source: xtideuniversalbios/trunk/XTIDE_Universal_BIOS/Src/Initialization/AtaID.asm@ 567

; Project name  :   XTIDE Universal BIOS
; Description   :   Functions for accessing ATA information read with
;                   IDENTIFY DEVICE command.

;
; 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

;--------------------------------------------------------------------
; AtaID_VerifyFromESSI
;   Parameters:
;       ES:SI:  Ptr to 512-byte ATA information read from the drive
;   Returns:
;       ZF:     Set if ATA-ID verified successfully
;               Cleared if failed to verify ATA-ID
;   Corrupts registers:
;       AX, BX, CX
;--------------------------------------------------------------------
AtaID_VerifyFromESSI:
    ; We cannot start by reading ATA version since the ID might be
    ; corrupted. We start by making sure P-CHS values are valid.
    ; If they are, we assume the ATA ID to be valid. Fortunately we can do
    ; further checking for ATA-5 and later since they contain signature and
    ; checksum bytes. Those are not available for ATA-4 and older.

    ; Verify P-CHS cylinders
    mov     bx, ATA1.wCylCnt
    mov     ax, MAX_VALID_PCHS_CYLINDERS
    call    .CompareCHorSfromOffsetBXtoMaxValueInAX

    mov     bl, ATA1.wHeadCnt & 0FFh
    mov     ax, MAX_VALID_PCHS_HEADS
    call    .CompareCHorSfromOffsetBXtoMaxValueInAX

    mov     bl, ATA1.wSPT & 0FFh
    mov     al, MAX_VALID_PCHS_SECTORS_PER_TRACK
    call    .CompareCHorSfromOffsetBXtoMaxValueInAX

    ; Check signature byte. It is only found on ATA-5 and later. It should be zero on
    ; ATA-4 and older.
    mov     al, [es:si+ATA6.bSignature]
    test    al, al
    jz      SHORT .AtaIDverifiedSuccessfully    ; Old ATA so Signature and Checksum is not available
    cmp     al, A6_wIntegrity_SIGNATURE
    jne     SHORT .FailedToVerifyAtaID

    ; Check checksum byte since signature was present
    mov     cx, ATA6_size
    jmp     Memory_SumCXbytesFromESSItoAL       ; Returns with ZF set according to result

;--------------------------------------------------------------------
; .CompareCHorSfromOffsetBXtoMaxValueInAX
;   Parameters:
;       AX:     Maximum valid C, H or S value
;       BX:     C, H or S offset to ATA-ID
;       ES:SI:  Ptr to 512-byte ATA information read from the drive
;   Returns:
;       Exits from AtaID_VerifyFromESSI with ZF cleared if invalid value
;   Corrupts registers:
;       CX
;--------------------------------------------------------------------
.CompareCHorSfromOffsetBXtoMaxValueInAX:
    mov     cx, [es:bx+si]
    jcxz    .InvalidPCHorSinOffsetBX
    cmp     cx, ax          ; Compare to max valid value
    jbe     SHORT .ValidPCHorSinOffsetBX
.InvalidPCHorSinOffsetBX:
    pop     cx              ; Clear return address for this function
    inc     cx              ; Clear ZF to indicate invalid ATA-ID (safe to do since return address in CX will never be FFFFh)
.AtaIDverifiedSuccessfully:
.FailedToVerifyAtaID:
.ValidPCHorSinOffsetBX:
    ret


;--------------------------------------------------------------------
; Writes user defined limits from ROMVARS to ATA ID read from the drive.
; Modifying the ATA ID reduces code and possibilities for bugs since
; only little further checks are needed elsewhere.
;
; AtaID_ModifyESSIforUserDefinedLimitsAndReturnTranslateModeInDX
;   Parameters:
;       DS:DI:  Ptr to incomplete Disk Parameter Table
;       ES:SI:  Ptr to 512-byte ATA information read from the drive
;       CS:BP:  Ptr to IDEVARS for the controller
;   Returns:
;       DX:     User defined P-CHS to L-CHS translate mode
;   Corrupts registers:
;       AX, BX, CX
;--------------------------------------------------------------------
AtaID_ModifyESSIforUserDefinedLimitsAndReturnTranslateModeInDX:
    call    AccessDPT_GetPointerToDRVPARAMStoCSBX
    push    ds
    push    es
    pop     ds      ; DS:SI now points to ATA information

    ; Load User Defined CHS or LBA to CX:AX
    mov     dx, [cs:bx+DRVPARAMS.wFlags]
    mov     ax, [cs:bx+DRVPARAMS.wCylinders]        ; Or .dwMaximumLBA
    mov     cx, [cs:bx+DRVPARAMS.wHeadsAndSectors]  ; Or .dwMaximumLBA+2

    ; * User defined CHS *
    test    dl, FLG_DRVPARAMS_USERCHS
    jz      SHORT .NoUserDefinedCHS

    ; Apply new CHS and disable LBA (we also want to set CHS addressing)
    mov     [si+ATA1.wCylCnt], ax
    eMOVZX  ax, cl
    mov     [si+ATA1.wHeadCnt], ax
    mov     al, ch
    mov     [si+ATA1.wSPT], ax
    and     BYTE [si+ATA1.wCaps+1], ~(A1_wCaps_LBA>>8)
    and     BYTE [si+ATA6.wSetSup83+1], ~(A6_wSetSup83_LBA48>>8)
.NoUserDefinedCHS:

    ; * User defined LBA *
    test    dl, FLG_DRVPARAMS_USERLBA
    jz      SHORT .NoUserDefinedLBA

    ; Apply new LBA and disable LBA48
    cmp     cx, [si+ATA1.dwLBACnt+2]
    ja      SHORT .NoUserDefinedLBA     ; Do not set larger than drive
    jb      SHORT .StoreNewLBA
    cmp     ax, [si+ATA1.dwLBACnt]
    ja      SHORT .NoUserDefinedLBA     ; Allow same size to disable LBA48
.StoreNewLBA:
    mov     [si+ATA1.dwLBACnt], ax
    mov     [si+ATA1.dwLBACnt+2], cx
    and     BYTE [si+ATA6.wSetSup83+1], ~(A6_wSetSup83_LBA48>>8)
.NoUserDefinedLBA:

    ; * Load P-CHS to L-CHS translate mode to DX *
    and     dx, BYTE MASK_DRVPARAMS_TRANSLATEMODE
    eSHR_IM dx, TRANSLATEMODE_FIELD_POSITION

    pop     ds
    ret


%ifdef MODULE_ADVANCED_ATA
;--------------------------------------------------------------------
; AtaID_GetMaxPioModeToAXandMinCycleTimeToCX
;   Parameters:
;       ES:SI:  Ptr to 512-byte ATA information read from the drive
;   Returns:
;       AL:     Max supported PIO mode
;       AH:     FLGH_DPT_IORDY if IORDY supported, zero otherwise
;       CX:     Minimum Cycle Time in nanosecs
;   Corrupts registers:
;       BX
;--------------------------------------------------------------------
AtaID_GetMaxPioModeToAXandMinCycleTimeToCX:
    ; Get PIO mode and cycle time for PIO 0...2
    mov     bx, [es:si+ATA1.bPioMode]
    mov     ax, bx                  ; AH = 0, AL = PIO mode 0, 1 or 2
    eSHL_IM bx, 1                   ; Shift for WORD lookup
    mov     cx, [cs:bx+.rgwPio0to2CycleTimeInNanosecs]

    ; Check if IORDY is supported
    test    BYTE [es:si+ATA2.wCaps+1], A2_wCaps_IORDY >> 8
    jz      SHORT .ReturnPioTimings ; No PIO 3 or higher if no IORDY
    mov     ah, FLGH_DPT_IORDY

    ; Check if Advanced PIO modes are supported (3 and above)
    test    BYTE [es:si+ATA2.wFields], A2_wFields_64to70
    jz      SHORT .ReturnPioTimings

    ; Get Advanced PIO mode
    ; (Hard Disks supports up to 4 but CF cards can support 5 and 6)
    mov     bl, [es:si+ATA2.bPIOSupp]
.CheckNextFlag:
    inc     ax
    shr     bl, 1
    jnz     SHORT .CheckNextFlag
    MIN_U   al, 6                       ; Make sure not above lookup tables
    mov     cx, [es:si+ATA2.wPIOMinCyF] ; Advanced modes use IORDY
.ReturnPioTimings:
    ret

.rgwPio0to2CycleTimeInNanosecs:
    dw      PIO_0_MIN_CYCLE_TIME_NS
    dw      PIO_1_MIN_CYCLE_TIME_NS
    dw      PIO_2_MIN_CYCLE_TIME_NS


;--------------------------------------------------------------------
; AtaID_GetRecoveryTimeToAXfromPioModeInBXandCycleTimeInCX
;   Parameters:
;       BX:     PIO Mode
;       CX:     PIO Cycle Time in nanosecs
;   Returns:
;       AX:     Active Time in nanosecs
;   Corrupts registers:
;       BX, CX
;--------------------------------------------------------------------
AtaID_GetRecoveryTimeToAXfromPioModeInBXandCycleTimeInCX:
    call    AtaID_GetActiveTimeToAXfromPioModeInBX
    mov     bl, [cs:bx+.rgbPioModeToAddressValidTimeNs]
    sub     cx, bx  ; Cycle Time (t0) - Address Valid Time (t1)
    sub     cx, ax  ; - Active Time (t2)
    xchg    ax, cx  ; AX = Recovery Time (t2i)
    ret

.rgbPioModeToAddressValidTimeNs:
    db      PIO_0_MIN_ADDRESS_VALID_NS
    db      PIO_1_MIN_ADDRESS_VALID_NS
    db      PIO_2_MIN_ADDRESS_VALID_NS
    db      PIO_3_MIN_ADDRESS_VALID_NS
    db      PIO_4_MIN_ADDRESS_VALID_NS
    db      PIO_5_MIN_ADDRESS_VALID_NS
    db      PIO_6_MIN_ADDRESS_VALID_NS


;--------------------------------------------------------------------
; AtaID_GetActiveTimeToAXfromPioModeInBX
;   Parameters:
;       BX:     PIO Mode
;   Returns:
;       AX:     Active Time in nanosecs
;   Corrupts registers:
;       Nothing
;--------------------------------------------------------------------
AtaID_GetActiveTimeToAXfromPioModeInBX:
    eMOVZX  ax, [cs:bx+.rgbPioModeToActiveTimeNs]
    ret

.rgbPioModeToActiveTimeNs:
    db      PIO_0_MIN_ACTIVE_TIME_NS
    db      PIO_1_MIN_ACTIVE_TIME_NS
    db      PIO_2_MIN_ACTIVE_TIME_NS
    db      PIO_3_MIN_ACTIVE_TIME_NS
    db      PIO_4_MIN_ACTIVE_TIME_NS
    db      PIO_5_MIN_ACTIVE_TIME_NS
    db      PIO_6_MIN_ACTIVE_TIME_NS

%endif ; MODULE_ADVANCED_ATA