x86: mbr: Copy by dword during relocation

diff --git a/boot/x86/mbr.s b/boot/x86/mbr.s
index b5d01c94f6ea86ccffd0752714db580280b6abce..5319f4b54dfdd772ca503bf50cb0c4f111995073 100644 (file)
--- a/boot/x86/mbr.s
+++ b/boot/x86/mbr.s
@@ -15,10 +15,10 @@ _start:
 
        ; perform self-relocation
        cld
-       mov si, 0x7c00
-       mov di, 0x600
-       mov cx, 0x100 ; 256 words = 512 bytes
-       rep movsw
+       mov esi, 0x7c00
+       mov edi, 0x600
+       mov ecx, 0x80 ; 128 dwords = 512 bytes
+       rep movsd
        ; some BIOSes may set CS to 0x7c0, work around that
        jmp 0:real_start
 real_start: