source: xtideuniversalbios/trunk/XTIDE_Universal_BIOS/Src/Handlers/Int13h/EBIOS/AH41h_CheckIfExtensionsPresent.asm@ 420

Last change on this file since 420 was 417, checked in by aitotat@…, 13 years ago

Changes to XTIDE Universal BIOS:

  • AT builds now relocate INT 13h stack to top of stolen conventional memory.
  • Some small fixes here and there.
File size: 1.9 KB
Line 
1; Project name : XTIDE Universal BIOS
2; Description : Int 13h function AH=41h, Check if Extensions Present.
3
4;
5; XTIDE Universal BIOS and Associated Tools
6; Copyright (C) 2009-2010 by Tomi Tilli, 2011-2012 by XTIDE Universal BIOS Team.
7;
8; This program is free software; you can redistribute it and/or modify
9; it under the terms of the GNU General Public License as published by
10; the Free Software Foundation; either version 2 of the License, or
11; (at your option) any later version.
12;
13; This program is distributed in the hope that it will be useful,
14; but WITHOUT ANY WARRANTY; without even the implied warranty of
15; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16; GNU General Public License for more details.
17; Visit http://www.gnu.org/licenses/old-licenses/gpl-2.0.html
18;
19
20; Section containing code
21SECTION .text
22
23;--------------------------------------------------------------------
24; Int 13h function AH=41h, Check if Extensions Present.
25;
26; AH41h_HandlerForCheckIfExtensionsPresent
27; Parameters:
28; DL: Translated Drive number
29; DS:DI: Ptr to DPT (in RAMVARS segment)
30; SS:BP: Ptr to IDEPACK
31; Parameters on INTPACK:
32; BX: 55AAh
33; Returns with INTPACK:
34; AH: Major version of EBIOS extensions
35; BX: AA55h
36; CX: Support bits
37; CF: 0 if successful, 1 if error
38;--------------------------------------------------------------------
39AH41h_HandlerForCheckIfExtensionsPresent:
40 cmp WORD [bp+IDEPACK.intpack+INTPACK.bx], 55AAh
41 jne SHORT .EbiosNotSupported
42
43 mov BYTE [bp+IDEPACK.intpack+INTPACK.ah], EBIOS_VERSION
44 mov WORD [bp+IDEPACK.intpack+INTPACK.bx], 0AA55h
45 mov WORD [bp+IDEPACK.intpack+INTPACK.cx], ENHANCED_DRIVE_ACCESS_SUPPORT
46 and BYTE [bp+IDEPACK.intpack+INTPACK.flags], ~FLG_FLAGS_CF ; Return with CF cleared
47 jmp Int13h_ReturnFromHandlerWithoutStoringErrorCode
48.EbiosNotSupported:
49 jmp Int13h_DirectCallToAnotherBios
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