aboutsummaryrefslogtreecommitdiffstatshomepage
path: root/libraries/irrlicht-1.8/source/Irrlicht/jpeglib/jmemdosa.asm
blob: c6ec48b346d477db66bf6b54590129330b63cf61 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
;
; jmemdosa.asm
;
; Copyright (C) 1992, Thomas G. Lane.
; This file is part of the Independent JPEG Group's software.
; For conditions of distribution and use, see the accompanying README file.
;
; This file contains low-level interface routines to support the MS-DOS
; backing store manager (jmemdos.c).  Routines are provided to access disk
; files through direct DOS calls, and to access XMS and EMS drivers.
;
; This file should assemble with Microsoft's MASM or any compatible
; assembler (including Borland's Turbo Assembler).  If you haven't got
; a compatible assembler, better fall back to jmemansi.c or jmemname.c.
;
; To minimize dependence on the C compiler's register usage conventions,
; we save and restore all 8086 registers, even though most compilers only
; require SI,DI,DS to be preserved.  Also, we use only 16-bit-wide return
; values, which everybody returns in AX.
;
; Based on code contributed by Ge' Weijers.
;

JMEMDOSA_TXT	segment byte public 'CODE'

		assume	cs:JMEMDOSA_TXT

		public	_jdos_open
		public	_jdos_close
		public	_jdos_seek
		public	_jdos_read
		public	_jdos_write
		public	_jxms_getdriver
		public	_jxms_calldriver
		public	_jems_available
		public	_jems_calldriver

;
; short far jdos_open (short far * handle, char far * filename)
;
; Create and open a temporary file
;
_jdos_open	proc	far
		push	bp			; linkage
		mov 	bp,sp
		push	si			; save all registers for safety
		push	di
		push	bx
		push	cx
		push	dx
		push	es
		push	ds
		mov	cx,0			; normal file attributes
		lds	dx,dword ptr [bp+10]	; get filename pointer
		mov	ah,3ch			; create file
		int	21h
		jc	open_err		; if failed, return error code
		lds	bx,dword ptr [bp+6]	; get handle pointer
		mov	word ptr [bx],ax	; save the handle
		xor	ax,ax			; return zero for OK
open_err:	pop	ds			; restore registers and exit
		pop	es
		pop	dx
		pop	cx
		pop	bx
		pop	di
		pop	si
		pop 	bp
		ret
_jdos_open	endp


;
; short far jdos_close (short handle)
;
; Close the file handle
;
_jdos_close	proc	far
		push	bp			; linkage
		mov 	bp,sp
		push	si			; save all registers for safety
		push	di
		push	bx
		push	cx
		push	dx
		push	es
		push	ds
		mov	bx,word ptr [bp+6]	; file handle
		mov	ah,3eh			; close file
		int	21h
		jc	close_err		; if failed, return error code
		xor	ax,ax			; return zero for OK
close_err:	pop	ds			; restore registers and exit
		pop	es
		pop	dx
		pop	cx
		pop	bx
		pop	di
		pop	si
		pop 	bp
		ret
_jdos_close	endp


;
; short far jdos_seek (short handle, long offset)
;
; Set file position
;
_jdos_seek	proc	far
		push	bp			; linkage
		mov 	bp,sp
		push	si			; save all registers for safety
		push	di
		push	bx
		push	cx
		push	dx
		push	es
		push	ds
		mov	bx,word ptr [bp+6]	; file handle
		mov	dx,word ptr [bp+8]	; LS offset
		mov	cx,word ptr [bp+10]	; MS offset
		mov	ax,4200h		; absolute seek
		int	21h
		jc	seek_err		; if failed, return error code
		xor	ax,ax			; return zero for OK
seek_err:	pop	ds			; restore registers and exit
		pop	es
		pop	dx
		pop	cx
		pop	bx
		pop	di
		pop	si
		pop 	bp
		ret
_jdos_seek	endp


;
; short far jdos_read (short handle, void far * buffer, unsigned short count)
;
; Read from file
;
_jdos_read	proc	far
		push	bp			; linkage
		mov 	bp,sp
		push	si			; save all registers for safety
		push	di
		push	bx
		push	cx
		push	dx
		push	es
		push	ds
		mov	bx,word ptr [bp+6]	; file handle
		lds	dx,dword ptr [bp+8]	; buffer address
		mov	cx,word ptr [bp+12]	; number of bytes
		mov	ah,3fh			; read file
		int	21h
		jc	read_err		; if failed, return error code
		cmp	ax,word ptr [bp+12]	; make sure all bytes were read
		je	read_ok
		mov	ax,1			; else return 1 for not OK
		jmp	short read_err
read_ok:	xor	ax,ax			; return zero for OK
read_err:	pop	ds			; restore registers and exit
		pop	es
		pop	dx
		pop	cx
		pop	bx
		pop	di
		pop	si
		pop 	bp
		ret
_jdos_read	endp


;
; short far jdos_write (short handle, void far * buffer, unsigned short count)
;
; Write to file
;
_jdos_write	proc	far
		push	bp			; linkage
		mov 	bp,sp
		push	si			; save all registers for safety
		push	di
		push	bx
		push	cx
		push	dx
		push	es
		push	ds
		mov	bx,word ptr [bp+6]	; file handle
		lds	dx,dword ptr [bp+8]	; buffer address
		mov	cx,word ptr [bp+12]	; number of bytes
		mov	ah,40h			; write file
		int	21h
		jc	write_err		; if failed, return error code
		cmp	ax,word ptr [bp+12]	; make sure all bytes written
		je	write_ok
		mov	ax,1			; else return 1 for not OK
		jmp	short write_err
write_ok:	xor	ax,ax			; return zero for OK
write_err:	pop	ds			; restore registers and exit
		pop	es
		pop	dx
		pop	cx
		pop	bx
		pop	di
		pop	si
		pop 	bp
		ret
_jdos_write	endp


;
; void far jxms_getdriver (XMSDRIVER far *)
;
; Get the address of the XMS driver, or NULL if not available
;
_jxms_getdriver	proc	far
		push	bp			; linkage
		mov 	bp,sp
		push	si			; save all registers for safety
		push	di
		push	bx
		push	cx
		push	dx
		push	es
		push	ds
		mov 	ax,4300h		; call multiplex interrupt with
		int	2fh			; a magic cookie, hex 4300
		cmp 	al,80h			; AL should contain hex 80
		je	xmsavail
		xor 	dx,dx			; no XMS driver available
		xor 	ax,ax			; return a nil pointer
		jmp	short xmsavail_done
xmsavail:	mov 	ax,4310h		; fetch driver address with
		int	2fh			; another magic cookie
		mov 	dx,es			; copy address to dx:ax
		mov 	ax,bx
xmsavail_done:	les 	bx,dword ptr [bp+6]	; get pointer to return value
		mov	word ptr es:[bx],ax
		mov	word ptr es:[bx+2],dx
		pop	ds			; restore registers and exit
		pop	es
		pop	dx
		pop	cx
		pop	bx
		pop	di
		pop	si
		pop	bp
		ret
_jxms_getdriver	endp


;
; void far jxms_calldriver (XMSDRIVER, XMScontext far *)
;
; The XMScontext structure contains values for the AX,DX,BX,SI,DS registers.
; These are loaded, the XMS call is performed, and the new values of the
; AX,DX,BX registers are written back to the context structure.
;
_jxms_calldriver 	proc	far
		push	bp			; linkage
		mov 	bp,sp
		push	si			; save all registers for safety
		push	di
		push	bx
		push	cx
		push	dx
		push	es
		push	ds
		les 	bx,dword ptr [bp+10]	; get XMScontext pointer
		mov 	ax,word ptr es:[bx]	; load registers
		mov 	dx,word ptr es:[bx+2]
		mov 	si,word ptr es:[bx+6]
		mov 	ds,word ptr es:[bx+8]
		mov 	bx,word ptr es:[bx+4]
		call	dword ptr [bp+6]	; call the driver
		mov	cx,bx			; save returned BX for a sec
		les 	bx,dword ptr [bp+10]	; get XMScontext pointer
		mov 	word ptr es:[bx],ax	; put back ax,dx,bx
		mov 	word ptr es:[bx+2],dx
		mov 	word ptr es:[bx+4],cx
		pop	ds			; restore registers and exit
		pop	es
		pop	dx
		pop	cx
		pop	bx
		pop	di
		pop	si
		pop 	bp
		ret
_jxms_calldriver 	endp


;
; short far jems_available (void)
;
; Have we got an EMS driver? (this comes straight from the EMS 4.0 specs)
;
_jems_available	proc	far
		push	si			; save all registers for safety
		push	di
		push	bx
		push	cx
		push	dx
		push	es
		push	ds
		mov	ax,3567h		; get interrupt vector 67h
		int	21h
		push	cs
		pop	ds
		mov	di,000ah		; check offs 10 in returned seg
		lea	si,ASCII_device_name	; against literal string
		mov	cx,8
		cld
		repe cmpsb
		jne	no_ems
		mov	ax,1			; match, it's there
		jmp	short avail_done
no_ems:		xor	ax,ax			; it's not there
avail_done:	pop	ds			; restore registers and exit
		pop	es
		pop	dx
		pop	cx
		pop	bx
		pop	di
		pop	si
		ret

ASCII_device_name	db	"EMMXXXX0"

_jems_available	endp


;
; void far jems_calldriver (EMScontext far *)
;
; The EMScontext structure contains values for the AX,DX,BX,SI,DS registers.
; These are loaded, the EMS trap is performed, and the new values of the
; AX,DX,BX registers are written back to the context structure.
;
_jems_calldriver	proc far
		push	bp			; linkage
		mov 	bp,sp
		push	si			; save all registers for safety
		push	di
		push	bx
		push	cx
		push	dx
		push	es
		push	ds
		les 	bx,dword ptr [bp+6]	; get EMScontext pointer
		mov 	ax,word ptr es:[bx]	; load registers
		mov 	dx,word ptr es:[bx+2]
		mov 	si,word ptr es:[bx+6]
		mov 	ds,word ptr es:[bx+8]
		mov 	bx,word ptr es:[bx+4]
		int	67h			; call the EMS driver
		mov	cx,bx			; save returned BX for a sec
		les 	bx,dword ptr [bp+6]	; get EMScontext pointer
		mov 	word ptr es:[bx],ax	; put back ax,dx,bx
		mov 	word ptr es:[bx+2],dx
		mov 	word ptr es:[bx+4],cx
		pop	ds			; restore registers and exit
		pop	es
		pop	dx
		pop	cx
		pop	bx
		pop	di
		pop	si
		pop 	bp
		ret
_jems_calldriver	endp

JMEMDOSA_TXT	ends

		end