[bpalmer] 15233: Support getting the boot drive from the BIOS or the value in the BPB.

Support getting the boot drive from the BIOS or the value in the BPB.
Modified: trunk/reactos/boot/freeldr/bootsect/fat.asm
  _____

Modified: trunk/reactos/boot/freeldr/bootsect/fat.asm
--- trunk/reactos/boot/freeldr/bootsect/fat.asm	2005-05-11 20:58:40 UTC
(rev 15232)
+++ trunk/reactos/boot/freeldr/bootsect/fat.asm	2005-05-12 02:57:13 UTC
(rev 15233)
@@ -73,7 +73,7 @@

NumberOfHeads   dw 2
 HiddenSectors   dd 0
 TotalSectorsBig dd 0
-BootDrive       db 0
+BootDrive       db 0xff
 Reserved        db 0
 ExtendSig       db 29h
 SerialNumber    dd 00000000h
@@ -89,6 +89,9 @@
         mov es,ax
; Make ES correct

+		cmp BYTE [BYTE bp+BootDrive],BYTE 0xff	; If they have
specified a boot drive then use it
+		jne GetDriveParameters
+
         mov [BYTE bp+BootDrive],dl				; Save
the boot drive