source: xtideuniversalbios/trunk/BIOS_Drive_Information_Tool/Src/Bios.asm@ 536

; Project name  :   BIOS Drive Information Tool
; Description   :   Functions to read information from BIOS.

;
; 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

;---------------------------------------------------------------------
; Bios_GetNumberOfHardDrivesToDX
;   Parameters:
;       Nothing
;   Returns: (if no errors)
;       DX:     Number of hard drives in system
;       CF:     Set if no hard drives found
;   Corrupts registers:
;       AX, BX, CX
;--------------------------------------------------------------------
Bios_GetNumberOfHardDrivesToDX:
    mov     dl, 80h     ; First hard drive
    mov     ah, GET_DRIVE_PARAMETERS
    int     BIOS_DISK_INTERRUPT_13h
    mov     dh, 0       ; Preserve CF
    ret


;---------------------------------------------------------------------
; Bios_ReadOldInt13hParametersFromDriveDL
;   Parameters:
;       DL:     BIOS drive number
;   Returns: (if no errors)
;       BL:     Drive Type (for floppies only)
;       AX:     Sectors per track (1...63)
;       DX:     Number of heads (1...255)
;       CX:     Number of cylinders (1...1024)
;       CF:     Cleared = no errors
;               Set = BIOS error code stored in AH
;   Corrupts registers:
;       Nothing
;--------------------------------------------------------------------
Bios_ReadOldInt13hParametersFromDriveDL:
    mov     ah, GET_DRIVE_PARAMETERS
    int     BIOS_DISK_INTERRUPT_13h
    jc      SHORT ReturnWithBiosErrorCodeInAH
    ; Fall to ExtractCHSfromOldInt13hDriveParameters

;---------------------------------------------------------------------
; ExtractCHSfromOldInt13hDriveParameters
;   Parameters:
;       CH:     Maximum cylinder number, bits 7...0
;       CL:     Bits 7...6: Maximum cylinder number, bits 9 and 8
;               Bits 5...0: Maximum sector number (1...63)
;       DH:     Maximum head number (0...254)
;   Returns:
;       BL:     Drive Type (for floppies only)
;       AX:     Sectors per track (1...63)
;       DX:     Number of heads (1...255)
;       CX:     Number of cylinders (1...1024)
;       CF:     Cleared
;   Corrupts registers:
;       Nothing
;--------------------------------------------------------------------
ExtractCHSfromOldInt13hDriveParameters:
    mov     al, cl              ; Copy sector number...
    and     ax, BYTE 3Fh        ; ...and limit to 1...63
    sub     cl, al              ; Remove from max cylinder high
    eROL_IM cl, 2               ; High bits to beginning
    eMOVZX  dx, dh              ; Copy Max head to DX
    xchg    cl, ch              ; Max cylinder now in CX
    inc     cx                  ; Max cylinder to number of cylinders
    inc     dx                  ; Max head to number of heads
    clc                         ; No errors
    ret


;---------------------------------------------------------------------
; Bios_ReadOldInt13hCapacityFromDriveDL
;   Parameters:
;       DL:     BIOS drive number
;   Returns: (if no errors)
;       CX:DX:  Total number of sectors
;       AH:     BIOS Error code
;       CF:     Cleared = no errors
;               Set = BIOS error code stored in AH
;   Corrupts registers:
;       Nothing
;--------------------------------------------------------------------
Bios_ReadOldInt13hCapacityFromDriveDL:
    mov     ah, GET_DISK_TYPE
    int     BIOS_DISK_INTERRUPT_13h
    jc      SHORT ReturnInvalidErrorCodeInAH
    xor     ah, ah
    ret


;---------------------------------------------------------------------
; Bios_ReadAtaInfoFromDriveDLtoBX
;   Parameters:
;       DL:     BIOS drive number
;   Returns: (if no errors)
;       DS:BX:  Ptr to ATA information
;       AH:     BIOS Error code
;       CF:     Cleared = no errors
;               Set = BIOS error code stored in AH
;   Corrupts registers:
;       ES
;--------------------------------------------------------------------
Bios_ReadAtaInfoFromDriveDLtoBX:
    mov     bx, g_rgbAtaInfo
    push    ds
    pop     es
    mov     ah, GET_DRIVE_INFORMATION
    int     BIOS_DISK_INTERRUPT_13h
    ret


;---------------------------------------------------------------------
; Bios_ReadEbiosVersionFromDriveDL
;   Parameters:
;       DL:     BIOS drive number
;   Returns:
;       AH:     BIOS error code
;       BX:     Version of extensions
;       CX:     Interface support bit map
;       CF:     Cleared = no errors
;               Set = BIOS error code stored in AH
;   Corrupts registers:
;       Nothing
;--------------------------------------------------------------------
Bios_ReadEbiosVersionFromDriveDL:
    mov     ah, CHECK_EXTENSIONS_PRESENT
    mov     bx, 55AAh
    int     BIOS_DISK_INTERRUPT_13h
    jc      SHORT .NoEbiosPresent
    cmp     bx, 0AA55h
    jne     SHORT .NoEbiosPresent
    eMOVZX  bx, ah          ; Copy version to BX
    xor     ah, ah
    ret
.NoEbiosPresent:
    mov     ah, RET_HD_INVALID
    stc
    ret


;---------------------------------------------------------------------
; Bios_ReadEbiosInfoFromDriveDLtoDSSI
;   Parameters:
;       DL:     BIOS drive number
;   Returns: (if no errors)
;       DS:SI:  Ptr to EDRIVE_INFO
;       AH:     BIOS Error code
;       CF:     Cleared = no errors
;               Set = BIOS error code stored in AH
;   Corrupts registers:
;       Nothing
;--------------------------------------------------------------------
Bios_ReadEbiosInfoFromDriveDLtoDSSI:
    mov     si, g_edriveInfo
    mov     WORD [si+EDRIVE_INFO.wSize], MINIMUM_EDRIVEINFO_SIZE
    mov     ah, GET_EXTENDED_DRIVE_INFORMATION
    int     BIOS_DISK_INTERRUPT_13h
    ret


;---------------------------------------------------------------------
; ReturnInvalidErrorCodeInAH
; ReturnWithBiosErrorCodeInAH
;   Parameters:
;       Nothing
;   Returns: (if no errors)
;       AH:     BIOS Error code
;       CF:     Set
;   Corrupts registers:
;       Nothing
;--------------------------------------------------------------------
ReturnInvalidErrorCodeInAH:
    stc
    mov     ah, RET_HD_INVALID
ReturnWithBiosErrorCodeInAH:
    ret


; Section containing uninitialized data
SECTION .bss

g_edriveInfo:
g_rgbAtaInfo:       resb    512