000-Preparation

# Final System can be built in a directory and later copied to a partition.
# If building on a seperate partition, create the file system and mount it.
# Set #MLFS to the mount point. Example:
# Perform as root:
mkfs.etx4 /dev/sdXY
mkdir -pv /mnt/mlfs
mount /dev/sdXY /mnt/mlfs
export MLFS=/mnt/mlfs

# Create directories to build tools and link them to host's root directory:
mkdir -v $MLFS/cross-tools
mkdir -v $MLFS/tools
ln -sv   $MLFS/cross-tools /
ln -sv   $MLFS/tools /

# Create directories to hold patches, files, packages, and build area:
mkdir -pv $MLFS/sources/{patches,files,packages,scripts}

# Download sources + patches
#  Use the list in sources folder with wget to download sources. Some sources 
#  may not download or are hard to find. Copy such sources from included 
#  sources folder.
# 
# Source directory should have this structure:
#  source
#  |
#  +-scripts
#  +-patches
#  +-files
#  +-(packages)
#
# Source tarballs should in root of $LFS/sources
# Patches & files can be symbolically linked to root of $LFS/sources to avoid 
# adding "../{patches,files}" to path

# Create user and group
# Change ownership to allow installation of tools
groupadd mlfs
useradd -s /bin/bash -g mlfs -m -k /dev/null mlfs
passwd mlfs

chown -v  mlfs $MLFS/cross-tools
chown -vR mlfs $MLFS/sources
chmod -v  a+wt $MLFS/sources
chown -v  mlfs $MLFS/tools

# Now run as mlfs user. All toolchain software should be built as this user, unless specified.
su - mlfs

# Set up the environment.
cat > ~/.bash_profile << "EOF"
exec env -i HOME=$HOME TERM=$TERM PS1='\u:\w\n\$ ' /bin/bash
EOF

cat > ~/.bashrc << "EOF"
set +h
umask 022
MLFS=/mnt/mlfs
LC_ALL=POSIX
PATH=/cross-tools/bin:/tools/bin:/bin:/usr/bin
export MLFS LC_ALL PATH
EOF

# Load the stored environment
source ~/.bash_profile

# CFLAGS and CXXFLAGS must not be set during the building of cross-tools. 
unset CFLAGS
unset CXXFLAGS
cat >> ~/.bashrc << EOF
unset CFLAGS
unset CXXFLAGS
EOF

# Build Variables
# For 64 bit x86 CPUs:
#  ARCH=x86
#  CPU=x86-64
# For 32-bit CPUs:
#  ARCH=x86
#  CPU=i686
# For ARM CPUs:
#  ARCH=arm
#  CPU= # depends on ARM SoC or CPU of target machine
#  CPU=armv7-a   # Odroid xu4 (cortex-a15)
#  CPU=armv6 # Raspberry Pi Zero or 1 (arm1176jzf-s)


case $(uname -m) in
   x86_64)  export MLFS_TARGET="x86_64-mlfs-linux-musl"
            export MLFS_ARCH="x86"
            export MLFS_CPU="x86-64"
            ;;
   i686)    export MLFS_TARGET="i686-mlfs-linux-musl"
            export MLFS_ARCH="x86"
            export MLFS_CPU="i686"
            ;;
   armv7l)  export MLFS_TARGET="armv7l-mlfs-linux-musleabihf"
            export MLFS_ARCH="arm"
            export MLFS_CPU="armv7-a"
            ;;
   armv6l)  export MLFS_TARGET="armv6l-lfs-linux-musleabihf"
            export MLFS_ARCH="arm"
            export MLFS_CPU="armv6"
            ;;
   aarch64) export MLFS_TARGET="aarch64-mlfs-linux-musleabihf"
            export MLFS_ARCH="arm64"
            export MLFS_CPU="armv8-a"
            ;;
esac

export MLFS_HOST="$(echo $MACHTYPE | \
    sed "s/$(echo $MACHTYPE | cut -d- -f2)/cross/")"


cat >> ~/.bashrc << EOF
export MLFS_HOST="${MLFS_HOST}"
export MLFS_TARGET="${MLFS_TARGET}"
export MLFS_ARCH="${MLFS_ARCH}"
export MLFS_CPU="${MLFS_CPU}"
EOF
source ~/.bashrc