Cross-Compiled Linux From Scratch - Version 1.0.0rc1-x86

Chapter 5. Constructing Cross-Compile Tools

5.6. Cross GCC-4.1.1 - Static

The GCC package contains the GNU compiler collection, which includes the C and C++ compilers.

5.6.1. Installation of Cross GCC Compiler with Static libgcc and no Threads

Make a couple of essential adjustments to the specs file to ensure GCC uses our build environment: 

patch -Np1 -i ../gcc-4.1.1-specs-1.patch

To make sure that a couple of tools use the proper syntax, apply the following patch: 

patch -Np1 -i ../gcc-4.1.1-posix-1.patch

The following patch ensures that gcc does not search the /usr directory for libgcc_s.so when cross-compiling: 

patch -Np1 -i ../gcc-4.1.1-cross_search_paths-1.patch

Change the StartFile Spec to point to the correct library location: 

echo "
#undef STARTFILE_PREFIX_SPEC
#define STARTFILE_PREFIX_SPEC \"/tools/lib/\"" >> gcc/config/linux.h

Now alter gcc's c preprocessor's default include search path to use /tools only: 

cp -v gcc/Makefile.in{,.orig}
sed -e "s@\(^CROSS_SYSTEM_HEADER_DIR =\).*@\1 /tools/include@g" \
    gcc/Makefile.in.orig > gcc/Makefile.in
[Important]

Important

The above patches and sed's are critical in ensuring a successful overall build. Do not forget to apply them.

The GCC documentation recommends building GCC outside of the source directory in a dedicated build directory: 

mkdir -v ../gcc-build
cd ../gcc-build

Prepare GCC for compilation: 

../gcc-4.1.1/configure --prefix=/cross-tools \
    --host=${LFS_HOST} --target=${LFS_TARGET} --disable-multilib \
    --with-local-prefix=/tools --disable-nls --disable-shared \
    --disable-threads --enable-languages=c

The meaning of the configure options:

--with-local-prefix=/tools

The purpose of this switch is to remove /usr/local/include from gcc's include search path. This is not absolutely essential, however, it helps to minimize the influence of the host system.

--disable-shared

Disables the creation of the shared libraries.

--disable-threads

This will prevent GCC from looking for the multi-thread include files, since they haven't been created for this architecture yet. GCC will be able to find the multi-thread information after the Glibc headers are created.

--enable-languages=c

This option ensures that only the C compiler is built.

Continue with compiling the package: 

make all-gcc

Install the package: 

make install-gcc

Details on this package are located in Section 10.9.2, “Contents of GCC.”