gptmbr: use xchgw %ax,... instead of movw %ax,... when %ax is dead

xhcgw with %ax and a register is one byte shorter than movw with %ax
if %ax is then dead.

diff --git a/mbr/gptmbr.S b/mbr/gptmbr.S
index 20a46a2..8bc5e41 100644 (file)
--- a/mbr/gptmbr.S
+++ b/mbr/gptmbr.S
@@ -161,7 +161,7 @@ find_part:
        .ascii  "Boot partition not found\r\n"
 
 found_part:
-       movw    %ax,%cx         /* Set up %cx for rep movsb further down */
+       xchgw   %ax,%cx         /* Set up %cx for rep movsb further down */
        
        movw    $dssi_out,%di
        pushw   %di