Dummy for loading rdos drvs via option rom

Makefile

@@ -73,6 +73,10 @@ fate.bs: boot/fat.asm
 %.rom: rom/%.asm utils/fix-rom
 	$(NASM) $(NASM_ARGS) -o $@ $< && utils/fix-rom $@
 
+# rdos drivers
+%.drv:	driver/%.asm
+	$(NASM) $(NASM_ARGS) -o $@ $<
+
 fdimage.img: fat1.bs $(DISTFILES)
 	mformat -C -i $@ -f $(FLOPPY) -B fat1.bs ::
 	mmd -i $@ ::rdos

rom/loaddrv.asm

@@ -0,0 +1,43 @@
+cpu 8086
+org 0x0000
+
+	db 0x55, 0xAA
+	db 0x00
+	jmp init
+	nop
+
+	times (0x18 - ($-$$)) db 0
+	dw 0
+	dw pnp
+
+pnp:
+  db "$PnP"
+.version:
+  db 1 ; version 1
+.length:
+  db 2 ; 2 * 16 length
+  dw 0 ; offset of next header
+  db 0
+.checksum:
+  db 0 ; checksum (filled by fix-rom)
+  dd 0 ; device identifier
+  dw 0 ; manufacturer string
+  dw name ; product name string
+  db 0,0,0 ; device type string
+  db 0x20 ; device indicator, bit for "read cacheable" set
+  dw 0 ; boot connection vector
+  dw 0 ; boot disconnect vector
+  dw 0 ; bootstrap entry point
+  dw 0 ; reserved
+  dw 0
+
+name:
+	db "rdos drv loader"
+
+init:
+	mov ax, 0x0e37
+	xor bx, bx
+	int 0x10
+	retf
+
+align 512