Add support for making ext[234] or btrfs hdd images bootable with extlinux (Closes: #745816)

extlinux configuration for the bootable image is installed to
/boot/extlinux, matching the extlinux-install script in Debian.

From the configuration point of view it's still called "syslinux",
the same as the rest of the syslinux family (pxelinux, isolinux etc.)

4 files changed, 61 insertions, 23 deletions

diff --git a/debian/live-build.bug-script b/debian/live-build.bug-script
index 4c2a21eeb..8a68d3038 100644
--- a/debian/live-build.bug-script
+++ b/debian/live-build.bug-script
@@ -6,7 +6,7 @@ DEFAULT_SETTINGS="/etc/live/build.conf"
 dpkg -l debootstrap cdebootstrap
 
 # Checking suggests
-dpkg -l dosfstools xorriso loadlin memtest86+ memtest86 mtools parted squashfs-tools mtd-tools syslinux grub uuid-runtime win32-loader
+dpkg -l dosfstools xorriso loadlin memtest86+ memtest86 mtools parted squashfs-tools mtd-tools syslinux syslinux-common extlinux grub uuid-runtime win32-loader
 
 if [ -e "${DEFAULT_SETTINGS}" ]; then
 	echo "Contents of ${DEFAULT_SETTINGS}:"
diff --git a/functions/defaults.sh b/functions/defaults.sh
index 92f006797..b1c22e2ad 100755
--- a/functions/defaults.sh
+++ b/functions/defaults.sh
@@ -1061,12 +1061,12 @@ Check_defaults ()
 
 	if [ "${LB_BOOTLOADER}" = "syslinux" ]
 	then
-		# syslinux + fat
+		# syslinux + fat or ntfs, or extlinux + ext[234] or btrfs
 		case "${LB_BINARY_FILESYSTEM}" in
-			fat*|ntfs)
+			fat*|ntfs|ext[234]|btrfs)
 				;;
 			*)
-				Echo_warning "You have selected values of LB_BOOTLOADER and LB_BINARY_FILESYSTEM which are incompatible - syslinux only supports FAT and NTFS filesystems."
+				Echo_warning "You have selected values of LB_BOOTLOADER and LB_BINARY_FILESYSTEM which are incompatible - the syslinux family only support FAT, NTFS, ext[234] or btrfs filesystems."
 				;;
 		esac
 	fi
diff --git a/scripts/build/binary_hdd b/scripts/build/binary_hdd
index e335a81b7..1868d9d9b 100755
--- a/scripts/build/binary_hdd
+++ b/scripts/build/binary_hdd
@@ -77,7 +77,19 @@ case "${LB_BOOTLOADER}" in
 		;;
 
 	syslinux)
-		Check_package chroot/usr/bin/syslinux syslinux
+		case ${LB_BINARY_FILESYSTEM} in
+			fat*|ntfs)
+				_BOOTLOADER=syslinux
+				;;
+			ext[234]|btrfs)
+				_BOOTLOADER=extlinux
+				;;
+			*)
+				Echo_error "syslinux/extlinux doesn't support ${LB_BINARY_FILESYSTEM}"
+				exit 1
+				;;
+		esac
+		Check_package chroot/usr/bin/${_BOOTLOADER} ${_BOOTLOADER}
 		;;
 esac
 
@@ -179,7 +191,7 @@ case "${LB_BUILD_WITH_CHROOT}" in
 
 		if [ "${LB_BOOTLOADER}" = "syslinux" ]
 		then
-			dd if=chroot/usr/lib/syslinux/mbr.bin of=${FREELO} bs=440 count=1
+			dd if=chroot/usr/lib/${_BOOTLOADER}/mbr.bin of=${FREELO} bs=440 count=1
 		fi
 		;;
 
@@ -191,7 +203,7 @@ case "${LB_BUILD_WITH_CHROOT}" in
 
 		if [ "${LB_BOOTLOADER}" = "syslinux" ]
 		then
-			dd if=/usr/lib/syslinux/mbr.bin of=${FREELO} bs=440 count=1
+			dd if=/usr/lib/${_BOOTLOADER}/mbr.bin of=${FREELO} bs=440 count=1
 		fi
 		;;
 esac
@@ -247,6 +259,8 @@ case "${LB_BINARY_FILESYSTEM}" in
 		;;
 esac
 
+Echo_message "Copying binary contents into image..."
+
 mkdir -p chroot/binary.tmp
 mount ${MOUNT_OPTIONS} ${FREELO} chroot/binary.tmp
 cp -T ${CP_OPTIONS} binary/ chroot/binary.tmp
@@ -282,22 +296,33 @@ EOF
 fi
 }
 
-umount chroot/binary.tmp
-rmdir chroot/binary.tmp
+case "${_BOOTLOADER}" in
+	syslinux)
+		_SYSLINUX_INSTALLER="syslinux ${FREELO}"
+		;;
+	extlinux)
+		_SYSLINUX_INSTALLER="extlinux --install /binary.tmp/boot/extlinux"
+		;;
+	*)
+		_SYSLINUX_INSTALLER=""
+		;;
+esac
 
-if [ "${LB_BOOTLOADER}" = "syslinux" ]
+if [ -n "${_SYSLINUX_INSTALLER}" ]
 then
 	case "${LB_BUILD_WITH_CHROOT}" in
 		true)
-			Chroot chroot "syslinux ${FREELO}"
+			Chroot chroot "${_SYSLINUX_INSTALLER}"
 			;;
-
 		false)
-			syslinux ${FREELO}
+			${_SYSLINUX_INSTALLER}
 			;;
 	esac
 fi
 
+umount chroot/binary.tmp
+rmdir chroot/binary.tmp
+
 Lodetach ${FREELO}
 
 echo "!!! The above error/warning messages can be ignored !!!"
diff --git a/scripts/build/binary_syslinux b/scripts/build/binary_syslinux
index 1cf7f75ff..9d32e222f 100755
--- a/scripts/build/binary_syslinux
+++ b/scripts/build/binary_syslinux
@@ -79,15 +79,28 @@ case "${LIVE_IMAGE_TYPE}" in
 		;;
 
 	hdd*|*)
-		_BOOTLOADER="syslinux"
-
-		case "${LB_MODE}" in
-			progress-linux)
-				_TARGET="binary/boot"
+		case ${LB_BINARY_FILESYSTEM} in
+			fat*|ntfs)
+				_BOOTLOADER=syslinux
+
+				case "${LB_MODE}" in
+					progress-linux)
+						_TARGET="binary/boot"
+						;;
+
+					*)
+						_TARGET="binary/syslinux"
+						;;
+				esac
 				;;
 
+			ext[234]|btrfs)
+				_BOOTLOADER=extlinux
+				_TARGET="binary/boot/extlinux"
+				;;
 			*)
-				_TARGET="binary/syslinux"
+				Echo_error "syslinux/extlinux doesn't support ${LB_BINARY_FILESYSTEM}"
+				exit 1
 				;;
 		esac
 		;;
@@ -110,7 +123,7 @@ fi
 # Checking depends
 case "${LB_BUILD_WITH_CHROOT}" in
 	true)
-		Check_package chroot/usr/bin/syslinux syslinux
+		Check_package chroot/usr/bin/${_BOOTLOADER} ${_BOOTLOADER}
 		Check_package chroot/usr/lib/syslinux syslinux-common
 
 		if ls "${_SOURCE}"/*.svg* > /dev/null 2>&1
@@ -120,10 +133,10 @@ case "${LB_BUILD_WITH_CHROOT}" in
 		;;
 
 	false)
-		if [ ! -e /usr/bin/syslinux ]
+		if [ ! -e /usr/bin/${_BOOTLOADER} ]
 		then
-			# syslinux
-			Echo_error "/usr/bin/syslinux - no such file."
+			# syslinux or extlinux
+			Echo_error "/usr/bin/${_BOOTLOADER} - no such file."
 			exit 1
 		fi