[romprefix] Fix ROM image copy on PCI 3.0 BIOSes

Add the missing instructions to the code path that I never tested due
to not having a PCI 3.0 system available.

(D'oh)

diff --git a/src/arch/i386/prefix/romprefix.S b/src/arch/i386/prefix/romprefix.S
index 698fa64..e304d00 100644 (file)
--- a/src/arch/i386/prefix/romprefix.S
+++ b/src/arch/i386/prefix/romprefix.S
@@ -290,7 +290,9 @@ no_pmm:
        movzbw  romheader_size, %cx
        shlw    $9, %cx
        movw    %ax, %es
-       rep     movsb
+       xorw    %si, %si
+       xorw    %di, %di
+       cs rep  movsb
 no_pci3:
 no_pci:
        /* Prompt for POST-time shell */