Changes in trunk/XTIDE_Universal_BIOS/Src/Boot/BootMenu.asm [28:3] in xtideuniversalbios

File:

• trunk/XTIDE_Universal_BIOS/Src/Boot/BootMenu.asm (modified) (3 diffs)

trunk/XTIDE_Universal_BIOS/Src/Boot/BootMenu.asm

@@ -2 +2 @@
 ; Project name  :   IDE BIOS
 ; Created date  :   25.3.2010
-; Last update   :   29.7.2010
+; Last update   :   1.4.2010
 ; Author        :   Tomi Tilli
 ; Description   :   Displays Boot Menu.
@@ -323 +323 @@
 ;       DS:     RAMVARS segment
 ;   Returns:
-;       CF:     Set if drive number is valid
+;       SF:     Set if drive number is valid
 ;               Clear if drive is not present in system
 ;   Corrupts registers:
-;       AX, CX
+;       AX
 ;--------------------------------------------------------------------
 ALIGN JUMP_ALIGN
@@ -332 +332 @@
     test    dl, 80h                 ; Floppy drive?
     jz      SHORT .IsFloppyDriveIsInSystem
-    call    RamVars_GetDriveCounts  ; Hard Disk count to CX
-    or      cl, 80h                 ; Set Hard Disk bit to CX
-    jmp     SHORT .CompareDriveNumberToDriveCount
+    call    RamVars_GetDriveCounts
+    mov     ax, 7Fh                 ; Load mask to clear floppy bit
+    and     ax, dx                  ; AX = Hard Disk index
+    cmp     ax, cx                  ; Valid drive index?
+    ret
+ALIGN JUMP_ALIGN
 .IsFloppyDriveIsInSystem:
-    call    FloppyDrive_GetCount    ; Floppy Drive count to CX
-.CompareDriveNumberToDriveCount:
+    call    FloppyDrive_GetCount
     cmp     dl, cl
     ret