summaryrefslogtreecommitdiff
path: root/hw/kdrive/vesa/vm86.c
blob: 9d1fa8bcf723fc20ad01ab2000c3904b3d53ce88 (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
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
/*
 * $RCSId: xc/programs/Xserver/hw/kdrive/vesa/vm86.c,v 1.2 2002/02/19 00:18:05 keithp Exp $
 *
 * Copyright © 2000 Keith Packard
 *
 * Permission to use, copy, modify, distribute, and sell this software and its
 * documentation for any purpose is hereby granted without fee, provided that
 * the above copyright notice appear in all copies and that both that
 * copyright notice and this permission notice appear in supporting
 * documentation, and that the name of Keith Packard not be used in
 * advertising or publicity pertaining to distribution of the software without
 * specific, written prior permission.  Keith Packard makes no
 * representations about the suitability of this software for any purpose.  It
 * is provided "as is" without express or implied warranty.
 *
 * KEITH PACKARD DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
 * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO
 * EVENT SHALL KEITH PACKARD BE LIABLE FOR ANY SPECIAL, INDIRECT OR
 * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE,
 * DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER
 * TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
 * PERFORMANCE OF THIS SOFTWARE.
 */
/* 
Copyright (c) 2000 by Juliusz Chroboczek
 
Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions: 
 
The above copyright notice and this permission notice shall be included in
all copies or substantial portions of the Software. 

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
THE SOFTWARE.
*/

#ifdef HAVE_CONFIG_H
#include <config.h>
#endif
#include "vm86.h"

#define PUSHW(vi, i) \
{ vi->vms.regs.esp -= 2;\
  LMW(vi,MAKE_POINTER(vi->vms.regs.ss, vi->vms.regs.esp)) = i;}

static int vm86old(struct vm86_struct *vms);
static int vm86_loop(Vm86InfoPtr vi);

static const U8 rev_ints[32] =
{ 0, 0, 0, 0, 0, 0, 0, 0,
  0, 0, 0, 0, 0, 0, 0, 0,
  0, 0, 0, 0, 0, 0, 0, 0,
  0, 0, 0, 0, 0, 0, 0, 0x80,
};

static const U8 retcode_data[2] =
{ 0xCD, 0xFF };

Vm86InfoPtr
Vm86Setup(int mapHoles)
{
    int devmem = -1, devzero = -1;
    void *magicMem, *loMem, *hiMem;
    void *hole1, *hole2;
    U32 stack_base, ret_code;
    Vm86InfoPtr vi = NULL;

    devmem = open("/dev/mem", O_RDWR);
    if(devmem < 0) {
	perror("open /dev/mem");
	goto fail;
    }

    devzero = open("/dev/zero", O_RDWR);
    if(devzero < 0) {
	perror("open /dev/zero");
	goto fail;
    }

    magicMem = MAP_FAILED;
    loMem = MAP_FAILED;
    hiMem = MAP_FAILED;
    hole1 = MAP_FAILED;
    hole2 = MAP_FAILED;


    magicMem = mmap((void*)MAGICMEM_BASE, MAGICMEM_SIZE,
		    PROT_READ | PROT_WRITE | PROT_EXEC,
		    MAP_PRIVATE | MAP_FIXED, devmem, MAGICMEM_BASE);
    
    if(magicMem == MAP_FAILED) {
	ErrorF("Couldn't map magic memory\n");
	goto unmapfail;
    }

    if(mapHoles) {
        hole1 = mmap((void*)HOLE1_BASE, HOLE1_SIZE,
                     PROT_READ | PROT_WRITE | PROT_EXEC,
                     MAP_PRIVATE | MAP_FIXED, devzero, HOLE1_BASE);
    
        if(hole1 == MAP_FAILED) {
            ErrorF("Couldn't map first hole\n");
            goto unmapfail;
        }
    }

    loMem = mmap((void*)LOMEM_BASE, LOMEM_SIZE,
		 PROT_READ | PROT_WRITE | PROT_EXEC,
		 MAP_PRIVATE | MAP_FIXED, devzero, LOMEM_BASE);
    if(loMem == MAP_FAILED) {
	ErrorF("Couldn't map low memory\n");
	munmap(magicMem, MAGICMEM_SIZE);
	goto unmapfail;
    }

    if(mapHoles) {
        hole2 = mmap((void*)HOLE2_BASE, HOLE2_SIZE,
                     PROT_READ | PROT_WRITE | PROT_EXEC,
                     MAP_PRIVATE | MAP_FIXED, devzero, HOLE2_BASE);
    
        if(hole2 == MAP_FAILED) {
            ErrorF("Couldn't map first hole\n");
            goto unmapfail;
        }
    }

    hiMem = mmap((void*)HIMEM_BASE, HIMEM_SIZE,
		 PROT_READ | PROT_WRITE | PROT_EXEC,
		 MAP_SHARED | MAP_FIXED,
		 devmem, HIMEM_BASE);
    if(hiMem == MAP_FAILED) {
	ErrorF("Couldn't map high memory\n");
	goto unmapfail;
    }

    vi = xalloc(sizeof(Vm86InfoRec));
    if (!vi)
	goto unmapfail;

    vi->magicMem = magicMem;
    vi->hole1 = hole1;
    vi->loMem = loMem;
    vi->hole2 = hole2;
    vi->hiMem = hiMem;
    vi->brk = LOMEM_BASE;

    stack_base = Vm86AllocateMemory(vi, STACK_SIZE);
    if(stack_base == ALLOC_FAIL)
	goto unmapfail;
    ret_code = Vm86AllocateMemory(vi, sizeof(retcode_data));
    if(ret_code == ALLOC_FAIL)
	goto unmapfail;

    vi->stack_base = stack_base;
    vi->ret_code = ret_code;

    memset(&vi->vms, 0, sizeof(struct vm86_struct));
    vi->vms.flags = 0;
    vi->vms.screen_bitmap = 0;
    vi->vms.cpu_type = CPU_586;
    memcpy(&vi->vms.int_revectored, rev_ints, sizeof(rev_ints));

    iopl(3);
    
    if(devmem >= 0)
	close(devmem);
    if(devzero >= 0)
	close(devzero);

    return vi;

unmapfail:
    if(magicMem != MAP_FAILED) munmap(magicMem, MAGICMEM_SIZE);
    if(hole1 != MAP_FAILED) munmap(hole1, HOLE1_SIZE);
    if(loMem != MAP_FAILED) munmap(loMem, LOMEM_SIZE);
    if(hole2 != MAP_FAILED) munmap(hole2, HOLE2_SIZE);
    if(hiMem != MAP_FAILED) munmap(hiMem, HIMEM_SIZE);
fail:
    if(devmem >= 0)
	close(devmem);
    if(devzero >= 0)
	close(devzero);
    if(vi)
	xfree(vi);
    return NULL;
}

void
Vm86Cleanup(Vm86InfoPtr vi)
{
    if(vi->magicMem != MAP_FAILED) munmap(vi->magicMem, MAGICMEM_SIZE);
    if(vi->hole1 != MAP_FAILED) munmap(vi->hole1, HOLE1_SIZE);
    if(vi->loMem != MAP_FAILED) munmap(vi->loMem, LOMEM_SIZE);
    if(vi->hole2 != MAP_FAILED) munmap(vi->hole2, HOLE2_SIZE);
    if(vi->hiMem != MAP_FAILED) munmap(vi->hiMem, HIMEM_SIZE);
    xfree(vi);
}

int
Vm86DoInterrupt(Vm86InfoPtr vi, int num)
{
    U16 seg, off;
    int code;

    if(num < 0 || num>256) {
	ErrorF("Interrupt %d doesn't exist\n");
	return -1;
    }
    seg = MMW(vi,num * 4 + 2);
    off = MMW(vi,num * 4);
    if(MAKE_POINTER(seg, off) < ROM_BASE ||
       MAKE_POINTER(seg, off) >= ROM_BASE + ROM_SIZE) {
	ErrorF("Interrupt pointer (seg %x off %x) doesn't point at ROM\n",
	       seg, off);
	return -1;
    }
    memcpy(&(LM(vi,vi->ret_code)), retcode_data, sizeof(retcode_data));
    vi->vms.regs.eflags = IF_MASK | IOPL_MASK;
    vi->vms.regs.ss = POINTER_SEGMENT(vi->stack_base);
    vi->vms.regs.esp = STACK_SIZE;
    PUSHW(vi, IF_MASK | IOPL_MASK);
    PUSHW(vi, POINTER_SEGMENT(vi->ret_code));
    PUSHW(vi, POINTER_OFFSET(vi->ret_code));
    vi->vms.regs.cs = seg;
    vi->vms.regs.eip = off;
    OsBlockSignals ();
    code = vm86_loop(vi);
    OsReleaseSignals ();
    if(code < 0) {
	ErrorF("vm86 failed (errno %d)\n", errno);
	return -1;
    } else if(code != 0) {
	ErrorF("vm86 returned 0x%04X\n", code);
	return -1;
    } else
	return 0;
}

int
Vm86DoPOST(Vm86InfoPtr vi)
{
    U16 seg, off;
    int code;

    seg = 0xC000;
    off = 3;
    if(MAKE_POINTER(seg, off) < ROM_BASE ||
       MAKE_POINTER(seg, off) >= ROM_BASE + ROM_SIZE) {
	ErrorF("BIOS pointer (seg %x off %x) doesn't point at ROM\n",
	       seg, off);
	return -1;
    }
    memcpy(&(LM(vi,vi->ret_code)), retcode_data, sizeof(retcode_data));
    vi->vms.regs.ss = POINTER_SEGMENT(vi->stack_base);
    vi->vms.regs.esp = STACK_SIZE;
    PUSHW(vi, POINTER_SEGMENT(vi->ret_code));
    PUSHW(vi, POINTER_OFFSET(vi->ret_code));
    vi->vms.regs.cs = seg;
    vi->vms.regs.eip = off;
    OsBlockSignals ();
    code = vm86_loop(vi);
    OsReleaseSignals ();
    if(code < 0) {
	ErrorF("vm86 failed (errno %d)\n", errno);
	return -1;
    } else if(code != 0) {
	ErrorF("vm86 returned 0x%04X\n", code);
	return -1;
    } else
	return 0;
}

#define DEBUG_VBE 0
#if DEBUG_VBE
#define DBG(x) ErrorF x; usleep(10*1000)
#else
#define DBG(x)
#endif

static inline U8 
vm86_inb(U16 port)
{
    U8 value;
    
    if (port != 0x3da)
    {
	DBG(("inb  0x%04x", port));
    }
    asm volatile ("inb %w1,%b0" : "=a" (value) : "d" (port));
    if (port != 0x3da)
    {
	DBG((" = 0x%02x\n", value));
    }
    return value;
}

static inline U16
vm86_inw(U16 port)
{
    U16 value;
    DBG(("inw  0x%04x", port));
    asm volatile ("inw %w1,%w0" : "=a" (value) : "d" (port));
    DBG((" = 0x%04x\n", value));
    return value;
}

static inline U32
vm86_inl(U16 port)
{
    U32 value;
    DBG(("inl  0x%04x", port));
    asm volatile ("inl %w1,%0" : "=a" (value) : "d" (port));
    DBG((" = 0x%08x\n", value));
    return value;
}

static inline void
vm86_outb(U16 port, U8 value)
{
#if 0
    static U8 CR;

    if (port == 0x3d4)
	CR = value;
    if (port == 0x3d5 && CR == 0xa4)
    {
	DBG(("outb 0x%04x = 0x%02x (skipped)\n", port, value));
	return;
    }
#endif
    DBG(("outb 0x%04x = 0x%02x\n", port, value));
    asm volatile ("outb %b0,%w1" : : "a" (value), "d" (port));
}

static inline void
vm86_outw(U16 port, U16 value)
{
    DBG(("outw 0x%04x = 0x%04x\n", port, value));
    asm volatile ("outw %w0,%w1" : : "a" (value), "d" (port));
}

static inline void
vm86_outl(U16 port, U32 value)
{
    DBG(("outl 0x%04x = 0x%08x\n", port, value));
    asm volatile ("outl %0,%w1" : : "a" (value), "d" (port));
}

#define SEG_CS 1
#define SEG_DS 2
#define SEG_ES 3
#define SEG_SS 4
#define SEG_GS 5
#define SEG_FS 6
#define REP 1
#define REPNZ 2
#define SET_8(_x, _y) (_x) = ((_x) & ~0xFF) | ((_y) & 0xFF);
#define SET_16(_x, _y) (_x) = ((_x) & ~0xFFFF) | ((_y) & 0xFFFF);
#define INC_IP(_i) SET_16(regs->eip, (regs->eip + _i))
#define AGAIN INC_IP(1); goto again;

static int
vm86_emulate(Vm86InfoPtr vi)
{
    struct vm86_regs *regs = &vi->vms.regs;
    U8 opcode;
    int size;
    int pref_seg = 0, pref_rep = 0, pref_66 = 0, pref_67 = 0;

  again:
    if(!Vm86IsMemory(vi, MAKE_POINTER(regs->cs, regs->eip))) {
        ErrorF("Trying to execute unmapped memory\n");
        return -1;
    }
    opcode = Vm86Memory(vi, MAKE_POINTER(regs->cs, regs->eip));
    switch(opcode) {
    case 0x2E: pref_seg = SEG_CS; AGAIN;
    case 0x3E: pref_seg = SEG_DS; AGAIN;
    case 0x26: pref_seg = SEG_ES; AGAIN;
    case 0x36: pref_seg = SEG_SS; AGAIN;
    case 0x65: pref_seg = SEG_GS; AGAIN;
    case 0x64: pref_seg = SEG_FS; AGAIN;
    case 0x66: pref_66 = 1; AGAIN;
    case 0x67: pref_67 = 1; AGAIN;
    case 0xF2: pref_rep = REPNZ; AGAIN;
    case 0xF3: pref_rep = REP; AGAIN;

    case 0xEC:                  /* IN AL, DX */
        SET_8(regs->eax, vm86_inb(regs->edx & 0xFFFF));
        INC_IP(1);
        break;
    case 0xED:                  /* IN AX, DX */
        if(pref_66)
            regs->eax = vm86_inl(regs->edx & 0xFFFF);
        else
            SET_16(regs->eax, vm86_inw(regs->edx & 0xFFFF));
	INC_IP(1);
        break;
    case 0xE4:                  /* IN AL, imm8 */
        SET_8(regs->eax, 
              vm86_inb(Vm86Memory(vi, MAKE_POINTER(regs->cs, regs->eip+1))));
        INC_IP(2);
        break;
    case 0xE5:                  /* IN AX, imm8 */
        if(pref_66)
            regs->eax =
                vm86_inl(Vm86Memory(vi, MAKE_POINTER(regs->cs, regs->eip+1)));
        else
            SET_16(regs->eax, 
                   vm86_inw(Vm86Memory(vi, MAKE_POINTER(regs->cs, regs->eip+1))));
        INC_IP(2);
        break;
    case 0x6C:                  /* INSB */
    case 0x6D:                  /* INSW */
        if(opcode == 0x6C) {
            Vm86WriteMemory(vi, MAKE_POINTER(regs->es, regs->edi),
                vm86_inb(regs->edx & 0xFFFF));
            size = 1;
        } else if(pref_66) {
            Vm86WriteMemoryL(vi, MAKE_POINTER(regs->es, regs->edi),
                vm86_inl(regs->edx & 0xFFFF));
            size = 4;
        } else {
            Vm86WriteMemoryW(vi, MAKE_POINTER(regs->es, regs->edi),
                vm86_inw(regs->edx & 0xFFFF));
            size = 2;
        }
        if(regs->eflags & (1<<10))
            regs->edi -= size;
        else
            regs->edi += size;
        if(pref_rep) {
            if(pref_66) {
                regs->ecx--;
                if(regs->ecx != 0)
                    goto again;
            } else {
                SET_16(regs->ecx, regs->ecx - 1);
                if((regs->ecx & 0xFFFF) != 0)
                    goto again;
            }
        }
        INC_IP(1);
        break;

    case 0xEE:                  /* OUT DX, AL */
        vm86_outb(regs->edx & 0xFFFF, regs->eax & 0xFF);
        INC_IP(1);
        break;
    case 0xEF:                  /* OUT DX, AX */
        if(pref_66)
            vm86_outl(regs->edx & 0xFFFF, regs->eax);
        else
            vm86_outw(regs->edx & 0xFFFF, regs->eax & 0xFFFF);
        INC_IP(1);
        break;
    case 0xE6:                  /* OUT imm8, AL */
        vm86_outb(Vm86Memory(vi, MAKE_POINTER(regs->cs, regs->eip+1)),
             regs->eax & 0xFF);
        INC_IP(2);
        break;
    case 0xE7:                  /* OUT imm8, AX */
        if(pref_66)
            vm86_outl(Vm86Memory(vi, MAKE_POINTER(regs->cs, regs->eip+1)),
                  regs->eax);
        else
            vm86_outw(Vm86Memory(vi, MAKE_POINTER(regs->cs, regs->eip+1)),
                 regs->eax & 0xFFFF);
        INC_IP(2);
        break;
    case 0x6E:                  /* OUTSB */
    case 0x6F:                  /* OUTSW */
        if(opcode == 0x6E) {
            vm86_outb(regs->edx & 0xFFFF, 
                 Vm86Memory(vi, MAKE_POINTER(regs->es, regs->edi)));
            size = 1;
        } else if(pref_66) {
            vm86_outl(regs->edx & 0xFFFF, 
                 Vm86Memory(vi, MAKE_POINTER(regs->es, regs->edi)));
            size = 4;
        } else {
            vm86_outw(regs->edx & 0xFFFF, 
                 Vm86Memory(vi, MAKE_POINTER(regs->es, regs->edi)));
            size = 2;
        }
        if(regs->eflags & (1<<10))
            regs->edi -= size;
        else
            regs->edi += size;
        if(pref_rep) {
            if(pref_66) {
                regs->ecx--;
                if(regs->ecx != 0)
                    goto again;
            } else {
                SET_16(regs->ecx, regs->ecx - 1);
                if((regs->ecx & 0xFFFF) != 0)
                    goto again;
            }
        }
        INC_IP(1);
        break;

    case 0x0F:
        ErrorF("Hit 0F trap in VM86 code\n");
        return -1;
    case 0xF0:
        ErrorF("Hit lock prefix in VM86 code\n");
        return -1;
    case 0xF4:
        ErrorF("Hit HLT in VM86 code\n");
        return -1;

    default:
        ErrorF("Unhandled GP fault in VM86 code (opcode = 0x%02X)\n",
               opcode);
        return -1;
    }
    return 0;
}
#undef SEG_CS
#undef SEG_DS
#undef SEG_ES
#undef SEG_SS
#undef SEG_GS
#undef SEG_FS
#undef REP
#undef REPNZ
#undef SET_8
#undef SET_16
#undef INC_IP
#undef AGAIN

static int
vm86_loop(Vm86InfoPtr vi)
{
    int code;
    
    while(1) {
        code = vm86old(&vi->vms);
        switch(VM86_TYPE(code)) {
        case VM86_SIGNAL:
            continue;
        case VM86_UNKNOWN:
            code = vm86_emulate(vi);
            if(code < 0) {
                Vm86Debug(vi);
                return -1;
            }
            break;
        case VM86_INTx:
            if(VM86_ARG(code) == 0xFF)
                return 0;
            else {
                PUSHW(vi, vi->vms.regs.eflags)
                PUSHW(vi, vi->vms.regs.cs);
                PUSHW(vi, vi->vms.regs.eip);
                vi->vms.regs.cs = MMW(vi,VM86_ARG(code) * 4 + 2);
                vi->vms.regs.eip = MMW(vi,VM86_ARG(code) * 4);
            }
            break;
        case VM86_STI:
            ErrorF("VM86 code enabled interrupts\n");
            Vm86Debug(vi);
            return -1;
        default:
            ErrorF("Unexpected result code 0x%X from vm86\n", code);
            Vm86Debug(vi);
            return -1;
        }
    }
}

int 
Vm86IsMemory(Vm86InfoPtr vi, U32 i) 
{
    if(i >= MAGICMEM_BASE && i< MAGICMEM_BASE + MAGICMEM_SIZE)
        return 1;
    else if(i >= LOMEM_BASE && i< LOMEM_BASE + LOMEM_SIZE)
        return 1;
    else if(i >= HIMEM_BASE && i< HIMEM_BASE + HIMEM_SIZE)
        return 1;
    else
        return 0;
}

U8 
Vm86Memory(Vm86InfoPtr vi, U32 i)
{
    if(i >= MAGICMEM_BASE && i< MAGICMEM_BASE + MAGICMEM_SIZE)
        return MM(vi, i);
    else if(i >= LOMEM_BASE && i< LOMEM_BASE + LOMEM_SIZE)
        return LM(vi, i);
    else if(i >= HIMEM_BASE && i< HIMEM_BASE + HIMEM_SIZE)
        return HM(vi, i);
    else {
        ErrorF("Reading unmapped memory at 0x%08X\n", i);
	return 0;
    }
}

U16
Vm86MemoryW(Vm86InfoPtr vi, U32 i)
{
    if(i >= MAGICMEM_BASE && i< MAGICMEM_BASE + MAGICMEM_SIZE)
        return MMW(vi, i);
    else if(i >= LOMEM_BASE && i< LOMEM_BASE + LOMEM_SIZE)
        return LMW(vi, i);
    else if(i >= HIMEM_BASE && i< HIMEM_BASE + HIMEM_SIZE)
        return HMW(vi, i);
    else {
        ErrorF("Reading unmapped memory at 0x%08X\n", i);
        return 0;
    }
}

U32
Vm86MemoryL(Vm86InfoPtr vi, U32 i)
{
    if(i >= MAGICMEM_BASE && i< MAGICMEM_BASE + MAGICMEM_SIZE)
        return MML(vi, i);
    else if(i >= LOMEM_BASE && i< LOMEM_BASE + LOMEM_SIZE)
        return LML(vi, i);
    else if(i >= HIMEM_BASE && i< HIMEM_BASE + HIMEM_SIZE)
        return HML(vi, i);
    else {
        ErrorF("Reading unmapped memory at 0x%08X\n", i);
        return 0;
    }
}

void
Vm86WriteMemory(Vm86InfoPtr vi, U32 i, U8 val)
{
    if(i >= MAGICMEM_BASE && i< MAGICMEM_BASE + MAGICMEM_SIZE)
        MM(vi, i) = val;
    else if(i >= LOMEM_BASE && i< LOMEM_BASE + LOMEM_SIZE)
        LM(vi, i) = val;
    else if(i >= HIMEM_BASE && i< HIMEM_BASE + HIMEM_SIZE)
        HM(vi, i) = val;
    else {
        ErrorF("Writing unmapped memory at 0x%08X\n", i);
    }
}

void
Vm86WriteMemoryW(Vm86InfoPtr vi, U32 i, U16 val)
{
    if(i >= MAGICMEM_BASE && i< MAGICMEM_BASE + MAGICMEM_SIZE)
        MMW(vi, i) = val;
    else if(i >= LOMEM_BASE && i< LOMEM_BASE + LOMEM_SIZE)
        LMW(vi, i) = val;
    else if(i >= HIMEM_BASE && i< HIMEM_BASE + HIMEM_SIZE)
        HMW(vi, i) = val;
    else {
        ErrorF("Writing unmapped memory at 0x%08X\n", i);
    }
}

void
Vm86WriteMemoryL(Vm86InfoPtr vi, U32 i, U32 val)
{
    if(i >= MAGICMEM_BASE && i< MAGICMEM_BASE + MAGICMEM_SIZE)
        MML(vi, i) = val;
    else if(i >= LOMEM_BASE && i< LOMEM_BASE + LOMEM_SIZE)
        LML(vi, i) = val;
    else if(i >= HIMEM_BASE && i< HIMEM_BASE + HIMEM_SIZE)
        HML(vi, i) = val;
    else {
        ErrorF("Writing unmapped memory at 0x%08X\n", i);
    }
}

int
Vm86AllocateMemory(Vm86InfoPtr vi, int n)
{
    int ret;
    if(n<0) {
        ErrorF("Asked to allocate negative amount of memory\n");
        return vi->brk;
    }
      
    n = (n + 15) & ~15;
    if(vi->brk + n > LOMEM_BASE + LOMEM_SIZE) {
        ErrorF("Out of low memory\n");
        exit(2);
    }
    ret = vi->brk;
    vi->brk += n;
    return ret;
}

int
Vm86MarkMemory (Vm86InfoPtr vi)
{
    return vi->brk;
}

void
Vm86ReleaseMemory (Vm86InfoPtr vi, int mark)
{
    vi->brk = mark;
}

static int
vm86old(struct vm86_struct *vm)
{
    int res;
    
    asm volatile (
	"pushl %%ebx\n\t"
	"movl %2, %%ebx\n\t"
	"movl %1,%%eax\n\t"
	"int $0x80\n\t"
	"popl %%ebx"
	: "=a" (res)  : "n" (113), "r" (vm));
    if(res < 0) {
	errno = -res;
	res = -1;
    } else 
	errno = 0;
    return res;
}

void
Vm86Debug(Vm86InfoPtr vi)
{
    struct vm86_regs *regs = &vi->vms.regs;
    int i;

    ErrorF("eax=0x%08lX ebx=0x%08lX ecx=0x%08lX edx=0x%08lX\n",
           regs->eax, regs->ebx, regs->ecx, regs->edx);
    ErrorF("esi=0x%08lX edi=0x%08lX ebp=0x%08lX\n",
           regs->esi, regs->edi, regs->ebp);
    ErrorF("eip=0x%08lX esp=0x%08lX eflags=0x%08lX\n",
           regs->eip, regs->esp, regs->eflags);
    ErrorF("cs=0x%04lX      ds=0x%04lX      es=0x%04lX      fs=0x%04lX      gs=0x%04lX\n",
           regs->cs, regs->ds, regs->es, regs->fs, regs->gs);
    for(i=-7; i<8; i++) {
        ErrorF(" %s%02X",
               i==0?"->":"",
               Vm86Memory(vi, MAKE_POINTER(regs->cs, regs->eip + i)));
    }
    ErrorF("\n");
}

#ifdef NOT_IN_X_SERVER
static void 
ErrorF(char *f, ...)
{
    va_list args;
    va_start(args, f);
    vfprintf(stderr, f, args);
    va_end(args);
}
#endif