source: xtideuniversalbios/trunk/XTIDE_Universal_BIOS/Src/Boot/BootMenu.asm@ 162

Last change on this file since 162 was 130, checked in by Tomi Tilli, 14 years ago

Changes to XTIDE Universal BIOS:

  • Boot menu finally works but timeout and drive numbers not yet implemented.
File size: 5.8 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
15; Corrupts registers:
16; All General Purpose Registers
17;--------------------------------------------------------------------
18ALIGN JUMP_ALIGN
19BootMenu_DisplayAndReturnSelection:
20 call DriveXlate_Reset
21 call BootMenuPrint_TheBottomOfScreen
22 call BootMenu_Enter ; Get selected menuitem index to CX
23 call BootMenuPrint_ClearScreen
24 cmp cx, BYTE NO_ITEM_SELECTED
25 je SHORT BootMenu_DisplayAndReturnSelection ; Clear screen and display menu
26 ; Fall to BootMenu_GetDriveToDXforMenuitemInCX
27
28;--------------------------------------------------------------------
29; BootMenu_GetDriveToDXforMenuitemInCX
30; Parameters:
31; CX: Index of menuitem selected from Boot Menu
32; DS: RAMVARS segment
33; Returns:
34; DX: Drive number to be used for booting
35; Corrupts registers:
36; CX
37;--------------------------------------------------------------------
38ALIGN JUMP_ALIGN
39BootMenu_GetDriveToDXforMenuitemInCX:
40 mov dx, cx ; Copy menuitem index to DX
41 call FloppyDrive_GetCountToCX
42 cmp dx, cx ; Floppy drive?
43 jb SHORT .ReturnFloppyDriveInDX
44 sub dx, cx ; Remove floppy drives from index
45 or dl, 80h
46.ReturnFloppyDriveInDX:
47 ret
48
49
50;--------------------------------------------------------------------
51; Enters Boot Menu or submenu.
52;
53; BootMenu_Enter
54; Parameters:
55; Nothing
56; Returns:
57; CX: Index of selected item or NO_ITEM_SELECTED
58; Corrupts registers:
59; AX, BX, DI
60;--------------------------------------------------------------------
61ALIGN JUMP_ALIGN
62BootMenu_Enter:
63 mov bx, BootMenuEvent_Handler
64 CALL_MENU_LIBRARY DisplayWithHandlerInBXandUserDataInDXAX
65 xchg cx, ax
66 ret
67
68
69;--------------------------------------------------------------------
70; Returns number of menuitems in Boot Menu.
71;
72; BootMenu_GetMenuitemCountToAX
73; Parameters:
74; DS: RAMVARS segment
75; Returns:
76; AX: Number of boot menu items
77; Corrupts registers:
78; CX
79;--------------------------------------------------------------------
80ALIGN JUMP_ALIGN
81BootMenu_GetMenuitemCountToAX:
82 call RamVars_GetHardDiskCountFromBDAtoCX
83 xchg ax, cx
84 call FloppyDrive_GetCountToCX
85 add ax, cx
86 ret
87
88
89;--------------------------------------------------------------------
90; BootMenu_GetHeightToAHwithItemCountInAL
91; Parameters:
92; AL: Number of menuitems
93; Returns:
94; AH: Boot menu height
95; Corrupts registers:
96; AL, CX, DI
97;--------------------------------------------------------------------
98ALIGN JUMP_ALIGN
99BootMenu_GetHeightToAHwithItemCountInAL:
100 add al, BOOT_MENU_HEIGHT_WITHOUT_ITEMS
101 xchg cx, ax
102 CALL_DISPLAY_LIBRARY GetColumnsToALandRowsToAH
103 sub ah, MENU_SCREEN_BOTTOM_LINES*2 ; Leave space for bottom info
104 MIN_U ah, cl
105 ret
106
107
108;--------------------------------------------------------------------
109; BootMenu_GetMenuitemToAXforAsciiHotkeyInAL
110; Parameters:
111; AL: ASCII hotkey
112; Returns:
113; AX: Menuitem index
114; Corrupts registers:
115; CX
116;--------------------------------------------------------------------
117ALIGN JUMP_ALIGN
118BootMenu_GetMenuitemToAXforAsciiHotkeyInAL:
119 call Char_ALtoUpperCaseLetter
120 call BootMenu_GetLetterForFirstHardDiskToCL
121 xor ah, ah
122 cmp al, cl ; Letter is for Hard Disk?
123 jae SHORT .StartFromHardDiskLetter
124 sub al, 'A' ; Letter to Floppy Drive menuitem
125 ret
126ALIGN JUMP_ALIGN
127.StartFromHardDiskLetter:
128 sub al, cl ; Hard Disk index
129 call FloppyDrive_GetCountToCX
130 add ax, cx ; Menuitem index
131 ret
132
133
134;--------------------------------------------------------------------
135; Returns letter for first hard disk. Usually it will be 'c' but it
136; can be higher if more than two floppy drives are found.
137;
138; BootMenu_GetLetterForFirstHardDiskToCL
139; Parameters:
140; Nothing
141; Returns:
142; CL: Upper case letter for first hard disk
143; Corrupts registers:
144; CH
145;--------------------------------------------------------------------
146ALIGN JUMP_ALIGN
147BootMenu_GetLetterForFirstHardDiskToCL:
148 call FloppyDrive_GetCountToCX
149 add cl, 'A'
150 MAX_U cl, 'C'
151 ret
152
153
154;--------------------------------------------------------------------
155; BootMenu_GetMenuitemToDXforDriveInDL
156; Parameters:
157; DL: Drive number
158; Returns:
159; DX: Menuitem index (assuming drive is available)
160; Corrupts registers:
161; Nothing
162;--------------------------------------------------------------------
163ALIGN JUMP_ALIGN
164BootMenu_GetMenuitemToDXforDriveInDL:
165 xor dh, dh ; Drive number now in DX
166 test dl, dl
167 jns SHORT .ReturnItemIndexInDX ; Return if floppy drive (HD bit not set)
168 call FloppyDrive_GetCountToCX
169 and dl, ~80h ; Clear HD bit
170 add dx, cx
171.ReturnItemIndexInDX:
172 ret
173
174
175;--------------------------------------------------------------------
176; Checks is drive number valid for this system.
177;
178; BootMenu_IsDriveInSystem
179; Parameters:
180; DL: Drive number
181; DS: RAMVARS segment
182; Returns:
183; CF: Set if drive number is valid
184; Clear if drive is not present in system
185; Corrupts registers:
186; AX, CX
187;--------------------------------------------------------------------
188ALIGN JUMP_ALIGN
189BootMenu_IsDriveInSystem:
190 test dl, dl ; Floppy drive?
191 jns SHORT .IsFloppyDriveInSystem
192 call RamVars_GetHardDiskCountFromBDAtoCX ; Hard Disk count to CX
193 or cl, 80h ; Set Hard Disk bit to CX
194 jmp SHORT .CompareDriveNumberToDriveCount
195.IsFloppyDriveInSystem:
196 call FloppyDrive_GetCountToCX
197.CompareDriveNumberToDriveCount:
198 cmp dl, cl ; Set CF when DL is smaller
199 ret
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