#!/bin/bash
#
# This script is the first stage in bootstrapping a Slackware build to
# a new platform or architecture.  Running with no arguments builds a
# cross-development environment, then cross-builds a minimal rootfs.
# Once you have this minimal rootfs booted, run stage2 in that rootfs
# to build the rest of the bootstrap packages.
#
# This script assumes that all the needed sources and SlackBuild
# scripts are available in $SLACKROOT/source (below).
# The resulting rootfs will be build in $ROOTFS (below).
#
# Note that SLACKSOURCE_LOCAL is for local SlackBuilds that override
# the official ones, for example, board-specific kernel packages.
#
# You may pass a single module name on the command line to rebuild
# just that one module.  Module names match the big case statement
# below.
#
# For reference, when a package is built multiple times...
#
# foo-host is the "runs on host" part of a standard cross-compiler
# foo-target is the target libraries etc
# target-foo is a cross-built target-native
#
# Note that the "dev" step requires sudo, as it installs special files
# in $ROOTFS/dev/
#
# The routine is:
# - Find the Slackware package source (either in $SLACKSOURCES_LOCAL/
#   or in $SLACKROOT/source)
# - Run the SlackBuild script with "--prep" parameter which unpacks
#   source tarballs, does any patching but does not actually compile
#   (the package source tarball is unpacked into $SLACKSOURCE)
# - Cross-compilation happens in $BUILDDIR
#
# ------------------------------------------------------------

export LANG=en_US

# What are we cross-compiling for?
export DISTRO=slackware
export ARCH=aarch64
export HWSPEC=sunxi
#export KVER=4.3.5
export KARCH=arm64
export CHOST="$ARCH-$DISTRO-linux"

export CPU=cortex-a53
export MARCH=armv8-a
export WITH_TUNE="--with-abi=ilp32"
#export WITH_FPU=neon-fp-armv8
#export WITH_ABI=lp64

export SLKCFLAGS="-O2 -march=$MARCH -mabi=ilp32"
export SLKLDFLAGS=""
export LIBDIRSUFFIX="64ilp32"

export DIR_INSTALL=install$LIBDIRSUFFIX
export DIR_BUILDS=builds$LIBDIRSUFFIX
export DIR_ROOTFS=rootfs$LIBDIRSUFFIX
export DONE="done$LIBDIRSUFFIX"

export LIBDIRSUFFIX=""  # Bootstrap should be done to "/lib"

# Where will we create the cross-compiler binaries?
TOP=`cd $(dirname $BASH_SOURCE);pwd`

# Where do we look for sources?
#SRCDIR=$(cd $(dirname $0); pwd)

# Script to run in the rootfs, on the target:
STAGE2=$SRCDIR/stage2.sh

# Where to find the package sources;
# The symlink '$DISTRO' points to your distro development tree
# (with 'source' as a subdirectory):
SLACKROOT=$TOP/$DISTRO

# Local sources:
SLACKSOURCE_LOCAL=$SRCDIR/source.local

NUMJOBS=${NUMJOBS:--j4}

# Where we configure and build our cross-tools:
BUILDDIR=$TOP/$DIR_BUILDS

# Where we extract our original Slackware sources:
SLACKSOURCE=$TOP/sources

# Where we store our Slackware packages:
SLACKBUILD=$TOP/pkgs

# Cross-tools have their own specific prefix:
PREFIX=$TOP/$DIR_INSTALL

# Kernel specifics:
KCONFIGDIR=$SLACKSOURCE_LOCAL/k/configs-$ARCH
KCONFIG=config-$HWSPEC-$KVER

# The cross-compiler target
TARGET=$CHOST

# This is where the new rootfs will be built
ROOTFS=$TOP/$DIR_ROOTFS

# Needed during build:
export CFLAGS="$SLKCFLAGS"
export LDFLAGS="$SLKLDFLAGS"

if [ -f $SRCDIR/local.conf ]; then
  . $SRCDIR/local.conf
fi

# ------------------------------------------------------------
# Sanity checks

KERNELARGS="ARCH=${KARCH} CROSS_COMPILE=${TARGET}-"

export PATH=$PREFIX/bin:$PATH