source: xtideuniversalbios/trunk/XTIDE_Universal_BIOS/Inc/RamVars.inc @ 589

; Project name  :   XTIDE Universal BIOS
; Description   :   RAMVARS struct containing BIOS variables stored in RAM.

;
; 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
;

%ifndef RAMVARS_INC
%define RAMVARS_INC

; Segment when RAMVARS is stored to top of interrupt vectors.
%ifndef USE_AT
    LITE_MODE_RAMVARS_SEGMENT   EQU     30h
%endif


%ifdef MODULE_SERIAL_FLOPPY OR MODULE_DRIVEXLATE
    %define NEED_XLATEVARS
%endif


; RAM Variables.
; Variables should be kept to minimum since they might be located
; at the top of interrupt vectors.
struc RAMVARS
%ifdef RELOCATE_INT13H_STACK
                            resb    252
    .dwStackChangeDSDI:
    .wStackChangeDI         resb    2   ; Used during stack
    .wStackChangeDS         resb    2   ; switching only
    .rgbTopOfStack:                     ; 256 bytes of stack
    .fpInt13hEntryStack     resb    4
%endif
    .fpOldI13h              resb    4   ; Far pointer to old INT 13h handler
    .wDrvDetectSignature    resb    2   ; Signature when BIOS is in drive detection mode
    .wSignature             resb    2   ; Sign for finding stolen 1...64 kiB
    .bTimeoutTicksLeft      resb    1
    .bLastTimeoutUpdate     resb    1

    .wFirstDrvAndCount:
    .bFirstDrv              resb    1   ; Number of first drive for this BIOS
    .wDrvCntAndFlopCnt:                 ; Both the hard disk and floppy counts in one word
                                        ; (yes, misaligned, but it is only used this way during initialization)
    .bDrvCnt                resb    1   ; Number of drives handled by this BIOS

    ; Variables for drive number translation
%ifdef NEED_XLATEVARS
    .xlateVars              resb    XLATEVARS_size
%endif
endstruc

; Note!!! .wDrvDetectSignature and .wSignature are intentionally in different locations.
RAMVARS_RAM_SIGNATURE           EQU "Xu"    ; RAMVARS signature for .wSignature
RAMVARS_DRV_DETECT_SIGNATURE    EQU 5A5Ah   ; Signature when BIOS is in drive detection mode


%ifdef NEED_XLATEVARS
; Variables for translating drive numbers.
    struc XLATEVARS
    %ifdef MODULE_SERIAL_FLOPPY
        .bFlopCreateCnt:
        .bFlopCntAndFirst   resb    1   ; Normally, packed starting floppy drive number (high order 7 bits)
                                        ; and number of drives (low order bit, max 2 drives supported).
                                        ; During initialization, until the end of DetectDrives_FromAllIDEControllers,
                                        ; this byte contains the raw number of floppy drives seen
                                        ; (using .bFlopCreateCnt)
    %else
                            resb    1   ; alignment
    %endif

    %ifdef MODULE_DRIVEXLATE
        .bXlatedDrv         resb    1   ; Drive number after translation
        .wFDandHDswap:
        .bFDSwap            resb    1   ; Floppy Drive to swap to 00h and vice versa
        .bHDSwap            resb    1   ; Hard Drive to swap to 80h and vice versa
    %else
                            resb    1   ; alignment
    %endif
    endstruc
%endif

%ifdef MODULE_SERIAL_FLOPPY
  %ifndef CHECK_FOR_UNUSED_ENTRYPOINTS
    %if RAMVARS.xlateVars != RAMVARS.bDrvCnt+1 || XLATEVARS.bFlopCreateCnt != 0
        %error "bFlopCreateCnt needs to be the first thing in XLATEVARS, and .xlateVars needs to come immediately after .bDrvCnt.  In at least one place, we read .wDrvCntAndFlopCnt to get both counts in one fetch"
    %endif
  %endif
%endif



;
; IDEPACK NOTE: The first six bytes of this structure are directly put on the
; wire for MODULE_SERIAL, please do not change the order or insert other members.
;
struc IDEPACK   ; PIOVARS and MEMPIOVARS overwrite the first 7 bytes
    .bFeatures              resb    1
    .bDrvAndHead            resb    1   ; LBA28 27...24

    .wSectorCountAndLbaLow:
    .bSectorCount           resb    1
    .bSectorNumber:
    .bLbaLow                resb    1   ; LBA 7...0

    .wCylinder:
    .wLbaMiddleAndHigh:
    .bLbaMiddle             resb    1   ; LBA 15...8
    .bLbaHigh               resb    1   ; LBA 23...16

    .bCommand               resb    1
    .bDeviceControl         resb    1   ; Offset 7 shared with PIOVARS and MEMPIOVARS
                            resb    1   ; Used by PIOVARS and MEMPIOVARS

%ifdef MODULE_EBIOS
    ; Parameters for 48-bit LBA
    .bLbaLowExt             resb    1   ; LBA48 31...24
    .wLbaMiddleAndHighExt:
    .bLbaMiddleExt          resb    1   ; LBA48 39...32
    .bLbaHighExt            resb    1   ; LBA48 47...40
%endif

                            alignb  2   ; Keep the INTPACK structure and stack pointer WORD aligned

    .intpack                resb    INTPACK_size
endstruc

SIZE_OF_IDEPACK_WITHOUT_INTPACK     EQU (IDEPACK_size - INTPACK_size)


%endif ; RAMVARS_INC