2 * Emulation of privileged instructions
4 * Copyright 1995 Alexandre Julliard
9 #include "wine/winuser16.h"
12 #include "selectors.h"
13 #include "debugtools.h"
15 DEFAULT_DEBUG_CHANNEL(int);
16 DECLARE_DEBUG_CHANNEL(io);
20 inline static void add_stack( CONTEXT86 *context, int offset )
22 if (ISV86(context) || !IS_SELECTOR_32BIT(context->SegSs))
23 ADD_LOWORD( context->Esp, offset );
25 context->Esp += offset;
28 inline static void *make_ptr( CONTEXT86 *context, DWORD seg, DWORD off, int long_addr )
30 if (ISV86(context)) return PTR_REAL_TO_LIN( seg, off );
31 if (IS_SELECTOR_SYSTEM(seg)) return (void *)off;
32 if (!long_addr) off = LOWORD(off);
33 return MapSL( MAKESEGPTR( seg, off ) );
36 inline static void *get_stack( CONTEXT86 *context )
39 return PTR_REAL_TO_LIN( context->SegSs, context->Esp );
40 if (IS_SELECTOR_SYSTEM(context->SegSs))
41 return (void *)context->Esp;
42 if (IS_SELECTOR_32BIT(context->SegSs))
43 return MapSL( MAKESEGPTR( context->SegSs, context->Esp ) );
44 return MapSL( MAKESEGPTR( context->SegSs, LOWORD(context->Esp) ) );
47 /***********************************************************************
48 * INSTR_ReplaceSelector
50 * Try to replace an invalid selector by a valid one.
51 * The only selector where it is allowed to do "mov ax,40;mov es,ax"
52 * is the so called 'bimodal' selector 0x40, which points to the BIOS
53 * data segment. Used by (at least) Borland products (and programs compiled
54 * using Borland products).
56 * See Undocumented Windows, Chapter 5, __0040.
58 static BOOL INSTR_ReplaceSelector( CONTEXT86 *context, WORD *sel )
60 extern char Call16_Start, Call16_End;
62 if (IS_SELECTOR_SYSTEM(context->SegCs))
63 if ( (char *)context->Eip >= &Call16_Start
64 && (char *)context->Eip < &Call16_End )
66 /* Saved selector may have become invalid when the relay code */
67 /* tries to restore it. We simply clear it. */
74 static WORD sys_timer = 0;
76 sys_timer = CreateSystemTimer( 55, DOSMEM_Tick );
77 *sel = DOSMEM_BiosDataSeg;
80 if (!IS_SELECTOR_SYSTEM(*sel) && !IS_SELECTOR_FREE(*sel))
81 ERR("Got protection fault on valid selector, maybe your kernel is too old?\n" );
82 return FALSE; /* Can't replace selector, crashdump */
86 /***********************************************************************
87 * INSTR_GetOperandAddr
89 * Return the address of an instruction operand (from the mod/rm byte).
91 static BYTE *INSTR_GetOperandAddr( CONTEXT86 *context, BYTE *instr,
92 int long_addr, int segprefix, int *len )
94 int mod, rm, base, index = 0, ss = 0, seg = 0, off;
96 #define GET_VAL(val,type) \
97 { *val = *(type *)instr; instr += sizeof(type); *len += sizeof(type); }
100 GET_VAL( &mod, BYTE );
108 case 0: return (BYTE *)&context->Eax;
109 case 1: return (BYTE *)&context->Ecx;
110 case 2: return (BYTE *)&context->Edx;
111 case 3: return (BYTE *)&context->Ebx;
112 case 4: return (BYTE *)&context->Esp;
113 case 5: return (BYTE *)&context->Ebp;
114 case 6: return (BYTE *)&context->Esi;
115 case 7: return (BYTE *)&context->Edi;
124 GET_VAL( &sib, BYTE );
129 case 0: index = context->Eax; break;
130 case 1: index = context->Ecx; break;
131 case 2: index = context->Edx; break;
132 case 3: index = context->Ebx; break;
133 case 4: index = 0; break;
134 case 5: index = context->Ebp; break;
135 case 6: index = context->Esi; break;
136 case 7: index = context->Edi; break;
142 case 0: base = context->Eax; seg = context->SegDs; break;
143 case 1: base = context->Ecx; seg = context->SegDs; break;
144 case 2: base = context->Edx; seg = context->SegDs; break;
145 case 3: base = context->Ebx; seg = context->SegDs; break;
146 case 4: base = context->Esp; seg = context->SegSs; break;
147 case 5: base = context->Ebp; seg = context->SegSs; break;
148 case 6: base = context->Esi; seg = context->SegDs; break;
149 case 7: base = context->Edi; seg = context->SegDs; break;
154 if (rm == 5) /* special case: ds:(disp32) */
156 GET_VAL( &base, DWORD );
157 seg = context->SegDs;
161 case 1: /* 8-bit disp */
162 GET_VAL( &off, BYTE );
163 base += (signed char)off;
166 case 2: /* 32-bit disp */
167 GET_VAL( &off, DWORD );
168 base += (signed long)off;
172 else /* short address */
176 case 0: /* ds:(bx,si) */
177 base = LOWORD(context->Ebx) + LOWORD(context->Esi);
178 seg = context->SegDs;
180 case 1: /* ds:(bx,di) */
181 base = LOWORD(context->Ebx) + LOWORD(context->Edi);
182 seg = context->SegDs;
184 case 2: /* ss:(bp,si) */
185 base = LOWORD(context->Ebp) + LOWORD(context->Esi);
186 seg = context->SegSs;
188 case 3: /* ss:(bp,di) */
189 base = LOWORD(context->Ebp) + LOWORD(context->Edi);
190 seg = context->SegSs;
192 case 4: /* ds:(si) */
193 base = LOWORD(context->Esi);
194 seg = context->SegDs;
196 case 5: /* ds:(di) */
197 base = LOWORD(context->Edi);
198 seg = context->SegDs;
200 case 6: /* ss:(bp) */
201 base = LOWORD(context->Ebp);
202 seg = context->SegSs;
204 case 7: /* ds:(bx) */
205 base = LOWORD(context->Ebx);
206 seg = context->SegDs;
213 if (rm == 6) /* special case: ds:(disp16) */
215 GET_VAL( &base, WORD );
216 seg = context->SegDs;
220 case 1: /* 8-bit disp */
221 GET_VAL( &off, BYTE );
222 base += (signed char)off;
225 case 2: /* 16-bit disp */
226 GET_VAL( &off, WORD );
227 base += (signed short)off;
232 if (segprefix != -1) seg = segprefix;
234 /* Make sure the segment and offset are valid */
235 if (IS_SELECTOR_SYSTEM(seg)) return (BYTE *)(base + (index << ss));
236 if (((seg & 7) != 7) || IS_SELECTOR_FREE(seg)) return NULL;
237 if (wine_ldt_copy.limit[seg >> 3] < (base + (index << ss))) return NULL;
238 return MapSL( MAKESEGPTR( seg, (base + (index << ss))) );
243 /***********************************************************************
246 * Emulate the LDS (and LES,LFS,etc.) instruction.
248 static BOOL INSTR_EmulateLDS( CONTEXT86 *context, BYTE *instr, int long_op,
249 int long_addr, int segprefix, int *len )
252 BYTE *regmodrm = instr + 1 + (*instr == 0x0f);
253 BYTE *addr = INSTR_GetOperandAddr( context, regmodrm,
254 long_addr, segprefix, len );
256 return FALSE; /* Unable to emulate it */
257 seg = *(WORD *)(addr + (long_op ? 4 : 2));
259 if (!INSTR_ReplaceSelector( context, &seg ))
260 return FALSE; /* Unable to emulate it */
262 /* Now store the offset in the correct register */
264 switch((*regmodrm >> 3) & 7)
267 if (long_op) context->Eax = *(DWORD *)addr;
268 else SET_LOWORD(context->Eax,*(WORD *)addr);
271 if (long_op) context->Ecx = *(DWORD *)addr;
272 else SET_LOWORD(context->Ecx,*(WORD *)addr);
275 if (long_op) context->Edx = *(DWORD *)addr;
276 else SET_LOWORD(context->Edx,*(WORD *)addr);
279 if (long_op) context->Ebx = *(DWORD *)addr;
280 else SET_LOWORD(context->Ebx,*(WORD *)addr);
283 if (long_op) context->Esp = *(DWORD *)addr;
284 else SET_LOWORD(context->Esp,*(WORD *)addr);
287 if (long_op) context->Ebp = *(DWORD *)addr;
288 else SET_LOWORD(context->Ebp,*(WORD *)addr);
291 if (long_op) context->Esi = *(DWORD *)addr;
292 else SET_LOWORD(context->Esi,*(WORD *)addr);
295 if (long_op) context->Edi = *(DWORD *)addr;
296 else SET_LOWORD(context->Edi,*(WORD *)addr);
300 /* Store the correct segment in the segment register */
304 case 0xc4: context->SegEs = seg; break; /* les */
305 case 0xc5: context->SegDs = seg; break; /* lds */
306 case 0x0f: switch(instr[1])
308 case 0xb2: context->SegSs = seg; break; /* lss */
309 case 0xb4: context->SegFs = seg; break; /* lfs */
310 case 0xb5: context->SegGs = seg; break; /* lgs */
315 /* Add the opcode size to the total length */
317 *len += 1 + (*instr == 0x0f);
321 /***********************************************************************
324 * input on a I/O port
326 static DWORD INSTR_inport( WORD port, int size, CONTEXT86 *context )
328 DWORD res = IO_inport( port, size );
334 DPRINTF( "0x%x < %02x @ %04x:%04x\n", port, LOBYTE(res),
335 (WORD)context->SegCs, LOWORD(context->Eip));
338 DPRINTF( "0x%x < %04x @ %04x:%04x\n", port, LOWORD(res),
339 (WORD)context->SegCs, LOWORD(context->Eip));
342 DPRINTF( "0x%x < %08lx @ %04x:%04x\n", port, res,
343 (WORD)context->SegCs, LOWORD(context->Eip));
351 /***********************************************************************
354 * output on a I/O port
356 static void INSTR_outport( WORD port, int size, DWORD val, CONTEXT86 *context )
358 IO_outport( port, size, val );
364 DPRINTF("0x%x > %02x @ %04x:%04x\n", port, LOBYTE(val),
365 (WORD)context->SegCs, LOWORD(context->Eip));
368 DPRINTF("0x%x > %04x @ %04x:%04x\n", port, LOWORD(val),
369 (WORD)context->SegCs, LOWORD(context->Eip));
372 DPRINTF("0x%x > %08lx @ %04x:%04x\n", port, val,
373 (WORD)context->SegCs, LOWORD(context->Eip));
380 /***********************************************************************
381 * INSTR_EmulateInstruction
383 * Emulate a privileged instruction. Returns TRUE if emulation successful.
385 BOOL INSTR_EmulateInstruction( CONTEXT86 *context )
387 int prefix, segprefix, prefixlen, len, repX, long_op, long_addr;
391 long_op = long_addr = (!ISV86(context) && IS_SELECTOR_32BIT(context->SegCs));
392 instr = make_ptr( context, context->SegCs, context->Eip, TRUE );
393 if (!instr) return FALSE;
395 /* First handle any possible prefix */
397 segprefix = -1; /* no prefix */
406 segprefix = context->SegCs;
409 segprefix = context->SegSs;
412 segprefix = context->SegDs;
415 segprefix = context->SegEs;
418 segprefix = context->SegFs;
421 segprefix = context->SegGs;
424 long_op = !long_op; /* opcode size prefix */
427 long_addr = !long_addr; /* addr size prefix */
429 case 0xf0: /* lock */
431 case 0xf2: /* repne */
434 case 0xf3: /* repe */
438 prefix = 0; /* no more prefixes */
448 /* Now look at the actual instruction */
452 case 0x07: /* pop es */
453 case 0x17: /* pop ss */
454 case 0x1f: /* pop ds */
456 WORD seg = *(WORD *)get_stack( context );
457 if (INSTR_ReplaceSelector( context, &seg ))
461 case 0x07: context->SegEs = seg; break;
462 case 0x17: context->SegSs = seg; break;
463 case 0x1f: context->SegDs = seg; break;
465 add_stack(context, long_op ? 4 : 2);
466 context->Eip += prefixlen + 1;
470 break; /* Unable to emulate it */
472 case 0x0f: /* extended instruction */
475 case 0x22: /* mov eax, crX */
478 ERR("mov eax,cr0 at 0x%08lx, EAX=0x%08lx\n",
479 context->Eip,context->Eax );
480 context->Eip += prefixlen+3;
483 break; /*fallthrough to bad instruction handling */
485 break; /*fallthrough to bad instruction handling */
486 case 0x20: /* mov crX, eax */
488 case 0xe0: /* mov cr4, eax */
489 /* CR4 register . See linux/arch/i386/mm/init.c, X86_CR4_ defs
490 * bit 0: VME Virtual Mode Exception ?
491 * bit 1: PVI Protected mode Virtual Interrupt
492 * bit 2: TSD Timestamp disable
493 * bit 3: DE Debugging extensions
494 * bit 4: PSE Page size extensions
495 * bit 5: PAE Physical address extension
496 * bit 6: MCE Machine check enable
497 * bit 7: PGE Enable global pages
498 * bit 8: PCE Enable performance counters at IPL3
500 ERR("mov cr4,eax at 0x%08lx\n",context->Eip);
502 context->Eip += prefixlen+3;
504 case 0xc0: /* mov cr0, eax */
505 ERR("mov cr0,eax at 0x%08lx\n",context->Eip);
506 context->Eax = 0x10; /* FIXME: set more bits ? */
507 context->Eip += prefixlen+3;
509 default: /* fallthrough to illegal instruction */
512 /* fallthrough to illegal instruction */
514 case 0xa1: /* pop fs */
516 WORD seg = *(WORD *)get_stack( context );
517 if (INSTR_ReplaceSelector( context, &seg ))
519 context->SegFs = seg;
520 add_stack(context, long_op ? 4 : 2);
521 context->Eip += prefixlen + 2;
526 case 0xa9: /* pop gs */
528 WORD seg = *(WORD *)get_stack( context );
529 if (INSTR_ReplaceSelector( context, &seg ))
531 context->SegGs = seg;
532 add_stack(context, long_op ? 4 : 2);
533 context->Eip += prefixlen + 2;
538 case 0xb2: /* lss addr,reg */
539 case 0xb4: /* lfs addr,reg */
540 case 0xb5: /* lgs addr,reg */
541 if (INSTR_EmulateLDS( context, instr, long_op,
542 long_addr, segprefix, &len ))
544 context->Eip += prefixlen + len;
549 break; /* Unable to emulate it */
551 case 0x6c: /* insb */
552 case 0x6d: /* insw/d */
553 case 0x6e: /* outsb */
554 case 0x6f: /* outsw/d */
556 int typ = *instr; /* Just in case it's overwritten. */
557 int outp = (typ >= 0x6e);
558 unsigned long count = repX ?
559 (long_addr ? context->Ecx : LOWORD(context->Ecx)) : 1;
560 int opsize = (typ & 1) ? (long_op ? 4 : 2) : 1;
561 int step = (context->EFlags & 0x400) ? -opsize : +opsize;
562 int seg = outp ? context->SegDs : context->SegEs; /* FIXME: is this right? */
565 /* FIXME: Check segment readable. */
568 /* FIXME: Check segment writeable. */
573 if (long_addr) context->Ecx = 0;
574 else SET_LOWORD(context->Ecx,0);
580 WORD dx = LOWORD(context->Edx);
583 data = make_ptr( context, seg, context->Esi, long_addr );
584 if (long_addr) context->Esi += step;
585 else ADD_LOWORD(context->Esi,step);
589 data = make_ptr( context, seg, context->Edi, long_addr );
590 if (long_addr) context->Edi += step;
591 else ADD_LOWORD(context->Edi,step);
597 *(BYTE *)data = INSTR_inport( dx, 1, context );
601 *(DWORD *)data = INSTR_inport( dx, 4, context );
603 *(WORD *)data = INSTR_inport( dx, 2, context );
606 INSTR_outport( dx, 1, *(BYTE *)data, context );
610 INSTR_outport( dx, 4, *(DWORD *)data, context );
612 INSTR_outport( dx, 2, *(WORD *)data, context );
616 context->Eip += prefixlen + 1;
620 case 0x8e: /* mov XX,segment_reg */
623 BYTE *addr = INSTR_GetOperandAddr(context, instr + 1,
624 long_addr, segprefix, &len );
626 break; /* Unable to emulate it */
628 if (!INSTR_ReplaceSelector( context, &seg ))
629 break; /* Unable to emulate it */
631 switch((instr[1] >> 3) & 7)
634 context->SegEs = seg;
635 context->Eip += prefixlen + len + 1;
640 context->SegSs = seg;
641 context->Eip += prefixlen + len + 1;
644 context->SegDs = seg;
645 context->Eip += prefixlen + len + 1;
648 context->SegFs = seg;
649 context->Eip += prefixlen + len + 1;
652 context->SegGs = seg;
653 context->Eip += prefixlen + len + 1;
660 break; /* Unable to emulate it */
662 case 0xc4: /* les addr,reg */
663 case 0xc5: /* lds addr,reg */
664 if (INSTR_EmulateLDS( context, instr, long_op,
665 long_addr, segprefix, &len ))
667 context->Eip += prefixlen + len;
670 break; /* Unable to emulate it */
672 case 0xcd: /* int <XX> */
675 ERR("int xx from 32-bit code is not supported.\n");
676 break; /* Unable to emulate it */
680 FARPROC16 addr = INT_GetPMHandler( instr[1] );
681 WORD *stack = get_stack( context );
684 FIXME("no handler for interrupt %02x, ignoring it\n", instr[1]);
685 context->Eip += prefixlen + 2;
688 /* Push the flags and return address on the stack */
689 *(--stack) = LOWORD(context->EFlags);
690 *(--stack) = context->SegCs;
691 *(--stack) = LOWORD(context->Eip) + prefixlen + 2;
692 add_stack(context, -3 * sizeof(WORD));
693 /* Jump to the interrupt handler */
694 context->SegCs = HIWORD(addr);
695 context->Eip = LOWORD(addr);
699 case 0xcf: /* iret */
702 DWORD *stack = get_stack( context );
703 context->Eip = *stack++;
704 context->SegCs = *stack++;
705 context->EFlags = *stack;
706 add_stack(context, 3*sizeof(DWORD)); /* Pop the return address and flags */
710 WORD *stack = get_stack( context );
711 context->Eip = *stack++;
712 context->SegCs = *stack++;
713 SET_LOWORD(context->EFlags,*stack);
714 add_stack(context, 3*sizeof(WORD)); /* Pop the return address and flags */
718 case 0xe4: /* inb al,XX */
719 SET_LOBYTE(context->Eax,INSTR_inport( instr[1], 1, context ));
720 context->Eip += prefixlen + 2;
723 case 0xe5: /* in (e)ax,XX */
725 context->Eax = INSTR_inport( instr[1], 4, context );
727 SET_LOWORD(context->Eax, INSTR_inport( instr[1], 2, context ));
728 context->Eip += prefixlen + 2;
731 case 0xe6: /* outb XX,al */
732 INSTR_outport( instr[1], 1, LOBYTE(context->Eax), context );
733 context->Eip += prefixlen + 2;
736 case 0xe7: /* out XX,(e)ax */
738 INSTR_outport( instr[1], 4, context->Eax, context );
740 INSTR_outport( instr[1], 2, LOWORD(context->Eax), context );
741 context->Eip += prefixlen + 2;
744 case 0xec: /* inb al,dx */
745 SET_LOBYTE(context->Eax, INSTR_inport( LOWORD(context->Edx), 1, context ) );
746 context->Eip += prefixlen + 1;
749 case 0xed: /* in (e)ax,dx */
751 context->Eax = INSTR_inport( LOWORD(context->Edx), 4, context );
753 SET_LOWORD(context->Eax, INSTR_inport( LOWORD(context->Edx), 2, context ));
754 context->Eip += prefixlen + 1;
757 case 0xee: /* outb dx,al */
758 INSTR_outport( LOWORD(context->Edx), 1, LOBYTE(context->Eax), context );
759 context->Eip += prefixlen + 1;
762 case 0xef: /* out dx,(e)ax */
764 INSTR_outport( LOWORD(context->Edx), 4, context->Eax, context );
766 INSTR_outport( LOWORD(context->Edx), 2, LOWORD(context->Eax), context );
767 context->Eip += prefixlen + 1;
770 case 0xfa: /* cli, ignored */
771 context->Eip += prefixlen + 1;
774 case 0xfb: /* sti, ignored */
775 context->Eip += prefixlen + 1;
780 /* Check for Win16 __GP handler */
781 gpHandler = HasGPHandler16( MAKESEGPTR( context->SegCs, context->Eip ) );
784 WORD *stack = get_stack( context );
785 *--stack = context->SegCs;
786 *--stack = context->Eip;
787 add_stack(context, -2*sizeof(WORD));
789 context->SegCs = SELECTOROF( gpHandler );
790 context->Eip = OFFSETOF( gpHandler );
793 return FALSE; /* Unable to emulate it */
796 #endif /* __i386__ */