diff --git a/fs/iso9660/iso9660.mk b/fs/iso9660/iso9660.mk
index 1f1ef00a59..1eb6abb1b6 100644
--- a/fs/iso9660/iso9660.mk
+++ b/fs/iso9660/iso9660.mk
@@ -148,7 +148,7 @@ define ROOTFS_ISO9660_INSTALL_GRUB2_EFI
 	$(INSTALL) -D -m 0644 $(ROOTFS_ISO9660_EFI_PARTITION_CONTENT)/$(ROOTFS_ISO9660_GRUB2_EFI_PREFIX)/$(ROOTFS_ISO9660_EFI_NAME) \
 		$(ROOTFS_ISO9660_TMP_TARGET_DIR)/$(ROOTFS_ISO9660_GRUB2_EFI_PREFIX)/$(ROOTFS_ISO9660_EFI_NAME)
 	# Create EFI FAT partition
-	rm -rf $(ROOTFS_ISO9660_EFI_PARTITION_PATH)
+	$(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=$(ROOTFS_ISO9660_GRUB2_EFI_PARTITION_SIZE) count=1
 	$(HOST_DIR)/sbin/mkfs.vfat $(ROOTFS_ISO9660_VFAT_OPTS) $(ROOTFS_ISO9660_EFI_PARTITION_PATH)
@@ -159,7 +159,7 @@ define ROOTFS_ISO9660_INSTALL_GRUB2_EFI
 	# Delete the EFI bootloader that is NOT for the platform we're building for
 	$(HOST_DIR)/bin/mdel -i $(ROOTFS_ISO9660_EFI_PARTITION_PATH) \
 		::$(ROOTFS_ISO9660_GRUB2_EFI_PREFIX)/$(ROOTFS_ISO9660_EFI_NOTNAME) || true
-	# Copy EFI configuration to EFI partition
+	# Overwrite generic EFI configuration with our EFI configuration
 	$(HOST_DIR)/bin/mcopy -n -o -p -m -i $(ROOTFS_ISO9660_EFI_PARTITION_PATH) \
 		$(ROOTFS_ISO9660_GRUB2_EFI_CONFIG_PATH) ::$(ROOTFS_ISO9660_GRUB2_EFI_PREFIX)/grub.cfg
 	$(ROOTFS_ISO9660_FIX_TIME) $(ROOTFS_ISO9660_EFI_PARTITION_PATH)
@@ -255,7 +255,7 @@ define ROOTFS_ISO9660_INSTALL_GRUB2_EFI
 	$(INSTALL) -D -m 0644 $(ROOTFS_ISO9660_EFI_PARTITION_CONTENT)/$(ROOTFS_ISO9660_GRUB2_EFI_PREFIX)/$(ROOTFS_ISO9660_EFI_NAME) \
 		$(ROOTFS_ISO9660_TMP_TARGET_DIR)/$(ROOTFS_ISO9660_GRUB2_EFI_PREFIX)/$(ROOTFS_ISO9660_EFI_NAME)
 	# Create EFI FAT partition
-	rm -rf $(ROOTFS_ISO9660_EFI_PARTITION_PATH)
+	$(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=$(ROOTFS_ISO9660_GRUB2_EFI_PARTITION_SIZE) count=1
 	$(HOST_DIR)/sbin/mkfs.vfat $(ROOTFS_ISO9660_VFAT_OPTS) $(ROOTFS_ISO9660_EFI_PARTITION_PATH)
@@ -266,7 +266,7 @@ define ROOTFS_ISO9660_INSTALL_GRUB2_EFI
 	# Delete the EFI bootloader that is NOT for the platform we're building for
 	$(HOST_DIR)/bin/mdel -i $(ROOTFS_ISO9660_EFI_PARTITION_PATH) \
 		::$(ROOTFS_ISO9660_GRUB2_EFI_PREFIX)/$(ROOTFS_ISO9660_EFI_NOTNAME) || true
-	# Copy EFI configuration to EFI partition
+	# Overwrite generic EFI configuration with our EFI configuration
 	$(HOST_DIR)/bin/mcopy -n -o -p -m -i $(ROOTFS_ISO9660_EFI_PARTITION_PATH) \
 		$(ROOTFS_ISO9660_GRUB2_EFI_CONFIG_PATH) ::$(ROOTFS_ISO9660_GRUB2_EFI_PREFIX)/grub.cfg
 	$(ROOTFS_ISO9660_FIX_TIME) $(ROOTFS_ISO9660_EFI_PARTITION_PATH)