#!/bin/bash
#
# Build a gcc + uClibc toolchain
#
# References:
# http://gcc.gnu.org/ml/gcc/2007-08/msg00327.html
# http://busybox.net/~vda/HOWTO/i486-linux-uclibc/HOWTO.txt
# http://wiki.osdev.org/GCC_Cross-Compiler

set -ex

arch=$1
sysroot=$2
uclibc=$3
binutils=$4
gcc=$5
gmp=$6
mpfr=$7
kernel_headers=$8

unset CPATH LIBRARY_PATH INSTALL
PATH=/usr/lib/ccache:/bin:/usr/bin
rm -rf ${sysroot}
mkdir ${sysroot}
ln -s . ${sysroot}/usr

# Link target-specific usr directory to usr, otherwise gcc has trouble finding ld
ln -s . ${sysroot}/usr/${arch}-linux-uclibc

# Install kernel headers
mkdir ${sysroot}/usr/include
cp -pLR ${kernel_headers}/{asm,linux,asm-generic} ${sysroot}/usr/include/

# Build binutils
mkdir binutils-${arch}
( cd binutils-${arch}; ${binutils}/configure --prefix=/usr --target=${arch}-linux-uclibc --with-gmp-include=${gmp} --with-gmp-lib=${gmp}/.libs --with-mpfr-include=${mpfr} --with-mpfr-lib=${mpfr}/.libs --with-sysroot=${sysroot} --program-prefix=${arch}-linux-uclibc- )
make -C binutils-${arch} all install DESTDIR=${sysroot}

# Build stage 1 gcc (required to build uClibc)
mkdir gcc-stage1-${arch}
( cd gcc-stage1-${arch}; ${gcc}/configure --prefix=/usr --target=${arch}-linux-uclibc --enable-languages=c --with-gmp-include=${gmp} --with-gmp-lib=${gmp}/.libs --with-mpfr-include=${mpfr} --with-mpfr-lib=${mpfr}/.libs --disable-shared --disable-nls --disable-multilib --disable-threads --disable-libmudflap --disable-libssp --disable-libgomp --disable-decimal-float --disable-tls --without-headers --with-build-time-tools=${sysroot}/usr/bin --with-gnu-ld )
make -C gcc-stage1-${arch} all-gcc all-target-libgcc install-gcc install-target-libgcc DESTDIR=${sysroot}

# Build uClibc
cp -a ${uclibc} uclibc-${arch}
cp uclibc-${arch}.config uclibc-${arch}/.config
make -C uclibc-${arch} oldconfig
make -C uclibc-${arch} extra/scripts/unifdef
PATH=${sysroot}/usr/bin:${PATH} make -C uclibc-${arch} CROSS=${arch}-linux-uclibc- KERNEL_HEADERS=${sysroot}/usr/include PREFIX=${sysroot} RUNTIME_PREFIX=/ DEVEL_PREFIX=/ RUNTIME_PREFIX_LIB_FROM_DEVEL_PREFIX_LIB= V=1 all install
PATH=${sysroot}/usr/bin:${PATH} make -C uclibc-${arch}/utils CROSS=${arch}-linux-uclibc- KERNEL_HEADERS=${sysroot}/usr/include PREFIX=${sysroot} RUNTIME_PREFIX=/ DEVEL_PREFIX=/ RUNTIME_PREFIX_LIB_FROM_DEVEL_PREFIX_LIB= V=1 hostutils utils_install

# Build final gcc targeting uClibc
mkdir gcc-final-${arch}
( cd gcc-final-${arch}; ${gcc}/configure --prefix=/usr --target=${arch}-linux-uclibc --enable-languages=c --with-sysroot=${sysroot} --with-gmp-include=${gmp} --with-gmp-lib=${gmp}/.libs --with-mpfr-include=${mpfr} --with-mpfr-lib=${mpfr}/.libs --disable-nls --disable-multilib --disable-threads --disable-libgomp --disable-decimal-float --with-build-time-tools=${sysroot}/usr/bin --with-gnu-ld )
make -C gcc-final-${arch} all install DESTDIR=${sysroot}