#!/bin/sh
#
# builddeb 1.3
# Copyright 2003 Wichert Akkerman <wichert@wiggy.net>
#
# Simple script to generate a deb package for a GNU Linux-libre. All the
# complexity of what to do with a kernel after it is installed or removed
# is left to other scripts and packages: they can install scripts in the
# /etc/kernel/{pre,post}{inst,rm}.d/ directories (or an alternative location
# specified in KDEB_HOOKDIR) that will be called on package install and
# removal.

set -e

create_package() {
	local pname="$1" pdir="$2"

	mkdir -m 755 -p "$pdir/DEBIAN"
	mkdir -p "$pdir/usr/share/doc/$pname"
	cp debian/copyright "$pdir/usr/share/doc/$pname/"
	cp debian/changelog "$pdir/usr/share/doc/$pname/changelog.Debian"
	gzip -9 "$pdir/usr/share/doc/$pname/changelog.Debian"
	sh -c "cd '$pdir'; find . -type f ! -path './DEBIAN/*' -printf '%P\0' \
		| xargs -r0 md5sum > DEBIAN/md5sums"

	# Fix ownership and permissions
	chown -R root:root "$pdir"
	chmod -R go-w "$pdir"
	# in case we are in a restrictive umask environment like 0077
	chmod -R a+rX "$pdir"

	# Create the package
	dpkg-gencontrol $forcearch -Vkernel:debarch="${debarch}" -p$pname -P"$pdir"
	dpkg --build "$pdir" ..
}

set_debarch() {
	# Attempt to find the correct Debian architecture
	case "$UTS_MACHINE" in
	i386|ia64|alpha)
		debarch="$UTS_MACHINE" ;;
	x86_64)
		debarch=amd64 ;;
	sparc*)
		debarch=sparc ;;
	s390*)
		debarch=s390$(grep -q CONFIG_64BIT=y $KCONFIG_CONFIG && echo x || true) ;;
	ppc*)
		debarch=$(grep -q CPU_LITTLE_ENDIAN=y $KCONFIG_CONFIG && echo ppc64el || echo powerpc) ;;
	parisc*)
		debarch=hppa ;;
	mips*)
		debarch=mips$(grep -q CPU_LITTLE_ENDIAN=y $KCONFIG_CONFIG && echo el || true) ;;
	aarch64|arm64)
		debarch=arm64 ;;
	arm*)
		if grep -q CONFIG_AEABI=y $KCONFIG_CONFIG; then
		    if grep -q CONFIG_VFP=y $KCONFIG_CONFIG; then
			debarch=armhf
		    else
			debarch=armel
		    fi
		else
		    debarch=arm
		fi
		;;
	*)
		debarch=$(dpkg --print-architecture)
		echo "" >&2
		echo "** ** **  WARNING  ** ** **" >&2
		echo "" >&2
		echo "Your architecture doesn't have its equivalent" >&2
		echo "Debian userspace architecture defined!" >&2
		echo "Falling back to using your current userspace instead!" >&2
		echo "Please add support for $UTS_MACHINE to ${0} ..." >&2
		echo "" >&2
	esac
	if [ -n "$KBUILD_DEBARCH" ] ; then
		debarch="$KBUILD_DEBARCH"
	fi
	forcearch="-DArchitecture=$debarch"

}

# Some variables and settings used throughout the script
version=$KERNELRELEASE
revision=$(cat .version)
if [ -n "$KDEB_PKGVERSION" ]; then
	packageversion=$KDEB_PKGVERSION
else
	packageversion=$version-$revision
fi
sourcename=$KDEB_SOURCENAME
tmpdir="$objtree/debian/tmp"
kernel_headers_dir="$objtree/debian/hdrtmp"
libc_headers_dir="$objtree/debian/headertmp"
dbg_dir="$objtree/debian/dbgtmp"
packagename=linux-image-$version
kernel_headers_packagename=linux-headers-$version
libc_headers_packagename=linux-libc-dev
dbg_packagename=$packagename-dbg
debarch=
forcearch=
set_debarch

if [ "$ARCH" = "um" ] ; then
	packagename=user-mode-linux-$version
fi

# Not all arches have the same installed path in debian
# XXX: have each arch Makefile export a variable of the canonical image install
# path instead
case $ARCH in
um)
	installed_image_path="usr/bin/linux-$version"
	;;
parisc|mips|powerpc)
	installed_image_path="boot/vmlinux-$version"
	;;
*)
	installed_image_path="boot/vmlinuz-$version"
esac

BUILD_DEBUG="$(grep -s '^CONFIG_DEBUG_INFO=y' $KCONFIG_CONFIG || true)"

# Setup the directory structure
rm -rf "$tmpdir" "$kernel_headers_dir" "$libc_headers_dir" "$dbg_dir" $objtree/debian/files
mkdir -m 755 -p "$tmpdir/DEBIAN"
mkdir -p "$tmpdir/lib" "$tmpdir/boot"
mkdir -p "$kernel_headers_dir/lib/modules/$version/"

# Build and install the kernel
if [ "$ARCH" = "um" ] ; then
	mkdir -p "$tmpdir/usr/lib/uml/modules/$version" "$tmpdir/usr/bin" "$tmpdir/usr/share/doc/$packagename"
	$MAKE linux
	cp System.map "$tmpdir/usr/lib/uml/modules/$version/System.map"
	cp $KCONFIG_CONFIG "$tmpdir/usr/share/doc/$packagename/config"
	gzip "$tmpdir/usr/share/doc/$packagename/config"
else
	cp System.map "$tmpdir/boot/System.map-$version"
	cp $KCONFIG_CONFIG "$tmpdir/boot/config-$version"
fi
cp "$($MAKE -s -f $srctree/Makefile image_name)" "$tmpdir/$installed_image_path"

if grep -q "^CONFIG_OF=y" $KCONFIG_CONFIG ; then
	# Only some architectures with OF support have this target
	if grep -q dtbs_install "${srctree}/arch/$SRCARCH/Makefile"; then
		$MAKE KBUILD_SRC= INSTALL_DTBS_PATH="$tmpdir/usr/lib/$packagename" dtbs_install
	fi
fi

if grep -q '^CONFIG_MODULES=y' $KCONFIG_CONFIG ; then
	INSTALL_MOD_PATH="$tmpdir" $MAKE KBUILD_SRC= modules_install
	rm -f "$tmpdir/lib/modules/$version/build"
	rm -f "$tmpdir/lib/modules/$version/source"
	if [ "$ARCH" = "um" ] ; then
		mv "$tmpdir/lib/modules/$version"/* "$tmpdir/usr/lib/uml/modules/$version/"
		rmdir "$tmpdir/lib/modules/$version"
	fi
	if [ -n "$BUILD_DEBUG" ] ; then
		for module in $(find $tmpdir/lib/modules/ -name *.ko -printf '%P\n'); do
			module=lib/modules/$module
			mkdir -p $(dirname $dbg_dir/usr/lib/debug/$module)
			# only keep debug symbols in the debug file
			$OBJCOPY --only-keep-debug $tmpdir/$module $dbg_dir/usr/lib/debug/$module
			# strip original module from debug symbols
			$OBJCOPY --strip-debug $tmpdir/$module
			# then add a link to those
			$OBJCOPY --add-gnu-debuglink=$dbg_dir/usr/lib/debug/$module $tmpdir/$module
		done

		# resign stripped modules
		MODULE_SIG_ALL="$(grep -s '^CONFIG_MODULE_SIG_ALL=y' $KCONFIG_CONFIG || true)"
		if [ -n "$MODULE_SIG_ALL" ]; then
			INSTALL_MOD_PATH="$tmpdir" $MAKE KBUILD_SRC= modules_sign
		fi
	fi
fi

if [ "$ARCH" != "um" ]; then
	$MAKE headers_check KBUILD_SRC=
	$MAKE headers_install KBUILD_SRC= INSTALL_HDR_PATH="$libc_headers_dir/usr"
fi

# Install the maintainer scripts
# Note: hook scripts under /etc/kernel are also executed by official Debian
# kernel packages, as well as kernel packages built using make-kpkg.
# make-kpkg sets $INITRD to indicate whether an initramfs is wanted, and
# so do we; recent versions of dracut and initramfs-tools will obey this.
debhookdir=${KDEB_HOOKDIR:-/etc/kernel}
if grep -q '^CONFIG_BLK_DEV_INITRD=y' $KCONFIG_CONFIG; then
	want_initrd=Yes
else
	want_initrd=No
fi
for script in postinst postrm preinst prerm ; do
	mkdir -p "$tmpdir$debhookdir/$script.d"
	cat <<EOF > "$tmpdir/DEBIAN/$script"
#!/bin/sh

set -e

# Pass maintainer script parameters to hook scripts
export DEB_MAINT_PARAMS="\$*"

# Tell initramfs builder whether it's wanted
export INITRD=$want_initrd

test -d $debhookdir/$script.d && run-parts --arg="$version" --arg="/$installed_image_path" $debhookdir/$script.d
exit 0
EOF
	chmod 755 "$tmpdir/DEBIAN/$script"
done

# Try to determine maintainer and email values
if [ -n "$DEBEMAIL" ]; then
       email=$DEBEMAIL
elif [ -n "$EMAIL" ]; then
       email=$EMAIL
else
       email=$(id -nu)@$(hostname -f 2>/dev/null || hostname)
fi
if [ -n "$DEBFULLNAME" ]; then
       name=$DEBFULLNAME
elif [ -n "$NAME" ]; then
       name=$NAME
else
       name="Anonymous"
fi
maintainer="$name <$email>"

# Try to determine distribution
if [ -n "$KDEB_CHANGELOG_DIST" ]; then
        distribution=$KDEB_CHANGELOG_DIST
# In some cases lsb_release returns the codename as n/a, which breaks dpkg-parsechangelog
elif distribution=$(lsb_release -cs 2>/dev/null) && [ -n "$distribution" ] && [ "$distribution" != "n/a" ]; then
        : # nothing to do in this case
else
        distribution="unstable"
        echo >&2 "Using default distribution of 'unstable' in the changelog"
        echo >&2 "Install lsb-release or set \$KDEB_CHANGELOG_DIST explicitly"
fi

# Generate a simple changelog template
cat <<EOF > debian/changelog
$sourcename ($packageversion) $distribution; urgency=low

  * Custom built GNU Linux-libre.

 -- $maintainer  $(date -R)
EOF

# Generate copyright file
cat <<EOF > debian/copyright
This is a packacked upstream version of the GNU Linux-libre.

The sources may be found at most Linux archive sites, including:
https://linux-libre.fsfla.org/

Copyright: 1991 - 2017 Linus Torvalds and others.

The git repository for mainline kernel development is at:
/*(DEBLOBBED)*/

    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation; version 2 dated June, 1991.

On Debian GNU/Linux systems, the complete text of the GNU General Public
License version 2 can be found in \`/usr/share/common-licenses/GPL-2'.
EOF


build_depends="bc, kmod, cpio "

# Generate a control file
cat <<EOF > debian/control
Source: $sourcename
Section: kernel
Priority: optional
Maintainer: $maintainer
Build-Depends: $build_depends
Homepage: https://linux-libre.fsfla.org/
EOF

if [ "$ARCH" = "um" ]; then
	cat <<EOF >> debian/control

Package: $packagename
Architecture: any
Description: User Mode GNU Linux-libre, version $version
 User-mode Linux is a port of the GNU Linux-libre to its own system call
 interface.  It provides a kind of virtual machine, which runs Linux
 as a user process under another GNU Linux-libre.  This is useful for
 kernel development, sandboxes, jails, experimentation, and
 many other things.
 .
 This package contains the GNU Linux-libre, modules and corresponding other
 files, version: $version.
EOF

else
	cat <<EOF >> debian/control

Package: $packagename
Architecture: any
Description: GNU Linux-libre, version $version
 This package contains the GNU Linux-libre, modules and corresponding other
 files, version: $version.
EOF

fi

# Build kernel header package
(cd $srctree; find . -name Makefile\* -o -name Kconfig\* -o -name \*.pl) > "$objtree/debian/hdrsrcfiles"
(cd $srctree; find arch/*/include include scripts -type f -o -type l) >> "$objtree/debian/hdrsrcfiles"
(cd $srctree; find arch/$SRCARCH -name module.lds -o -name Kbuild.platforms -o -name Platform) >> "$objtree/debian/hdrsrcfiles"
(cd $srctree; find $(find arch/$SRCARCH -name include -o -name scripts -type d) -type f) >> "$objtree/debian/hdrsrcfiles"
if grep -q '^CONFIG_STACK_VALIDATION=y' $KCONFIG_CONFIG ; then
	(cd $objtree; find tools/objtool -type f -executable) >> "$objtree/debian/hdrobjfiles"
fi
(cd $objtree; find arch/$SRCARCH/include Module.symvers include scripts -type f) >> "$objtree/debian/hdrobjfiles"
if grep -q '^CONFIG_GCC_PLUGINS=y' $KCONFIG_CONFIG ; then
	(cd $objtree; find scripts/gcc-plugins -name \*.so -o -name gcc-common.h) >> "$objtree/debian/hdrobjfiles"
fi
destdir=$kernel_headers_dir/usr/src/linux-headers-$version
mkdir -p "$destdir"
(cd $srctree; tar -c -f - -T -) < "$objtree/debian/hdrsrcfiles" | (cd $destdir; tar -xf -)
(cd $objtree; tar -c -f - -T -) < "$objtree/debian/hdrobjfiles" | (cd $destdir; tar -xf -)
(cd $objtree; cp $KCONFIG_CONFIG $destdir/.config) # copy .config manually to be where it's expected to be
ln -sf "/usr/src/linux-headers-$version" "$kernel_headers_dir/lib/modules/$version/build"
rm -f "$objtree/debian/hdrsrcfiles" "$objtree/debian/hdrobjfiles"

cat <<EOF >> debian/control

Package: $kernel_headers_packagename
Architecture: any
Description: GNU Linux-libre headers for $KERNELRELEASE on \${kernel:debarch}
 This package provides kernel header files for $KERNELRELEASE on \${kernel:debarch}
 .
 This is useful for people who need to build external modules
EOF

cat <<EOF >> debian/control

Package: $libc_headers_packagename
Section: devel
Provides: linux-kernel-headers
Architecture: any
Description: Linux support headers for userspace development
 This package provides userspaces headers from the GNU Linux-libre.  These headers
 are used by the installed headers for GNU glibc and other system libraries.
EOF

if [ "$ARCH" != "um" ]; then
	create_package "$kernel_headers_packagename" "$kernel_headers_dir"
	create_package "$libc_headers_packagename" "$libc_headers_dir"
fi

create_package "$packagename" "$tmpdir"

if [ -n "$BUILD_DEBUG" ] ; then
	# Build debug package
	# Different tools want the image in different locations
	# perf
	mkdir -p $dbg_dir/usr/lib/debug/lib/modules/$version/
	cp vmlinux $dbg_dir/usr/lib/debug/lib/modules/$version/
	# systemtap
	mkdir -p $dbg_dir/usr/lib/debug/boot/
	ln -s ../lib/modules/$version/vmlinux $dbg_dir/usr/lib/debug/boot/vmlinux-$version
	# kdump-tools
	ln -s lib/modules/$version/vmlinux $dbg_dir/usr/lib/debug/vmlinux-$version

	cat <<EOF >> debian/control

Package: $dbg_packagename
Section: debug
Architecture: any
Description: GNU Linux-libre debugging symbols for $version
 This package will come in handy if you need to debug the kernel. It provides
 all the necessary debug symbols for the kernel and its modules.
EOF

	create_package "$dbg_packagename" "$dbg_dir"
fi

if [ "x$1" = "xdeb-pkg" ]
then
    cat <<EOF > debian/rules
#!/usr/bin/make -f

build:
	\$(MAKE)

binary-arch:
	\$(MAKE) KDEB_SOURCENAME=${sourcename} KDEB_PKGVERSION=${packageversion} bindeb-pkg

clean:
	rm -rf debian/*tmp debian/files
	mv debian/ debian.backup # debian/ might be cleaned away
	\$(MAKE) clean
	mv debian.backup debian

binary: binary-arch
EOF
	mv ${sourcename}.tar.gz ../${sourcename}_${version}.orig.tar.gz
	tar caf ../${sourcename}_${packageversion}.debian.tar.gz debian/{copyright,rules,changelog,control}
	dpkg-source -cdebian/control -ldebian/changelog --format="3.0 (custom)" --target-format="3.0 (quilt)" \
		-b / ../${sourcename}_${version}.orig.tar.gz  ../${sourcename}_${packageversion}.debian.tar.gz
	mv ${sourcename}_${packageversion}*dsc ..
	dpkg-genchanges -Vkernel:debarch="${debarch}" > ../${sourcename}_${packageversion}_${debarch}.changes
else
	dpkg-genchanges -b -Vkernel:debarch="${debarch}" > ../${sourcename}_${packageversion}_${debarch}.changes
fi

exit 0
