source: xtideuniversalbios/trunk/XTIDE_Universal_BIOS/Src/Device/IDE/IdeIO.asm@ 401

; Project name  :   XTIDE Universal BIOS
; Description   :   IDE Register I/O functions.

;
; XTIDE Universal BIOS and Associated Tools 
; Copyright (C) 2009-2010 by Tomi Tilli, 2011-2012 by XTIDE Universal BIOS Team.
;
; This program is free software; you can redistribute it and/or modify
; it under the terms of the GNU General Public License as published by
; the Free Software Foundation; either version 2 of the License, or
; (at your option) any later version.
; 
; This program is distributed in the hope that it will be useful,
; but WITHOUT ANY WARRANTY; without even the implied warranty of
; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
; GNU General Public License for more details.      
; Visit http://www.gnu.org/licenses/old-licenses/gpl-2.0.html
;       

; Section containing code
SECTION .text

;--------------------------------------------------------------------
; IdeIO_OutputALtoIdeControlBlockRegisterInDL
;   Parameters:
;       AL:     Byte to output
;       DL:     IDE Control Block Register
;       DS:DI:  Ptr to DPT (in RAMVARS segment)
;   Returns:
;       Nothing
;   Corrupts registers:
;       BX, DX
;--------------------------------------------------------------------
IdeIO_OutputALtoIdeControlBlockRegisterInDL:
%ifdef MODULE_8BIT_IDE
    mov     dh, [di+DPT_ATA.bDevice]
%ifdef MODULE_JRIDE
    test    dh, dh
    jnz     SHORT .OutputToIoMappedIde

    add     dx, JRIDE_CONTROL_BLOCK_REGISTER_WINDOW_OFFSET
    jmp     SHORT OutputToJrIdeRegister
.OutputToIoMappedIde:
%endif
%endif

    mov     bl, IDEVARS.wPortCtrl
    jmp     SHORT OutputALtoIdeRegisterInDLwithIdevarsOffsetToBasePortInBL


;--------------------------------------------------------------------
; IdeIO_OutputALtoIdeRegisterInDL
;   Parameters:
;       AL:     Byte to output
;       DL:     IDE Command Block Register
;       DS:DI:  Ptr to DPT (in RAMVARS segment)
;   Returns:
;       Nothing
;   Corrupts registers:
;       BX, DX
;--------------------------------------------------------------------
ALIGN JUMP_ALIGN
IdeIO_OutputALtoIdeRegisterInDL:
%ifdef MODULE_8BIT_IDE
    mov     dh, [di+DPT_ATA.bDevice]
%ifdef MODULE_JRIDE
    test    dh, dh
    jnz     SHORT OutputALtoIOmappedIdeRegisterInDL

    add     dx, JRIDE_COMMAND_BLOCK_REGISTER_WINDOW_OFFSET
OutputToJrIdeRegister:
    mov     bx, dx
    mov     [cs:bx], al
    ret
ALIGN JUMP_ALIGN
OutputALtoIOmappedIdeRegisterInDL:
%endif
%endif

    mov     bl, IDEVARS.wPort
OutputALtoIdeRegisterInDLwithIdevarsOffsetToBasePortInBL:
    call    GetIdePortToDX
    out     dx, al
    ret


;--------------------------------------------------------------------
; IdeIO_InputStatusRegisterToAL
;   Parameters:
;       DS:DI:  Ptr to DPT (in RAMVARS segment)
;   Returns:
;       AL:     IDE Status Register contents
;   Corrupts registers:
;       BX, DX
;--------------------------------------------------------------------
ALIGN JUMP_ALIGN
IdeIO_InputStatusRegisterToAL:
    mov     dl, STATUS_REGISTER_in
    ; Fall to IdeIO_InputToALfromIdeRegisterInDL

;--------------------------------------------------------------------
; IdeIO_InputToALfromIdeRegisterInDL
;   Parameters:
;       DL:     IDE Register
;       DS:DI:  Ptr to DPT (in RAMVARS segment)
;   Returns:
;       AL:     Inputted byte
;   Corrupts registers:
;       BX, DX
;--------------------------------------------------------------------
IdeIO_InputToALfromIdeRegisterInDL:
%ifdef MODULE_8BIT_IDE
    mov     dh, [di+DPT_ATA.bDevice]
%ifdef MODULE_JRIDE
    test    dh, dh
    jnz     SHORT .InputToALfromIOmappedIdeRegisterInDL

    add     dx, JRIDE_COMMAND_BLOCK_REGISTER_WINDOW_OFFSET
    mov     bx, dx
    mov     al, [cs:bx]
    ret
.InputToALfromIOmappedIdeRegisterInDL:
%endif
%endif
    mov     bl, IDEVARS.wPort
    call    GetIdePortToDX
    in      al, dx
    ret


;--------------------------------------------------------------------
; GetIdePortToDX
;   Parameters:
;       BL:     Offset to port in IDEVARS (IDEVARS.wPort or IDEVARS.wPortCtrl)
;       DH:     Device Type (IDEVARS.bDevice)
;       DL:     IDE Register
;       DS:DI:  Ptr to DPT (in RAMVARS segment)
;   Returns:
;       DX:     Source/Destination Port
;   Corrupts registers:
;       BX
;--------------------------------------------------------------------
ALIGN JUMP_ALIGN
GetIdePortToDX:
%ifdef MODULE_8BIT_IDE
    ; Point CS:BX to IDEVARS
    xor     bh, bh
    add     bl, [di+DPT.bIdevarsOffset]         ; CS:BX now points port address

    ; Load port address and check if A0 and A3 address lines need to be reversed
    cmp     dh, DEVICE_8BIT_XTIDE_REV1
    mov     dh, bh                              ; DX now has IDE register offset
    jae     SHORT .ReturnUntranslatedPortInDX   ; No need to swap address lines

    ; Exchange address lines A0 and A3 from DL
    add     dx, [cs:bx]                         ; DX now has port address
    mov     bl, dl
    mov     bh, MASK_A3_AND_A0_ADDRESS_LINES
    and     bh, bl                              ; BH = 0, 1, 8 or 9, we can ignore 0 and 9
    jz      SHORT .ReturnTranslatedPortInDX     ; Jump out since DH is 0
    xor     bh, MASK_A3_AND_A0_ADDRESS_LINES
    jz      SHORT .ReturnTranslatedPortInDX     ; Jump out since DH was 9
    and     dl, ~MASK_A3_AND_A0_ADDRESS_LINES
    or      dl, bh                              ; Address lines now reversed
.ReturnTranslatedPortInDX:
    ret

.ReturnUntranslatedPortInDX:
    add     dx, [cs:bx]
    ret

%else   ; Only standard IDE devices
    xor     bh, bh
    xor     dh, dh
    add     bl, [di+DPT.bIdevarsOffset]     ; CS:BX now points port address
    add     dx, [cs:bx]                     ; DX now has port address
    ret
%endif