#!/bin/bash
#
# Copyright (c) 2016 Jiri Svoboda
# All rights reserved.
#
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions
# are met:
#
# - Redistributions of source code must retain the above copyright
#   notice, this list of conditions and the following disclaimer.
# - Redistributions in binary form must reproduce the above copyright
#   notice, this list of conditions and the following disclaimer in the
#   documentation and/or other materials provided with the distribution.
# - The name of the author may not be used to endorse or promote products
#   derived from this software without specific prior written permission.
#
# THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
# IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
# OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
# IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
# INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
# NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
# THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
#

#
# Script to generate/update prebuilt Grub2 in HelenOS source tree
# Be sure you know what you are doing!
#

origdir="$(cd "$(dirname "$0")" && pwd)"
helenosdir="$origdir/../.."
workdir="$origdir/grub-src"
builddir="$origdir/grub-build"
git_repo="git://git.savannah.gnu.org/grub.git"
grub_rev="bc220962e366b1b46769ed6f9fa5be603ba58ab5"

function grub_build()
{
	target="$1"
	platform="$2"

	./configure --prefix="$builddir/$target-$platform" --target="$target" --with-platform="$platform" || exit 1
	make clean || exit 1
	make install || exit 1
}

function grub_files_update()
{
	gdir="$1"
	platform="$2"

	rm -rf "$helenosdir"/boot/"$gdir"/"$platform" || exit 1
	cp -R "$builddir"/"$platform"/lib64/grub/"$platform" "$helenosdir"/boot/"$gdir" || exit 1
	rm -f "$helenosdir"/boot/"$gdir"/"$platform"/*.image || exit 1
	rm -f "$helenosdir"/boot/"$gdir"/"$platform"/*.module || exit 1
	bzr add "$helenosdir"/boot/"$gdir"/"$platform" || exit 1
}

# Prepare a clone of Grub2 repo
if [ ! -d "$workdir" ] ; then
	rm -rf "$workdir" "$builddir" || exit 1
	git clone "$git_repo" "$workdir" || exit 1
fi

cd "$workdir" || exit 1
git pull || exit 1
git reset --hard "$grub_rev" || exit 1

echo "$grub_rev" >"$helenosdir"/boot/grub.pc/REVISION || exit 1
echo "$grub_rev" > "$helenosdir"/boot/grub.efi/REVISION || exit 1

# Build each platform to a different directory
./autogen.sh || exit 1
grub_build i386 pc
grub_build i386 efi
grub_build x86_64 efi

# Extract El Torrito boot image for i386-pc
cd "$helenosdir"/boot/grub.pc || exit 1
rm -f pc.img || exit 1
"$builddir"/i386-pc/bin/grub-mkrescue -o phony --xorriso="$origdir/getimage.sh" || exit 1

# Extract El Torrito boot image for i386-efi
cd "$helenosdir"/boot/grub.efi || exit 1
rm -f efi.img.gz || exit 1
"$builddir"/i386-efi/bin/grub-mkrescue -o phony --xorriso="$origdir/getimage.sh" || exit 1
mv efi.img i386-efi.img

# Extract El Torrito boot image for x86_64-efi
cd "$helenosdir"/boot/grub.efi || exit 1
rm -f efi.img.gz || exit 1
"$builddir"/x86_64-efi/bin/grub-mkrescue -o phony --xorriso="$origdir/getimage.sh" || exit 1

# Combine El Torrito boot images for x86_64-efi and i386-efi
mkdir tmp || exit 1
mcopy -ns -i i386-efi.img ::efi tmp || exit 1
mcopy -s -i efi.img tmp/* :: || exit 1
gzip efi.img || exit 1
rm -rf tmp || exit 1
rm -f i386-efi.img || exit 1

# Update Grub files for all platforms
grub_files_update grub.pc i386-pc
grub_files_update grub.efi i386-efi
grub_files_update grub.efi x86_64-efi

echo "GRUB update successful."