source: xtideuniversalbios/trunk/XTIDE_Universal_BIOS/Src/Initialization/AdvancedAta/AdvAtaInit.asm

; Project name  :   XTIDE Universal BIOS
; Description   :   Common functions for initializing different
;                   VLB and PCI IDE Controllers.

;
; XTIDE Universal BIOS and Associated Tools
; Copyright (C) 2009-2010 by Tomi Tilli, 2011-2013 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

;--------------------------------------------------------------------
; AdvAtaInit_DetectControllerForIdeBaseInBX
;   Parameters:
;       BX:     IDE Controller base port
;   Returns:
;       AX:     ID WORD specific for detected controller
;               Zero if no controller detected
;       DX:     Controller base port (not IDE)
;       CF:     Set if controller detected
;               Cleared if no controller
;   Corrupts registers:
;       BX, CX
;--------------------------------------------------------------------
AdvAtaInit_DetectControllerForIdeBaseInBX:
    ; Detect if system has PCI bus. If it does, we can skip VLB detection. This is a
    ; good thing since detecting Vision QD6580 is dangerous since Intel PIIX4 south bridge
    ; mirrors Interrupt Controller registers from Axh to Bxh. This can lead to faulty
    ; detection of QD6580 that will eventually crash the system when ports are written.

    ; We should save the 32-bit registers but we don't since system BIOS has stored
    ; them already and we don't use the 32-bit registers ourselves anywhere at the moment.
    push    bx
    push    di
;   xor     edi, edi        ; Some BIOSes require this to be set to zero
    ; *FIXME* The above instruction is commented away since RBIL says that this
    ; only applies to software looking for the protected-mode entry point.
    mov     ax, PCI_INSTALLATION_CHECK  ; May corrupt EAX, EBX, ECX, EDX, EDI
    int     BIOS_TIME_PCI_PNP_INTERRUPT_1Ah
    pop     di
    pop     bx
    test    ah, ah
    jz      SHORT .ThisSystemHasPCIbus

    ; Detect VLB controllers
    call    Vision_DetectAndReturnIDinAXandPortInDXifControllerPresent
    jnz     SHORT .NoVisionControllerFound

    call    Vision_DoesIdePortInBXbelongToControllerWithIDinAX
    jz      SHORT .AdvancedControllerFoundForPortBX

.NoVisionControllerFound:
    call    PDC20x30_DetectControllerForIdeBaseInBX
    jnc     SHORT .NoAdvancedControllerForPortBX

.AdvancedControllerFoundForPortBX:
    stc
    ret

.NoAdvancedControllerForPortBX:
.ThisSystemHasPCIbus:
    xor     ax, ax      ; Clear ID in AX and CF
    ret


;--------------------------------------------------------------------
; AdvAtaInit_GetControllerMaxPioModeToALandMinPioCycleTimeToBX
;   Parameters:
;       AX:     ID WORD specific for detected controller
;   Returns:
;       AL:     Max supported PIO mode (only if ZF set)
;       AH:     ~FLGH_DPT_IORDY if IORDY not supported, -1 otherwise (only if ZF set)
;       BX:     Min PIO cycle time (only if ZF set)
;       ZF:     Set if PIO limit necessary
;               Cleared if no need to limit timings
;   Corrupts registers:
;       Nothing
;--------------------------------------------------------------------
AdvAtaInit_GetControllerMaxPioModeToALandMinPioCycleTimeToBX:
    cmp     ah, ID_QD6580_ALTERNATE
%ifdef USE_386
    jae     Vision_GetMaxPioModeToALandMinCycleTimeToBX
    jmp     PDC20x30_GetMaxPioModeToALandMinPioCycleTimeToBX
%else
    jae     SHORT .Vision
    jmp     PDC20x30_GetMaxPioModeToALandMinPioCycleTimeToBX
.Vision:
    jmp     Vision_GetMaxPioModeToALandMinCycleTimeToBX
%endif


;--------------------------------------------------------------------
; AdvAtaInit_InitializeControllerForDPTinDSDI
;   Parameters:
;       DS:DI:  Ptr to DPT for Single or Slave Drive
;   Returns:
;       AH:     Int 13h return status
;       CF:     Cleared if success or no controller to initialize
;               Set if error
;   Corrupts registers:
;       AL, BX, CX, DX
;--------------------------------------------------------------------
AdvAtaInit_InitializeControllerForDPTinDSDI:
    ; Call Controller Specific initialization function
    mov     ax, [di+DPT_ADVANCED_ATA.wControllerID]
    test    ax, ax
    jz      SHORT .NoAdvancedController ; Return with CF cleared

    cmp     ah, ID_QD6580_ALTERNATE
    jae     SHORT .Vision
    jmp     PDC20x30_InitializeForDPTinDSDI

.Vision:
    push    bp
    push    si

    call    AdvAtaInit_LoadMasterDPTtoDSSIifSlaveInDSDI
    call    Vision_InitializeWithIDinAH
    xor     ax, ax                      ; Success

    pop     si
    pop     bp

.NoAdvancedController:
    ret


;--------------------------------------------------------------------
; AdvAtaInit_LoadMasterDPTtoDSSIifSlaveInDSDI
;   Parameters:
;       DS:DI:  Ptr to DPT for Single or Slave Drive
;   Returns:
;       SI:     Offset to Master DPT if Slave Drive present
;               Zero if Slave Drive not present
;   Corrupts registers:
;       AL
;--------------------------------------------------------------------
AdvAtaInit_LoadMasterDPTtoDSSIifSlaveInDSDI:
    ; Must be Slave Drive if previous DPT has same IDEVARS offset
    lea     si, [di-LARGEST_DPT_SIZE]   ; DS:SI points to previous DPT
    mov     al, [di+DPT.bIdevarsOffset]
    cmp     al, [si+DPT.bIdevarsOffset]
    je      SHORT .MasterAndSlaveDrivePresent

    ; We only have single drive so zero SI
    xor     si, si
.MasterAndSlaveDrivePresent:
    ret


;--------------------------------------------------------------------
; AdvAtaInit_SelectSlowestCommonPioTimingsToBXandCXfromDSSIandDSDI
;   Parameters:
;       DS:DI:  Ptr to DPT for Single or Slave Drive
;       SI:     Offset to Master DPT if Slave Drive present
;               Zero if Slave Drive not present
;   Returns:
;       BX:     Best common PIO mode
;       CX:     Slowest common PIO Cycle Time in nanosecs
;   Corrupts registers:
;       Nothing
;--------------------------------------------------------------------
AdvAtaInit_SelectSlowestCommonPioTimingsToBXandCXfromDSSIandDSDI:
    eMOVZX  bx, [di+DPT_ADVANCED_ATA.bPioMode]
    mov     cx, [di+DPT_ADVANCED_ATA.wMinPioCycleTime]
    test    si, si
    jz      SHORT .PioTimingsLoadedToBXandCX
    MIN_U   bl, [si+DPT_ADVANCED_ATA.bPioMode]
    MAX_U   cx, [si+DPT_ADVANCED_ATA.wMinPioCycleTime]
.PioTimingsLoadedToBXandCX:
    ret


;--------------------------------------------------------------------
; Just a simple IN AL, DX instruction but the function call works
; as I/O delay.
;
; AdvAtaInit_InputWithDelay
;   Parameters:
;       DX:     Port to read from
;   Returns:
;       AL:     Byte read from port
;   Corrupts registers:
;       Nothing
;--------------------------------------------------------------------
AdvAtaInit_InputWithDelay:
    in      al, dx
    ret