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Diffstat (limited to 'arch/x86/boot/edd.c')
-rw-r--r--arch/x86/boot/edd.c7
1 files changed, 6 insertions, 1 deletions
diff --git a/arch/x86/boot/edd.c b/arch/x86/boot/edd.c
index d93cbc6464d0..1aae8f3e5ca1 100644
--- a/arch/x86/boot/edd.c
+++ b/arch/x86/boot/edd.c
@@ -41,6 +41,7 @@ static u32 read_mbr_sig(u8 devno, struct edd_info *ei, u32 *mbrsig)
char *mbrbuf_ptr, *mbrbuf_end;
u32 buf_base, mbr_base;
extern char _end[];
+ u16 mbr_magic;
sector_size = ei->params.bytes_per_sector;
if (!sector_size)
@@ -58,11 +59,15 @@ static u32 read_mbr_sig(u8 devno, struct edd_info *ei, u32 *mbrsig)
if (mbrbuf_end > (char *)(size_t)boot_params.hdr.heap_end_ptr)
return -1;
+ memset(mbrbuf_ptr, 0, sector_size);
if (read_mbr(devno, mbrbuf_ptr))
return -1;
*mbrsig = *(u32 *)&mbrbuf_ptr[EDD_MBR_SIG_OFFSET];
- return 0;
+ mbr_magic = *(u16 *)&mbrbuf_ptr[510];
+
+ /* check for valid MBR magic */
+ return mbr_magic == 0xAA55 ? 0 : -1;
}
static int get_edd_info(u8 devno, struct edd_info *ei)