source: xtideuniversalbios/trunk/XTIDE_Universal_BIOS/Src/Handlers/Int13h/EBIOS/AH41h_CheckIfExtensionsPresent.asm@ 539

Last change on this file since 539 was 535, checked in by aitotat@…, 12 years ago

Changes to XTIDE Universal BIOS:

  • AH=48h now returns Device Parameter Table Extension when RETURN_DPTE_ON_AH48H is defined.
  • Removed few unnecessary instructions from hardware interrupt handler.
  • P-Cylinders returned by AH=48h are no longer calculated from L-CHS capacity.
File size: 3.0 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, 2011-2013 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
46%ifdef RETURN_DPTE_ON_AH48H
47 call AH41h_GetSupportBitsToCX
48 mov [bp+IDEPACK.intpack+INTPACK.cx], cx
49%else
50 mov WORD [bp+IDEPACK.intpack+INTPACK.cx], ENHANCED_DRIVE_ACCESS_SUPPORT
51%endif
52
53 and BYTE [bp+IDEPACK.intpack+INTPACK.flags], ~FLG_FLAGS_CF ; Return with CF cleared
54 jmp Int13h_ReturnFromHandlerWithoutStoringErrorCode
55.EbiosNotSupported:
56 jmp Int13h_DirectCallToAnotherBios
57
58
59%ifdef RETURN_DPTE_ON_AH48H
60;--------------------------------------------------------------------
61; AH41h_GetSupportBitsToCX
62; Parameters:
63; DS:DI: Ptr to DPT (in RAMVARS segment)
64; Returns:
65; CX: Support bits returned by AH=41h
66; Corrupts registers:
67; Nothing
68;--------------------------------------------------------------------
69AH41h_GetSupportBitsToCX:
70 mov cx, ENHANCED_DRIVE_ACCESS_SUPPORT
71
72 ; DPTE needs buffer from RAM so do not return it in lite mode
73%ifndef USE_AT
74 test BYTE [cs:ROMVARS.wFlags], FLG_ROMVARS_FULLMODE
75 jz SHORT .DoNotSetEDDflag
76%endif
77
78%ifdef MODULE_8BIT_IDE OR MODULE_SERIAL
79 ; DPTE contains information for device drivers. We should not return
80 ; DPTE for 8-bit devices since software would think they are 16-bit devices.
81 cmp BYTE [di+DPT_ATA.bDevice], DEVICE_8BIT_ATA
82 jae SHORT .DoNotSetEDDflag
83%endif
84
85 or cl, ENHANCED_DISK_DRIVE_SUPPORT ; AH=48h returns DPTE
86.DoNotSetEDDflag:
87 ret
88
89%endif ; RETURN_DPTE_ON_AH48H
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