Changeset 148 in xtideuniversalbios for trunk/XTIDE_Universal_BIOS/Src/Handlers/Int13h/AH2h_HRead.asm

Timestamp:

Mar 19, 2011, 8:09:41 PM (14 years ago)

Author:

Tomi Tilli

google:author:

aitotat

Message:

Changes to XTIDE Universal BIOS:

• INT 13h optimizations to save almost 100 bytes.

File:

• trunk/XTIDE_Universal_BIOS/Src/Handlers/Int13h/AH2h_HRead.asm (modified) (4 diffs)

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

@@ -1 @@
-; File name     :   AH2h_HRead.asm
-; Project name  :   IDE BIOS
-; Created date  :   27.9.2007
-; Last update   :   24.8.2010
-; Author        :   Tomi Tilli
+; Project name  :   XTIDE Universal BIOS
 ; Description   :   Int 13h function AH=2h, Read Disk Sectors.
 
@@ -14 +10 @@
 ; AH2h_HandlerForReadDiskSectors
 ;   Parameters:
-;       AH:     Bios function 2h
+;       AL, CX, DH, ES: Same as in INTPACK
+;       DL:     Translated Drive number
+;       DS:DI:  Ptr to DPT (in RAMVARS segment)
+;       SS:BP:  Ptr to INTPACK
+;   Parameters on INTPACK in SS:BP:
 ;       AL:     Number of sectors to read (1...255)
 ;       CH:     Cylinder number, bits 7...0
@@ -20 +20 @@
 ;               Bits 5...0: Starting sector number (1...63)
 ;       DH:     Starting head number (0...255)
-;       DL:     Drive number (8xh)
 ;       ES:BX:  Pointer to buffer recieving data
-;   Parameters loaded by Int13h_Jump:
-;       DS:     RAMVARS segment
-;   Returns:
+;   Returns with INTPACK in SS:BP:
 ;       AH:     Int 13h/40h floppy return status
-;       AL:     Burst error length if AH=11h, undefined otherwise
+;       AL:     Burst error length if AH returns 11h, undefined otherwise
 ;       CF:     0 if successfull, 1 if error
-;       IF:     1
-;   Corrupts registers:
-;       Flags
 ;--------------------------------------------------------------------
 ALIGN JUMP_ALIGN
@@ -37 +31 @@
     jz      SHORT AH2h_ZeroCntErr       ;  If so, return with error
 
-    ; Save registers
-    push    dx
-    push    cx
-    push    bx
-    push    ax
-
     ; Select sector or block mode command
-    call    FindDPT_ForDriveNumber      ; DS:DI now points to DPT
     mov     ah, HCMD_READ_SECT          ; Load sector mode command
     cmp     BYTE [di+DPT.bSetBlock], 1  ; Block mode enabled?
-    jbe     SHORT .XferData             ;  If not, jump to transfer
-    mov     ah, HCMD_READ_MUL           ; Load block mode command
+    eCMOVA  ah, HCMD_READ_MUL           ; Load block mode command
 
     ; Transfer data
-ALIGN JUMP_ALIGN
-.XferData:
     call    HCommand_OutputCountAndLCHSandCommand
-    jc      SHORT .Return               ; Return if error
+    jc      SHORT .ReturnWithErrorCodeInAH
+    mov     bx, [bp+INTPACK.bx]
     call    HPIO_ReadBlock              ; Read data from IDE-controller
-.Return:
-    jmp     Int13h_PopXRegsAndReturn
+.ReturnWithErrorCodeInAH:
+    jmp     Int13h_ReturnFromHandlerAfterStoringErrorCodeFromAH
 
 ; Invalid sector count (also for AH=3h and AH=4h)
 AH2h_ZeroCntErr:
     mov     ah, RET_HD_INVALID          ; Invalid value passed
-    stc                                 ; Set CF since error
-    jmp     Int13h_PopDiDsAndReturn
+    jmp     Int13h_ReturnFromHandlerAfterStoringErrorCodeFromAH