source: xtideuniversalbios/trunk/XTIDE_Universal_BIOS/Src/Menus/BootMenu/BootMenu.asm@ 540

Last change on this file since 540 was 526, checked in by krille_n_@…, 11 years ago

Changes:

  • Update of the copyright notices to include the year 2013.
File size: 3.0 KB
Line 
1; Project name : XTIDE Universal BIOS
2; Description : Displays Boot Menu.
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; Displays Boot Menu and returns Drive or Function number.
25;
26; BootMenu_DisplayAndReturnDriveInDLRomBootClearCF
27; Parameters:
28; DS: RAMVARS segment
29; Returns:
30; DL: Drive number selected
31; CF: Set if selected item is an actual drive, DL is valid
32; Clear if selected item is Rom Boot, DL is invalid
33; Corrupts registers:
34; All General Purpose Registers
35;--------------------------------------------------------------------
36BootMenu_DisplayAndReturnDriveInDLRomBootClearCF:
37 call DriveXlate_Reset
38
39 mov bx, BootMenuEvent_Handler
40 CALL_MENU_LIBRARY DisplayWithHandlerInBXandUserDataInDXAX
41
42 xchg cx, ax
43
44 ; Clear Boot Menu from screen
45 mov ax, ' ' | (MONO_NORMAL<<8)
46 CALL_DISPLAY_LIBRARY ClearScreenWithCharInALandAttrInAH
47
48 ; fall through to BootMenu_GetDriveToDXforMenuitemInCX
49
50;--------------------------------------------------------------------
51; BootMenu_GetDriveToDXforMenuitemInCX
52; Parameters:
53; CX: Index of menuitem selected from Boot Menu
54; DS: RAMVARS segment
55; Returns:
56; DX: Drive number to be used for booting
57; CF: Set: There is a selected menu item, DL is valid
58; Clear: The item selected is Rom Boot, DL is not valid
59; Corrupts registers:
60; AX, BX
61;
62; NOTE: We can't use the menu structure in here, as we are falling through
63; from BootMenu_DisplayAndReturnDriveInDLRomBootClearCF when the
64; menu structure has already been destroyed.
65;--------------------------------------------------------------------
66BootMenu_GetDriveToDXforMenuitemInCX:
67 mov dl, cl ; Copy menuitem index to DX
68 call FloppyDrive_GetCountToAX
69 cmp dl, al ; Floppy drive?
70 jb SHORT .ReturnFloppyDriveInDX ; Set CF if branch taken
71 or al, 80h ; Or 80h into AL before the sub
72 ; shorter instruction than or'ing it in afterward
73 sub dl, al ; Remove floppy drives from index
74 call RamVars_GetHardDiskCountFromBDAtoAX
75 or al, 80h ; Or 80h into AL before the sub
76 cmp dl, al ; Set CF if hard disk
77 ; Clear CF if last item, beyond hard disk list, which indicates ROM boot
78.ReturnFloppyDriveInDX:
79 ret
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