[gPXE] early print message

[Geert Stappers]

Op 20100410 om 10:50 schreef Shao Miller:
> Op 20100405 om 19:06 schreef Michael Brown:
> > 
> > libprefix.S routines are not available from mbr.S.
> > 
> 
> If you've got 512 bytes of MBR to work with in your printing testing, is 
> your code getting truncated?  You could try 'objdump'ing the resulting 
> gpxe/src/bin/mbr.o module to see that its disassembly is what you're 
> expecting.

--- a/src/arch/i386/prefix/mbr.S
+++ b/src/arch/i386/prefix/mbr.S
@@ -5,6 +5,15 @@
        .org 0
 
 mbr:
+       movb    $0x0e, %ah
+       movb    $'N', %al
+       int     $0x10
+       movb    $'L', %al
+       int     $0x10
+       movb    $0x0d, %al
+       int     $0x10
+       movb    $0x0a, %al
+       int     $0x10
        movw    $exec_sector, %bp
        jmp     find_active_partition
 exec_sector: