source: xtideuniversalbios/trunk/XTIDE_Universal_BIOS/Src/Device/IDE/IdeIO.asm@ 465

; 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  ; MODULE_JRIDE
    %endif  ; MODULE_8BIT_IDE

    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
        
        %if JRIDE_COMMAND_BLOCK_REGISTER_WINDOW_OFFSET & 0FFh = 0
            mov     dh, JRIDE_COMMAND_BLOCK_REGISTER_WINDOW_OFFSET >> 8
        %else
            add     dx, JRIDE_COMMAND_BLOCK_REGISTER_WINDOW_OFFSET
        %endif
        OutputToJrIdeRegister:
            mov     bx, dx
            mov     [cs:bx], al
            ret
        ALIGN JUMP_ALIGN
        OutputALtoIOmappedIdeRegisterInDL:
        %endif  ; MODULE_JRIDE
    %endif  ; MODULE_8BIT_IDE

    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
        
        %if JRIDE_COMMAND_BLOCK_REGISTER_WINDOW_OFFSET & 0FFh = 0
            mov     dh, JRIDE_COMMAND_BLOCK_REGISTER_WINDOW_OFFSET >> 8
        %else
            add     dx, JRIDE_COMMAND_BLOCK_REGISTER_WINDOW_OFFSET
        %endif
            mov     bx, dx
            mov     al, [cs:bx]
            ret
        .InputToALfromIOmappedIdeRegisterInDL:
        %endif  ; MODULE_JRIDE
    %endif  ; MODULE_8BIT_IDE
    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                              ; Port low byte to BL
    and     bl, MASK_A3_AND_A0_ADDRESS_LINES    ; Clear all bits except A0 and A3
    jz      SHORT .ReturnTranslatedPortInDX     ; A0 and A3 both zeroes, no change needed
    cmp     bl, MASK_A3_AND_A0_ADDRESS_LINES
    je      SHORT .ReturnTranslatedPortInDX     ; A0 and A3 both ones, no change needed
    xor     dl, MASK_A3_AND_A0_ADDRESS_LINES    ; Invert A0 and A3
.ReturnTranslatedPortInDX:
    ret

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

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