add kernel stub to distfiles

this way i can test if the bootloader works as intended

Makefile

@@ -1,7 +1,7 @@
 FLOPPY = 360
 
 PROGRAMS = hello.com
-DISTFILES = $(PROGRAMS)
+DISTFILES = $(PROGRAMS) rdos86.bs
 ROMS =
 
 QEMU_ARCH = $(shell uname -m)
@@ -47,12 +47,6 @@ vga11.com: cp437.bin
 # Bootloaders, first sector on partition
 %.bs: %.asm
 	$(NASM) $(NASM_ARGS) -DBASE=0x7C00 -DBOOT -o $@ $<
-	: check boot signature
-	test "$$(echo $$(xxd -p -l 2 -s 510 $@))" == 55aa
-
-# Network bootstrap protocol as used for PXE
-%.0: %.asm
-	$(NASM) $(NASM_ARGS) -DBASE=0x7C00 -DNBP -o $@ $<
 
 # BIOS option roms
 %.rom: rom/%.asm utils/fix-rom
@@ -65,9 +59,11 @@ fdimage.img: fat.bs $(DISTFILES)
 hdimage.img: mbr.bs fdimage.img
 	cat mbr.bs fdimage.img >$@
 
-part.img: fat32.bs
+part.img: fat32.bs $(DISTFILES)
 	dd if=/dev/zero bs=1024 count=33k of=$@
-	mformat -F -i part.img -B fat32.bs ::
+	mformat -i $@ -F -B fat32.bs ::
+	mmd -i $@ ::rdos
+	mcopy -i $@ $(DISTFILES) ::rdos
 
 clean:
 	rm -f *.com *.bs *.0 *.lst *.img *.bin *.rom