Changeset 155 in xtideuniversalbios for trunk/XTIDE_Universal_BIOS/Src/Handlers/Int13h/AH2h_HRead.asm

Timestamp:

May 1, 2011, 6:44:29 PM (14 years ago)

Author:

Tomi Tilli

google:author:

aitotat

Message:

Changes to XTIDE Universal BIOS:

• AH=4h again uses VERIFY command (copy-pasting had changed it to WRITE).
• Timeout should now work on all overflow situations.
• Cleaned code a bit.

File:

• trunk/XTIDE_Universal_BIOS/Src/Handlers/Int13h/AH2h_HRead.asm (modified) (3 diffs)

trunk/XTIDE_Universal_BIOS/Src/Handlers/Int13h/AH2h_HRead.asm

@@ -15 +15 @@
 ;       SS:BP:  Ptr to IDEPACK
 ;   Parameters on INTPACK:
-;       AL:     Number of sectors to read (1...255, 0=256)
+;       AL:     Number of sectors to read (1...255)
 ;       CH:     Cylinder number, bits 7...0
 ;       CL:     Bits 7...6: Cylinder number bits 9 and 8
@@ -28 +28 @@
 ALIGN JUMP_ALIGN
 AH2h_HandlerForReadDiskSectors:
+    call    AH2h_ExitInt13hIfSectorCountInIntpackIsZero
     mov     ah, COMMAND_READ_SECTORS    ; Load sector mode command
     test    WORD [di+DPT.wFlags], FLG_DPT_BLOCK_MODE_SUPPORTED
@@ -40 +41 @@
     jmp     Int13h_ReturnFromHandlerAfterStoringErrorCodeFromAH
 %endif
+
+
+;--------------------------------------------------------------------
+; AH2h_ExitInt13hIfSectorCountInIntpackIsZero
+;   Parameters:
+;       SS:BP:  Ptr to IDEPACK
+;   Parameters on INTPACK:
+;       AL:     Number of sectors to transfer (1...255)
+;   Returns:
+;       Nothing (does not return if error)
+;   Corrupts registers:
+;       Nothing
+;--------------------------------------------------------------------
+ALIGN JUMP_ALIGN
+AH2h_ExitInt13hIfSectorCountInIntpackIsZero:
+    cmp     BYTE [bp+IDEPACK.intpack+INTPACK.al], 0
+    je      SHORT .InvalidSectorCount
+    ret
+.InvalidSectorCount:
+    mov     ah, RET_HD_INVALID
+    jmp     Int13h_ReturnFromHandlerAfterStoringErrorCodeFromAH