From bf29c4c700aef656d8725c61edf587ac74f3d8a4 Mon Sep 17 00:00:00 2001
From: Pawel Wieczorkiewicz <wipawel@grsecurity.net>
Date: Tue, 15 Feb 2022 16:19:45 +0100
Subject: [PATCH] Makefile,grub: generate ISO with grub-mkrescue

This allows to easily create a bootable ISO with all necessary modules
installed that boots on legacy BIOS and UEFI machines.

Also force adding serial module to have the grub over serial interface
working on all platforms.

Signed-off-by: Pawel Wieczorkiewicz <wipawel@grsecurity.net>
---
 Makefile | 7 +++----
 1 file changed, 3 insertions(+), 4 deletions(-)

diff --git a/Makefile b/Makefile
index d0623949..c856ed0c 100644
--- a/Makefile
+++ b/Makefile
@@ -89,8 +89,8 @@ endif
 
 GRUB_DIR := grub/boot
 GRUB_FILE := grub-file
-GRUB_MKIMAGE := grub-mkimage
-GRUB_MODULES := multiboot iso9660 biosdisk
+GRUB_MKRESCUE := grub-mkrescue
+GRUB_MODULES := multiboot iso9660 serial normal
 ifneq ($(UNITTEST),)
 GRUB_CONFIG := $(GRUB_DIR)/grub/grub-test.cfg
 else
@@ -257,8 +257,7 @@ $(ISO_FILE): $(TARGET)
 	$(VERBOSE) $(GRUB_FILE) --is-x86-multiboot $(TARGET) || { echo "Multiboot not supported"; exit 1; }
 	$(VERBOSE) cp $(TARGET) $(GRUB_DIR)/
 	$(VERBOSE) $(XZ) -q -f $(GRUB_DIR)/$(TARGET)
-	$(VERBOSE) $(GRUB_MKIMAGE) --format i386-pc-eltorito -c $(GRUB_CONFIG) -p /boot/grub -o grub/boot.img $(GRUB_MODULES)
-	$(VERBOSE) $(XORRISO) -as mkisofs -U -b boot.img -no-emul-boot -boot-load-size 4 -boot-info-table -o $(ISO_FILE) grub 2>> /dev/null
+	$(VERBOSE) $(GRUB_MKRESCUE) --install-modules="$(GRUB_MODULES)" --fonts=no --compress=xz -o $(ISO_FILE) grub &> /dev/null
 endif
 
 .PHONY: boot