source: xtideuniversalbios/trunk/XTIDE_Universal_BIOS/Src/Handlers/Int13hBiosInit.asm @ 552

; Project name  :   XTIDE Universal BIOS
; Description   :   Int 13h handler that is used to initialize
;                   XTIDE Universal BIOS when our INT 19h was not called.

;
; 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

TEMPORARY_VECTOR_FOR_SYSTEM_INT13h      EQU     21h ; MS-DOS


Int13hBiosInit_Handler:
    LOAD_BDA_SEGMENT_TO ds, ax

    ; Restore system INT 13h handler that we backuped
    les     ax, [TEMPORARY_VECTOR_FOR_SYSTEM_INT13h*4]
    mov     [BIOS_DISK_INTERRUPT_13h*4], ax
    mov     [BIOS_DISK_INTERRUPT_13h*4+2], es

    ; Now install our handler and call 19h since non-standard motherboard BIOS did not
    ; do that or our INT 19h hander was replaced by other BIOS.
    mov     WORD [BIOS_BOOT_LOADER_INTERRUPT_19h*4], Int19h_BootLoaderHandler
    mov     [BIOS_BOOT_LOADER_INTERRUPT_19h*4+2], cs
    int     BIOS_BOOT_LOADER_INTERRUPT_19h  ; Does not return