source: xtideuniversalbios/trunk/Assembly_Library/Src/Display/DisplayContext.asm@ 50

Last change on this file since 50 was 50, checked in by Tomi Tilli, 14 years ago

Changes to Assembly Library:
Removed Memory_ExchangeSSBPwithESDI since it obviously corrupted stack.
CGA detection is now only done once when initializing Display Context.
Moved File Library defines to File.inc.
File size: 8.9 KB
Line 
1; File name : DisplayContext.asm
2; Project name : Assembly Library
3; Created date : 25.6.2010
4; Last update : 9.10.2010
5; Author : Tomi Tilli
6; Description : Functions for managing display context.
7
8; Section containing code
9SECTION .text
10
11;--------------------------------------------------------------------
12; DisplayContext_Initialize
13; Parameters:
14; DS: BDA segment (zero)
15; Returns:
16; Nothing
17; Corrupts registers:
18; AX, DX, DI
19;--------------------------------------------------------------------
20ALIGN JUMP_ALIGN
21DisplayContext_Initialize:
22 call .DetectAndSetDisplaySegment ; and .InitializeFlags
23 mov WORD [VIDEO_BDA.displayContext+DISPLAY_CONTEXT.fnCharOut], DEFAULT_CHARACTER_OUTPUT
24 mov WORD [VIDEO_BDA.displayContext+DISPLAY_CONTEXT.wCursorShape], CURSOR_NORMAL
25 mov BYTE [VIDEO_BDA.displayContext+DISPLAY_CONTEXT.bAttribute], SCREEN_BACKGROUND_ATTRIBUTE
26 xor ax, ax
27 call DisplayCursor_SetCoordinatesFromAX
28 jmp DisplayContext_SynchronizeToHardware
29
30;--------------------------------------------------------------------
31; .DetectAndSetDisplaySegment
32; Parameters:
33; DS: BDA segment (zero)
34; Returns:
35; Nothing
36; Corrupts registers:
37; AX, DX
38;--------------------------------------------------------------------
39.DetectAndSetDisplaySegment:
40 mov ax, COLOR_TEXT_SEGMENT
41 cmp BYTE [VIDEO_BDA.bMode], MDA_TEXT_MODE
42 jne SHORT .StoreSegmentToDisplayContext
43 mov ax, MONO_TEXT_SEGMENT
44.StoreSegmentToDisplayContext:
45 mov [VIDEO_BDA.displayContext+DISPLAY_CONTEXT.fpCursorPosition+2], ax
46 ; Fall to InitializeFlags
47
48;--------------------------------------------------------------------
49; .InitializeFlags
50; Parameters:
51; DS: BDA segment (zero)
52; Returns:
53; Nothing
54; Corrupts registers:
55; AX, DX
56;--------------------------------------------------------------------
57.InitializeFlags:
58 mov dl, FLG_CONTEXT_ATTRIBUTES
59 call CgaSnow_IsCgaPresent
60 jnc SHORT .DoNotSetCgaFlag
61 or dl, FLG_CONTEXT_CGA
62.DoNotSetCgaFlag:
63 mov [VIDEO_BDA.displayContext+DISPLAY_CONTEXT.bFlags], dl
64 ret
65
66
67;--------------------------------------------------------------------
68; DisplayContext_Push
69; Parameters:
70; Nothing
71; Returns:
72; Nothing
73; Corrupts registers:
74; AX, DI
75;--------------------------------------------------------------------
76ALIGN JUMP_ALIGN
77DisplayContext_Push:
78 mov di, ds ; Backup DS
79 LOAD_BDA_SEGMENT_TO ds, ax
80 pop ax ; Pop return address
81
82 %assign i 0
83 %rep DISPLAY_CONTEXT_size / 2
84 push WORD [VIDEO_BDA.displayContext + i]
85 %assign i i+2
86 %endrep
87
88 mov ds, di ; Restore DS
89 jmp ax
90
91;--------------------------------------------------------------------
92; DisplayContext_Pop
93; Parameters:
94; Nothing
95; Returns:
96; Nothing
97; Corrupts registers:
98; AX, DI
99;--------------------------------------------------------------------
100ALIGN JUMP_ALIGN
101DisplayContext_Pop:
102 mov di, ds ; Backup DS
103 LOAD_BDA_SEGMENT_TO ds, ax
104 pop ax ; Pop return address
105
106 %assign i DISPLAY_CONTEXT_size-2
107 %rep DISPLAY_CONTEXT_size / 2
108 pop WORD [VIDEO_BDA.displayContext + i]
109 %assign i i-2
110 %endrep
111
112 push ax ; Push return address
113 push dx
114 call DisplayContext_SynchronizeToHardware
115 pop dx
116 mov ds, di ; Restore DS
117 ret
118
119
120;--------------------------------------------------------------------
121; DisplayContext_PrepareOffScreenBufferInESBXtoESDI
122; Parameters:
123; BX:AX: Ptr to off screen buffer
124; Returns:
125; Nothing
126; Corrupts registers:
127; AX
128;--------------------------------------------------------------------
129ALIGN JUMP_ALIGN
130DisplayContext_PrepareOffScreenBufferInESBXtoESDI:
131 push ds
132
133 LOAD_BDA_SEGMENT_TO ds, di
134 xchg ax, bx
135 mov bx, es
136 call DisplayContext_SetCharacterPointerFromBXAX ; ES:DI now has the pointer
137
138 mov bl, ATTRIBUTES_NOT_USED
139 mov ax, BUFFER_OUTPUT_WITH_CHAR_ONLY
140 call DisplayContext_SetCharOutputFunctionFromAXwithAttribFlagInBL
141
142 mov bx, di
143 pop ds
144 ret
145
146
147;--------------------------------------------------------------------
148; DisplayContext_SynchronizeToHardware
149; Parameters:
150; DS: BDA segment (zero)
151; Returns:
152; Nothing
153; Corrupts registers:
154; AX, DX
155;--------------------------------------------------------------------
156ALIGN JUMP_ALIGN
157DisplayContext_SynchronizeToHardware:
158 call DisplayPage_SynchronizeToHardware
159 call DisplayCursor_SynchronizeShapeToHardware
160 jmp DisplayCursor_SynchronizeCoordinatesToHardware
161
162
163;--------------------------------------------------------------------
164; DisplayContext_SetCharacterPointerFromBXAX
165; Parameters:
166; BX:AX: Ptr to destination for next character to output
167; DS: BDA segment (zero)
168; Returns:
169; ES:DI: Pointer that was in BX:AX
170; Corrupts registers:
171; AX
172;--------------------------------------------------------------------
173ALIGN JUMP_ALIGN
174DisplayContext_SetCharacterPointerFromBXAX:
175 mov [VIDEO_BDA.displayContext+DISPLAY_CONTEXT.fpCursorPosition], ax
176 mov [VIDEO_BDA.displayContext+DISPLAY_CONTEXT.fpCursorPosition+2], bx
177 xchg di, ax
178 mov es, bx
179 ret
180
181
182;--------------------------------------------------------------------
183; DisplayContext_GetCharacterPointerToBXAX
184; Parameters:
185; DS: BDA segment (zero)
186; Returns:
187; BX:AX: Ptr to destination for next character to output
188; Corrupts registers:
189; Nothing
190;--------------------------------------------------------------------
191ALIGN JUMP_ALIGN
192DisplayContext_GetCharacterPointerToBXAX:
193 mov ax, [VIDEO_BDA.displayContext+DISPLAY_CONTEXT.fpCursorPosition]
194 mov bx, [VIDEO_BDA.displayContext+DISPLAY_CONTEXT.fpCursorPosition+2]
195 ret
196
197
198;--------------------------------------------------------------------
199; DisplayContext_SetCharOutputFunctionFromAXwithAttribFlagInBL
200; Parameters:
201; AX: Offset to character output function
202; BL: Attribute Flag
203; DS: BDA segment (zero)
204; Returns:
205; Nothing
206; Corrupts registers:
207; BL
208;--------------------------------------------------------------------
209ALIGN JUMP_ALIGN
210DisplayContext_SetCharOutputFunctionFromAXwithAttribFlagInBL:
211 and bl, FLG_CONTEXT_ATTRIBUTES
212 and BYTE [VIDEO_BDA.displayContext+DISPLAY_CONTEXT.bFlags], ~FLG_CONTEXT_ATTRIBUTES
213 or [VIDEO_BDA.displayContext+DISPLAY_CONTEXT.bFlags], bl
214 mov [VIDEO_BDA.displayContext+DISPLAY_CONTEXT.fnCharOut], ax
215 ret
216
217
218;--------------------------------------------------------------------
219; DisplayContext_SetCharacterAttributeFromAL
220; Parameters:
221; AL: Character attribute
222; DS: BDA segment (zero)
223; Returns:
224; Nothing
225; Corrupts registers:
226; Nothing
227;--------------------------------------------------------------------
228ALIGN JUMP_ALIGN
229DisplayContext_SetCharacterAttributeFromAL:
230 mov [VIDEO_BDA.displayContext+DISPLAY_CONTEXT.bAttribute], al
231 ret
232
233
234;--------------------------------------------------------------------
235; DisplayContext_SetCharacterOutputParameterFromAX
236; Parameters:
237; AX: Parameter for Character Output function
238; DS: BDA segment (zero)
239; Returns:
240; Nothing
241; Corrupts registers:
242; Nothing
243;--------------------------------------------------------------------
244ALIGN JUMP_ALIGN
245DisplayContext_SetCharacterOutputParameterFromAX:
246 mov [VIDEO_BDA.displayContext+DISPLAY_CONTEXT.wCharOutParam], ax
247 ret
248
249;--------------------------------------------------------------------
250; DisplayContext_GetCharacterOutputParameterToDX
251; Parameters:
252; DS: BDA segment (zero)
253; Returns:
254; DX: User parameter for Character Output function
255; Corrupts registers:
256; Nothing
257;--------------------------------------------------------------------
258ALIGN JUMP_ALIGN
259DisplayContext_GetCharacterOutputParameterToDX:
260 mov dx, [VIDEO_BDA.displayContext+DISPLAY_CONTEXT.wCharOutParam]
261 ret
262
263
264;--------------------------------------------------------------------
265; DisplayContext_GetCharacterOffsetToAXfromByteOffsetInAX
266; Parameters:
267; AX: Offset in bytes from some character to another
268; DS: BDA segment (zero)
269; Returns:
270; AX: Offset in characters from some character to another
271; Corrupts registers:
272; Nothing
273;--------------------------------------------------------------------
274ALIGN JUMP_ALIGN
275DisplayContext_GetCharacterOffsetToAXfromByteOffsetInAX:
276 test BYTE [VIDEO_BDA.displayContext+DISPLAY_CONTEXT.bFlags], FLG_CONTEXT_ATTRIBUTES
277 jz SHORT ReturnOffsetInAX
278 sar ax, 1 ; BYTE count to WORD count
279 ret
280
281;--------------------------------------------------------------------
282; DisplayContext_GetByteOffsetToAXfromCharacterOffsetInAX
283; Parameters:
284; AX: Offset in characters from some character to another
285; DS: BDA segment (zero)
286; Returns:
287; AX: Offset in bytes from some character to another
288; Corrupts registers:
289; Nothing
290;--------------------------------------------------------------------
291ALIGN JUMP_ALIGN
292DisplayContext_GetByteOffsetToAXfromCharacterOffsetInAX:
293 test BYTE [VIDEO_BDA.displayContext+DISPLAY_CONTEXT.bFlags], FLG_CONTEXT_ATTRIBUTES
294 jz SHORT ReturnOffsetInAX
295 sal ax, 1 ; WORD count to BYTE count
296ALIGN JUMP_ALIGN, ret
297ReturnOffsetInAX:
298 ret
Note: See TracBrowser for help on using the repository browser.