BuildSystem: Add support for building initrd image

This is nice for testing when there isn't xhci controller available or
my usb stack fails :)

script/image.sh

@@ -33,9 +33,15 @@ if [ ! -b $ROOT_PARTITION ]; then
 fi
 
 if sudo mount $ROOT_PARTITION $MOUNT_DIR; then
+	if (($BANAN_INITRD)); then
+		sudo mkdir -p $MOUNT_DIR/boot
+		sudo cp $BANAN_BUILD_DIR/kernel/banan-os.kernel $MOUNT_DIR/boot/banan-os.kernel
+		sudo cp $BANAN_SYSROOT_TAR $MOUNT_DIR/boot/banan-os.initrd
+	else
 		cd $MOUNT_DIR
 		sudo tar xf $BANAN_SYSROOT_TAR
 		cd
+	fi
 
 	sudo umount $MOUNT_DIR
 fi

script/install-bootloader.sh

@@ -44,7 +44,11 @@ install_grub_legacy() {
 		--boot-directory="$mount_dir/boot"	\
 		$loop_dev
 	sudo mkdir -p "$mount_dir/boot/grub"
-	sudo cp "$BANAN_BUILD_DIR/grub-legacy-boot.cfg" "$mount_dir/boot/grub/grub.cfg"
+	if (($BANAN_INITRD)); then
+		sudo cp "$BANAN_BUILD_DIR/grub-legacy-initrd.cfg" "$mount_dir/boot/grub/grub.cfg"
+	else
+		sudo cp "$BANAN_BUILD_DIR/grub-legacy.cfg" "$mount_dir/boot/grub/grub.cfg"
+	fi
 	sudo umount "$mount_dir"
 }
 
@@ -62,6 +66,11 @@ install_grub_uefi() {
 }
 
 install_banan_legacy() {
+	if (($BANAN_INITRD)); then
+		echo "banan bootloader does not support initrd" >&2
+		exit 1
+	fi
+
 	root_disk_info=$(fdisk -x "$BANAN_DISK_IMAGE_PATH" | tr -s ' ')
 	root_part_guid=$(echo "$root_disk_info" | grep "^$BANAN_DISK_IMAGE_PATH" | head -2 | tail -1 | cut -d' ' -f6)
 

toolchain/grub-legacy-initrd.cfg

@@ -0,0 +1,4 @@
+menuentry "banan-os" {
+	multiboot2 /boot/banan-os.kernel readonly
+	module2 /boot/banan-os.initrd
+}

toolchain/grub-uefi-initrd.cfg

@@ -0,0 +1,11 @@
+insmod part_gpt
+insmod search_fs_uuid
+
+search --no-floppy --fs-uuid --set=root <ROOT_FS>
+
+insmod all_video
+
+menuentry "banan-os" {
+	multiboot2 /boot/banan-os.kernel readonly
+	module2 /boot/banan-os.initrd
+}