source: xtideuniversalbios/trunk/XTIDE_Universal_BIOS_Configurator_v2/Src/IdeAutodetect.asm @ 498

; 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, 2011-2012 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

;--------------------------------------------------------------------
; IdeAutodetect_DetectIdeDeviceFromPortDX
;   Parameters:
;       DX:     IDE Base Port
;       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, CX
;--------------------------------------------------------------------
IdeAutodetect_DetectIdeDeviceFromPortDX:
    cmp     dx, FIRST_MEMORY_SEGMENT_ADDRESS
    jb      SHORT .DetectPortMappedDevices

    ; Try to detect JR-IDE/ISA (only if MODULE_8BIT_IDE_ADVANCED is present)
    test    WORD [di+ROMVARS.wFlags], FLG_ROMVARS_MODULE_8BIT_IDE_ADVANCED
    jz      SHORT .SkipRestOfDetection

    push    ds
    mov     ds, dx
    cli                         ; Disable Interrupts
    mov     ah, [JRIDE_COMMAND_BLOCK_REGISTER_WINDOW_OFFSET + STATUS_REGISTER_in]
    mov     al, [JRIDE_CONTROL_BLOCK_REGISTER_WINDOW_OFFSET + ALTERNATE_STATUS_REGISTER_in]
    sti                         ; Enable Interrupts
    pop     ds
    call    CompareIdeStatusRegistersFromALandAH
    mov     al, DEVICE_8BIT_JRIDE_ISA
    ret
.DetectPortMappedDevices:


    ; Try to detect Standard 16- and 32-bit IDE Devices
    mov     bh, DEVICE_16BIT_ATA        ; Assume 16-bit ISA slot for AT builds
    call    Buffers_IsXTbuildLoaded
    eCMOVE  bh, DEVICE_8BIT_ATA         ; Assume 8-bit ISA slot for XT builds
    mov     bl, STATUS_REGISTER_in
    mov     cx, STANDARD_CONTROL_BLOCK_OFFSET + ALTERNATE_STATUS_REGISTER_in
    call    DetectIdeDeviceFromPortDXwithStatusRegOffsetsInBLandCX
    mov     al, bh
    jnc     SHORT .IdeDeviceFound


    ; Detect 8-bit devices only if MODULE_8BIT_IDE is available
    test    BYTE [di+ROMVARS.wFlags], FLG_ROMVARS_MODULE_8BIT_IDE
    jz      SHORT .SkipRestOfDetection

    ; Try to detect XT-CF
    mov     bl, STATUS_REGISTER_in << 1
    mov     cx, (XTIDE_CONTROL_BLOCK_OFFSET + ALTERNATE_STATUS_REGISTER_in) << 1
    call    DetectIdeDeviceFromPortDXwithStatusRegOffsetsInBLandCX
    mov     al, DEVICE_8BIT_XTCF_PIO8
    jnc     SHORT .IdeDeviceFound

    ; 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.
    shr     cx, 1
    call    DetectIdeDeviceFromPortDXwithStatusRegOffsetsInBLandCX
    jc      SHORT .SkipRestOfDetection  ; 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
    clc
.IdeDeviceFound:
    ret
.SkipRestOfDetection:
    stc
    ret


;--------------------------------------------------------------------
; DetectIdeDeviceFromPortDXwithStatusRegOffsetsInBLandCX
;   Parameters:
;       BL:     Offset to IDE Status Register
;       CX:     Offset to Alternative Status Register
;       DX:     IDE Base Port
;   Returns:
;       CF:     Clear if IDE Device found
;               Set if IDE Device not found
;   Corrupts registers:
;       AX
;--------------------------------------------------------------------
DetectIdeDeviceFromPortDXwithStatusRegOffsetsInBLandCX:
    ; Read Status and Alternative Status Registers
    push    cx
    push    dx

    add     cx, dx              ; CX = Address to Alternative Status Register
    add     dl, bl              ; DX = Address to Status Register
    cli                         ; Disable Interrupts
    in      al, dx              ; Read Status Register
    mov     ah, al
    mov     dx, cx
    in      al, dx              ; Read Alternative Status Register
    sti                         ; Enable Interrupts

    pop     dx
    pop     cx
    ; Fall to CompareIdeStatusRegistersFromALandAH


;--------------------------------------------------------------------
; CompareIdeStatusRegistersFromALandAH
;   Parameters:
;       AL:     Possible IDE Status Register contents
;       AH:     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 .InvalidStatusRegister

    ; Bytes were the same but it is possible they were both FFh, for 
    ; example. We must make sure bit are what is expected from valid
    ; IDE Status Register.
    test    al, FLG_STATUS_BSY | FLG_STATUS_DF | FLG_STATUS_DRQ | FLG_STATUS_ERR
    jnz     SHORT .InvalidStatusRegister    ; Busy or Errors cannot be set
    test    al, FLG_STATUS_DRDY
    jz      SHORT .InvalidStatusRegister    ; Device needs to be ready
    ret                                     ; Return with CF cleared

.InvalidStatusRegister:
AllPortsAlreadyDetected:
    stc
    ret


;--------------------------------------------------------------------
; IdeAutodetect_IncrementDXtoNextIdeBasePort
;   Parameters:
;       DX:     Previous IDE Base Port
;   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
    ; JR-IDE/ISA (Memory Segment Addresses)
    dw      0C000h
    dw      0C400h
    dw      0C800h
    dw      0CC00h
    dw      0D000h
    dw      0D400h
    dw      0D800h
.wLastIdePort:
    dw      0DC00h