source: xtideuniversalbios/trunk/XTIDE_Universal_BIOS/Src/Initialization/AtaID.asm@ 363

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

; Section containing code
SECTION .text

;--------------------------------------------------------------------
; AtaID_GetPCHStoAXBLBHfromAtaInfoInESSI
;   Parameters:
;       ES:SI:  Ptr to 512-byte ATA information read from the drive
;   Returns:
;       AX:     Number of user specified P-CHS cylinders
;       BH:     Number of user specified P-CHS sectors per track
;       BL:     Number of user specified P-CHS heads
;   Corrupts registers:
;       Nothing
;--------------------------------------------------------------------
AtaID_GetPCHStoAXBLBHfromAtaInfoInESSI:
    mov     ax, [es:si+ATA1.wCylCnt]    ; Cylinders (1...16383)
    mov     bl, [es:si+ATA1.wHeadCnt]   ; Heads (1...16)
    mov     bh, [es:si+ATA1.wSPT]       ; Sectors per Track (1...63)
    ret


;--------------------------------------------------------------------
; AtaID_GetTotalSectorCountToBXDXAXfromAtaInfoInESSI
;   Parameters:
;       ES:SI:  Ptr to 512-byte ATA information read from the drive
;   Returns:
;       BX:DX:AX:   48-bit sector count
;   Corrupts registers:
;       Nothing
;--------------------------------------------------------------------
AtaID_GetTotalSectorCountToBXDXAXfromAtaInfoInESSI:
    mov     bx, Registers_ExchangeDSSIwithESDI
    call    bx  ; ATA info now in DS:DI
    push    bx  ; We will return via Registers_ExchangeDSSIwithESDI
    xor     bx, bx
    test    BYTE [di+ATA1.wCaps+1], A1_wCaps_LBA>>8
    jz      SHORT .GetChsSectorCount
    ; Fall to .GetLbaSectorCount

;--------------------------------------------------------------------
; .GetLbaSectorCount
; .GetLba28SectorCount
; .GetChsSectorCount
;   Parameters:
;       BX:     Zero
;       DS:DI:  Ptr to 512-byte ATA information read from the drive
;   Returns:
;       BX:DX:AX:   48-bit sector count
;   Corrupts registers:
;       Nothing
;--------------------------------------------------------------------
.GetLbaSectorCount:
    test    BYTE [di+ATA6.wSetSup83+1], A6_wSetSup83_LBA48>>8
    jz      SHORT .GetLba28SectorCount
    mov     ax, [di+ATA6.qwLBACnt]
    mov     dx, [di+ATA6.qwLBACnt+2]
    mov     bx, [di+ATA6.qwLBACnt+4]
    ret

.GetLba28SectorCount:
    mov     ax, [di+ATA1.dwLBACnt]
    mov     dx, [di+ATA1.dwLBACnt+2]
    ret

.GetChsSectorCount:
    mov     al, [di+ATA1.wSPT]      ; AL=Sectors per track
    mul     BYTE [di+ATA1.wHeadCnt] ; AX=Sectors per track * number of heads
    mul     WORD [di+ATA1.wCylCnt]  ; DX:AX=Sectors per track * number of heads * number of cylinders
    ret


%ifdef MODULE_ADVANCED_ATA
;--------------------------------------------------------------------
; AtaID_GetMaxPioModeToAXandMinCycleTimeToDX
;   Parameters:
;       ES:SI:  Ptr to 512-byte ATA information read from the drive
;   Returns:
;       AX:     Max supported PIO mode
;       DX:     Minimum Cycle Time in nanosecs
;   Corrupts registers:
;       BX
;--------------------------------------------------------------------
AtaID_GetMaxPioModeToAXandMinCycleTimeToDX:
    ; Get PIO mode and cycle time for PIO 0...2
    mov     bx, [es:si+ATA1.bPioMode]
    shl     bx, 1                   ; Shift for WORD lookup
    mov     dx, [cs:bx+.rgwPio0to2CycleTimeInNanosecs]
    shr     bx, 1
    xchg    ax, bx                  ; AL = PIO mode 0, 1 or 2

    ; 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 might support 5)
    mov     bx, [es:si+ATA2.bPIOSupp]
.CheckNextFlag:
    inc     ax
    shr     bx, 1
    jnz     SHORT .CheckNextFlag
    mov     dx, [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_ConvertPioModeFromAXandMinCycleTimeFromDXtoActiveAndRecoveryTime
;   Parameters:
;       AX:     Max supported PIO mode
;       DX:     Minimum PIO Cycle Time in nanosecs
;   Returns:
;       CX:     Minimum Active time in nanosecs
;       DX:     Minimum Recovery time in nanosecs
;   Corrupts registers:
;       BX
;--------------------------------------------------------------------
AtaID_ConvertPioModeFromAXandMinCycleTimeFromDXtoActiveAndRecoveryTime:
    ; Subtract Address Valid Time (t1) from Cycle Time (t0)
    mov     bx, ax
    eMOVZX  cx, BYTE [cs:bx+.rgbPioModeToAddressValidTimeNs]
    sub     dx, cx

    ; Subtract Active Time (t2) from previous result to get Recovery Time (t2i)
    shl     bx, 1           ; Shift PIO Mode for WORD lookup
    mov     cx, [cs:bx+.rgwPioModeToActiveTimeNs]
    sub     dx, cx
    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

.rgwPioModeToActiveTimeNs:
    dw      PIO_0_MIN_ACTIVE_TIME_NS
    dw      PIO_1_MIN_ACTIVE_TIME_NS
    dw      PIO_2_MIN_ACTIVE_TIME_NS
    dw      PIO_3_MIN_ACTIVE_TIME_NS
    dw      PIO_4_MIN_ACTIVE_TIME_NS

%endif ; MODULE_ADVANCED_ATA