamp-libs:/' Makefile
make
cd ../..
make install_libs

The 'sed ...' line is there to disable avr-threads support, since it assumes Windows build system by default and we are building on Linux. If one feels brave enough, he/she can skip the sed command and try to build the avr-threads part also.

When 'make install_libs' completes, you should have complete AVR-Ada setup at $HOME/programs/avrada.

Testing the setup

To verify that you can actually compile AVR-Ada programs, you can download some example code from my Sourcehut repositories and build them.

export PATH=$HOME/programs/avrada/bin:$PATH
hg clone https://hg.sr.ht/~tkoskine/arduino-hello-uart
cd arduino-hello-uart
make

After successful build, there is file 'hello.hex' in the arduino-hello-uart directory. If you have Arduino UNO, you can upload the file on it using avrdude tool.

sudo avrdude -c arduino -p atmega328p -P /dev/ttyACM0 -b 115200 -U flash:w:hello.hex
# or simply "make upload-uno"

Final notes

Some final notes:

• Be careful with the version numbers. I use somewhat old releases on purpose, since they are proven to work with AVR-Ada better than later releases.
• If you get some strange compiler errors, check that you compile the code with correct GNAT. ("gnatls -v" shows the version number of GNAT)
• It is possible that AVR-Ada installation scripts do not set all permission bits properly, so AVR-GNAT (avr-gnatmake) might recompile some parts of AVR-Ada when you compile your AVR-Ada applications.
• Root (sudo) rights are necessary only with avrdude, other parts of this guide can be done with normal user rights.