source: xtideuniversalbios/trunk/XTIDE_Universal_BIOS/Src/Boot/BootMenu.asm@ 94

Last change on this file since 94 was 93, checked in by Tomi Tilli, 14 years ago

Changes to XTIDE Universal BIOS:

  • Diagnostic cylinder can no longer be reserved.
File size: 6.0 KB
Line 
1; Project name : XTIDE Universal BIOS
2; Description : Displays Boot Menu.
3
4; Section containing code
5SECTION .text
6
7;--------------------------------------------------------------------
8; Displays Boot Menu and returns Drive or Function number.
9;
10; BootMenu_DisplayAndReturnSelection
11; Parameters:
12; DS: RAMVARS segment
13; Returns:
14; DX: Untranslated drive number to be used for booting (if CF cleared)
15; Function number (if CF set)
16; CF: Cleared if drive selected
17; Set if function selected
18; Corrupts registers:
19; All General Purpose Registers
20;--------------------------------------------------------------------
21ALIGN JUMP_ALIGN
22BootMenu_DisplayAndReturnSelection:
23 call DriveXlate_Reset
24 call BootMenuPrint_TheBottomOfScreen
25 call BootMenu_Enter ; Get selected menuitem index to CX
26 call BootMenuPrint_ClearScreen
27 cmp cx, BYTE NO_ITEM_SELECTED
28 je SHORT BootMenu_DisplayAndReturnSelection
29 jmp SHORT BootMenu_ConvertMenuitemFromCXtoDriveInDX
30
31
32;--------------------------------------------------------------------
33; Enters Boot Menu or submenu.
34;
35; BootMenu_Enter
36; Parameters:
37; Nothing
38; Returns:
39; CX: Index of selected item or NO_ITEM_SELECTED
40; Corrupts registers:
41; BX, DI
42;--------------------------------------------------------------------
43ALIGN JUMP_ALIGN
44BootMenu_Enter:
45 mov bx, BootMenuEvent_Handler
46 CALL_MENU_LIBRARY DisplayWithHandlerInBXandUserDataInDXAX
47 xchg cx, ax
48 ret
49
50
51;--------------------------------------------------------------------
52; Returns number of menuitems in Boot Menu.
53;
54; BootMenu_GetMenuitemCountToCX
55; Parameters:
56; DS: RAMVARS segment
57; Returns:
58; CX: Number of boot menu items
59; Corrupts registers:
60; AX
61;--------------------------------------------------------------------
62ALIGN JUMP_ALIGN
63BootMenu_GetMenuitemCountToCX:
64 call RamVars_GetHardDiskCountFromBDAtoCX
65 xchg ax, cx
66 call FloppyDrive_GetCount
67 add ax, cx
68 ret
69
70
71;--------------------------------------------------------------------
72; BootMenu_GetHeightToALwithItemCountInCL
73; Parameters:
74; CL: Number of menuitems
75; Returns:
76; AH: Boot menu height
77; Corrupts registers:
78; AL, CL, DI
79;--------------------------------------------------------------------
80ALIGN JUMP_ALIGN
81BootMenu_GetHeightToAHwithItemCountInCL:
82 add cl, BOOT_MENU_HEIGHT_WITHOUT_ITEMS
83 CALL_DISPLAY_LIBRARY GetColumnsToALandRowsToAH
84 sub ah, MENU_SCREEN_BOTTOM_LINES*2
85 MIN_U ah, cl
86 ret
87
88
89;--------------------------------------------------------------------
90; BootMenu_ConvertAsciiHotkeyFromALtoMenuitemInCX
91; Parameters:
92; AL: ASCII hotkey starting from upper case 'A'
93; Returns:
94; CX: Menuitem index
95; Corrupts registers:
96; AX
97;--------------------------------------------------------------------
98ALIGN JUMP_ALIGN
99BootMenu_ConvertAsciiHotkeyFromALtoMenuitemInCX:
100 call BootMenu_GetLetterForFirstHardDiskToCL
101 cmp al, cl ; Letter is for Hard Disk?
102 jae SHORT .StartFromHardDiskLetter
103 sub al, 'A' ; Letter to Floppy Drive menuitem
104 xchg ax, cx ; Menuitem index to CX
105 ret
106ALIGN JUMP_ALIGN
107.StartFromHardDiskLetter:
108 sub al, cl ; Hard Disk index
109 call FloppyDrive_GetCount
110 add cx, ax ; Menuitem index
111 ret
112
113;--------------------------------------------------------------------
114; Returns letter for first hard disk. Usually it will be 'c' but it
115; can be higher if more than two floppy drives are found.
116;
117; BootMenu_GetLetterForFirstHardDiskToCL
118; Parameters:
119; Nothing
120; Returns:
121; CL: Upper case letter for first hard disk
122; Corrupts registers:
123; CH
124;--------------------------------------------------------------------
125ALIGN JUMP_ALIGN
126BootMenu_GetLetterForFirstHardDiskToCL:
127 call FloppyDrive_GetCount
128 add cl, 'A'
129 MAX_U cl, 'C'
130 ret
131
132
133;--------------------------------------------------------------------
134; BootMenu_ConvertMenuitemFromCXtoDriveInDX
135; Parameters:
136; CX: Index of menuitem selected from Boot Menu
137; DS: RAMVARS segment
138; Returns:
139; DX: Drive number to be used for booting
140; Corrupts registers:
141; CX
142;--------------------------------------------------------------------
143ALIGN JUMP_ALIGN
144BootMenu_ConvertMenuitemFromCXtoDriveInDX:
145 mov dx, cx ; Copy menuitem index to DX
146 call FloppyDrive_GetCount
147 cmp dx, cx ; Floppy drive?
148 jb SHORT .ReturnFloppyDriveInDX
149 sub dx, cx ; Remove floppy drives from index
150 or dl, 80h
151.ReturnFloppyDriveInDX:
152 ret
153
154
155;--------------------------------------------------------------------
156; Converts Floppy or Hard Disk Drive number to menuitem index.
157; This function does not check does the drive really exists.
158;
159; BootMenu_ConvertDriveToMenuitem
160; Parameters:
161; DL: Drive number
162; Returns:
163; CX: Menuitem index (assuming drive is available)
164; Corrupts registers:
165; AX
166;--------------------------------------------------------------------
167ALIGN JUMP_ALIGN
168BootMenu_ConvertDriveToMenuitem:
169 test dl, 80h ; Floppy drive?
170 jz SHORT .ReturnFloppyMenuitem
171 call FloppyDrive_GetCount
172 mov ax, 7Fh ; Load mask to clear floppy bit
173 and ax, dx ; AX = Hard Disk index
174 add cx, ax ; Add hard disk index to floppy drive count
175 ret
176ALIGN JUMP_ALIGN
177.ReturnFloppyMenuitem:
178 eMOVZX cx, dl ; Drive number and item index are equal
179 ret
180
181
182;--------------------------------------------------------------------
183; Checks is drive number valid for this system.
184;
185; BootMenu_IsDriveInSystem
186; Parameters:
187; DL: Drive number
188; DS: RAMVARS segment
189; Returns:
190; CF: Set if drive number is valid
191; Clear if drive is not present in system
192; Corrupts registers:
193; AX, CX
194;--------------------------------------------------------------------
195ALIGN JUMP_ALIGN
196BootMenu_IsDriveInSystem:
197 test dl, 80h ; Floppy drive?
198 jz SHORT .IsFloppyDriveIsInSystem
199 call RamVars_GetHardDiskCountFromBDAtoCX ; Hard Disk count to CX
200 or cl, 80h ; Set Hard Disk bit to CX
201 jmp SHORT .CompareDriveNumberToDriveCount
202.IsFloppyDriveIsInSystem:
203 call FloppyDrive_GetCount ; Floppy Drive count to CX
204.CompareDriveNumberToDriveCount:
205 cmp dl, cl
206 ret
Note: See TracBrowser for help on using the repository browser.