HANDLE FileHandle;
LARGE_INTEGER FileOffset;
PUCHAR BootSector;
- ULONG Instruction;
/* Allocate buffer for bootsector */
BootSector = RtlAllocateHeap(ProcessHeap, 0, SECTORSIZE);
if (!NT_SUCCESS(Status))
goto Quit;
- /* Check the instruction; we use a ULONG to read three bytes */
- Instruction = (*(PULONG)BootSector) & 0x00FFFFFF;
- IsValid = (Instruction != 0x00000000);
-
- /* Check the bootsector signature */
- IsValid &= (*(PUSHORT)(BootSector + 0x1fe) == 0xaa55);
+ /* Check for the existence of the bootsector signature */
+ IsValid = (*(PUSHORT)(BootSector + 0x1FE) == 0xAA55);
+ if (IsValid)
+ {
+ /* Check for the first instruction encoded on three bytes */
+ IsValid = (((*(PULONG)BootSector) & 0x00FFFFFF) != 0x00000000);
+ }
Quit:
/* Free the boot sector */
RtlFreeHeap(ProcessHeap, 0, BootSector);
- return IsValid; // Status;
+ return IsValid;
}
static