projects / reactos.git / blob
? search:
summary | shortlog | log | commit | commitdiff | tree
history | raw | HEAD
[FAST486]
[reactos.git] / lib / fast486 / fast486.c
1 /*
2 * Fast486 386/486 CPU Emulation Library
3 * fast486.c
4 *
5 * Copyright (C) 2013 Aleksandar Andrejevic <theflash AT sdf DOT lonestar DOT org>
6 *
7 * This program is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU General Public License
9 * as published by the Free Software Foundation; either version 2
10 * of the License, or (at your option) any later version.
11 *
12 * This program is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 * GNU General Public License for more details.
16 *
17 * You should have received a copy of the GNU General Public License
18 * along with this program; if not, write to the Free Software
19 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
20 */
21
22 /* INCLUDES *******************************************************************/
23
24 #include <windef.h>
25
26 // #define NDEBUG
27 #include <debug.h>
28
29 #include <fast486.h>
30 #include "common.h"
31 #include "opcodes.h"
32
33 /* DEFINES ********************************************************************/
34
35 typedef enum
36 {
37 FAST486_STEP_INTO,
38 FAST486_STEP_OVER,
39 FAST486_STEP_OUT,
40 FAST486_CONTINUE
41 } FAST486_EXEC_CMD;
42
43 /* PRIVATE FUNCTIONS **********************************************************/
44
45 static
46 inline
47 VOID
48 NTAPI
49 Fast486ExecutionControl(PFAST486_STATE State, INT Command)
50 {
51 UCHAR Opcode;
52 INT ProcedureCallCount = 0;
53
54 /* Main execution loop */
55 do
56 {
57 /* Check if this is a new instruction */
58 if (State->PrefixFlags == 0) State->SavedInstPtr = State->InstPtr;
59
60 /* Perform an instruction fetch */
61 if (!Fast486FetchByte(State, &Opcode))
62 {
63 /* Exception occurred */
64 State->PrefixFlags = 0;
65 continue;
66 }
67
68 // TODO: Check for CALL/RET to update ProcedureCallCount.
69
70 if (Fast486OpcodeHandlers[Opcode] != NULL)
71 {
72 /* Call the opcode handler */
73 Fast486OpcodeHandlers[Opcode](State, Opcode);
74 }
75 else
76 {
77 /* This is not a valid opcode */
78 Fast486Exception(State, FAST486_EXCEPTION_UD);
79 }
80
81 if (Fast486OpcodeHandlers[Opcode] == Fast486OpcodePrefix)
82 {
83 /* This is a prefix, go to the next instruction immediately */
84 continue;
85 }
86
87 /*
88 * Check if there is an interrupt to execute, or a hardware interrupt signal
89 * while interrupts are enabled.
90 */
91 if (State->IntStatus == FAST486_INT_EXECUTE)
92 {
93 FAST486_IDT_ENTRY IdtEntry;
94
95 /* Get the interrupt vector */
96 if (Fast486GetIntVector(State, State->PendingIntNum, &IdtEntry))
97 {
98 /* Perform the interrupt */
99 Fast486InterruptInternal(State,
100 IdtEntry.Selector,
101 MAKELONG(IdtEntry.Offset, IdtEntry.OffsetHigh),
102 IdtEntry.Type);
103 }
104
105 /* Clear the interrupt status */
106 State->IntStatus = FAST486_INT_NONE;
107 }
108 else if (State->Flags.If
109 && (State->IntAckCallback != NULL)
110 && (State->IntStatus == FAST486_INT_SIGNAL))
111 {
112 /* Acknowledge the interrupt to get the number */
113 State->PendingIntNum = State->IntAckCallback(State);
114
115 /* Set the interrupt status to execute on the next instruction */
116 State->IntStatus = FAST486_INT_EXECUTE;
117 }
118
119 /* A non-prefix opcode has been executed, reset the prefix flags */
120 State->PrefixFlags = 0;
121 }
122 while ((Command == FAST486_CONTINUE)
123 || (Command == FAST486_STEP_OVER && ProcedureCallCount > 0)
124 || (Command == FAST486_STEP_OUT && ProcedureCallCount >= 0)
125 || (Fast486OpcodeHandlers[Opcode] == Fast486OpcodePrefix));
126 }
127
128 /* DEFAULT CALLBACKS **********************************************************/
129
130 static VOID
131 NTAPI
132 Fast486MemReadCallback(PFAST486_STATE State, ULONG Address, PVOID Buffer, ULONG Size)
133 {
134 UNREFERENCED_PARAMETER(State);
135
136 RtlMoveMemory(Buffer, (PVOID)Address, Size);
137 }
138
139 static VOID
140 NTAPI
141 Fast486MemWriteCallback(PFAST486_STATE State, ULONG Address, PVOID Buffer, ULONG Size)
142 {
143 UNREFERENCED_PARAMETER(State);
144
145 RtlMoveMemory((PVOID)Address, Buffer, Size);
146 }
147
148 static VOID
149 NTAPI
150 Fast486IoReadCallback(PFAST486_STATE State, ULONG Port, PVOID Buffer, ULONG DataCount, UCHAR DataSize)
151 {
152 UNREFERENCED_PARAMETER(State);
153 UNREFERENCED_PARAMETER(Port);
154 UNREFERENCED_PARAMETER(Buffer);
155 UNREFERENCED_PARAMETER(DataCount);
156 UNREFERENCED_PARAMETER(DataSize);
157 }
158
159 static VOID
160 NTAPI
161 Fast486IoWriteCallback(PFAST486_STATE State, ULONG Port, PVOID Buffer, ULONG DataCount, UCHAR DataSize)
162 {
163 UNREFERENCED_PARAMETER(State);
164 UNREFERENCED_PARAMETER(Port);
165 UNREFERENCED_PARAMETER(Buffer);
166 UNREFERENCED_PARAMETER(DataCount);
167 UNREFERENCED_PARAMETER(DataSize);
168 }
169
170 static VOID
171 NTAPI
172 Fast486IdleCallback(PFAST486_STATE State)
173 {
174 UNREFERENCED_PARAMETER(State);
175 }
176
177 static VOID
178 NTAPI
179 Fast486BopCallback(PFAST486_STATE State, UCHAR BopCode)
180 {
181 UNREFERENCED_PARAMETER(State);
182 UNREFERENCED_PARAMETER(BopCode);
183 }
184
185 static UCHAR
186 NTAPI
187 Fast486IntAckCallback(PFAST486_STATE State)
188 {
189 UNREFERENCED_PARAMETER(State);
190
191 /* Return something... */
192 return 0;
193 }
194
195 /* PUBLIC FUNCTIONS ***********************************************************/
196
197 VOID
198 NTAPI
199 Fast486Initialize(PFAST486_STATE State,
200 FAST486_MEM_READ_PROC MemReadCallback,
201 FAST486_MEM_WRITE_PROC MemWriteCallback,
202 FAST486_IO_READ_PROC IoReadCallback,
203 FAST486_IO_WRITE_PROC IoWriteCallback,
204 FAST486_IDLE_PROC IdleCallback,
205 FAST486_BOP_PROC BopCallback,
206 FAST486_INT_ACK_PROC IntAckCallback,
207 PULONG Tlb)
208 {
209 /* Set the callbacks (or use default ones if some are NULL) */
210 State->MemReadCallback = (MemReadCallback ? MemReadCallback : Fast486MemReadCallback );
211 State->MemWriteCallback = (MemWriteCallback ? MemWriteCallback : Fast486MemWriteCallback);
212 State->IoReadCallback = (IoReadCallback ? IoReadCallback : Fast486IoReadCallback );
213 State->IoWriteCallback = (IoWriteCallback ? IoWriteCallback : Fast486IoWriteCallback );
214 State->IdleCallback = (IdleCallback ? IdleCallback : Fast486IdleCallback );
215 State->BopCallback = (BopCallback ? BopCallback : Fast486BopCallback );
216 State->IntAckCallback = (IntAckCallback ? IntAckCallback : Fast486IntAckCallback );
217
218 /* Set the TLB (if given) */
219 State->Tlb = Tlb;
220
221 /* Reset the CPU */
222 Fast486Reset(State);
223 }
224
225 VOID
226 NTAPI
227 Fast486Reset(PFAST486_STATE State)
228 {
229 FAST486_SEG_REGS i;
230
231 FAST486_MEM_READ_PROC MemReadCallback = State->MemReadCallback;
232 FAST486_MEM_WRITE_PROC MemWriteCallback = State->MemWriteCallback;
233 FAST486_IO_READ_PROC IoReadCallback = State->IoReadCallback;
234 FAST486_IO_WRITE_PROC IoWriteCallback = State->IoWriteCallback;
235 FAST486_IDLE_PROC IdleCallback = State->IdleCallback;
236 FAST486_BOP_PROC BopCallback = State->BopCallback;
237 FAST486_INT_ACK_PROC IntAckCallback = State->IntAckCallback;
238 PULONG Tlb = State->Tlb;
239
240 /* Clear the entire structure */
241 RtlZeroMemory(State, sizeof(*State));
242
243 /* Initialize the registers */
244 State->Flags.AlwaysSet = 1;
245 State->InstPtr.LowWord = 0xFFF0;
246
247 /* Set the CPL to 0 */
248 State->Cpl = 0;
249
250 /* Initialize segments */
251 for (i = 0; i < FAST486_NUM_SEG_REGS; i++)
252 {
253 State->SegmentRegs[i].Selector = 0;
254 State->SegmentRegs[i].Base = 0;
255 State->SegmentRegs[i].Limit = 0xFFFF;
256 State->SegmentRegs[i].Present = TRUE;
257 State->SegmentRegs[i].ReadWrite = TRUE;
258 State->SegmentRegs[i].Executable = FALSE;
259 State->SegmentRegs[i].DirConf = FALSE;
260 State->SegmentRegs[i].SystemType = 1; // Segment descriptor
261 State->SegmentRegs[i].Dpl = 0;
262 State->SegmentRegs[i].Size = FALSE; // 16-bit
263 }
264
265 /* Initialize the code segment */
266 State->SegmentRegs[FAST486_REG_CS].Executable = TRUE;
267 State->SegmentRegs[FAST486_REG_CS].Selector = 0xF000;
268 State->SegmentRegs[FAST486_REG_CS].Base = 0xFFFF0000;
269
270 /* Initialize the IDT */
271 State->Idtr.Size = 0x3FF;
272 State->Idtr.Address = 0;
273
274 #ifndef FAST486_NO_FPU
275 /* Initialize CR0 */
276 State->ControlRegisters[FAST486_REG_CR0] |= FAST486_CR0_ET;
277 #endif
278
279 /* Restore the callbacks and TLB */
280 State->MemReadCallback = MemReadCallback;
281 State->MemWriteCallback = MemWriteCallback;
282 State->IoReadCallback = IoReadCallback;
283 State->IoWriteCallback = IoWriteCallback;
284 State->IdleCallback = IdleCallback;
285 State->BopCallback = BopCallback;
286 State->IntAckCallback = IntAckCallback;
287 State->Tlb = Tlb;
288 }
289
290 VOID
291 NTAPI
292 Fast486DumpState(PFAST486_STATE State)
293 {
294 DPRINT1("\nCPU currently executing in %s mode at %04X:%08X\n",
295 (State->ControlRegisters[0] & FAST486_CR0_PE) ? "protected" : "real",
296 State->SegmentRegs[FAST486_REG_CS].Selector,
297 State->InstPtr.Long);
298 DPRINT1("\nGeneral purpose registers:\n"
299 "EAX = %08X\tECX = %08X\tEDX = %08X\tEBX = %08X\n"
300 "ESP = %08X\tEBP = %08X\tESI = %08X\tEDI = %08X\n",
301 State->GeneralRegs[FAST486_REG_EAX].Long,
302 State->GeneralRegs[FAST486_REG_ECX].Long,
303 State->GeneralRegs[FAST486_REG_EDX].Long,
304 State->GeneralRegs[FAST486_REG_EBX].Long,
305 State->GeneralRegs[FAST486_REG_ESP].Long,
306 State->GeneralRegs[FAST486_REG_EBP].Long,
307 State->GeneralRegs[FAST486_REG_ESI].Long,
308 State->GeneralRegs[FAST486_REG_EDI].Long);
309 DPRINT1("\nSegment registers:\n"
310 "ES = %04X (Base: %08X, Limit: %08X, Dpl: %u)\n"
311 "CS = %04X (Base: %08X, Limit: %08X, Dpl: %u)\n"
312 "SS = %04X (Base: %08X, Limit: %08X, Dpl: %u)\n"
313 "DS = %04X (Base: %08X, Limit: %08X, Dpl: %u)\n"
314 "FS = %04X (Base: %08X, Limit: %08X, Dpl: %u)\n"
315 "GS = %04X (Base: %08X, Limit: %08X, Dpl: %u)\n",
316 State->SegmentRegs[FAST486_REG_ES].Selector,
317 State->SegmentRegs[FAST486_REG_ES].Base,
318 State->SegmentRegs[FAST486_REG_ES].Limit,
319 State->SegmentRegs[FAST486_REG_ES].Dpl,
320 State->SegmentRegs[FAST486_REG_CS].Selector,
321 State->SegmentRegs[FAST486_REG_CS].Base,
322 State->SegmentRegs[FAST486_REG_CS].Limit,
323 State->SegmentRegs[FAST486_REG_CS].Dpl,
324 State->SegmentRegs[FAST486_REG_SS].Selector,
325 State->SegmentRegs[FAST486_REG_SS].Base,
326 State->SegmentRegs[FAST486_REG_SS].Limit,
327 State->SegmentRegs[FAST486_REG_SS].Dpl,
328 State->SegmentRegs[FAST486_REG_DS].Selector,
329 State->SegmentRegs[FAST486_REG_DS].Base,
330 State->SegmentRegs[FAST486_REG_DS].Limit,
331 State->SegmentRegs[FAST486_REG_DS].Dpl,
332 State->SegmentRegs[FAST486_REG_FS].Selector,
333 State->SegmentRegs[FAST486_REG_FS].Base,
334 State->SegmentRegs[FAST486_REG_FS].Limit,
335 State->SegmentRegs[FAST486_REG_FS].Dpl,
336 State->SegmentRegs[FAST486_REG_GS].Selector,
337 State->SegmentRegs[FAST486_REG_GS].Base,
338 State->SegmentRegs[FAST486_REG_GS].Limit,
339 State->SegmentRegs[FAST486_REG_GS].Dpl);
340 DPRINT1("\nFlags: %08X (%s %s %s %s %s %s %s %s %s %s %s %s) Iopl: %u\n",
341 State->Flags.Long,
342 State->Flags.Cf ? "CF" : "cf",
343 State->Flags.Pf ? "PF" : "pf",
344 State->Flags.Af ? "AF" : "af",
345 State->Flags.Zf ? "ZF" : "zf",
346 State->Flags.Sf ? "SF" : "sf",
347 State->Flags.Tf ? "TF" : "tf",
348 State->Flags.If ? "IF" : "if",
349 State->Flags.Df ? "DF" : "df",
350 State->Flags.Of ? "OF" : "of",
351 State->Flags.Nt ? "NT" : "nt",
352 State->Flags.Rf ? "RF" : "rf",
353 State->Flags.Vm ? "VM" : "vm",
354 State->Flags.Iopl);
355 DPRINT1("\nControl Registers:\n"
356 "CR0 = %08X\tCR2 = %08X\tCR3 = %08X\n",
357 State->ControlRegisters[FAST486_REG_CR0],
358 State->ControlRegisters[FAST486_REG_CR2],
359 State->ControlRegisters[FAST486_REG_CR3]);
360 DPRINT1("\nDebug Registers:\n"
361 "DR0 = %08X\tDR1 = %08X\tDR2 = %08X\n"
362 "DR3 = %08X\tDR4 = %08X\tDR5 = %08X\n",
363 State->DebugRegisters[FAST486_REG_DR0],
364 State->DebugRegisters[FAST486_REG_DR1],
365 State->DebugRegisters[FAST486_REG_DR2],
366 State->DebugRegisters[FAST486_REG_DR3],
367 State->DebugRegisters[FAST486_REG_DR4],
368 State->DebugRegisters[FAST486_REG_DR5]);
369 }
370
371 VOID
372 NTAPI
373 Fast486Continue(PFAST486_STATE State)
374 {
375 /* Call the internal function */
376 Fast486ExecutionControl(State, FAST486_CONTINUE);
377 }
378
379 VOID
380 NTAPI
381 Fast486StepInto(PFAST486_STATE State)
382 {
383 /* Call the internal function */
384 Fast486ExecutionControl(State, FAST486_STEP_INTO);
385 }
386
387 VOID
388 NTAPI
389 Fast486StepOver(PFAST486_STATE State)
390 {
391 /* Call the internal function */
392 Fast486ExecutionControl(State, FAST486_STEP_OVER);
393 }
394
395 VOID
396 NTAPI
397 Fast486StepOut(PFAST486_STATE State)
398 {
399 /* Call the internal function */
400 Fast486ExecutionControl(State, FAST486_STEP_OUT);
401 }
402
403 VOID
404 NTAPI
405 Fast486Interrupt(PFAST486_STATE State, UCHAR Number)
406 {
407 /* Set the interrupt status and the number */
408 State->IntStatus = FAST486_INT_EXECUTE;
409 State->PendingIntNum = Number;
410 }
411
412 VOID
413 NTAPI
414 Fast486InterruptSignal(PFAST486_STATE State)
415 {
416 /* Set the interrupt status */
417 State->IntStatus = FAST486_INT_SIGNAL;
418 }
419
420 VOID
421 NTAPI
422 Fast486ExecuteAt(PFAST486_STATE State, USHORT Segment, ULONG Offset)
423 {
424 /* Load the new CS */
425 if (!Fast486LoadSegment(State, FAST486_REG_CS, Segment))
426 {
427 /* An exception occurred, let the handler execute instead */
428 return;
429 }
430
431 /* Set the new IP */
432 State->InstPtr.Long = Offset;
433 }
434
435 VOID
436 NTAPI
437 Fast486SetStack(PFAST486_STATE State, USHORT Segment, ULONG Offset)
438 {
439 /* Load the new SS */
440 if (!Fast486LoadSegment(State, FAST486_REG_SS, Segment))
441 {
442 /* An exception occurred, let the handler execute instead */
443 return;
444 }
445
446 /* Set the new SP */
447 State->GeneralRegs[FAST486_REG_ESP].Long = Offset;
448 }
449
450 VOID
451 NTAPI
452 Fast486SetSegment(PFAST486_STATE State,
453 FAST486_SEG_REGS Segment,
454 USHORT Selector)
455 {
456 /* Call the internal function */
457 Fast486LoadSegment(State, Segment, Selector);
458 }
459
460 /* EOF */
A free Windows-compatible Operating System