From 647d351278bbfc806980ac1043dfe08e42e2d3c3 Mon Sep 17 00:00:00 2001
From: Eric Kohl <eric.kohl@reactos.org>
Date: Sun, 1 Dec 2024 21:32:53 +0100
Subject: [PATCH] [DISKPART] Use the MBR_MAGIC to check for a valid MBR

---
 base/system/diskpart/partlist.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/base/system/diskpart/partlist.c b/base/system/diskpart/partlist.c
index dbd0ef0e24a..167858cfbb9 100644
--- a/base/system/diskpart/partlist.c
+++ b/base/system/diskpart/partlist.c
@@ -37,6 +37,8 @@
 
 #define PARTITION_TBL_SIZE 4
 
+#define MBR_MAGIC 0xAA55
+
 #include <pshpack1.h>
 
 typedef struct _PARTITION
@@ -870,7 +872,7 @@ AddDiskToList(
     DiskEntry->BiosFound = FALSE;
 
     /* Check if this disk has a valid MBR */
-    if (Mbr->BootCode[0] == 0 && Mbr->BootCode[1] == 0)
+    if (Mbr->Magic != MBR_MAGIC)
         DiskEntry->NoMbr = TRUE;
     else
         DiskEntry->NoMbr = FALSE;