From: nbd <nbd@3c298f89-4303-0410-b956-a3cf2f4a3e73>
Date: Sun, 7 Oct 2012 23:01:52 +0000
Subject: x86: add grub2 iso support

diff --git a/Config.in b/Config.in
index 5b4522e..54df7c8 100644
--- a/Config.in
+++ b/Config.in
@@ -81,7 +81,7 @@ menu "Target Images"
 	config TARGET_ROOTFS_ISO
 		bool "iso"
 		default n
-		depends TARGET_ROOTFS_INITRAMFS && TARGET_x86
+		depends on TARGET_x86_generic
 		help
 		  Create some bootable ISO image
 
diff --git a/target/linux/x86/base-files/lib/preinit/20_check_iso b/target/linux/x86/base-files/lib/preinit/20_check_iso
new file mode 100644
index 0000000..beff6eb
--- /dev/null
+++ b/target/linux/x86/base-files/lib/preinit/20_check_iso
@@ -0,0 +1,5 @@
+check_for_iso() {
+	grep -qE '/dev/root.*iso9660' /proc/mounts && ramoverlay
+}
+
+boot_hook_add preinit_mount_root check_for_iso
diff --git a/target/linux/x86/image/Makefile b/target/linux/x86/image/Makefile
index 13da511..8f0debd 100644
--- a/target/linux/x86/image/Makefile
+++ b/target/linux/x86/image/Makefile
@@ -9,7 +9,8 @@ include $(INCLUDE_DIR)/image.mk
 
 export PATH=$(TARGET_PATH):/sbin
 
-GRUB2_MODULES = biosdisk boot chain configfile ext2 linux ls part_msdos reboot serial vga
+GRUB2_MODULES = at_keyboard biosdisk boot chain configfile ext2 linux ls part_msdos reboot serial vga
+GRUB2_MODULES_ISO = at_keyboard biosdisk boot chain configfile iso9660 linux ls part_msdos reboot serial vga
 GRUB_TERMINALS =
 GRUB_SERIAL_CONFIG =
 GRUB_TERMINAL_CONFIG =
@@ -51,7 +52,7 @@ ifneq ($(CONFIG_X86_GRUB_IMAGES),)
   define Image/cmdline/ext4
     root=$(ROOTPART) rootfstype=ext4 rootwait
   endef
-  
+
   define Image/cmdline/jffs2-64k
     block2mtd.block2mtd=$(ROOTPART),65536,rootfs root=/dev/mtdblock0 rootfstype=jffs2 rootwait
   endef
@@ -165,7 +166,31 @@ define Image/Build/squashfs
 	$(call prepare_generic_squashfs,$(KDIR)/root.squashfs)
 endef
 
-define Image/Build/iso 
+ifdef CONFIG_X86_USE_GRUB2
+  define Image/Build/iso
+	$(INSTALL_DIR) $(KDIR)/root.grub/boot/grub $(KDIR)/grub2
+	$(CP) $(KDIR)/bzImage $(KDIR)/root.grub/boot/vmlinuz
+	grub-mkimage \
+		-o $(KDIR)/grub2/eltorito.img \
+		-O i386-pc \
+		-c ./grub-early.cfg \
+		$(GRUB2_MODULES_ISO)
+	cat \
+		$(STAGING_DIR_HOST)/lib/grub/i386-pc/cdboot.img \
+		$(KDIR)/grub2/eltorito.img \
+		> $(KDIR)/root.grub/boot/grub/eltorito.img
+	sed \
+		-e 's#@SERIAL_CONFIG@#$(strip $(GRUB_SERIAL_CONFIG))#g' \
+		-e 's#@TERMINAL_CONFIG@#$(strip $(GRUB_TERMINAL_CONFIG))#g' \
+		-e 's#@CMDLINE@#root=/dev/sr0 rootfstype=iso9660 rootwait $(strip $(call Image/cmdline/$(1)) $(BOOTOPTS) $(GRUB_CONSOLE_CMDLINE))#g' \
+		-e 's#@TIMEOUT@#$(GRUB_TIMEOUT)#g' \
+		./grub-iso.cfg > $(KDIR)/root.grub/boot/grub/grub.cfg
+	$(CP) $(KDIR)/bzImage $(KDIR)/root.grub/boot/vmlinuz
+	mkisofs -R -b boot/grub/eltorito.img -no-emul-boot -boot-info-table \
+		-o $(KDIR)/root.iso $(KDIR)/root.grub $(TARGET_DIR)
+  endef
+else
+  define Image/Build/iso
 	$(INSTALL_DIR) $(KDIR)/root.grub/boot/grub
 	$(CP) \
 		$(KDIR)/stage2_eltorito \
@@ -179,7 +204,8 @@ define Image/Build/iso
 	$(CP) $(KDIR)/bzImage $(KDIR)/root.grub/boot/vmlinuz 
 	mkisofs -R -b boot/grub/stage2_eltorito -no-emul-boot -boot-load-size 4 -boot-info-table \
 		-o $(KDIR)/root.iso $(KDIR)/root.grub 
-endef 
+  endef
+endif
 
 ifneq ($(CONFIG_X86_VDI_IMAGES),)
   define Image/Build/vdi
diff --git a/target/linux/x86/image/grub-iso.cfg b/target/linux/x86/image/grub-iso.cfg
new file mode 100644
index 0000000..4d5d697
--- /dev/null
+++ b/target/linux/x86/image/grub-iso.cfg
@@ -0,0 +1,10 @@
+@SERIAL_CONFIG@
+@TERMINAL_CONFIG@
+
+set default="0"
+set timeout="@TIMEOUT@"
+set root='(cd)'
+
+menuentry "OpenWrt" {
+	linux /boot/vmlinuz @CMDLINE@ noinitrd reboot=bios
+}