source: xtideuniversalbios/trunk/XTIDE_Universal_BIOS/Src/Libraries/keys.asm@ 82

Last change on this file since 82 was 77, checked in by krille_n_@…, 14 years ago

Minor size optimizations plus a bug fix in print.asm in Print_IntSW (DI was left hanging on the stack if the parameter in AX was positive). Also a very minor speed optimization in keys.asm in Keys_Backspace.
File size: 8.3 KB
Line 
1; File name : keys.asm
2; Project name : Keyboard library
3; Created date : 17.11.2009
4; Last update : 4.1.2011
5; Author : Tomi Tilli,
6; : Krister Nordvall (optimizations)
7; Description : ASM library to for keyboard related functions.
8
9;--------------- Equates -----------------------------
10
11; String library function to include
12%define USE_KEYS_STROKE ; Keys_GetStroke, Keys_IsStroke and Keys_WaitStroke
13;%define USE_KEYS_PRNTGETUINT ; Keys_PrintGetUint
14;%define USE_KEYS_PRNTGETYN ; Keys_PrintGetYN
15%define USE_KEYS_CLRBUFFER ; Keys_ClrBuffer
16
17; Some BIOS Scan Codes
18KEY_BSC_F1 EQU 3Bh
19KEY_BSC_F2 EQU 3Ch
20KEY_BSC_F3 EQU 3Dh
21KEY_BSC_F4 EQU 3Eh
22KEY_BSC_F5 EQU 3Fh
23KEY_BSC_F6 EQU 40h
24KEY_BSC_F7 EQU 41h
25KEY_BSC_F8 EQU 42h
26KEY_BSC_F9 EQU 43h
27KEY_BSC_F10 EQU 44h
28KEY_BSC_F11 EQU 57h
29KEY_BSC_F12 EQU 58h
30
31
32;-------------- Private global variables -------------
33; Section containing initialized data
34;SECTION .data
35
36
37;-------------- Public functions ---------------------
38; Section containing code
39SECTION .text
40
41
42;--------------------------------------------------------------------
43; Checks is keystroke available in keyboard buffer.
44;
45; Keys_GetStroke Removes key from buffer if keystroke available
46; Keys_IsStroke Does not remove key from buffer
47; Keys_WaitStroke Waits until keystroke is available and removes it from buffer
48; Parameters:
49; Nothing
50; Returns:
51; AL: ASCII character (if keystroke available)
52; AH: BIOS scan code (if keystroke available)
53; ZF: Set if no keystroke available
54; Cleared if keystroke available
55; Corrupts registers:
56; Nothing
57;--------------------------------------------------------------------
58%ifdef USE_KEYS_STROKE
59ALIGN JUMP_ALIGN
60Keys_GetStroke:
61 call Keys_IsStroke
62 jnz Keys_WaitStroke
63 ret
64ALIGN JUMP_ALIGN
65Keys_IsStroke:
66 mov ah, 01h ; Check for Keystroke
67 int 16h
68 ret
69ALIGN JUMP_ALIGN
70Keys_WaitStroke:
71 xor ah, ah ; Get Keystroke
72 int 16h
73 test ax, ax ; Clear ZF
74 ret
75%endif
76
77
78;--------------------------------------------------------------------
79; Reads keystokes, prints them and converts them to unsigned WORD
80; after user has pressed ENTER. Returned value is always valid unless
81; user has cancelled by pressing ESC.
82;
83; Keys_PrintGetUint
84; Parameters:
85; CX: Base (10=dec, 16=hex etc.)
86; DX: Max number of characters wanted
87; Returns:
88; DX:AX: Unsigned DWORD that the user has entered
89; CF: Set if unsigned DWORD read successfully
90; Cleared is user has cancelled
91; Corrupts registers:
92; BX
93;--------------------------------------------------------------------
94%ifdef USE_KEYS_PRNTGETUINT
95ALIGN JUMP_ALIGN
96Keys_PrintGetUint:
97 push es
98 push di
99 push si
100
101 ; Reserve stack for buffer
102 inc dx ; Increment for STOP char
103 push ss ; Copy SS...
104 pop es ; ...to ES
105 mov si, sp ; Backup SP
106 sub sp, dx ; Reserve buffer from stack
107 mov di, sp ; ES:DI now points to buffer
108
109 ; Get user inputted string
110 mov bx, String_IsBaseChar
111 call Keys_GetStrToBuffer
112 jnc .Return ; Return if user cancellation
113
114 ; Convert string to DWORD
115 call String_StrToUInt ; Get DWORD to DX:AX
116
117 ; Return
118ALIGN JUMP_ALIGN
119.Return:
120 mov sp, si ; Destroy stack buffer
121 pop si
122 pop di
123 pop es
124 ret
125%endif
126
127
128;--------------------------------------------------------------------
129; Reads keystokes until Y or N is pressed.
130; CF will be set to match selection.
131;
132; Keys_PrintGetYN
133; Parameters:
134; Nothing
135; Returns:
136; AX: 'Y' if Y pressed
137; 'N' if N pressed
138; Zero if ESC pressed
139; CF: Set if Y pressed
140; Cleared if N or ESC pressed
141; Corrupts registers:
142; Nothing
143;--------------------------------------------------------------------
144%ifdef USE_KEYS_PRNTGETYN
145ALIGN JUMP_ALIGN
146Keys_PrintGetYN:
147 call Keys_WaitStroke ; Wait until keystroke
148 call String_ToLower ; Char in AL to lower case
149 cmp al, 'y' ; Y pressed?
150 je .RetY ; If so, return
151 cmp al, 'n' ; N pressed?
152 je .RetN ; If so, return
153 cmp al, ESC ; ESC pressed?
154 je .RetEsc ; If so, return N
155 call Keys_Bell ; Play error sound
156 jmp Keys_PrintGetYN ; Loop until right key pressed
157ALIGN JUMP_ALIGN
158.RetY:
159 mov ax, 'Y'
160 stc
161 ret
162ALIGN JUMP_ALIGN
163.RetN:
164 mov ax, 'N'
165 ret
166ALIGN JUMP_ALIGN
167.RetEsc:
168 xor ax, ax
169 ret
170%endif
171
172
173;--------------------------------------------------------------------
174; Clears BIOS keystroke buffer.
175;
176; Keys_ClrBuffer
177; Parameters:
178; Nothing
179; Returns:
180; Nothing
181; Corrupts registers:
182; AX
183;--------------------------------------------------------------------
184%ifdef USE_KEYS_CLRBUFFER
185ALIGN JUMP_ALIGN
186Keys_ClrBuffer:
187 call Keys_GetStroke ; Get keystroke
188 jnz Keys_ClrBuffer ; Loop if keystroke found in buffer
189 ret
190%endif
191
192
193;-------------- Private functions ---------------------
194
195;--------------------------------------------------------------------
196; Reads user inputted string to buffer. Character verification is
197; supported to ignore unwanted characters.
198; Function returns when ENTER or ESC will be pressed.
199;
200; Keys_GetStrToBuffer
201; Parameters:
202; DX: Buffer length in characters with STOP included
203; ES:DI: Ptr to buffer
204; CS:BX: Ptr to char verification function:
205; Parameters:
206; AL: Character to verify
207; CX: Anything passed to Keys_GetStrToBuffer
208; Returns:
209; CF: Set if character is wanted type
210; Cleared if character is not wanted
211; Corrupts registers:
212; Nothing
213; Returns:
214; AX: String length in characters without STOP
215; CF: Set if string has been read successfully
216; Cleared if user cancellation
217; Corrupts registers:
218; DX
219;--------------------------------------------------------------------
220%ifdef USE_KEYS_PRNTGETUINT
221ALIGN JUMP_ALIGN
222Keys_GetStrToBuffer:
223 push di
224 push si
225 dec dx ; Decrement for STOP char
226 xor si, si ; Zero char counter
227 cld ; STOSB to increment DI
228ALIGN JUMP_ALIGN
229.CharLoop:
230 call Keys_WaitStroke ; Wait for keystroke
231 cmp al, CR ; Enter pressed?
232 je .End ; If so, return (CF cleared)
233 cmp al, ESC ; Esc pressed?
234 je .Cancel ; If so, jump to cancel
235 cmp al, BS ; Backspace pressed?
236 je .Backspace ; If so, jump to process it
237 call bx ; Is wanted character?
238 jnc .Bell ; If not, play error sound and wait next key
239
240 ; Limit char count
241 cmp si, dx ; Max number of chars entered?
242 jae .CharLoop ; If so, wait for ENTER or BACKSPACE
243
244 ; Write base character in AL
245 stosb ; Store char from AL to [ES:DI]
246 inc si ; Increment char count
247 push dx
248 mov dl, al ; Copy char to DL
249 PRINT_CHAR ; Print character
250 pop dx
251 jmp .CharLoop ; Jump to wait next char
252ALIGN JUMP_ALIGN
253.Bell:
254 call Keys_Bell
255 jmp .CharLoop ; Jump to wait next char
256ALIGN JUMP_ALIGN
257.Backspace:
258 call Keys_Backspace
259 jmp .CharLoop ; Jump to wait next char
260ALIGN JUMP_ALIGN
261.Cancel:
262 xor si, si ; Zero string length (clear CF)
263 jmp .Return
264ALIGN JUMP_ALIGN
265.End:
266 stc ; Set CF since success
267.Return:
268 mov al, STOP ; End string
269 stosb
270 mov ax, si ; String length
271 pop si
272 pop di
273 ret
274%endif
275
276
277;--------------------------------------------------------------------
278; Plays bell sound for invalid key presses.
279;
280; Keys_Bell
281; Parameters:
282; Nothing
283; Returns:
284; Nothing
285; Corrupts registers:
286; AX
287;--------------------------------------------------------------------
288%ifdef USE_KEYS_PRNTGETUINT or USE_KEYS_PRNTGETYN
289ALIGN JUMP_ALIGN
290Keys_Bell:
291 push dx
292 mov dl, BELL
293 PRINT_CHAR
294 pop dx
295 ret
296%endif
297
298
299;--------------------------------------------------------------------
300; Handles backspace key by removing last written character.
301;
302; Keys_Backspace
303; Parameters:
304; SI: Character counter
305; ES:DI: Ptr to buffer
306; Returns:
307; Nothing
308; Corrupts registers:
309; AX
310;--------------------------------------------------------------------
311%ifdef USE_KEYS_PRNTGETUINT
312ALIGN JUMP_ALIGN
313Keys_Backspace:
314 test si, si ; At the beginning?
315 jz .Return ; If so, return
316 push dx ; Save DX
317 dec si ; Decrement char counter
318 dec di ; Decrement offset to buffer
319 mov dl, BS ; Write backspace
320 PRINT_CHAR
321 mov dl, ' ' ; Write space
322 PRINT_CHAR
323 mov dl, BS ; Back again
324 PRINT_CHAR
325 pop dx ; Restore DX
326ALIGN JUMP_ALIGN
327.Return:
328 ret
329%endif
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