From a791710776bd21fc2bc64d647ee2af61e23c4585 Mon Sep 17 00:00:00 2001
From: =?utf8?q?Paul=20H=C3=A4nsch?= <paul@plutz.net>
Date: Mon, 20 Apr 2026 06:35:39 +0200
Subject: [PATCH] target for UEFI hard disk images

---
 targets/hddimage.mk | 152 ++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 152 insertions(+)
 create mode 100644 targets/hddimage.mk

diff --git a/targets/hddimage.mk b/targets/hddimage.mk
new file mode 100644
index 0000000..c57d106
--- /dev/null
+++ b/targets/hddimage.mk
@@ -0,0 +1,152 @@
+fstype := ext4
+
+# Partition Table (1M) + Boot Partition Root Partition + Slack Space (1M)
+imagesize ?= 4096
+BOOT_MB := 127
+ROOT_MB := $(shell printf '%i\n' "$$(( ${imagesize} - ${BOOT_MB} - 2 ))")
+
+define PARTLAYOUT :=
+label: gpt
+: start=1MiB, size=${BOOT_MB}MiB, type=C12A7328-F81F-11D2-BA4B-00A0C93EC93B, attrs="LegacyBIOSBootable"
+: size=${ROOT_MB}MiB, type=0FC63DAF-8483-4772-8E79-3D69D8477DE4
+endef
+
+define FSTAB :=
+LABEL=FSROOT	/		${fstype}	auto,nofail,rw	0 0
+LABEL=SYSTEM	/boot/efi	vfat	auto,nofail,ro	0 0
+endef
+
+define GRUBCFG :=
+insmod normal
+insmod linux
+insmod all_video
+set timeout=3
+default=${release}
+
+menuentry 'Debian ${release}' --id '${release}' {
+  linux '/vmlinuz' root=LABEL=FSROOT
+  initrd '/initrd.img'
+}
+endef
+
+define GRUBINIT :=
+search --no-floppy --label FSROOT --set root
+set prefix=/boot/grub
+configfile grub.cfg
+endef
+
+VOLUME = ${image}
+PBOOT = part_boot.img.temp
+PROOT = part_root.img.temp
+CFGROOT := img_mount
+
+PACKAGES += grub-efi-amd64 grub-efi-ia32-bin
+  
+_sparse: ${PBOOT} ${PROOT}
+_format: _sparse
+_partition_gpt: _sparse
+_partcopy: _format
+_img_mount: _partcopy _partition_gpt
+_copy: _img_mount
+_bootloader_efi: _config
+_umount: _config _bootloader_efi
+_target: _umount
+_clean: _hddimage_clean
+
+export VOLUME PBOOT PROOT PARTLAYOUT GRUBCFG GRUBINIT
+
+img_mount:
+	mkdir -p -m 755 "$@"
+	chmod 755 "$@"
+
+${VOLUME}: .FORCE
+	dd count=0 of="$${VOLUME}"  # truncate
+	dd bs=1M count=0 seek=$$((2 + ${BOOT_MB} + ${ROOT_MB})) \
+	   of="$${VOLUME}"
+	chmod g+w "$${VOLUME}"
+
+${PBOOT}: .FORCE
+	dd count=0 of="$${PBOOT}"  # truncate
+	dd bs=1M count=0 seek=${BOOT_MB} of="$${PBOOT}"
+
+${PROOT}: .FORCE
+	dd count=0 of="$${PROOT}"  # truncate
+	dd bs=1M count=0 seek=${ROOT_MB} of="$${PROOT}"
+
+_partition_gpt: ${VOLUME}
+	printf '%s\n' "$${PARTLAYOUT}" | sfdisk "$${VOLUME}"
+
+_format_root: ${PROOT}
+	mkfs.${fstype} -L FSROOT "$${PROOT}"
+
+_format_boot: ${PBOOT}
+	mkfs.fat -F 32 -n SYSTEM "$${PBOOT}"
+
+_format: _format_root _format_boot
+
+_grub_mbr: ${VOLUME}
+	grub-mkimage -p / -O i386-pc ${fstype} \
+	  part_gpt normal linux all_video \
+	| dd conv=notrunc of="$${VOLUME}"
+
+${CFGROOT}/boot/efi/EFI/BOOT/BOOTIA32.EFI: _mount_boot
+	mkdir -p "$(@D)"
+	printf '%s\n' "$${GRUBINIT}" >"${@F}.temp"
+	grub-mkimage -p / -O i386-efi -o "$@" \
+	  ext2 fat part_gpt configfile search_label search \
+	  -c "${@F}.temp"
+	rm -- "${@F}.temp"
+
+${CFGROOT}/boot/efi/EFI/BOOT/BOOTX64.EFI: _mount_boot
+	mkdir -p "$(@D)"
+	printf '%s\n' "$${GRUBINIT}" >"${@F}.temp"
+	grub-mkimage -p / -O x86_64-efi -o "$@" \
+	  ext2 fat part_gpt configfile search_label search \
+	  -c "${@F}.temp"
+	rm -- "${@F}.temp"
+
+${CFGROOT}/boot/grub/grub.cfg: _copy
+	mkdir -p "$(@D)"
+	cp  -a "$${CFGROOT}"/usr/lib/grub/x86_64-efi/. "$(@D)/x86_64-efi"
+	-cp -a "$${CFGROOT}"/usr/lib/grub/i386-efi/.   "$(@D)/i386-efi"
+	printf '%s\n' "$${GRUBCFG}" >"$@"
+
+_bootloader_efi: ${CFGROOT}/boot/efi/EFI/BOOT/BOOTIA32.EFI
+_bootloader_efi: ${CFGROOT}/boot/efi/EFI/BOOT/BOOTX64.EFI
+_bootloader_efi: ${CFGROOT}/boot/grub/grub.cfg
+
+_partcopy: ${VOLUME} ${PROOT} ${PBOOT}
+	dd conv=notrunc,sparse bs=1M seek=1 \
+	   if="$${PBOOT}" of="$${VOLUME}"
+	dd conv=notrunc,sparse bs=1M seek=$$((1 + ${BOOT_MB})) \
+	   if="$${PROOT}" of="$${VOLUME}"
+	rm -- "$${PBOOT}" "$${PROOT}"
+
+_mount_root: ${CFGROOT}
+	mountpoint "$${CFGROOT}" \
+	|| mount \
+	   -o rw,loop,offset="$$((${BOOT_MB} + 1))"M,sizelimit=${ROOT_MB}M \
+	   -t ${fstype} "$${VOLUME}" "$${CFGROOT}"
+	chmod 755 "$${CFGROOT}"
+
+_mount_boot: _mount_root
+	mkdir -p -m 755 "$${CFGROOT}/boot/efi"
+	mountpoint "$${CFGROOT}/boot/efi" \
+	|| mount -o loop,offset=1M,sizelimit=${BOOT_MB}M \
+		 -t vfat "$${VOLUME}" "$${CFGROOT}/boot/efi"
+
+_img_mount: _mount_boot _mount_root
+
+_umount_boot: _config
+	-umount "$${CFGROOT}/boot/efi"
+
+_umount_root: _umount_boot _config
+	-umount "$${CFGROOT}"
+	rmdir "$${CFGROOT}"
+
+_umount: _umount_boot _umount_root
+
+_hddimage_clean: _umount_boot _umount_root
+	-rm -- "$${PBOOT}"
+	-rm -- "$${PROOT}"
+	-rm -- "$${VOLUME}"
-- 
2.39.5