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ece92f85 JJ |
1 | /**************************************************************************** |
2 | * | |
9c7e4b06 | 3 | * Realmode X86 Emulator Library |
ece92f85 | 4 | * |
9c7e4b06 WD |
5 | * Copyright (C) 1991-2004 SciTech Software, Inc. |
6 | * Copyright (C) David Mosberger-Tang | |
7 | * Copyright (C) 1999 Egbert Eich | |
ece92f85 JJ |
8 | * |
9 | * ======================================================================== | |
10 | * | |
11 | * Permission to use, copy, modify, distribute, and sell this software and | |
12 | * its documentation for any purpose is hereby granted without fee, | |
13 | * provided that the above copyright notice appear in all copies and that | |
14 | * both that copyright notice and this permission notice appear in | |
15 | * supporting documentation, and that the name of the authors not be used | |
16 | * in advertising or publicity pertaining to distribution of the software | |
9c7e4b06 | 17 | * without specific, written prior permission. The authors makes no |
ece92f85 JJ |
18 | * representations about the suitability of this software for any purpose. |
19 | * It is provided "as is" without express or implied warranty. | |
20 | * | |
21 | * THE AUTHORS DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE, | |
22 | * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO | |
23 | * EVENT SHALL THE AUTHORS BE LIABLE FOR ANY SPECIAL, INDIRECT OR | |
24 | * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF | |
25 | * USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR | |
26 | * OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR | |
27 | * PERFORMANCE OF THIS SOFTWARE. | |
28 | * | |
29 | * ======================================================================== | |
30 | * | |
9c7e4b06 WD |
31 | * Language: ANSI C |
32 | * Environment: Any | |
33 | * Developer: Kendall Bennett | |
ece92f85 | 34 | * |
9c7e4b06 WD |
35 | * Description: This file includes subroutines which are related to |
36 | * instruction decoding and accessess of immediate data via IP. etc. | |
ece92f85 JJ |
37 | * |
38 | ****************************************************************************/ | |
d678a59d | 39 | #include <common.h> |
1e94b46f | 40 | #include <linux/printk.h> |
5b4de930 MS |
41 | #include "x86emu/x86emui.h" |
42 | ||
ece92f85 JJ |
43 | /*----------------------------- Implementation ----------------------------*/ |
44 | ||
45 | /**************************************************************************** | |
46 | REMARKS: | |
47 | Handles any pending asychronous interrupts. | |
48 | ****************************************************************************/ | |
49 | static void x86emu_intr_handle(void) | |
50 | { | |
9c7e4b06 | 51 | u8 intno; |
ece92f85 JJ |
52 | |
53 | if (M.x86.intr & INTR_SYNCH) { | |
9c7e4b06 WD |
54 | intno = M.x86.intno; |
55 | if (_X86EMU_intrTab[intno]) { | |
56 | (*_X86EMU_intrTab[intno])(intno); | |
57 | } else { | |
58 | push_word((u16)M.x86.R_FLG); | |
59 | CLEAR_FLAG(F_IF); | |
60 | CLEAR_FLAG(F_TF); | |
61 | push_word(M.x86.R_CS); | |
62 | M.x86.R_CS = mem_access_word(intno * 4 + 2); | |
63 | push_word(M.x86.R_IP); | |
64 | M.x86.R_IP = mem_access_word(intno * 4); | |
65 | M.x86.intr = 0; | |
66 | } | |
ece92f85 JJ |
67 | } |
68 | } | |
69 | ||
70 | /**************************************************************************** | |
71 | PARAMETERS: | |
72 | intrnum - Interrupt number to raise | |
73 | ||
74 | REMARKS: | |
75 | Raise the specified interrupt to be handled before the execution of the | |
76 | next instruction. | |
77 | ****************************************************************************/ | |
78 | void x86emu_intr_raise( | |
79 | u8 intrnum) | |
80 | { | |
81 | M.x86.intno = intrnum; | |
82 | M.x86.intr |= INTR_SYNCH; | |
83 | } | |
84 | ||
85 | /**************************************************************************** | |
86 | REMARKS: | |
87 | Main execution loop for the emulator. We return from here when the system | |
88 | halts, which is normally caused by a stack fault when we return from the | |
89 | original real mode call. | |
90 | ****************************************************************************/ | |
91 | void X86EMU_exec(void) | |
92 | { | |
93 | u8 op1; | |
94 | ||
95 | M.x86.intr = 0; | |
96 | DB(x86emu_end_instr();) | |
97 | ||
98 | for (;;) { | |
9c7e4b06 WD |
99 | DB( if (CHECK_IP_FETCH()) |
100 | x86emu_check_ip_access();) | |
101 | /* If debugging, save the IP and CS values. */ | |
102 | SAVE_IP_CS(M.x86.R_CS, M.x86.R_IP); | |
103 | INC_DECODED_INST_LEN(1); | |
104 | if (M.x86.intr) { | |
105 | if (M.x86.intr & INTR_HALTED) { | |
106 | DB( if (M.x86.R_SP != 0) { | |
107 | printk("halted\n"); | |
108 | X86EMU_trace_regs(); | |
109 | } | |
110 | else { | |
111 | if (M.x86.debug) | |
112 | printk("Service completed successfully\n"); | |
113 | }) | |
114 | return; | |
115 | } | |
116 | if (((M.x86.intr & INTR_SYNCH) && (M.x86.intno == 0 || M.x86.intno == 2)) || | |
117 | !ACCESS_FLAG(F_IF)) { | |
118 | x86emu_intr_handle(); | |
119 | } | |
120 | } | |
121 | op1 = (*sys_rdb)(((u32)M.x86.R_CS << 4) + (M.x86.R_IP++)); | |
122 | (*x86emu_optab[op1])(op1); | |
123 | if (M.x86.debug & DEBUG_EXIT) { | |
124 | M.x86.debug &= ~DEBUG_EXIT; | |
125 | return; | |
126 | } | |
ece92f85 JJ |
127 | } |
128 | } | |
129 | ||
130 | /**************************************************************************** | |
131 | REMARKS: | |
132 | Halts the system by setting the halted system flag. | |
133 | ****************************************************************************/ | |
134 | void X86EMU_halt_sys(void) | |
135 | { | |
136 | M.x86.intr |= INTR_HALTED; | |
137 | } | |
138 | ||
139 | /**************************************************************************** | |
140 | PARAMETERS: | |
9c7e4b06 WD |
141 | mod - Mod value from decoded byte |
142 | regh - Reg h value from decoded byte | |
143 | regl - Reg l value from decoded byte | |
ece92f85 JJ |
144 | |
145 | REMARKS: | |
146 | Raise the specified interrupt to be handled before the execution of the | |
147 | next instruction. | |
148 | ||
149 | NOTE: Do not inline this function, as (*sys_rdb) is already inline! | |
150 | ****************************************************************************/ | |
151 | void fetch_decode_modrm( | |
152 | int *mod, | |
153 | int *regh, | |
154 | int *regl) | |
155 | { | |
156 | int fetched; | |
157 | ||
158 | DB( if (CHECK_IP_FETCH()) | |
9c7e4b06 | 159 | x86emu_check_ip_access();) |
ece92f85 JJ |
160 | fetched = (*sys_rdb)(((u32)M.x86.R_CS << 4) + (M.x86.R_IP++)); |
161 | INC_DECODED_INST_LEN(1); | |
162 | *mod = (fetched >> 6) & 0x03; | |
163 | *regh = (fetched >> 3) & 0x07; | |
164 | *regl = (fetched >> 0) & 0x07; | |
165 | } | |
166 | ||
167 | /**************************************************************************** | |
168 | RETURNS: | |
169 | Immediate byte value read from instruction queue | |
170 | ||
171 | REMARKS: | |
172 | This function returns the immediate byte from the instruction queue, and | |
173 | moves the instruction pointer to the next value. | |
174 | ||
175 | NOTE: Do not inline this function, as (*sys_rdb) is already inline! | |
176 | ****************************************************************************/ | |
177 | u8 fetch_byte_imm(void) | |
178 | { | |
179 | u8 fetched; | |
180 | ||
181 | DB( if (CHECK_IP_FETCH()) | |
9c7e4b06 | 182 | x86emu_check_ip_access();) |
ece92f85 JJ |
183 | fetched = (*sys_rdb)(((u32)M.x86.R_CS << 4) + (M.x86.R_IP++)); |
184 | INC_DECODED_INST_LEN(1); | |
185 | return fetched; | |
186 | } | |
187 | ||
188 | /**************************************************************************** | |
189 | RETURNS: | |
190 | Immediate word value read from instruction queue | |
191 | ||
192 | REMARKS: | |
193 | This function returns the immediate byte from the instruction queue, and | |
194 | moves the instruction pointer to the next value. | |
195 | ||
196 | NOTE: Do not inline this function, as (*sys_rdw) is already inline! | |
197 | ****************************************************************************/ | |
198 | u16 fetch_word_imm(void) | |
199 | { | |
200 | u16 fetched; | |
201 | ||
202 | DB( if (CHECK_IP_FETCH()) | |
9c7e4b06 | 203 | x86emu_check_ip_access();) |
ece92f85 JJ |
204 | fetched = (*sys_rdw)(((u32)M.x86.R_CS << 4) + (M.x86.R_IP)); |
205 | M.x86.R_IP += 2; | |
206 | INC_DECODED_INST_LEN(2); | |
207 | return fetched; | |
208 | } | |
209 | ||
210 | /**************************************************************************** | |
211 | RETURNS: | |
212 | Immediate lone value read from instruction queue | |
213 | ||
214 | REMARKS: | |
215 | This function returns the immediate byte from the instruction queue, and | |
216 | moves the instruction pointer to the next value. | |
217 | ||
218 | NOTE: Do not inline this function, as (*sys_rdw) is already inline! | |
219 | ****************************************************************************/ | |
220 | u32 fetch_long_imm(void) | |
221 | { | |
222 | u32 fetched; | |
223 | ||
224 | DB( if (CHECK_IP_FETCH()) | |
9c7e4b06 | 225 | x86emu_check_ip_access();) |
ece92f85 JJ |
226 | fetched = (*sys_rdl)(((u32)M.x86.R_CS << 4) + (M.x86.R_IP)); |
227 | M.x86.R_IP += 4; | |
228 | INC_DECODED_INST_LEN(4); | |
229 | return fetched; | |
230 | } | |
231 | ||
232 | /**************************************************************************** | |
233 | RETURNS: | |
234 | Value of the default data segment | |
235 | ||
236 | REMARKS: | |
237 | Inline function that returns the default data segment for the current | |
238 | instruction. | |
239 | ||
240 | On the x86 processor, the default segment is not always DS if there is | |
241 | no segment override. Address modes such as -3[BP] or 10[BP+SI] all refer to | |
242 | addresses relative to SS (ie: on the stack). So, at the minimum, all | |
243 | decodings of addressing modes would have to set/clear a bit describing | |
244 | whether the access is relative to DS or SS. That is the function of the | |
1cc0a9f4 | 245 | cpu-state-variable M.x86.mode. There are several potential states: |
ece92f85 JJ |
246 | |
247 | repe prefix seen (handled elsewhere) | |
248 | repne prefix seen (ditto) | |
249 | ||
250 | cs segment override | |
251 | ds segment override | |
252 | es segment override | |
253 | fs segment override | |
254 | gs segment override | |
255 | ss segment override | |
256 | ||
257 | ds/ss select (in absense of override) | |
258 | ||
259 | Each of the above 7 items are handled with a bit in the mode field. | |
260 | ****************************************************************************/ | |
261 | _INLINE u32 get_data_segment(void) | |
262 | { | |
263 | #define GET_SEGMENT(segment) | |
264 | switch (M.x86.mode & SYSMODE_SEGMASK) { | |
9c7e4b06 | 265 | case 0: /* default case: use ds register */ |
ece92f85 JJ |
266 | case SYSMODE_SEGOVR_DS: |
267 | case SYSMODE_SEGOVR_DS | SYSMODE_SEG_DS_SS: | |
9c7e4b06 WD |
268 | return M.x86.R_DS; |
269 | case SYSMODE_SEG_DS_SS: /* non-overridden, use ss register */ | |
270 | return M.x86.R_SS; | |
ece92f85 JJ |
271 | case SYSMODE_SEGOVR_CS: |
272 | case SYSMODE_SEGOVR_CS | SYSMODE_SEG_DS_SS: | |
9c7e4b06 | 273 | return M.x86.R_CS; |
ece92f85 JJ |
274 | case SYSMODE_SEGOVR_ES: |
275 | case SYSMODE_SEGOVR_ES | SYSMODE_SEG_DS_SS: | |
9c7e4b06 | 276 | return M.x86.R_ES; |
ece92f85 JJ |
277 | case SYSMODE_SEGOVR_FS: |
278 | case SYSMODE_SEGOVR_FS | SYSMODE_SEG_DS_SS: | |
9c7e4b06 | 279 | return M.x86.R_FS; |
ece92f85 JJ |
280 | case SYSMODE_SEGOVR_GS: |
281 | case SYSMODE_SEGOVR_GS | SYSMODE_SEG_DS_SS: | |
9c7e4b06 | 282 | return M.x86.R_GS; |
ece92f85 JJ |
283 | case SYSMODE_SEGOVR_SS: |
284 | case SYSMODE_SEGOVR_SS | SYSMODE_SEG_DS_SS: | |
9c7e4b06 | 285 | return M.x86.R_SS; |
ece92f85 | 286 | default: |
9c7e4b06 WD |
287 | #ifdef DEBUG |
288 | printk("error: should not happen: multiple overrides.\n"); | |
ece92f85 | 289 | #endif |
9c7e4b06 WD |
290 | HALT_SYS(); |
291 | return 0; | |
ece92f85 JJ |
292 | } |
293 | } | |
294 | ||
295 | /**************************************************************************** | |
296 | PARAMETERS: | |
9c7e4b06 | 297 | offset - Offset to load data from |
ece92f85 JJ |
298 | |
299 | RETURNS: | |
300 | Byte value read from the absolute memory location. | |
301 | ||
302 | NOTE: Do not inline this function as (*sys_rdX) is already inline! | |
303 | ****************************************************************************/ | |
304 | u8 fetch_data_byte( | |
305 | uint offset) | |
306 | { | |
b3521f2e | 307 | #ifdef CONFIG_X86EMU_DEBUG |
ece92f85 | 308 | if (CHECK_DATA_ACCESS()) |
9c7e4b06 | 309 | x86emu_check_data_access((u16)get_data_segment(), offset); |
ece92f85 JJ |
310 | #endif |
311 | return (*sys_rdb)((get_data_segment() << 4) + offset); | |
312 | } | |
313 | ||
314 | /**************************************************************************** | |
315 | PARAMETERS: | |
9c7e4b06 | 316 | offset - Offset to load data from |
ece92f85 JJ |
317 | |
318 | RETURNS: | |
319 | Word value read from the absolute memory location. | |
320 | ||
321 | NOTE: Do not inline this function as (*sys_rdX) is already inline! | |
322 | ****************************************************************************/ | |
323 | u16 fetch_data_word( | |
324 | uint offset) | |
325 | { | |
b3521f2e | 326 | #ifdef CONFIG_X86EMU_DEBUG |
ece92f85 | 327 | if (CHECK_DATA_ACCESS()) |
9c7e4b06 | 328 | x86emu_check_data_access((u16)get_data_segment(), offset); |
ece92f85 JJ |
329 | #endif |
330 | return (*sys_rdw)((get_data_segment() << 4) + offset); | |
331 | } | |
332 | ||
333 | /**************************************************************************** | |
334 | PARAMETERS: | |
9c7e4b06 | 335 | offset - Offset to load data from |
ece92f85 JJ |
336 | |
337 | RETURNS: | |
338 | Long value read from the absolute memory location. | |
339 | ||
340 | NOTE: Do not inline this function as (*sys_rdX) is already inline! | |
341 | ****************************************************************************/ | |
342 | u32 fetch_data_long( | |
343 | uint offset) | |
344 | { | |
b3521f2e | 345 | #ifdef CONFIG_X86EMU_DEBUG |
ece92f85 | 346 | if (CHECK_DATA_ACCESS()) |
9c7e4b06 | 347 | x86emu_check_data_access((u16)get_data_segment(), offset); |
ece92f85 JJ |
348 | #endif |
349 | return (*sys_rdl)((get_data_segment() << 4) + offset); | |
350 | } | |
351 | ||
352 | /**************************************************************************** | |
353 | PARAMETERS: | |
354 | segment - Segment to load data from | |
9c7e4b06 | 355 | offset - Offset to load data from |
ece92f85 JJ |
356 | |
357 | RETURNS: | |
358 | Byte value read from the absolute memory location. | |
359 | ||
360 | NOTE: Do not inline this function as (*sys_rdX) is already inline! | |
361 | ****************************************************************************/ | |
362 | u8 fetch_data_byte_abs( | |
363 | uint segment, | |
364 | uint offset) | |
365 | { | |
b3521f2e | 366 | #ifdef CONFIG_X86EMU_DEBUG |
ece92f85 | 367 | if (CHECK_DATA_ACCESS()) |
9c7e4b06 | 368 | x86emu_check_data_access(segment, offset); |
ece92f85 JJ |
369 | #endif |
370 | return (*sys_rdb)(((u32)segment << 4) + offset); | |
371 | } | |
372 | ||
373 | /**************************************************************************** | |
374 | PARAMETERS: | |
375 | segment - Segment to load data from | |
9c7e4b06 | 376 | offset - Offset to load data from |
ece92f85 JJ |
377 | |
378 | RETURNS: | |
379 | Word value read from the absolute memory location. | |
380 | ||
381 | NOTE: Do not inline this function as (*sys_rdX) is already inline! | |
382 | ****************************************************************************/ | |
383 | u16 fetch_data_word_abs( | |
384 | uint segment, | |
385 | uint offset) | |
386 | { | |
b3521f2e | 387 | #ifdef CONFIG_X86EMU_DEBUG |
ece92f85 | 388 | if (CHECK_DATA_ACCESS()) |
9c7e4b06 | 389 | x86emu_check_data_access(segment, offset); |
ece92f85 JJ |
390 | #endif |
391 | return (*sys_rdw)(((u32)segment << 4) + offset); | |
392 | } | |
393 | ||
394 | /**************************************************************************** | |
395 | PARAMETERS: | |
396 | segment - Segment to load data from | |
9c7e4b06 | 397 | offset - Offset to load data from |
ece92f85 JJ |
398 | |
399 | RETURNS: | |
400 | Long value read from the absolute memory location. | |
401 | ||
402 | NOTE: Do not inline this function as (*sys_rdX) is already inline! | |
403 | ****************************************************************************/ | |
404 | u32 fetch_data_long_abs( | |
405 | uint segment, | |
406 | uint offset) | |
407 | { | |
b3521f2e | 408 | #ifdef CONFIG_X86EMU_DEBUG |
ece92f85 | 409 | if (CHECK_DATA_ACCESS()) |
9c7e4b06 | 410 | x86emu_check_data_access(segment, offset); |
ece92f85 JJ |
411 | #endif |
412 | return (*sys_rdl)(((u32)segment << 4) + offset); | |
413 | } | |
414 | ||
415 | /**************************************************************************** | |
416 | PARAMETERS: | |
9c7e4b06 WD |
417 | offset - Offset to store data at |
418 | val - Value to store | |
ece92f85 JJ |
419 | |
420 | REMARKS: | |
421 | Writes a word value to an segmented memory location. The segment used is | |
422 | the current 'default' segment, which may have been overridden. | |
423 | ||
424 | NOTE: Do not inline this function as (*sys_wrX) is already inline! | |
425 | ****************************************************************************/ | |
426 | void store_data_byte( | |
427 | uint offset, | |
428 | u8 val) | |
429 | { | |
b3521f2e | 430 | #ifdef CONFIG_X86EMU_DEBUG |
ece92f85 | 431 | if (CHECK_DATA_ACCESS()) |
9c7e4b06 | 432 | x86emu_check_data_access((u16)get_data_segment(), offset); |
ece92f85 JJ |
433 | #endif |
434 | (*sys_wrb)((get_data_segment() << 4) + offset, val); | |
435 | } | |
436 | ||
437 | /**************************************************************************** | |
438 | PARAMETERS: | |
9c7e4b06 WD |
439 | offset - Offset to store data at |
440 | val - Value to store | |
ece92f85 JJ |
441 | |
442 | REMARKS: | |
443 | Writes a word value to an segmented memory location. The segment used is | |
444 | the current 'default' segment, which may have been overridden. | |
445 | ||
446 | NOTE: Do not inline this function as (*sys_wrX) is already inline! | |
447 | ****************************************************************************/ | |
448 | void store_data_word( | |
449 | uint offset, | |
450 | u16 val) | |
451 | { | |
b3521f2e | 452 | #ifdef CONFIG_X86EMU_DEBUG |
ece92f85 | 453 | if (CHECK_DATA_ACCESS()) |
9c7e4b06 | 454 | x86emu_check_data_access((u16)get_data_segment(), offset); |
ece92f85 JJ |
455 | #endif |
456 | (*sys_wrw)((get_data_segment() << 4) + offset, val); | |
457 | } | |
458 | ||
459 | /**************************************************************************** | |
460 | PARAMETERS: | |
9c7e4b06 WD |
461 | offset - Offset to store data at |
462 | val - Value to store | |
ece92f85 JJ |
463 | |
464 | REMARKS: | |
465 | Writes a long value to an segmented memory location. The segment used is | |
466 | the current 'default' segment, which may have been overridden. | |
467 | ||
468 | NOTE: Do not inline this function as (*sys_wrX) is already inline! | |
469 | ****************************************************************************/ | |
470 | void store_data_long( | |
471 | uint offset, | |
472 | u32 val) | |
473 | { | |
b3521f2e | 474 | #ifdef CONFIG_X86EMU_DEBUG |
ece92f85 | 475 | if (CHECK_DATA_ACCESS()) |
9c7e4b06 | 476 | x86emu_check_data_access((u16)get_data_segment(), offset); |
ece92f85 JJ |
477 | #endif |
478 | (*sys_wrl)((get_data_segment() << 4) + offset, val); | |
479 | } | |
480 | ||
481 | /**************************************************************************** | |
482 | PARAMETERS: | |
483 | segment - Segment to store data at | |
9c7e4b06 WD |
484 | offset - Offset to store data at |
485 | val - Value to store | |
ece92f85 JJ |
486 | |
487 | REMARKS: | |
488 | Writes a byte value to an absolute memory location. | |
489 | ||
490 | NOTE: Do not inline this function as (*sys_wrX) is already inline! | |
491 | ****************************************************************************/ | |
492 | void store_data_byte_abs( | |
493 | uint segment, | |
494 | uint offset, | |
495 | u8 val) | |
496 | { | |
b3521f2e | 497 | #ifdef CONFIG_X86EMU_DEBUG |
ece92f85 | 498 | if (CHECK_DATA_ACCESS()) |
9c7e4b06 | 499 | x86emu_check_data_access(segment, offset); |
ece92f85 JJ |
500 | #endif |
501 | (*sys_wrb)(((u32)segment << 4) + offset, val); | |
502 | } | |
503 | ||
504 | /**************************************************************************** | |
505 | PARAMETERS: | |
506 | segment - Segment to store data at | |
9c7e4b06 WD |
507 | offset - Offset to store data at |
508 | val - Value to store | |
ece92f85 JJ |
509 | |
510 | REMARKS: | |
511 | Writes a word value to an absolute memory location. | |
512 | ||
513 | NOTE: Do not inline this function as (*sys_wrX) is already inline! | |
514 | ****************************************************************************/ | |
515 | void store_data_word_abs( | |
516 | uint segment, | |
517 | uint offset, | |
518 | u16 val) | |
519 | { | |
b3521f2e | 520 | #ifdef CONFIG_X86EMU_DEBUG |
ece92f85 | 521 | if (CHECK_DATA_ACCESS()) |
9c7e4b06 | 522 | x86emu_check_data_access(segment, offset); |
ece92f85 JJ |
523 | #endif |
524 | (*sys_wrw)(((u32)segment << 4) + offset, val); | |
525 | } | |
526 | ||
527 | /**************************************************************************** | |
528 | PARAMETERS: | |
529 | segment - Segment to store data at | |
9c7e4b06 WD |
530 | offset - Offset to store data at |
531 | val - Value to store | |
ece92f85 JJ |
532 | |
533 | REMARKS: | |
534 | Writes a long value to an absolute memory location. | |
535 | ||
536 | NOTE: Do not inline this function as (*sys_wrX) is already inline! | |
537 | ****************************************************************************/ | |
538 | void store_data_long_abs( | |
539 | uint segment, | |
540 | uint offset, | |
541 | u32 val) | |
542 | { | |
b3521f2e | 543 | #ifdef CONFIG_X86EMU_DEBUG |
ece92f85 | 544 | if (CHECK_DATA_ACCESS()) |
9c7e4b06 | 545 | x86emu_check_data_access(segment, offset); |
ece92f85 JJ |
546 | #endif |
547 | (*sys_wrl)(((u32)segment << 4) + offset, val); | |
548 | } | |
549 | ||
550 | /**************************************************************************** | |
551 | PARAMETERS: | |
552 | reg - Register to decode | |
553 | ||
554 | RETURNS: | |
555 | Pointer to the appropriate register | |
556 | ||
557 | REMARKS: | |
558 | Return a pointer to the register given by the R/RM field of the | |
559 | modrm byte, for byte operands. Also enables the decoding of instructions. | |
560 | ****************************************************************************/ | |
561 | u8* decode_rm_byte_register( | |
562 | int reg) | |
563 | { | |
564 | switch (reg) { | |
565 | case 0: | |
9c7e4b06 WD |
566 | DECODE_PRINTF("AL"); |
567 | return &M.x86.R_AL; | |
ece92f85 | 568 | case 1: |
9c7e4b06 WD |
569 | DECODE_PRINTF("CL"); |
570 | return &M.x86.R_CL; | |
ece92f85 | 571 | case 2: |
9c7e4b06 WD |
572 | DECODE_PRINTF("DL"); |
573 | return &M.x86.R_DL; | |
ece92f85 | 574 | case 3: |
9c7e4b06 WD |
575 | DECODE_PRINTF("BL"); |
576 | return &M.x86.R_BL; | |
ece92f85 | 577 | case 4: |
9c7e4b06 WD |
578 | DECODE_PRINTF("AH"); |
579 | return &M.x86.R_AH; | |
ece92f85 | 580 | case 5: |
9c7e4b06 WD |
581 | DECODE_PRINTF("CH"); |
582 | return &M.x86.R_CH; | |
ece92f85 | 583 | case 6: |
9c7e4b06 WD |
584 | DECODE_PRINTF("DH"); |
585 | return &M.x86.R_DH; | |
ece92f85 | 586 | case 7: |
9c7e4b06 WD |
587 | DECODE_PRINTF("BH"); |
588 | return &M.x86.R_BH; | |
ece92f85 JJ |
589 | } |
590 | HALT_SYS(); | |
9c7e4b06 | 591 | return NULL; /* NOT REACHED OR REACHED ON ERROR */ |
ece92f85 JJ |
592 | } |
593 | ||
594 | /**************************************************************************** | |
595 | PARAMETERS: | |
596 | reg - Register to decode | |
597 | ||
598 | RETURNS: | |
599 | Pointer to the appropriate register | |
600 | ||
601 | REMARKS: | |
602 | Return a pointer to the register given by the R/RM field of the | |
9c7e4b06 | 603 | modrm byte, for word operands. Also enables the decoding of instructions. |
ece92f85 JJ |
604 | ****************************************************************************/ |
605 | u16* decode_rm_word_register( | |
606 | int reg) | |
607 | { | |
608 | switch (reg) { | |
609 | case 0: | |
9c7e4b06 WD |
610 | DECODE_PRINTF("AX"); |
611 | return &M.x86.R_AX; | |
ece92f85 | 612 | case 1: |
9c7e4b06 WD |
613 | DECODE_PRINTF("CX"); |
614 | return &M.x86.R_CX; | |
ece92f85 | 615 | case 2: |
9c7e4b06 WD |
616 | DECODE_PRINTF("DX"); |
617 | return &M.x86.R_DX; | |
ece92f85 | 618 | case 3: |
9c7e4b06 WD |
619 | DECODE_PRINTF("BX"); |
620 | return &M.x86.R_BX; | |
ece92f85 | 621 | case 4: |
9c7e4b06 WD |
622 | DECODE_PRINTF("SP"); |
623 | return &M.x86.R_SP; | |
ece92f85 | 624 | case 5: |
9c7e4b06 WD |
625 | DECODE_PRINTF("BP"); |
626 | return &M.x86.R_BP; | |
ece92f85 | 627 | case 6: |
9c7e4b06 WD |
628 | DECODE_PRINTF("SI"); |
629 | return &M.x86.R_SI; | |
ece92f85 | 630 | case 7: |
9c7e4b06 WD |
631 | DECODE_PRINTF("DI"); |
632 | return &M.x86.R_DI; | |
ece92f85 JJ |
633 | } |
634 | HALT_SYS(); | |
9c7e4b06 | 635 | return NULL; /* NOTREACHED OR REACHED ON ERROR */ |
ece92f85 JJ |
636 | } |
637 | ||
638 | /**************************************************************************** | |
639 | PARAMETERS: | |
640 | reg - Register to decode | |
641 | ||
642 | RETURNS: | |
643 | Pointer to the appropriate register | |
644 | ||
645 | REMARKS: | |
646 | Return a pointer to the register given by the R/RM field of the | |
9c7e4b06 | 647 | modrm byte, for dword operands. Also enables the decoding of instructions. |
ece92f85 JJ |
648 | ****************************************************************************/ |
649 | u32* decode_rm_long_register( | |
650 | int reg) | |
651 | { | |
652 | switch (reg) { | |
653 | case 0: | |
9c7e4b06 WD |
654 | DECODE_PRINTF("EAX"); |
655 | return &M.x86.R_EAX; | |
ece92f85 | 656 | case 1: |
9c7e4b06 WD |
657 | DECODE_PRINTF("ECX"); |
658 | return &M.x86.R_ECX; | |
ece92f85 | 659 | case 2: |
9c7e4b06 WD |
660 | DECODE_PRINTF("EDX"); |
661 | return &M.x86.R_EDX; | |
ece92f85 | 662 | case 3: |
9c7e4b06 WD |
663 | DECODE_PRINTF("EBX"); |
664 | return &M.x86.R_EBX; | |
ece92f85 | 665 | case 4: |
9c7e4b06 WD |
666 | DECODE_PRINTF("ESP"); |
667 | return &M.x86.R_ESP; | |
ece92f85 | 668 | case 5: |
9c7e4b06 WD |
669 | DECODE_PRINTF("EBP"); |
670 | return &M.x86.R_EBP; | |
ece92f85 | 671 | case 6: |
9c7e4b06 WD |
672 | DECODE_PRINTF("ESI"); |
673 | return &M.x86.R_ESI; | |
ece92f85 | 674 | case 7: |
9c7e4b06 WD |
675 | DECODE_PRINTF("EDI"); |
676 | return &M.x86.R_EDI; | |
ece92f85 JJ |
677 | } |
678 | HALT_SYS(); | |
9c7e4b06 | 679 | return NULL; /* NOTREACHED OR REACHED ON ERROR */ |
ece92f85 JJ |
680 | } |
681 | ||
682 | /**************************************************************************** | |
683 | PARAMETERS: | |
684 | reg - Register to decode | |
685 | ||
686 | RETURNS: | |
687 | Pointer to the appropriate register | |
688 | ||
689 | REMARKS: | |
690 | Return a pointer to the register given by the R/RM field of the | |
691 | modrm byte, for word operands, modified from above for the weirdo | |
692 | special case of segreg operands. Also enables the decoding of instructions. | |
693 | ****************************************************************************/ | |
694 | u16* decode_rm_seg_register( | |
695 | int reg) | |
696 | { | |
697 | switch (reg) { | |
698 | case 0: | |
9c7e4b06 WD |
699 | DECODE_PRINTF("ES"); |
700 | return &M.x86.R_ES; | |
ece92f85 | 701 | case 1: |
9c7e4b06 WD |
702 | DECODE_PRINTF("CS"); |
703 | return &M.x86.R_CS; | |
ece92f85 | 704 | case 2: |
9c7e4b06 WD |
705 | DECODE_PRINTF("SS"); |
706 | return &M.x86.R_SS; | |
ece92f85 | 707 | case 3: |
9c7e4b06 WD |
708 | DECODE_PRINTF("DS"); |
709 | return &M.x86.R_DS; | |
ece92f85 | 710 | case 4: |
9c7e4b06 WD |
711 | DECODE_PRINTF("FS"); |
712 | return &M.x86.R_FS; | |
ece92f85 | 713 | case 5: |
9c7e4b06 WD |
714 | DECODE_PRINTF("GS"); |
715 | return &M.x86.R_GS; | |
ece92f85 JJ |
716 | case 6: |
717 | case 7: | |
9c7e4b06 WD |
718 | DECODE_PRINTF("ILLEGAL SEGREG"); |
719 | break; | |
ece92f85 JJ |
720 | } |
721 | HALT_SYS(); | |
9c7e4b06 | 722 | return NULL; /* NOT REACHED OR REACHED ON ERROR */ |
ece92f85 JJ |
723 | } |
724 | ||
725 | /**************************************************************************** | |
726 | PARAMETERS: | |
727 | scale - scale value of SIB byte | |
728 | index - index value of SIB byte | |
729 | ||
730 | RETURNS: | |
731 | Value of scale * index | |
732 | ||
733 | REMARKS: | |
734 | Decodes scale/index of SIB byte and returns relevant offset part of | |
735 | effective address. | |
736 | ****************************************************************************/ | |
737 | unsigned decode_sib_si( | |
738 | int scale, | |
739 | int index) | |
740 | { | |
741 | scale = 1 << scale; | |
742 | if (scale > 1) { | |
9c7e4b06 | 743 | DECODE_PRINTF2("[%d*", scale); |
ece92f85 | 744 | } else { |
9c7e4b06 | 745 | DECODE_PRINTF("["); |
ece92f85 JJ |
746 | } |
747 | switch (index) { | |
748 | case 0: | |
9c7e4b06 WD |
749 | DECODE_PRINTF("EAX]"); |
750 | return M.x86.R_EAX * index; | |
ece92f85 | 751 | case 1: |
9c7e4b06 WD |
752 | DECODE_PRINTF("ECX]"); |
753 | return M.x86.R_ECX * index; | |
ece92f85 | 754 | case 2: |
9c7e4b06 WD |
755 | DECODE_PRINTF("EDX]"); |
756 | return M.x86.R_EDX * index; | |
ece92f85 | 757 | case 3: |
9c7e4b06 WD |
758 | DECODE_PRINTF("EBX]"); |
759 | return M.x86.R_EBX * index; | |
ece92f85 | 760 | case 4: |
9c7e4b06 WD |
761 | DECODE_PRINTF("0]"); |
762 | return 0; | |
ece92f85 | 763 | case 5: |
9c7e4b06 WD |
764 | DECODE_PRINTF("EBP]"); |
765 | return M.x86.R_EBP * index; | |
ece92f85 | 766 | case 6: |
9c7e4b06 WD |
767 | DECODE_PRINTF("ESI]"); |
768 | return M.x86.R_ESI * index; | |
ece92f85 | 769 | case 7: |
9c7e4b06 WD |
770 | DECODE_PRINTF("EDI]"); |
771 | return M.x86.R_EDI * index; | |
ece92f85 JJ |
772 | } |
773 | HALT_SYS(); | |
9c7e4b06 | 774 | return 0; /* NOT REACHED OR REACHED ON ERROR */ |
ece92f85 JJ |
775 | } |
776 | ||
777 | /**************************************************************************** | |
778 | PARAMETERS: | |
779 | mod - MOD value of preceding ModR/M byte | |
780 | ||
781 | RETURNS: | |
782 | Offset in memory for the address decoding | |
783 | ||
784 | REMARKS: | |
785 | Decodes SIB addressing byte and returns calculated effective address. | |
786 | ****************************************************************************/ | |
787 | unsigned decode_sib_address( | |
788 | int mod) | |
789 | { | |
790 | int sib = fetch_byte_imm(); | |
791 | int ss = (sib >> 6) & 0x03; | |
792 | int index = (sib >> 3) & 0x07; | |
793 | int base = sib & 0x07; | |
794 | int offset = 0; | |
795 | int displacement; | |
796 | ||
797 | switch (base) { | |
798 | case 0: | |
9c7e4b06 WD |
799 | DECODE_PRINTF("[EAX]"); |
800 | offset = M.x86.R_EAX; | |
801 | break; | |
ece92f85 | 802 | case 1: |
9c7e4b06 WD |
803 | DECODE_PRINTF("[ECX]"); |
804 | offset = M.x86.R_ECX; | |
805 | break; | |
ece92f85 | 806 | case 2: |
9c7e4b06 WD |
807 | DECODE_PRINTF("[EDX]"); |
808 | offset = M.x86.R_EDX; | |
809 | break; | |
ece92f85 | 810 | case 3: |
9c7e4b06 WD |
811 | DECODE_PRINTF("[EBX]"); |
812 | offset = M.x86.R_EBX; | |
813 | break; | |
ece92f85 | 814 | case 4: |
9c7e4b06 WD |
815 | DECODE_PRINTF("[ESP]"); |
816 | offset = M.x86.R_ESP; | |
817 | break; | |
ece92f85 | 818 | case 5: |
9c7e4b06 WD |
819 | switch (mod) { |
820 | case 0: | |
821 | displacement = (s32)fetch_long_imm(); | |
822 | DECODE_PRINTF2("[%d]", displacement); | |
823 | offset = displacement; | |
824 | break; | |
825 | case 1: | |
826 | displacement = (s8)fetch_byte_imm(); | |
827 | DECODE_PRINTF2("[%d][EBP]", displacement); | |
828 | offset = M.x86.R_EBP + displacement; | |
829 | break; | |
830 | case 2: | |
831 | displacement = (s32)fetch_long_imm(); | |
832 | DECODE_PRINTF2("[%d][EBP]", displacement); | |
833 | offset = M.x86.R_EBP + displacement; | |
834 | break; | |
835 | default: | |
836 | HALT_SYS(); | |
837 | } | |
838 | DECODE_PRINTF("[EAX]"); | |
839 | offset = M.x86.R_EAX; | |
840 | break; | |
ece92f85 | 841 | case 6: |
9c7e4b06 WD |
842 | DECODE_PRINTF("[ESI]"); |
843 | offset = M.x86.R_ESI; | |
844 | break; | |
ece92f85 | 845 | case 7: |
9c7e4b06 WD |
846 | DECODE_PRINTF("[EDI]"); |
847 | offset = M.x86.R_EDI; | |
848 | break; | |
ece92f85 | 849 | default: |
9c7e4b06 | 850 | HALT_SYS(); |
ece92f85 JJ |
851 | } |
852 | offset += decode_sib_si(ss, index); | |
853 | return offset; | |
854 | ||
855 | } | |
856 | ||
857 | /**************************************************************************** | |
858 | PARAMETERS: | |
859 | rm - RM value to decode | |
860 | ||
861 | RETURNS: | |
862 | Offset in memory for the address decoding | |
863 | ||
864 | REMARKS: | |
865 | Return the offset given by mod=00 addressing. Also enables the | |
866 | decoding of instructions. | |
867 | ||
9c7e4b06 WD |
868 | NOTE: The code which specifies the corresponding segment (ds vs ss) |
869 | below in the case of [BP+..]. The assumption here is that at the | |
870 | point that this subroutine is called, the bit corresponding to | |
871 | SYSMODE_SEG_DS_SS will be zero. After every instruction | |
872 | except the segment override instructions, this bit (as well | |
873 | as any bits indicating segment overrides) will be clear. So | |
874 | if a SS access is needed, set this bit. Otherwise, DS access | |
875 | occurs (unless any of the segment override bits are set). | |
ece92f85 JJ |
876 | ****************************************************************************/ |
877 | unsigned decode_rm00_address( | |
878 | int rm) | |
879 | { | |
880 | unsigned offset; | |
881 | ||
882 | if (M.x86.mode & SYSMODE_PREFIX_ADDR) { | |
9c7e4b06 WD |
883 | /* 32-bit addressing */ |
884 | switch (rm) { | |
885 | case 0: | |
886 | DECODE_PRINTF("[EAX]"); | |
887 | return M.x86.R_EAX; | |
888 | case 1: | |
889 | DECODE_PRINTF("[ECX]"); | |
890 | return M.x86.R_ECX; | |
891 | case 2: | |
892 | DECODE_PRINTF("[EDX]"); | |
893 | return M.x86.R_EDX; | |
894 | case 3: | |
895 | DECODE_PRINTF("[EBX]"); | |
896 | return M.x86.R_EBX; | |
897 | case 4: | |
898 | return decode_sib_address(0); | |
899 | case 5: | |
900 | offset = fetch_long_imm(); | |
901 | DECODE_PRINTF2("[%08x]", offset); | |
902 | return offset; | |
903 | case 6: | |
904 | DECODE_PRINTF("[ESI]"); | |
905 | return M.x86.R_ESI; | |
906 | case 7: | |
907 | DECODE_PRINTF("[EDI]"); | |
908 | return M.x86.R_EDI; | |
909 | } | |
ece92f85 | 910 | } else { |
9c7e4b06 WD |
911 | /* 16-bit addressing */ |
912 | switch (rm) { | |
913 | case 0: | |
914 | DECODE_PRINTF("[BX+SI]"); | |
915 | return (M.x86.R_BX + M.x86.R_SI) & 0xffff; | |
916 | case 1: | |
917 | DECODE_PRINTF("[BX+DI]"); | |
918 | return (M.x86.R_BX + M.x86.R_DI) & 0xffff; | |
919 | case 2: | |
920 | DECODE_PRINTF("[BP+SI]"); | |
921 | M.x86.mode |= SYSMODE_SEG_DS_SS; | |
922 | return (M.x86.R_BP + M.x86.R_SI) & 0xffff; | |
923 | case 3: | |
924 | DECODE_PRINTF("[BP+DI]"); | |
925 | M.x86.mode |= SYSMODE_SEG_DS_SS; | |
926 | return (M.x86.R_BP + M.x86.R_DI) & 0xffff; | |
927 | case 4: | |
928 | DECODE_PRINTF("[SI]"); | |
929 | return M.x86.R_SI; | |
930 | case 5: | |
931 | DECODE_PRINTF("[DI]"); | |
932 | return M.x86.R_DI; | |
933 | case 6: | |
934 | offset = fetch_word_imm(); | |
935 | DECODE_PRINTF2("[%04x]", offset); | |
936 | return offset; | |
937 | case 7: | |
938 | DECODE_PRINTF("[BX]"); | |
939 | return M.x86.R_BX; | |
940 | } | |
ece92f85 JJ |
941 | } |
942 | HALT_SYS(); | |
943 | return 0; | |
944 | } | |
945 | ||
946 | /**************************************************************************** | |
947 | PARAMETERS: | |
948 | rm - RM value to decode | |
949 | ||
950 | RETURNS: | |
951 | Offset in memory for the address decoding | |
952 | ||
953 | REMARKS: | |
954 | Return the offset given by mod=01 addressing. Also enables the | |
955 | decoding of instructions. | |
956 | ****************************************************************************/ | |
957 | unsigned decode_rm01_address( | |
958 | int rm) | |
959 | { | |
960 | int displacement; | |
961 | ||
962 | if (M.x86.mode & SYSMODE_PREFIX_ADDR) { | |
9c7e4b06 WD |
963 | /* 32-bit addressing */ |
964 | if (rm != 4) | |
965 | displacement = (s8)fetch_byte_imm(); | |
966 | else | |
967 | displacement = 0; | |
968 | ||
969 | switch (rm) { | |
970 | case 0: | |
971 | DECODE_PRINTF2("%d[EAX]", displacement); | |
972 | return M.x86.R_EAX + displacement; | |
973 | case 1: | |
974 | DECODE_PRINTF2("%d[ECX]", displacement); | |
975 | return M.x86.R_ECX + displacement; | |
976 | case 2: | |
977 | DECODE_PRINTF2("%d[EDX]", displacement); | |
978 | return M.x86.R_EDX + displacement; | |
979 | case 3: | |
980 | DECODE_PRINTF2("%d[EBX]", displacement); | |
981 | return M.x86.R_EBX + displacement; | |
982 | case 4: { | |
983 | int offset = decode_sib_address(1); | |
984 | displacement = (s8)fetch_byte_imm(); | |
985 | DECODE_PRINTF2("[%d]", displacement); | |
986 | return offset + displacement; | |
987 | } | |
988 | case 5: | |
989 | DECODE_PRINTF2("%d[EBP]", displacement); | |
990 | return M.x86.R_EBP + displacement; | |
991 | case 6: | |
992 | DECODE_PRINTF2("%d[ESI]", displacement); | |
993 | return M.x86.R_ESI + displacement; | |
994 | case 7: | |
995 | DECODE_PRINTF2("%d[EDI]", displacement); | |
996 | return M.x86.R_EDI + displacement; | |
997 | } | |
ece92f85 | 998 | } else { |
9c7e4b06 WD |
999 | /* 16-bit addressing */ |
1000 | displacement = (s8)fetch_byte_imm(); | |
1001 | switch (rm) { | |
1002 | case 0: | |
1003 | DECODE_PRINTF2("%d[BX+SI]", displacement); | |
1004 | return (M.x86.R_BX + M.x86.R_SI + displacement) & 0xffff; | |
1005 | case 1: | |
1006 | DECODE_PRINTF2("%d[BX+DI]", displacement); | |
1007 | return (M.x86.R_BX + M.x86.R_DI + displacement) & 0xffff; | |
1008 | case 2: | |
1009 | DECODE_PRINTF2("%d[BP+SI]", displacement); | |
1010 | M.x86.mode |= SYSMODE_SEG_DS_SS; | |
1011 | return (M.x86.R_BP + M.x86.R_SI + displacement) & 0xffff; | |
1012 | case 3: | |
1013 | DECODE_PRINTF2("%d[BP+DI]", displacement); | |
1014 | M.x86.mode |= SYSMODE_SEG_DS_SS; | |
1015 | return (M.x86.R_BP + M.x86.R_DI + displacement) & 0xffff; | |
1016 | case 4: | |
1017 | DECODE_PRINTF2("%d[SI]", displacement); | |
1018 | return (M.x86.R_SI + displacement) & 0xffff; | |
1019 | case 5: | |
1020 | DECODE_PRINTF2("%d[DI]", displacement); | |
1021 | return (M.x86.R_DI + displacement) & 0xffff; | |
1022 | case 6: | |
1023 | DECODE_PRINTF2("%d[BP]", displacement); | |
1024 | M.x86.mode |= SYSMODE_SEG_DS_SS; | |
1025 | return (M.x86.R_BP + displacement) & 0xffff; | |
1026 | case 7: | |
1027 | DECODE_PRINTF2("%d[BX]", displacement); | |
1028 | return (M.x86.R_BX + displacement) & 0xffff; | |
1029 | } | |
ece92f85 JJ |
1030 | } |
1031 | HALT_SYS(); | |
9c7e4b06 | 1032 | return 0; /* SHOULD NOT HAPPEN */ |
ece92f85 JJ |
1033 | } |
1034 | ||
1035 | /**************************************************************************** | |
1036 | PARAMETERS: | |
1037 | rm - RM value to decode | |
1038 | ||
1039 | RETURNS: | |
1040 | Offset in memory for the address decoding | |
1041 | ||
1042 | REMARKS: | |
1043 | Return the offset given by mod=10 addressing. Also enables the | |
1044 | decoding of instructions. | |
1045 | ****************************************************************************/ | |
1046 | unsigned decode_rm10_address( | |
1047 | int rm) | |
1048 | { | |
1049 | if (M.x86.mode & SYSMODE_PREFIX_ADDR) { | |
9c7e4b06 WD |
1050 | int displacement; |
1051 | ||
1052 | /* 32-bit addressing */ | |
1053 | if (rm != 4) | |
1054 | displacement = (s32)fetch_long_imm(); | |
1055 | else | |
1056 | displacement = 0; | |
1057 | ||
1058 | switch (rm) { | |
1059 | case 0: | |
1060 | DECODE_PRINTF2("%d[EAX]", displacement); | |
1061 | return M.x86.R_EAX + displacement; | |
1062 | case 1: | |
1063 | DECODE_PRINTF2("%d[ECX]", displacement); | |
1064 | return M.x86.R_ECX + displacement; | |
1065 | case 2: | |
1066 | DECODE_PRINTF2("%d[EDX]", displacement); | |
1067 | return M.x86.R_EDX + displacement; | |
1068 | case 3: | |
1069 | DECODE_PRINTF2("%d[EBX]", displacement); | |
1070 | return M.x86.R_EBX + displacement; | |
1071 | case 4: { | |
1072 | int offset = decode_sib_address(2); | |
1073 | displacement = (s32)fetch_long_imm(); | |
1074 | DECODE_PRINTF2("[%d]", displacement); | |
1075 | return offset + displacement; | |
1076 | } | |
1077 | case 5: | |
1078 | DECODE_PRINTF2("%d[EBP]", displacement); | |
1079 | return M.x86.R_EBP + displacement; | |
1080 | case 6: | |
1081 | DECODE_PRINTF2("%d[ESI]", displacement); | |
1082 | return M.x86.R_ESI + displacement; | |
1083 | case 7: | |
1084 | DECODE_PRINTF2("%d[EDI]", displacement); | |
1085 | return M.x86.R_EDI + displacement; | |
1086 | } | |
ece92f85 | 1087 | } else { |
9c7e4b06 WD |
1088 | int displacement = (s16)fetch_word_imm(); |
1089 | ||
1090 | /* 16-bit addressing */ | |
1091 | switch (rm) { | |
1092 | case 0: | |
1093 | DECODE_PRINTF2("%d[BX+SI]", displacement); | |
1094 | return (M.x86.R_BX + M.x86.R_SI + displacement) & 0xffff; | |
1095 | case 1: | |
1096 | DECODE_PRINTF2("%d[BX+DI]", displacement); | |
1097 | return (M.x86.R_BX + M.x86.R_DI + displacement) & 0xffff; | |
1098 | case 2: | |
1099 | DECODE_PRINTF2("%d[BP+SI]", displacement); | |
1100 | M.x86.mode |= SYSMODE_SEG_DS_SS; | |
1101 | return (M.x86.R_BP + M.x86.R_SI + displacement) & 0xffff; | |
1102 | case 3: | |
1103 | DECODE_PRINTF2("%d[BP+DI]", displacement); | |
1104 | M.x86.mode |= SYSMODE_SEG_DS_SS; | |
1105 | return (M.x86.R_BP + M.x86.R_DI + displacement) & 0xffff; | |
1106 | case 4: | |
1107 | DECODE_PRINTF2("%d[SI]", displacement); | |
1108 | return (M.x86.R_SI + displacement) & 0xffff; | |
1109 | case 5: | |
1110 | DECODE_PRINTF2("%d[DI]", displacement); | |
1111 | return (M.x86.R_DI + displacement) & 0xffff; | |
1112 | case 6: | |
1113 | DECODE_PRINTF2("%d[BP]", displacement); | |
1114 | M.x86.mode |= SYSMODE_SEG_DS_SS; | |
1115 | return (M.x86.R_BP + displacement) & 0xffff; | |
1116 | case 7: | |
1117 | DECODE_PRINTF2("%d[BX]", displacement); | |
1118 | return (M.x86.R_BX + displacement) & 0xffff; | |
1119 | } | |
ece92f85 JJ |
1120 | } |
1121 | HALT_SYS(); | |
9c7e4b06 | 1122 | return 0; /* SHOULD NOT HAPPEN */ |
ece92f85 JJ |
1123 | } |
1124 | ||
ece92f85 JJ |
1125 | /**************************************************************************** |
1126 | PARAMETERS: | |
1127 | mod - modifier | |
1128 | rm - RM value to decode | |
1129 | ||
1130 | RETURNS: | |
1131 | Offset in memory for the address decoding, multiplexing calls to | |
1132 | the decode_rmXX_address functions | |
1133 | ||
1134 | REMARKS: | |
1135 | Return the offset given by "mod" addressing. | |
1136 | ****************************************************************************/ | |
1137 | ||
1138 | unsigned decode_rmXX_address(int mod, int rm) | |
1139 | { | |
1140 | if(mod == 0) | |
1141 | return decode_rm00_address(rm); | |
1142 | if(mod == 1) | |
1143 | return decode_rm01_address(rm); | |
1144 | return decode_rm10_address(rm); | |
1145 | } |