source: xtideuniversalbios/trunk/XTIDE_Universal_BIOS_Configurator_v2/Src/IdeAutodetect.asm@ 591

; Project name  :   XTIDE Universal BIOS Configurator v2
; Description   :   Functions to detect ports and devices.

;
; 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

IDE_PORT_TO_START_DETECTION         EQU 00h     ; Must be zero (not actual port)
FIRST_MEMORY_SEGMENT_ADDRESS        EQU 0C000h

;--------------------------------------------------------------------
; IdeAutodetect_DetectIdeDeviceFromPortDXAndReturnControlBlockInSI
;   Parameters:
;       DX:     IDE Base Port or segment address (Command Block)
;       DS:DI:  Ptr to ROMVARS
;   Returns:
;       AL:     Device Type
;       SI:     IDE Control Block Base port (port mapped devices only)
;       CF:     Clear if IDE Device found
;               Set if IDE Device not found
;   Corrupts registers:
;       AH, BX
;--------------------------------------------------------------------
IdeAutodetect_DetectIdeDeviceFromPortDXAndReturnControlBlockInSI:
    cmp     dh, FIRST_MEMORY_SEGMENT_ADDRESS >> 8
    jb      SHORT DetectPortMappedDeviceFromPortDX
    ; Fall to DetectMemoryMappedDeviceFromSegmentDX

;--------------------------------------------------------------------
; DetectMemoryMappedDeviceFromSegmentDX
;   Parameters:
;       DX:     Segment address for Memory Mapped Device
;       DS:DI:  Ptr to ROMVARS
;   Returns:
;       AL:     Device Type
;       CF:     Clear if IDE Device found
;               Set if IDE Device not found
;   Corrupts registers:
;       AH, BX
;--------------------------------------------------------------------
DetectMemoryMappedDeviceFromSegmentDX:
    ; *** Try to detect JR-IDE/ISA and ADP50L (only if MODULE_8BIT_IDE_ADVANCED is present) ***
    test    BYTE [di+ROMVARS.wFlags], FLG_ROMVARS_MODULE_8BIT_IDE_ADVANCED
    stc
    jz      SHORT .NoIdeDeviceFound

    push    ds
    mov     ds, dx

    cli
    mov     ah, [JRIDE_COMMAND_BLOCK_REGISTER_WINDOW_OFFSET + STATUS_REGISTER_in]
    mov     al, [JRIDE_CONTROL_BLOCK_REGISTER_WINDOW_OFFSET + ALTERNATE_STATUS_REGISTER_in]
    sti
    call    CompareIdeStatusRegistersFromALandAH
    mov     al, DEVICE_8BIT_JRIDE_ISA
    jnc     .IdeDeviceFound

    cli
    mov     ah, [ADP50L_COMMAND_BLOCK_REGISTER_WINDOW_OFFSET + (STATUS_REGISTER_in << 1)]
    mov     al, [ADP50L_CONTROL_BLOCK_REGISTER_WINDOW_OFFSET + (ALTERNATE_STATUS_REGISTER_in << 1)]
    sti
    call    CompareIdeStatusRegistersFromALandAH
    mov     al, DEVICE_8BIT_ADP50L

.IdeDeviceFound:
    mov     si, dx                      ; For IDEDTCT.COM
    pop     ds
.NoIdeDeviceFound:
    ret


;--------------------------------------------------------------------
; DetectPortMappedDeviceFromPortDX
;   Parameters:
;       DX:     IDE Base Port (Command Block)
;       DS:DI:  Ptr to ROMVARS
;   Returns:
;       AL:     Device Type
;       SI:     IDE Control Block Base port
;       CF:     Clear if IDE Device found
;               Set if IDE Device not found
;   Corrupts registers:
;       AH, BX
;--------------------------------------------------------------------
DetectPortMappedDeviceFromPortDX:
    ; *** Try to detect Standard 16- and 32-bit IDE Devices ***
    mov     al, DEVICE_16BIT_ATA        ; Assume 16-bit ISA slot for AT builds
    call    Buffers_IsXTbuildLoaded
    eCMOVE  al, DEVICE_8BIT_ATA         ; Assume 8-bit ISA slot for XT builds

    ; Start with standard Control Block base port used by Primary and Secondary IDE
    mov     si, dx
    add     si, STANDARD_CONTROL_BLOCK_OFFSET
    mov     bx, STATUS_REGISTER_in | (ALTERNATE_STATUS_REGISTER_in << 8)
.RedetectTertiaryOrQuaternaryWithDifferentControlBlockAddress:
    push    ax                          ; Store device type
    call    DetectIdeDeviceFromPortsDXandSIwithOffsetsInBLandBH
    pop     ax                          ; Restore device type
    jnc     SHORT .IdeDeviceFound

    ; 16- or 32-bit IDE Device was not found but we may have used wrong Control Block port if we were trying
    ; to detect Tertiary or Quaternary IDE controllers. Control Block port location is not standardized. For
    ; example Promise FloppyMAX has Control Block at STANDARD_CONTROL_BLOCK_OFFSET but Sound Blaster 16 (CT2290)
    ; use DEVICE_ATA_SECONDARY_PORTCTRL for Tertiary and Quaternary even though only Secondary should use that.
    call    ChangeDifferentControlBlockAddressToSI
    je      SHORT .RedetectTertiaryOrQuaternaryWithDifferentControlBlockAddress


    ; Detect 8-bit devices only if MODULE_8BIT_IDE is available
    test    BYTE [di+ROMVARS.wFlags], FLG_ROMVARS_MODULE_8BIT_IDE | FLG_ROMVARS_MODULE_8BIT_IDE_ADVANCED
    jz      SHORT NoIdeDeviceFound
    jpo     SHORT .SkipXTCF             ; Only 1 bit set means no MODULE_8BIT_IDE_ADVANCED

    ; *** Try to detect XT-CF ***
    mov     si, dx
    add     si, BYTE XTCF_CONTROL_BLOCK_OFFSET
    shl     bx, 1                       ; SHL 1 register offsets for XT-CF
    call    DetectIdeDeviceFromPortsDXandSIwithOffsetsInBLandBH
    mov     al, DEVICE_8BIT_XTCF_PIO8
    jnc     SHORT .IdeDeviceFound
    shr     bx, 1
.SkipXTCF:

    ; *** Try to detect 8-bit XT-IDE rev 1 or rev 2 ***
    ; Note that A0<->A3 address swaps Status Register and Alternative
    ; Status Register addresses. That is why we need another step
    ; to check is this XT-IDE rev 1 or rev 2.
    mov     si, dx
    add     si, BYTE XTIDE_CONTROL_BLOCK_OFFSET
    call    DetectIdeDeviceFromPortsDXandSIwithOffsetsInBLandBH
    jc      SHORT NoIdeDeviceFound      ; No XT-IDE rev 1 or rev 2 found

    ; Now we can be sure that we have XT-IDE rev 1 or rev 2.
    ; Rev 2 swaps address lines A0 and A3 thus LBA Low Register
    ; moves from offset 3h to offset Ah. There is no Register at
    ; offset Ah so if we can write to it and read back, then we
    ; must have XT-IDE rev 2 or modded rev 1.
    push    dx
    add     dx, BYTE 0Ah                ; LBA Low Register for XT-IDE rev 2
    mov     al, DEVICE_8BIT_XTIDE_REV2  ; Our test byte
    out     dx, al                      ; Output our test byte
    JMP_DELAY
    in      al, dx                      ; Read back
    pop     dx
    cmp     al, DEVICE_8BIT_XTIDE_REV2
    je      SHORT .IdeDeviceFound
    mov     al, DEVICE_8BIT_XTIDE_REV1  ; We must have rev 1
.IdeDeviceFound:
    clc
    ret


;--------------------------------------------------------------------
; DetectIdeDeviceFromPortsDXandSIwithOffsetsInBLandBH
;   Parameters:
;       BL:     Offset to IDE Status Register
;       BH:     Offset to Alternative Status Register
;       DX:     IDE Base Port address
;       SI:     IDE Control Block address
;   Returns:
;       CF:     Clear if IDE Device found
;               Set if IDE Device not found
;   Corrupts registers:
;       AX
;--------------------------------------------------------------------
DetectIdeDeviceFromPortsDXandSIwithOffsetsInBLandBH:
    ; Read Status and Alternative Status Registers
    push    dx

    add     dl, bl
    cli                         ; Disable Interrupts
    in      al, dx              ; Read Status Register...
    mov     ah, al              ; ...to AH
    mov     dx, si
    add     dl, bh
    in      al, dx              ; Read Alternative Status Register to AL
    sti                         ; Enable Interrupts

    pop     dx
    ; Fall to CompareIdeStatusRegistersFromALandAH


;--------------------------------------------------------------------
; CompareIdeStatusRegistersFromALandAH
;   Parameters:
;       AH:     Possible IDE Status Register contents
;       AL:     Possible IDE Alternative Status Register contents
;   Returns:
;       CF:     Clear if valid Status Register Contents
;               Set if not possible IDE Status Registers
;   Corrupts registers:
;       Nothing
;--------------------------------------------------------------------
CompareIdeStatusRegistersFromALandAH:
    ; Status Register now in AH and Alternative Status Register in AL.
    ; They must be the same if base port was in use by IDE device.
    cmp     al, ah
    jne     SHORT NoIdeDeviceFound

    ; Bytes were the same but it is possible they were both FFh, for
    ; example. We must make sure bits are what is expected from valid
    ; IDE Status Register. So far all drives I've tested return 50h
    ; (FLG_STATUS_DRDY and FLG_STATUS_DSC set) or 00h.
    ; I suspect that the zero might mean non available drive is selected. For example if Master
    ; drive is present but Slave is selected from IDE Drive and Head Select Register,
    ; then the Status Register can be 00h. We cannot accept 00h as valid byte
    ; since that can easily cause invalid JR-IDE/ISA detections.
    test    al, FLG_STATUS_BSY | FLG_STATUS_DF | FLG_STATUS_DRQ | FLG_STATUS_ERR
    jnz     SHORT NoIdeDeviceFound  ; Busy or Errors cannot be set
    test    al, FLG_STATUS_DRDY
    jz      SHORT NoIdeDeviceFound  ; Device needs to be ready
    ret                             ; Return with CF cleared

NoIdeDeviceFound:
    stc
    ret


;--------------------------------------------------------------------
; ChangeDifferentControlBlockAddressToSI
;   Parameters:
;       DX:     IDE Base Port address
;       SI:     IDE Control Block address
;   Returns:
;       ZF:     Set if SI changed
;               Cleared if different control block address is not possible
;   Corrupts registers:
;       AH
;--------------------------------------------------------------------
ChangeDifferentControlBlockAddressToSI:
    cmp     si, 368h
    je      SHORT .TrySecondAlternative
    cmp     si, 3E8h
    je      SHORT .TrySecondAlternative

    cmp     si, 360h
    je      SHORT .TryLastAlternative
    cmp     si, 3E0h
    je      SHORT .TryLastAlternative
    ret     ; Return with ZF cleared

.TryLastAlternative:
    mov     si, DEVICE_ATA_SECONDARY_PORTCTRL + 8   ; Changes to 370h used by Sound Blaster 16 (CT2290)
    ; Fall to .TrySecondAlternative
.TrySecondAlternative:
    sub     si, BYTE 8h     ; 368h to 360h, 3E8h to 3E0h
    xor     ah, ah          ; Set ZF
    ret


;--------------------------------------------------------------------
; IdeAutodetect_IncrementDXtoNextIdeBasePort
;   Parameters:
;       DX:     Previous IDE Base Port or IDE_PORT_TO_START_DETECTION
;   Returns:
;       DX:     Next IDE Base Port
;       ZF:     Set if no more Base Ports (DX was last base port on entry)
;               Clear if new base port returned in DX
;   Corrupts registers:
;       AX
;--------------------------------------------------------------------
ALIGN JUMP_ALIGN
IdeAutodetect_IncrementDXtoNextIdeBasePort:
    cmp     dx, [cs:.wLastIdePort]
    je      SHORT .AllPortsAlreadyDetected

    push    si
    mov     si, .rgwIdeBasePorts
.CompareNextIdeBasePort:
    cmp     [cs:si], dx
    lea     si, [si+2]  ; Increment SI and preserve FLAGS
    jne     SHORT .CompareNextIdeBasePort

    mov     dx, [cs:si]         ; Get next port
    test    dx, dx              ; Clear ZF
    pop     si
.AllPortsAlreadyDetected:
    ret


    ; All ports used in autodetection. Ports can be in any order.
ALIGN WORD_ALIGN
.rgwIdeBasePorts:
    dw      IDE_PORT_TO_START_DETECTION     ; Must be first
    ; Standard IDE
    dw      DEVICE_ATA_PRIMARY_PORT
    dw      DEVICE_ATA_SECONDARY_PORT
    dw      DEVICE_ATA_TERTIARY_PORT
    dw      DEVICE_ATA_QUATERNARY_PORT
    ; 8-bit Devices
    dw      200h
    dw      220h
    dw      240h
    dw      260h
    dw      280h
    dw      2A0h
    dw      2C0h
    dw      2E0h
    dw      300h
    dw      320h
    dw      340h
    dw      360h
    dw      380h
    dw      3A0h
    dw      3C0h
    dw      3E0h
    ; Memory Segment Addresses
    dw      0C000h  ; JR-IDE/ISA
    dw      0C400h  ; JR-IDE/ISA
    dw      0C800h  ; JR-IDE/ISA and ADP50L
    dw      0CA00h  ; ADP50L
    dw      0CC00h  ; JR-IDE/ISA and ADP50L
    dw      0CE00h  ; ADP50L
    dw      0D000h  ; JR-IDE/ISA
    dw      0D400h  ; JR-IDE/ISA
    dw      0D800h  ; JR-IDE/ISA
.wLastIdePort:
    dw      0DC00h  ; JR-IDE/ISA