===========================
Building the ARM Tool chain
===========================


Build Environment
-----------------

::

    export target=arm-elf
    export tools=$HOME/Dev_UW/EmbSys/Tools
    export prefix=$tools/$target
    export PATH=$prefix/bin:$PATH


FTP URLs
--------

    gcc
        ftp://anonymous@gcc.gnu.org/pub/gcc/releases

    gmp, mpc, mpf
        ftp://anonymous@gcc.gnu.org/pub/gcc/infrastructure
    
    gdb
        ftp://anonymous@gcc.gnu.org/pub/gdb/releases
    
    binutils
        ftp://anonymous@gcc.gnu.org/pub/binutils/releases
    
    newlib
        ftp://anonymous@sources.redhat.com/pub/newlib


Downloading and uncompressing
-----------------------------

::

    cd $tools
    mkdir Sources
    cd Sources

    $ curl -O ftp://gcc.gnu.org/pub/binutils/releases/binutils-2.20.tar.bz2
    $ curl -O ftp://gcc.gnu.org/pub/gcc/releases/gcc-4.5.1/gcc-core-4.5.1.tar.bz2
    $ curl -O ftp://gcc.gnu.org/pub/gcc/releases/gcc-4.5.1/gcc-g++-4.5.1.tar.bz2
    $ curl -O ftp://gcc.gnu.org/pub/gcc/infrastructure/gmp-4.3.2.tar.bz2
    $ curl -O ftp://gcc.gnu.org/pub/gcc/infrastructure/mpc-0.8.1.tar.gz
    $ curl -O ftp://gcc.gnu.org/pub/gcc/infrastructure/mpfr-2.4.2.tar.bz2
    $ curl -O ftp://sourceware.org/pub/gdb/releases/gdb-7.2.tar.bz2
    $ curl -O ftp://sources.redhat.com/pub/newlib/newlib-1.18.0.tar.gz
    
    $ tar -xjf binutils-2.20.tar.bz2
    $ tar -xjf gcc-core-4.5.1.tar.bz2
    $ tar -xjf gcc-g++-4.5.1.tar.bz2
    $ tar -xjf gmp-4.3.2.tar.bz2
    $ tar -xjf mpc-0.8.1.tar.gz
    $ tar -xjf mpfr-2.4.2.tar.bz2
    $ tar -xjf gdb-7.2.tar.bz2
    
    $ tar -xzf newlib-1.18.0.tar.gz


Building the Binary Utilities
-----------------------------
GNU binutils is a collection of binary tools, which needs to 
be build first. As with all parts of the toolchain, we create 
a specific build directory inside the package's directory.

::

    $ cd $tools/Sources/binutils-2.18
    $ mkdir build-$target
    $ cd build-$target/

    $ ../configure --target=$target --prefix=$prefix --enable-interwork --enable-multilib \
        --disable-nls --disable-shared --disable-threads --with-gcc --with-gnu-as --with-gnu-ld

    $ make
    $ sudo make install
    $ cd ../..

To check the ARM variant.

::

    $ arm-elf-as --version


Building the Compiler
---------------------
The ARM compiler build is a two pass build. First we build just gcc
using the headers from newlib. That gives us an arm-elf compiler. 
We then build newlib with the arm-elf compiler, which will give us 
c runtime binaries built for ARM. Then we can build the rest of 
the gcc sources using the ARM runtime binaries.


Arranging the sources
---------------------
The GCC build requires gmp, mpc, mpfr. The easiest way to add them
to the build is to move their source distributions into the gcc tree.
The build also requires newlib. 

Moving the required libraries into gcc-4.5.1 and renaming them:

::

    $ cd $tools/Sources
    mv gmp-4.3.2 gcc-4.5.1/gmp
    mv mpc-0.8.1 gcc-4.5.1/mpc
    mv mpfr-2.4.2 gcc-4.5.1/mpfr
    
Renaming newlib:

::

    mv newlib-1.18.0 newlib


GMP Library
-----------
GNU Multiple Precision library.
Download, uncompress, and copy it into the top level of the gcc 
directory as gmp. Or use --with-gmp, --with-gmp-lib and 
--with-gmp-include configure options with gcc.

MPFR Library
------------
C library for multiple-precision floating-point computations.
Download, uncompress, and copy it into the top level of the gcc 
directory as mpfr. Or use --with-mpfr, --with-mpfr-lib and 
--with-mpfr-include configure options with gcc.

MPC Library
-----------
C library for the arithmetic of complex numbers.
Download, uncompress, and copy it into the top level of the gcc 
directory as mpfr. Or use --with-mpc, --with-mpc-lib and 
--with-mpc-include configure options with gcc.

Newlib Library
--------------
C runtime library.
Download, uncompress and use --with-headers to set the path
to its includes in the configure options with gcc.


Configuring GCC build
----------------------------

::

    cd $tools/gcc-4.5.1
    mddir build-$target
    cd build-$target

    ../configure --target=$target --prefix=$prefix \
    --disable-nls --disable-shared --disable-threads \
    --with-gcc --with-gnu-ld --with-gnu-as --with-dwarf2 \
    --enable-languages=c,c++ --enable-interwork \
    --enable-multilib --with-newlib \
    --with-headers=../../newlib/newlib/libc/include \
    --disable-libssp --disable-libstdcxx-pch \
    --disable-libmudflap --disable-libgomp -v


GCC build first pass
--------------------
First just build gcc itself. That will give us an arm compiler which
we will use to build the runtime. Then with a built runtime we can
rebuild all of the sources in gcc.

::

    make all-gcc
    make install-gcc


Configuring and building CRT library
------------------------------------

::

    $ cd $tools/newlib
    $ mkdir build-$target
    $ cd build-$target/
    $ ../configure --target=$target --prefix=$prefix --enable-interwork --enable-multilib

    $ make
    $ sudo make install
    $ cd ../..


Building full GCC
-----------------
Now build the rest of gcc.

::

    cd $tools/gcc-4.5.1/build-$target
    make
    make install


Building the Debugger
---------------------
Build the gdb debugger.

::

    $ cd $tools/gdb-7.2
    $ mkdir build-$target
    $ cd build-$target/
    $ ../configure --target=$target --prefix=$prefix --disable-nls
    $ sudo make install
    $ cd ../..


Stripping the Binaries
-----------------------
In an additional step we may strip the installed binaries 
to save disk space and decrease load times.

::

    $ sudo strip $prefix/bin/*		  
    $ sudo strip $prefix/$target/bin/*		  
    $ sudo strip $prefix/libexec/gcc/$target/4.2.2/*