source: xtideuniversalbios/trunk/XTIDE_Universal_BIOS/Src/Device/Idepack.asm@ 240

; Project name  :   XTIDE Universal BIOS
; Description   :   Functions for managing IDEPACK struct.

; Section containing code
SECTION .text

;--------------------------------------------------------------------
; Idepack_FakeToSSBP
;   Parameters:
;       Nothing
;   Returns:
;       SS:BP:  Ptr to IDEPACK
;   Corrupts registers:
;       AX
;--------------------------------------------------------------------
Idepack_FakeToSSBP:
    pop     ax
    sub     sp, BYTE EXTRA_BYTES_FOR_INTPACK
    mov     bp, sp
    jmp     ax


;--------------------------------------------------------------------
; Idepack_ConvertDapToIdepackAndIssueCommandFromAH
;   Parameters:
;       AH:     IDE command to issue
;       BH:     Timeout ticks
;       BL:     IDE Status Register flag to wait after command
;       DS:DI:  Ptr to DPT (in RAMVARS segment)
;       ES:SI:  Ptr to DAP (EBIOS Disk Address Packet)
;       SS:BP:  Ptr to IDEPACK
;   Returns:
;       AH:     INT 13h Error Code
;       CF:     Cleared if success, Set if error
;   Corrupts registers:
;       AL, BX, CX, DX, SI, ES
;--------------------------------------------------------------------
%ifdef MODULE_EBIOS
ALIGN JUMP_ALIGN
Idepack_ConvertDapToIdepackAndIssueCommandFromAH:
    mov     al, [es:si+DAP.wSectorCount]
    mov     [bp+IDEPACK.bSectorCount], al
    mov     [bp+IDEPACK.bCommand], ah

    mov     al, [es:si+DAP.qwLBA]       ; LBA byte 0
    mov     [bp+IDEPACK.bLbaLow], al
    mov     ax, [es:si+DAP.qwLBA+1]     ; LBA bytes 1 and 2
    mov     [bp+IDEPACK.wLbaMiddleAndHigh], ax
    mov     ah, [es:si+DAP.qwLBA+3]     ; LBA byte 3, LBA28 bits 24...27
    mov     [bp+IDEPACK.bLbaLowExt], ah
    mov     cx, [es:si+DAP.qwLBA+4]     ; LBA bytes 4 and 5
    mov     [bp+IDEPACK.wLbaMiddleAndHighExt], cx

    and     ah, 0Fh                     ; Limit bits for LBA28
    call    AccessDPT_GetDriveSelectByteToAL
    or      al, ah
    mov     [bp+IDEPACK.bDrvAndHead], al

    ; Normalize data buffer pointer to ES:SI
    mov     ax, [es:si+DAP.wOffset]
    mov     cx, ax
    eSHR_IM ax, 4                               ; Divide offset by 16
    add     ax, [es:si+DAP.wSegment]            ; Add segment
    mov     es, ax                              ; Segment normalized
    mov     si, cx
    and     si, BYTE 0Fh                        ; Offset normalized
    jmp     SHORT GetDeviceControlByteToIdepackAndStartTransfer
%endif


;--------------------------------------------------------------------
; Idepack_TranslateOldInt13hAddressAndIssueCommandFromAH
;   Parameters:
;       AH:     IDE command to issue
;       AL:     Number of sectors to transfer (for xfer commands)
;       BH:     Timeout ticks
;       BL:     IDE Status Register flag to wait after command
;       CH:     Cylinder number, bits 7...0
;       CL:     Bits 7...6: Cylinder number bits 9 and 8
;               Bits 5...0: Starting sector number (1...63)
;       DH:     Starting head number (0...255)
;       DS:DI:  Ptr to DPT (in RAMVARS segment)
;       ES:SI:  Ptr to normalized data buffer (for xfer commands)
;       SS:BP:  Ptr to IDEPACK (containing INTPACK)
;   Returns:
;       AH:     INT 13h Error Code
;       CF:     Cleared if success, Set if error
;   Corrupts registers:
;       AL, BX, CX, DX
;--------------------------------------------------------------------
ALIGN JUMP_ALIGN
Idepack_TranslateOldInt13hAddressAndIssueCommandFromAH:
    mov     [bp+IDEPACK.bSectorCount], al
    mov     [bp+IDEPACK.bCommand], ah

    push    bx
    call    Address_OldInt13hAddressToIdeAddress
    call    AccessDPT_GetDriveSelectByteToAL
    or      al, bh          ; AL now has Drive and Head Select Byte
    mov     [bp+IDEPACK.bDrvAndHead], al
    mov     [bp+IDEPACK.bLbaLow], bl
    mov     [bp+IDEPACK.wLbaMiddleAndHigh], cx
    pop     bx

GetDeviceControlByteToIdepackAndStartTransfer:
    call    AccessDPT_GetDeviceControlByteToAL
    mov     [bp+IDEPACK.bDeviceControl], al
    jmp     Device_OutputCommandWithParameters


;--------------------------------------------------------------------
; Idepack_StoreNonExtParametersAndIssueCommandFromAL
;   Parameters:
;       BH:     Timeout ticks
;       BL:     IDE Status Register flag to wait after command
;       AL:     IDE command to issue
;       AH:     Parameter to Drive and Head Select Register (Head bits only)
;       DL:     Parameter to Sector Count Register
;       DH:     Parameter to LBA Low / Sector Number Register
;       CL:     Parameter to LBA Middle / Cylinder Low Register
;       CH:     Parameter to LBA High / Cylinder High Register
;       SI:     Parameter to Features Register
;       DS:DI:  Ptr to DPT (in RAMVARS segment)
;       SS:BP:  Ptr to IDEPACK
;   Returns:
;       AH:     INT 13h Error Code
;       CF:     Cleared if success, Set if error
;   Corrupts registers:
;       AL, BX, CX, DX
;--------------------------------------------------------------------
ALIGN JUMP_ALIGN
Idepack_StoreNonExtParametersAndIssueCommandFromAL:
    mov     [bp+IDEPACK.bFeatures], si
    mov     [bp+IDEPACK.bCommand], al
    mov     [bp+IDEPACK.wSectorCountAndLbaLow], dx
    mov     [bp+IDEPACK.wLbaMiddleAndHigh], cx

    ; Drive and Head select byte
    and     ah, MASK_DRVNHEAD_HEAD      ; Keep head bits only
    call    AccessDPT_GetDriveSelectByteToAL
    or      al, ah
    mov     [bp+IDEPACK.bDrvAndHead], al

    ; Device Control byte with interrupts disabled
    call    AccessDPT_GetDeviceControlByteToAL
    or      al, FLG_DEVCONTROL_nIEN     ; Disable interrupt
    mov     [bp+IDEPACK.bDeviceControl], al

    jmp     Device_OutputCommandWithParameters