[Buildroot] [PATCH v2 3/6] fs/iso9660: add support for hybrid image using Grub bootloader on BIOS and EFI

[Kory Maincent]

Add support for building an hybrid ISO9660 image compatible with legacy
and UEFI BIOS.
The option -eltorito-alt-boot need to be used in the xorriso command
to generate the hybrid image.

Signed-off-by: Kory Maincent <kory.maincent at bootlin.com>
---

Changes in v2:
- Fix typos

 fs/iso9660/iso9660.mk | 34 ++++++++++++++++++++++++----------
 1 file changed, 24 insertions(+), 10 deletions(-)

diff --git a/fs/iso9660/iso9660.mk b/fs/iso9660/iso9660.mk
index d46aec002b..499d19c9bb 100644
--- a/fs/iso9660/iso9660.mk
+++ b/fs/iso9660/iso9660.mk
@@ -66,18 +66,20 @@ ROOTFS_ISO9660_DEPENDENCIES += grub2
 ROOTFS_ISO9660_BOOTLOADER_CONFIG_PATH = \
 	$(ROOTFS_ISO9660_TMP_TARGET_DIR)/boot/grub/grub.cfg
 ROOTFS_ISO9660_BOOT_IMAGE = boot/grub/grub-eltorito.img
-define ROOTFS_ISO9660_INSTALL_BOOTLOADER
+define ROOTFS_ISO9660_INSTALL_BOOTLOADER_BIOS
 	$(INSTALL) -D -m 0644 $(BINARIES_DIR)/grub-eltorito.img \
 		$(ROOTFS_ISO9660_TMP_TARGET_DIR)/boot/grub/grub-eltorito.img
 endef
-else ifeq ($(BR2_TARGET_ROOTFS_ISO9660_GRUB2)$(BR2_TARGET_ROOTFS_ISO9660_EFI_BOOTLOADER),yy)
+endif
+
+ifeq ($(BR2_TARGET_ROOTFS_ISO9660_GRUB2)$(BR2_TARGET_ROOTFS_ISO9660_EFI_BOOTLOADER),yy)
 ROOTFS_ISO9660_DEPENDENCIES += grub2 host-dosfstools host-mtools
 ROOTFS_ISO9660_EFI_PARTITION = boot/fat.efi
 ROOTFS_ISO9660_EFI_PARTITION_PATH = $(ROOTFS_ISO9660_TMP_TARGET_DIR)/$(ROOTFS_ISO9660_EFI_PARTITION)
 ROOTFS_ISO9660_EFI_PARTITION_CONTENT = $(BINARIES_DIR)/efi-part
 ROOTFS_ISO9660_BOOTLOADER_CONFIG_PATH = \
 	$(ROOTFS_ISO9660_TMP_TARGET_DIR)/boot/grub/grub.cfg
-define ROOTFS_ISO9660_INSTALL_BOOTLOADER
+define ROOTFS_ISO9660_INSTALL_BOOTLOADER_EFI
 	rm -rf $(ROOTFS_ISO9660_EFI_PARTITION_PATH)
 	mkdir -p $(dir $(ROOTFS_ISO9660_EFI_PARTITION_PATH))
 	dd if=/dev/zero of=$(ROOTFS_ISO9660_EFI_PARTITION_PATH) bs=1M count=1
@@ -85,12 +87,14 @@ define ROOTFS_ISO9660_INSTALL_BOOTLOADER
 	$(HOST_DIR)/bin/mcopy -p -m -i $(ROOTFS_ISO9660_EFI_PARTITION_PATH) -s \
 		$(ROOTFS_ISO9660_EFI_PARTITION_CONTENT)/* ::/
 endef
-else ifeq ($(BR2_TARGET_ROOTFS_ISO9660_ISOLINUX),y)
+endif
+
+ifeq ($(BR2_TARGET_ROOTFS_ISO9660_ISOLINUX),y)
 ROOTFS_ISO9660_DEPENDENCIES += syslinux
 ROOTFS_ISO9660_BOOTLOADER_CONFIG_PATH = \
 	$(ROOTFS_ISO9660_TMP_TARGET_DIR)/isolinux/isolinux.cfg
 ROOTFS_ISO9660_BOOT_IMAGE = isolinux/isolinux.bin
-define ROOTFS_ISO9660_INSTALL_BOOTLOADER
+define ROOTFS_ISO9660_INSTALL_BOOTLOADER_BIOS
 	$(INSTALL) -D -m 0644 $(BINARIES_DIR)/syslinux/* \
 		$(ROOTFS_ISO9660_TMP_TARGET_DIR)/isolinux/
 	$(INSTALL) -D -m 0644 $(HOST_DIR)/share/syslinux/ldlinux.c32 \
@@ -103,7 +107,8 @@ define ROOTFS_ISO9660_PREPARATION
 		$(ROOTFS_ISO9660_BOOTLOADER_CONFIG_PATH)
 	$(SED) "s%__KERNEL_PATH__%/boot/$(LINUX_IMAGE_NAME)%" \
 		$(ROOTFS_ISO9660_BOOTLOADER_CONFIG_PATH)
-	$(ROOTFS_ISO9660_INSTALL_BOOTLOADER)
+	$(ROOTFS_ISO9660_INSTALL_BOOTLOADER_BIOS)
+	$(ROOTFS_ISO9660_INSTALL_BOOTLOADER_EFI)
 endef
 
 ROOTFS_ISO9660_PRE_GEN_HOOKS += ROOTFS_ISO9660_PREPARATION
@@ -147,23 +152,32 @@ ROOTFS_ISO9660_PRE_GEN_HOOKS += ROOTFS_ISO9660_DISABLE_EXTERNAL_INITRD
 
 endif # ROOTFS_ISO9660_USE_INITRD
 
-ifeq ($(BR2_TARGET_ROOTFS_ISO9660_BIOS_BOOTLOADER),y)
-ROOTFS_ISO9660_OPTS += \
+ROOTFS_ISO9660_BOOTLOADER_OPTS_BIOS = \
 	-J \
 	-R \
 	-boot-load-size 4 \
 	-boot-info-table \
 	-no-emul-boot \
 	-b $(ROOTFS_ISO9660_BOOT_IMAGE)
-else ifeq ($(BR2_TARGET_ROOTFS_ISO9660_EFI_BOOTLOADER),y)
-ROOTFS_ISO9660_OPTS += \
+
+ROOTFS_ISO9660_BOOTLOADER_OPTS_EFI = \
 	--efi-boot $(ROOTFS_ISO9660_EFI_PARTITION) \
 	-no-emul-boot
+
+ifeq ($(BR2_TARGET_ROOTFS_ISO9660_BIOS_BOOTLOADER)$(BR2_TARGET_ROOTFS_ISO9660_EFI_BOOTLOADER),yy)
+ROOTFS_ISO9660_BOOTLOADER_OPTS = $(ROOTFS_ISO9660_BOOTLOADER_OPTS_BIOS)
+ROOTFS_ISO9660_BOOTLOADER_OPTS += -eltorito-alt-boot
+ROOTFS_ISO9660_BOOTLOADER_OPTS += $(ROOTFS_ISO9660_BOOTLOADER_OPTS_EFI)
+else ifeq ($(BR2_TARGET_ROOTFS_ISO9660_BIOS_BOOTLOADER),y)
+ROOTFS_ISO9660_BOOTLOADER_OPTS = $(ROOTFS_ISO9660_BOOTLOADER_OPTS_BIOS)
+else ifeq ($(BR2_TARGET_ROOTFS_ISO9660_EFI_BOOTLOADER),y)
+ROOTFS_ISO9660_BOOTLOADER_OPTS = $(ROOTFS_ISO9660_BOOTLOADER_OPTS_EFI)
 endif
 
 define ROOTFS_ISO9660_CMD
 	$(HOST_DIR)/bin/xorriso -as mkisofs \
 		$(ROOTFS_ISO9660_OPTS) \
+		$(ROOTFS_ISO9660_BOOTLOADER_OPTS) \
 		-o $@ $(ROOTFS_ISO9660_TMP_TARGET_DIR)
 endef
 
-- 
2.25.1