- Include <sys/reboot.h> to get the RB_* defines.

- Make the PROBE_KEYBOARD option better resemble the -P option in
  boot2, i.e., if keyboard isn't present then boot with both
  RB_SERIAL and RB_MULTIPLE set.

Reviewed by:	jhb

sys/boot/i386/pxeldr/pxeldr.S

@@ -25,6 +25,8 @@
  * separate PXE-aware client just to load the loader.
  */
 
+#include <sys/reboot.h>
+
 /*
  * Memory locations.
  */
@@ -52,10 +54,6 @@
  */
 		.set KARGS_FLAGS_PXE,0x2	# flag to indicate booting from
 						#  PXE loader
-/*
- * Boot howto bits
- */
-		.set RB_SERIAL,0x1000		# serial console
 /*
  * Segment selectors.
  */
@@ -119,11 +117,11 @@ start:		cld				# string ops inc
 #ifdef PROBE_KEYBOARD
 /*
  * Look at the BIOS data area to see if we have an enhanced keyboard.  If not,
- * set the RBX_SERIAL bit in the howto byte.
+ * set the RBX_DUAL and RBX_SERIAL bits in the howto byte.
  */
 		testb $KEYBOARD_BIT, MEM_BIOS_KEYBOARD # keyboard present?
 		jnz keyb			# yes, so skip
-		orl $RB_SERIAL, (%bx)		# enable serial console
+		orl $(RB_MULTIPLE | RB_SERIAL), (%bx) # enable serial console
 keyb:
 #endif
 /*