Add .pdsk target (padded .dsk, suitable for qemu).

contrib/bochs/README.qemu

 
 8.  Build Etherboot floppy disk images and pad to 1.44MB
       pushd ../../src
-      make bin/rtl8139.dsk
-      ./util/dskpad.pl bin/rtl8139.dsk
+      make bin/rtl8139.pdsk
       popd
 
 9.  Start qemu
       export SDL_VIDEO_X11_DGAMOUSE=0
       ./qemu/i386-softmmu/qemu -L qemu/pc-bios \
 			       -net nic,model=rtl8139 -net tap,ifname=tap0 \
-			       -boot a -fda ../../src/bin/rtl8139.dsk 
+			       -boot a -fda ../../src/bin/rtl8139.pdsk 
 
 You should see qemu start up, load up Etherboot and attempt to boot
 from the network.

src/arch/i386/Makefile

 	dd if=$< bs=512 conv=sync of=/dev/fd0
 	sync
 
+# rule to create padded disk images
+NON_AUTO_MEDIA		+= pdsk
+%pdsk : %dsk
+	cp $< $@
+	$(PERL) ./util/dskpad.pl $@
+
 # rule to make a non-emulation ISO boot image
 NON_AUTO_MEDIA		+= iso
 %iso:	%lilo util/geniso
 $(BIN)/usbdisk.bin : $(BIN)/usbdisk.o
 	$(OBJCOPY) -O binary $< $@
 
+NON_AUTO_MEDIA		+= usb
 %usb: $(BIN)/usbdisk.bin %hd
 	cat $^ > $@