From 4f4c945b3de79650cb76286967b182c79b1d1294 Mon Sep 17 00:00:00 2001
From: =?utf8?q?Paul=20H=C3=A4nsch?= <paul@plutz.net>
Date: Mon, 16 Sep 2019 11:21:45 +0200
Subject: [PATCH] produce BIOS bootable iso images

---
 Makefile | 49 +++++++++++++++++++++++++++++++++++++++----------
 1 file changed, 39 insertions(+), 10 deletions(-)

diff --git a/Makefile b/Makefile
index d3df894..887422c 100644
--- a/Makefile
+++ b/Makefile
@@ -5,10 +5,10 @@ comma_:= ,
 space_:= ${nul_} ${nul_}
 
 .PHONY: clean .FORCE _target
-.PHONY: _bootloader_raspi _bootloader_pc _partition_gpt _partition_raspi
+.PHONY: _bootloader_raspi _bootloader_pc _bootloader_iso _partition_gpt _partition_raspi
 .PHONY: _squash_modules
-.PHONY: _qemu _bootstrap _install _copy _config _squash
-.PHONY: _format _mount _sparse _umount _partcopy _mbr
+.PHONY: _qemu _bootstrap _install _copy _config _squash _isosquash
+.PHONY: _format _mount _sparse _umount _partcopy _mbr _iso_image
 
 ARCH := amd64
 BOOTSTRAP := http://cdn.debian.net/debian
@@ -34,11 +34,13 @@ else
   KEYRING := keys/debian-archive-stretch-stable.gpg
 endif
 
+ifndef SOURCES
 define SOURCES := 
 deb	http://cdn.debian.net/debian stretch main
 deb	http://cdn.debian.net/debian buster main
 deb	http://cdn.debian.net/debian ${release} main
 endef
+endif
 
 ifdef disk
   VOLUME := ${disk}
@@ -98,20 +100,21 @@ else ifdef squash
 
 else ifdef iso
   ISO := iso
-  SQUASH := rootfs.squash
+  ISOROOT := iso_root/
   SYSROOT := sys_root_${release}/
   CFGROOT := cfg_root/
 
   PACKAGES += squashfs-tools
   
-  _target: _isohybrid _install _config
+  _target: _iso_image _install _config
   
   _bootstrap:
   _install: _bootstrap
   _copy: _install
   _config: _copy _squash_modules
-  _squash: _config
-  _isohybrid: _squash
+  _isosquash: _config
+  _bootloader_iso: _config
+  _iso_image: _bootloader_iso _isosquash
 
 else ifdef raspi
   VOLUME := ${raspi}
@@ -163,20 +166,26 @@ else ifeq "${ARCH}" "i386"
   PACKAGES += linux-image-686
 endif
 
-export SOURCES SYSROOT CFGROOT VOLUME PBOOT PROOT SQUASH ARCH KEYRING BOOTSTRAP
+export SOURCES SYSROOT CFGROOT VOLUME PBOOT PROOT SQUASH ARCH KEYRING BOOTSTRAP ISOROOT ISO
 
 sys_root_${release}/:
 	btrfs subvol create "$@" || mkdir "$@"
 	chmod 755 "$@"
 
+rpi_root_${release}/:
+	btrfs subvol create "$@" || mkdir "$@"
+	chmod 755 "$@"
+
 cfg_root/: sys_root_${release}/ _install
 	-btrfs sub del "$@" || rm -r "$@"
 	btrfs sub snap "$<" "$@" || mkdir "$@"
 	chmod 755 "$@"
 
-rpi_root_${release}/:
+${ISOROOT}:
+	-btrfs sub del "$@" || rm -r "$@"
 	btrfs subvol create "$@" || mkdir "$@"
-	chmod 755 "$@"
+	mkdir "$@/live"
+	chmod 755 "$@" "$@/live"
 
 img_mount/:
 	mkdir -p -m 755 "$@"
@@ -245,6 +254,11 @@ _squash_modules: ${CFGROOT}
 
 _squash: ${SQUASH} _squash_modules
 
+_isosquash: ${ISOROOT}/live/live.squashfs
+${ISOROOT}/live/live.squashfs: ${CFGROOT} ${ISOROOT}
+	-rm "$@"
+	printf '%s\n' boot |mksquashfs "$${CFGROOT}" "$@" -comp xz -ef /dev/stdin
+
 ${VOLUME}: .FORCE
 	! printf '%s\n' "$${VOLUME}" |grep -q '^/dev/'  # abort if volume should be real device
 	dd count=0 of="$${VOLUME}"  # truncate
@@ -276,6 +290,12 @@ _format: ${PBOOT} ${PROOT}
 	mkfs.fat -F 32 -n BOOT "$${PBOOT}"
 	mkfs.ext4 -F -L FSROOT "$${PROOT}"
 
+_iso_image: ${ISOROOT}
+	xorriso -as mkisofs -o "$${ISO}" -b grub.bin -c boot.cat \
+		-no-emul-boot -boot-load-size 4 -boot-info-table \
+		-eltorito-alt-boot -e efi.img -no-emul-boot \
+		"$${ISOROOT}"
+
 .PHONY: _syslinux_efi32 _syslinux_efi64 _syslinux_bios
 .PHONY: _grub_efi32 _grub_efi64
 
@@ -327,6 +347,15 @@ _bootloader_pc: ${CFGROOT} _grub_efi32 _grub_efi64 _syslinux_bios #_syslinux_efi
 	printf "menuentry 'Rescue' --id 'rescue' {\n linux '/%s' root=LABEL=FSROOT init=/bin/sh\n initrd '/%s'\n}\n" \
 		"$$k" "$$i" >>"$${CFGROOT}/boot/grub.cfg"
 
+_bootloader_iso: ${CFGROOT} ${ISOROOT} _grub_efi32 _grub_efi64
+	grub-mkimage -p / -O i386-pc-eltorito biosdisk iso9660 normal linux all_video >"$${ISOROOT}/grub.bin"
+	grub-glue-efi -3 "$${CFGROOT}/boot/EFI/BOOT/BOOTIA32.EFI" -6 "$${CFGROOT}/boot/EFI/BOOT/BOOTX64.EFI" >"$${ISOROOT}/efi.img"
+	cp -L "$${CFGROOT}/vmlinuz" "$${CFGROOT}/initrd.img" "$${ISOROOT}"
+	printf '%s\n' "set timeout=10" "default=buster" \
+		"menuentry 'Debian Buster' --id 'buster' {" \
+		"linux '/vmlinuz' boot=live" "initrd '/initrd.img'" "}" \
+		>"$${ISOROOT}/grub.cfg"
+
 .PHONY: _syslinux_mbr _grub_mbr
 
 _syslinux_mbr: ${VOLUME}
-- 
2.39.2