-pxe-rom-e1000 : VID := 8086
-pxe-rom-e1000 : DID := 100e
-pxe-rom-eepro100 : VID := 8086
-pxe-rom-eepro100 : DID := 1209
-pxe-rom-ne2k_pci : VID := 1050
-pxe-rom-ne2k_pci : DID := 0940
-pxe-rom-pcnet : VID := 1022
-pxe-rom-pcnet : DID := 2000
-pxe-rom-rtl8139 : VID := 10ec
-pxe-rom-rtl8139 : DID := 8139
-pxe-rom-virtio : VID := 1af4
-pxe-rom-virtio : DID := 1000
+pxe-rom-e1000 efi-rom-e1000 : VID := 8086
+pxe-rom-e1000 efi-rom-e1000 : DID := 100e
+pxe-rom-eepro100 efi-rom-eepro100 : VID := 8086
+pxe-rom-eepro100 efi-rom-eepro100 : DID := 1209
+pxe-rom-ne2k_pci efi-rom-ne2k_pci : VID := 1050
+pxe-rom-ne2k_pci efi-rom-ne2k_pci : DID := 0940
+pxe-rom-pcnet efi-rom-pcnet : VID := 1022
+pxe-rom-pcnet efi-rom-pcnet : DID := 2000
+pxe-rom-rtl8139 efi-rom-rtl8139 : VID := 10ec
+pxe-rom-rtl8139 efi-rom-rtl8139 : DID := 8139
+pxe-rom-virtio efi-rom-virtio : VID := 1af4
+pxe-rom-virtio efi-rom-virtio : DID := 1000
+
+#
+# EfiRom utility is shipped with edk2 / tianocore, in BaseTools/
+#
+# We need that to combine multiple images (legacy bios,
+# efi ia32, efi x64) into a single rom binary.
+#
+# We try to find it in the path. You can also pass the location on
+# the command line, i.e. "make EFIROM=/path/to/EfiRom efirom"
+#
+EFIROM ?= $(shell which EfiRom 2>/dev/null)