Add grub-iso target in 64-bit make file for test purposes.

build64/Makefile

@@ -132,4 +132,57 @@ memtest.iso: memtest.mbr floppy.img esp.img
 iso: memtest.iso
 
 clean:
-	rm -rf boot system lib tests app *.img *.iso memtest* iso
+	rm -rf boot system lib tests app *.img *.iso memtest* iso grub-*
+
+# grub-memtest.iso can be used for testing the various different boot modes,
+# using GRUB as an intermediate bootloader. Upstream GRUB only supports the
+# 16-bit and 32-bit boot protocols, via the "linux16" and "linux" commands.
+# Fedora add support for the EFI handover boot protocols, via the "linuxefi"
+# command, and, since 2019, remove support for the 32-bit protocol, aliasing
+# the "linux" command to either "linux16" or "linuxefi", depending on whether
+# you boot in legacy or EFI mode. Mageia follows Fedora, but restores support
+# for the 32-bit protocol, via the "linux32" command. Other distributions no
+# doubt do their own thing. The boot menu on grub-memtest.iso attempts to
+# support all these options.
+
+GRUB_FONT_DIR ?= /usr/share/grub
+
+GRUB_LIB_DIR ?= /usr/lib/grub
+
+GRUB_MKIMAGE ?= grub2-mkimage
+
+GRUB_MODULES = iso9660 fat part_msdos all_video font gfxterm gfxmenu \
+               boot chain configfile echo ls
+
+grub-eltorito.img:
+	$(GRUB_MKIMAGE) --output $@ --prefix /boot/grub --format i386-pc-eltorito biosdisk $(GRUB_MODULES)
+
+grub-bootx64.efi:
+	$(GRUB_MKIMAGE) --output $@ --prefix /EFI/BOOT/grub --format x86_64-efi $(GRUB_MODULES)
+
+grub-esp.img: memtest.efi grub-bootx64.efi grub/grub-efi.cfg
+	@mkdir -p grub-iso/EFI/BOOT/grub/x86_64-efi grub-iso/EFI/BOOT/grub/fonts
+	cp memtest.efi grub-iso/EFI/BOOT/pcmemtest
+	cp grub-bootx64.efi grub-iso/EFI/BOOT/bootx64.efi
+	cp grub/grub-efi.cfg grub-iso/EFI/BOOT/grub/grub.cfg
+	cp $(GRUB_FONT_DIR)/unicode.pf2 grub-iso/EFI/BOOT/grub/fonts/
+	cp $(GRUB_LIB_DIR)/x86_64-efi/*.mod grub-iso/EFI/BOOT/grub/x86_64-efi/
+	@rm -f grub-esp.img
+	/sbin/mkdosfs -n MEMTEST-ESP -F12 -C grub-esp.img 8192
+	mcopy -s -i grub-esp.img grub-iso/EFI ::
+
+grub-memtest.iso: memtest.bin grub-eltorito.img grub/grub-legacy.cfg grub-esp.img
+	@mkdir -p grub-iso/boot/grub/i386-pc grub-iso/boot/grub/fonts
+	cp memtest.bin grub-iso/boot/pcmemtest
+	cp grub-eltorito.img grub-iso/boot/eltorito.img
+	cp grub/grub-legacy.cfg grub-iso/boot/grub/grub.cfg
+	cp $(GRUB_FONT_DIR)/unicode.pf2 grub-iso/boot/grub/fonts/
+	cp $(GRUB_LIB_DIR)/i386-pc/*.mod grub-iso/boot/grub/i386-pc/
+	xorrisofs -pad -R -J -volid PCMemTest64 -graft-points -hide-rr-moved \
+		  --grub2-mbr $(GRUB_LIB_DIR)/i386-pc/boot_hybrid.img \
+		  -b /boot/eltorito.img -no-emul-boot -boot-load-size 4 -boot-info-table --grub2-boot-info \
+		  --efi-boot --interval:appended_partition_2:all:: \
+		  -part_like_isohybrid -iso_mbr_part_type 0x00 -append_partition 2 0xef ./grub-esp.img \
+		  -o ./grub-memtest.iso /boot=./grub-iso/boot /EFI=./grub-iso/EFI
+
+grub-iso: grub-memtest.iso

build64/grub/grub-efi.cfg

@@ -0,0 +1,22 @@
+if loadfont unicode ; then
+    set gfxmode=1024x768,800x600,auto
+    set gfxpayload=800x600,1024x768
+    terminal_output gfxterm
+fi
+
+set default=0
+set timeout=-1
+
+insmod linux
+insmod linuxefi
+insmod linux32
+
+menuentry "Start PCMemTest using 'linux' command" {
+    linux /EFI/BOOT/pcmemtest
+}
+menuentry "Start PCMemTest using 'linuxefi' command" {
+    linuxefi /EFI/BOOT/pcmemtest
+}
+menuentry "Start PCMemTest using 'linux32' command" {
+    linux32 /EFI/BOOT/pcmemtest
+}

build64/grub/grub-legacy.cfg

@@ -0,0 +1,22 @@
+if loadfont unicode ; then
+    set gfxmode=1024x768,800x600,auto
+    set gfxpayload=800x600,1024x768
+    terminal_output gfxterm
+fi
+
+set default=0
+set timeout=-1
+
+insmod linux
+insmod linux16
+insmod linux32
+
+menuentry "Start PCMemTest using 'linux' command" {
+    linux /boot/pcmemtest
+}
+menuentry "Start PCMemTest using 'linux16' command" {
+    linux16 /boot/pcmemtest
+}
+menuentry "Start PCMemTest using 'linux32' command" {
+    linux32 /boot/pcmemtest
+}