source: xtideuniversalbios/trunk/XTIDE_Universal_BIOS/Inc/CustomDPT.inc@ 363

; Project name  :   XTIDE Universal BIOS
; Description   :   Defines for DPT structs containing custom
;                   Disk Parameter Table used by this BIOS.
%ifndef CUSTOMDPT_INC
%define CUSTOMDPT_INC

; Base DPT for all device types
struc DPT   ; 10 bytes
    ; General Disk Parameter Table related
    .wFlags:
    .bFlagsLow                  resb    1
    .bFlagsHigh                 resb    1
    .bIdevarsOffset             resb    1   ; Offset to IDEVARS for this drive

    ; IDE Drive related
    ; .bLbaHeads and .twLbaSectors are used for LBA addressing only.
    .bLbaHeads:                 resb    1   ; Number of LBA assisted heads (1...255)
    .twLbaSectors               resb    2   ; 48-bit sector count for LBA addressing

    ; .wPchsCylinders and .bPchsSectors are used for CHS addressing only.
    .wPchsCylinders             resb    2   ; Number of P-CHS Cylinders (1...16383)
    .wPchsHeadsAndSectors:
    .bPchsHeads                 resb    1   ; Number of P-CHS heads (1...16)
    .bPchsSectors               resb    1   ; Number of P-CHS Sectors per Track (1...63)
endstruc

; Bit definitions for DPT.bFlagsLow
MASKL_DPT_CHS_SHIFT_COUNT       EQU (7<<0)  ; Bits 0...3, P-CHS to L-CHS bit shift count (0...4)
FLGL_DPT_SLAVE                  EQU FLG_DRVNHEAD_DRV    ; (1<<4), Drive is slave drive
MASKL_DPT_ADDRESSING_MODE       EQU (3<<5)  ; Bits 5..6, Addressing Mode (bit 6 == FLG_DRVNHEAD_LBA)
FLGL_DPT_ENABLE_IRQ             EQU (1<<7)

; Bit definitions for DPT.bFlagsHigh
FLGH_DPT_REVERSED_A0_AND_A3     EQU (1<<0)  ; XTIDE mod, Address lines 0 and 3 reversed
FLGH_DPT_BLOCK_MODE_SUPPORTED   EQU (1<<1)  ; Use block transfer commands (must be bit 1!)
%ifdef MODULE_SERIAL
FLGH_DPT_SERIAL_DEVICE          EQU (1<<2)  ; Serial Port Device
%endif
FLGH_DPT_INTERRUPT_IN_SERVICE   EQU (1<<3)  ; Set when waiting for IRQ

; IDE device only
FLGH_DPT_INITERROR              EQU (1<<7)

; Serial device only
FLGH_DPT_SERIAL_FLOPPY                      EQU (1<<4)
FLGH_DPT_SERIAL_FLOPPY_TYPE_MASK            EQU 0e0h
FLGH_DPT_SERIAL_FLOPPY_TYPE_FIELD_POSITION  EQU 5

; Addressing modes for DPT.wFlags
ADDRESSING_MODE_FIELD_POSITION  EQU     5
ADDRESSING_MODE_LCHS            EQU     0   ; L-CHS Addressing Mode (NORMAL in many other BIOSes)
ADDRESSING_MODE_PCHS            EQU     1   ; P-CHS Addressing Mode (LARGE in many other BIOSes)
ADDRESSING_MODE_LBA28           EQU     2   ; 28-bit LBA Addressing Mode
ADDRESSING_MODE_LBA48           EQU     3   ; 48-bit LBA Addressing Mode


; DPT for ATA devices
struc DPT_ATA   ; 10 + 2 bytes = 12 bytes
    .dpt                        resb    DPT_size

    ; Block size is specified in sectors (1, 2, 4, 8, 16, 32, 64 or 128)
    .wSetAndMaxBlock:
    .bSetBlock                  resb    1   ; Current block size (do not set to zero!)
    .bMaxBlock                  resb    1   ; Maximum block size, 0 = block mode not supported

%ifdef MODULE_ADVANCED_ATA  ; +2 extra bytes = 14 bytes
    .bPioMode                   resb    1
    .bDevice                    resb    1
%endif
endstruc


%ifdef MODULE_ADVANCED_ATA
; Temporary extension for DPT_ATA. Contents will be copied to BOOTMENUINFO and
; then these variables will be overridden by next DPT.
struc DPT_ADVANCED_ATA
    .dpt_ata                resb    DPT_ATA_size
    .wIdeBasePort           resb    2   ; IDE Base Port
    .wMinPioActiveTimeNs    resb    2   ; Minimum PIO Active Time in ns
    .wMinPioRecoveryTimeNs  resb    2   ; Minimum PIO Recovery Time in ns
    .wControllerID          resb    2   ; Controller specific ID WORD
    .wControllerBasePort    resb    2   ; Advanced Controller port (not IDE port)
endstruc
%endif


%ifdef MODULE_SERIAL
; DPT for Serial devices
struc DPT_SERIAL
    .dpt                        resb    DPT_size

    .wSerialPortAndBaud:
    .bSerialPort                resb    1   ; Serial connection I/O port address, divided by 4
    .bSerialBaud                resb    1   ; Serial connection baud rate divisor
endstruc
%endif


; This is the common size for all DPTs. All DPTs must be equal size.
LARGEST_DPT_SIZE                EQU     DPT_ATA_size


; Number of Sectors per Track is fixed to 63 for LBA assist calculation.
; 1024 cylinders, 256 heads, 63 sectors = 8.4 GB limit (but DOS does not support more than 255 heads)
MAX_LCHS_CYLINDERS              EQU     1024
LBA_ASSIST_SPT                  EQU     63


;--------------------------------------------------------------------
; LIMIT_LBA_CYLINDERS_IN_DXAX_TO_LCHS_CYLINDERS
;   Parameters:
;       DX:AX:  Number of LBA cylinders
;   Returns:
;       AX:     Number of L-CHS cylinders
;   Corrupts registers:
;       Nothing
;--------------------------------------------------------------------
%macro LIMIT_LBA_CYLINDERS_IN_DXAX_TO_LCHS_CYLINDERS 0
    test    dx, dx
    jnz     SHORT %%LoadMaxValueToAX
    cmp     ax, MAX_LCHS_CYLINDERS
    jbe     SHORT %%NoNeedToModify
%%LoadMaxValueToAX:
    mov     ax, MAX_LCHS_CYLINDERS
%%NoNeedToModify:
%endmacro


%endif ; CUSTOMDPT_INC