From 8739e2ff9ba3f92652c8df846924fd00e1ce2753 Mon Sep 17 00:00:00 2001
From: Martin Str|mberg <ams@ludd.ltu.se>
Date: Sun, 26 Mar 2017 07:54:29 -0400
Subject: [PATCH] mbr/isohdpfx.S: Clear CX on INT 13h AH 41h failure

If anything goes wrong, clear CX in case it contains garbage.

Signed-off-by: Gene Cumm <gene.cumm@gmail.com>
---
 mbr/isohdpfx.S | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/mbr/isohdpfx.S b/mbr/isohdpfx.S
index f9e96919..4b107e4b 100644
--- a/mbr/isohdpfx.S
+++ b/mbr/isohdpfx.S
@@ -167,8 +167,10 @@ next:
 	   read_sector_cbios: movb $0x42, %ah ;  jmp read_common */
 	movl	$0xeb42b4+((read_common-read_sector_cbios-4) << 24), \
 		(read_sector_cbios)
-	jmp	1f
+	jmp	2f
 1:
+	xor	%cx, %cx	/* Clear EBIOS flag. */
+2:
 	popw	%dx
 	pushw	%cx		/* EBIOS flag */
 
-- 
2.11.4.GIT