source: xtideuniversalbios/trunk/XTIDE_Universal_BIOS/Src/VariablesAndDPTs/DrvDetectInfo.asm@ 611

; Project name  :   XTIDE Universal BIOS
; Description   :   Functions for generating and accessing drive
;                   information to be displayed on boot menu.

;
; 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

;--------------------------------------------------------------------
; Creates new DRVDETECTINFO struct for detected hard disk.
;
; DriveDetectInfo_CreateForHardDisk
;   Parameters:
;       DL:     Drive number
;       DS:DI:  Ptr to Disk Parameter Table
;       ES:SI:  Ptr to 512-byte ATA information read from the drive
;   Returns:
;       ES:BX:  Ptr to DRVDETECTINFO (if successful)
;   Corrupts registers:
;       AX, BX, CX, DX, DI
;--------------------------------------------------------------------
DriveDetectInfo_CreateForHardDisk:
    call    DriveDetectInfo_ConvertDPTtoBX      ; ES:BX now points to new DRVDETECTINFO

    ; Store Drive Name
    push    ds                                  ; Preserve RAMVARS
    push    si

    push    es                                  ; ES copied to DS
    pop     ds

    add     si, BYTE ATA1.strModel              ; DS:SI now points drive name (Clears CF)
%ifndef CHECK_FOR_UNUSED_ENTRYPOINTS
%if DRVDETECTINFO.szDrvName = 0
    mov     di, bx
%else
    lea     di, [bx+DRVDETECTINFO.szDrvName]    ; ES:DI now points to name destination
%endif
%endif
    mov     cx, MAX_HARD_DISK_NAME_LENGTH / 2   ; Max number of WORDs allowed
.CopyNextWord:
    lodsw
    xchg    al, ah                              ; Change endianness
    stosw
    loop    .CopyNextWord
    xchg    cx, ax                              ; Zero AX (CF already cleared from the ADD above)
    stosw                                       ; Terminate with NULL

    pop     si
    pop     ds

    ret


;--------------------------------------------------------------------
; Returns offset to DRVDETECTINFO based on DPT pointer.
;
; DriveDetectInfo_ConvertDPTtoBX
;   Parameters:
;       DS:DI:  DPT Pointer
;   Returns:
;       BX:     Offset to DRVDETECTINFO struct
;   Corrupts registers:
;       AX
;--------------------------------------------------------------------
DriveDetectInfo_ConvertDPTtoBX:
%ifndef CHECK_FOR_UNUSED_ENTRYPOINTS
%if DPT_DRVDETECTINFO_SIZE_MULTIPLIER = 2
%if BOOTVARS.rgDrvDetectInfo & 1                    ; Should never be odd but better safe than sorry
    lea     bx, [di-RAMVARS_size]
    eSHL_IM bx, 1
    add     bx, BOOTVARS.rgDrvDetectInfo
%else
    lea     bx, [di-RAMVARS_size+(BOOTVARS.rgDrvDetectInfo/2)]
    eSHL_IM bx, 1
%endif
%else
%ifdef USE_186
    lea     bx, [di-RAMVARS_size]
    imul    bx, DPT_DRVDETECTINFO_SIZE_MULTIPLIER
    add     bx, BOOTVARS.rgDrvDetectInfo
%else
    lea     ax, [di-RAMVARS_size]                   ; subtract off base of DPTs
    mov     bl, DPT_DRVDETECTINFO_SIZE_MULTIPLIER   ; DRVDETECTINFO are a whole number multiple of DPT size
    mul     bl
    add     ax, BOOTVARS.rgDrvDetectInfo            ; add base of DRVDETECTINFO
    xchg    bx, ax
%endif
%endif
%endif
    ret