[nbiprefix] Set up real-mode stack before jumping to .text16

Signed-off-by: Michael Brown <mcb30@ipxe.org>

diff --git a/src/arch/i386/prefix/nbiprefix.S b/src/arch/i386/prefix/nbiprefix.S
index 20d224d69b724aa00bc5f14260a362476bbecf25..06e7df5b747bc791e57ea3608cfb2c2ace61807a 100644 (file)
--- a/src/arch/i386/prefix/nbiprefix.S
+++ b/src/arch/i386/prefix/nbiprefix.S
@@ -54,6 +54,10 @@ _nbi_start:
        /* Install iPXE */
        call    install
 
+       /* Set up real-mode stack */
+       movw    %bx, %ss
+       movw    $_estack16, %sp
+
        /* Jump to .text16 segment */
        pushw   %ax
        pushw   $1f