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c906108c SS |
1 | /* thumbemu.c -- Thumb instruction emulation. |
2 | Copyright (C) 1996, Cygnus Software Technologies Ltd. | |
3 | ||
4 | This program is free software; you can redistribute it and/or modify | |
5 | it under the terms of the GNU General Public License as published by | |
6 | the Free Software Foundation; either version 2 of the License, or | |
7 | (at your option) any later version. | |
8 | ||
9 | This program is distributed in the hope that it will be useful, | |
10 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
11 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
12 | GNU General Public License for more details. | |
13 | ||
14 | You should have received a copy of the GNU General Public License | |
15 | along with this program; if not, write to the Free Software | |
380d9419 | 16 | Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston, MA 02110-1301, USA. */ |
c906108c SS |
17 | |
18 | /* We can provide simple Thumb simulation by decoding the Thumb | |
19 | instruction into its corresponding ARM instruction, and using the | |
20 | existing ARM simulator. */ | |
21 | ||
dfcd3bfb | 22 | #ifndef MODET /* required for the Thumb instruction support */ |
c906108c SS |
23 | #if 1 |
24 | #error "MODET needs to be defined for the Thumb world to work" | |
25 | #else | |
26 | #define MODET (1) | |
27 | #endif | |
28 | #endif | |
29 | ||
30 | #include "armdefs.h" | |
31 | #include "armemu.h" | |
7a292a7a | 32 | #include "armos.h" |
c906108c | 33 | |
546aee7a NC |
34 | /* Attempt to emulate an ARMv6 instruction. |
35 | Stores t_branch into PVALUE upon success or t_undefined otherwise. */ | |
36 | ||
37 | static void | |
38 | handle_v6_thumb_insn (ARMul_State * state, | |
39 | ARMword tinstr, | |
40 | tdstate * pvalid) | |
41 | { | |
42 | ARMword Rd; | |
43 | ARMword Rm; | |
44 | ||
45 | if (! state->is_v6) | |
46 | { | |
47 | * pvalid = t_undefined; | |
48 | return; | |
49 | } | |
50 | ||
51 | switch (tinstr & 0xFFC0) | |
52 | { | |
53 | case 0xb660: /* cpsie */ | |
54 | case 0xb670: /* cpsid */ | |
55 | case 0x4600: /* cpy */ | |
56 | case 0xba00: /* rev */ | |
57 | case 0xba40: /* rev16 */ | |
58 | case 0xbac0: /* revsh */ | |
59 | case 0xb650: /* setend */ | |
60 | default: | |
61 | printf ("Unhandled v6 thumb insn: %04x\n", tinstr); | |
62 | * pvalid = t_undefined; | |
63 | return; | |
64 | ||
65 | case 0xb200: /* sxth */ | |
66 | Rm = state->Reg [(tinstr & 0x38) >> 3]; | |
67 | if (Rm & 0x8000) | |
68 | state->Reg [(tinstr & 0x7)] = (Rm & 0xffff) | 0xffff0000; | |
69 | else | |
70 | state->Reg [(tinstr & 0x7)] = Rm & 0xffff; | |
71 | break; | |
72 | case 0xb240: /* sxtb */ | |
73 | Rm = state->Reg [(tinstr & 0x38) >> 3]; | |
74 | if (Rm & 0x80) | |
75 | state->Reg [(tinstr & 0x7)] = (Rm & 0xff) | 0xffffff00; | |
76 | else | |
77 | state->Reg [(tinstr & 0x7)] = Rm & 0xff; | |
78 | break; | |
79 | case 0xb280: /* uxth */ | |
80 | Rm = state->Reg [(tinstr & 0x38) >> 3]; | |
81 | state->Reg [(tinstr & 0x7)] = Rm & 0xffff; | |
82 | break; | |
83 | case 0xb2c0: /* uxtb */ | |
84 | Rm = state->Reg [(tinstr & 0x38) >> 3]; | |
85 | state->Reg [(tinstr & 0x7)] = Rm & 0xff; | |
86 | break; | |
87 | } | |
88 | /* Indicate that the instruction has been processed. */ | |
89 | * pvalid = t_branch; | |
90 | } | |
91 | ||
c906108c SS |
92 | /* Decode a 16bit Thumb instruction. The instruction is in the low |
93 | 16-bits of the tinstr field, with the following Thumb instruction | |
94 | held in the high 16-bits. Passing in two Thumb instructions allows | |
95 | easier simulation of the special dual BL instruction. */ | |
96 | ||
546aee7a NC |
97 | tdstate |
98 | ARMul_ThumbDecode (ARMul_State * state, | |
99 | ARMword pc, | |
100 | ARMword tinstr, | |
101 | ARMword * ainstr) | |
c906108c | 102 | { |
dfcd3bfb | 103 | tdstate valid = t_decoded; /* default assumes a valid instruction */ |
c906108c | 104 | ARMword next_instr; |
dfcd3bfb | 105 | |
c906108c SS |
106 | if (state->bigendSig) |
107 | { | |
108 | next_instr = tinstr & 0xFFFF; | |
109 | tinstr >>= 16; | |
110 | } | |
111 | else | |
112 | { | |
113 | next_instr = tinstr >> 16; | |
114 | tinstr &= 0xFFFF; | |
115 | } | |
dfcd3bfb JM |
116 | |
117 | #if 1 /* debugging to catch non updates */ | |
c906108c SS |
118 | *ainstr = 0xDEADC0DE; |
119 | #endif | |
120 | ||
121 | switch ((tinstr & 0xF800) >> 11) | |
122 | { | |
dfcd3bfb JM |
123 | case 0: /* LSL */ |
124 | case 1: /* LSR */ | |
125 | case 2: /* ASR */ | |
c906108c | 126 | /* Format 1 */ |
dfcd3bfb JM |
127 | *ainstr = 0xE1B00000 /* base opcode */ |
128 | | ((tinstr & 0x1800) >> (11 - 5)) /* shift type */ | |
129 | | ((tinstr & 0x07C0) << (7 - 6)) /* imm5 */ | |
130 | | ((tinstr & 0x0038) >> 3) /* Rs */ | |
131 | | ((tinstr & 0x0007) << 12); /* Rd */ | |
c906108c | 132 | break; |
dfcd3bfb | 133 | case 3: /* ADD/SUB */ |
c906108c SS |
134 | /* Format 2 */ |
135 | { | |
dfcd3bfb JM |
136 | ARMword subset[4] = { |
137 | 0xE0900000, /* ADDS Rd,Rs,Rn */ | |
138 | 0xE0500000, /* SUBS Rd,Rs,Rn */ | |
139 | 0xE2900000, /* ADDS Rd,Rs,#imm3 */ | |
140 | 0xE2500000 /* SUBS Rd,Rs,#imm3 */ | |
141 | }; | |
142 | /* It is quicker indexing into a table, than performing switch | |
143 | or conditionals: */ | |
144 | *ainstr = subset[(tinstr & 0x0600) >> 9] /* base opcode */ | |
145 | | ((tinstr & 0x01C0) >> 6) /* Rn or imm3 */ | |
146 | | ((tinstr & 0x0038) << (16 - 3)) /* Rs */ | |
147 | | ((tinstr & 0x0007) << (12 - 0)); /* Rd */ | |
c906108c SS |
148 | } |
149 | break; | |
dfcd3bfb JM |
150 | case 4: /* MOV */ |
151 | case 5: /* CMP */ | |
152 | case 6: /* ADD */ | |
153 | case 7: /* SUB */ | |
c906108c SS |
154 | /* Format 3 */ |
155 | { | |
dfcd3bfb JM |
156 | ARMword subset[4] = { |
157 | 0xE3B00000, /* MOVS Rd,#imm8 */ | |
158 | 0xE3500000, /* CMP Rd,#imm8 */ | |
159 | 0xE2900000, /* ADDS Rd,Rd,#imm8 */ | |
160 | 0xE2500000, /* SUBS Rd,Rd,#imm8 */ | |
161 | }; | |
162 | *ainstr = subset[(tinstr & 0x1800) >> 11] /* base opcode */ | |
163 | | ((tinstr & 0x00FF) >> 0) /* imm8 */ | |
164 | | ((tinstr & 0x0700) << (16 - 8)) /* Rn */ | |
165 | | ((tinstr & 0x0700) << (12 - 8)); /* Rd */ | |
c906108c | 166 | } |
dfcd3bfb JM |
167 | break; |
168 | case 8: /* Arithmetic and high register transfers */ | |
c906108c SS |
169 | /* TODO: Since the subsets for both Format 4 and Format 5 |
170 | instructions are made up of different ARM encodings, we could | |
171 | save the following conditional, and just have one large | |
172 | subset. */ | |
173 | if ((tinstr & (1 << 10)) == 0) | |
dfcd3bfb JM |
174 | { |
175 | /* Format 4 */ | |
176 | struct | |
177 | { | |
178 | ARMword opcode; | |
179 | enum | |
180 | { t_norm, t_shift, t_neg, t_mul } | |
181 | otype; | |
182 | } | |
183 | subset[16] = | |
184 | { | |
185 | { 0xE0100000, t_norm}, /* ANDS Rd,Rd,Rs */ | |
186 | { 0xE0300000, t_norm}, /* EORS Rd,Rd,Rs */ | |
187 | { 0xE1B00010, t_shift}, /* MOVS Rd,Rd,LSL Rs */ | |
188 | { 0xE1B00030, t_shift}, /* MOVS Rd,Rd,LSR Rs */ | |
189 | { 0xE1B00050, t_shift}, /* MOVS Rd,Rd,ASR Rs */ | |
190 | { 0xE0B00000, t_norm}, /* ADCS Rd,Rd,Rs */ | |
191 | { 0xE0D00000, t_norm}, /* SBCS Rd,Rd,Rs */ | |
192 | { 0xE1B00070, t_shift}, /* MOVS Rd,Rd,ROR Rs */ | |
193 | { 0xE1100000, t_norm}, /* TST Rd,Rs */ | |
194 | { 0xE2700000, t_neg}, /* RSBS Rd,Rs,#0 */ | |
195 | { 0xE1500000, t_norm}, /* CMP Rd,Rs */ | |
196 | { 0xE1700000, t_norm}, /* CMN Rd,Rs */ | |
197 | { 0xE1900000, t_norm}, /* ORRS Rd,Rd,Rs */ | |
198 | { 0xE0100090, t_mul} , /* MULS Rd,Rd,Rs */ | |
199 | { 0xE1D00000, t_norm}, /* BICS Rd,Rd,Rs */ | |
200 | { 0xE1F00000, t_norm} /* MVNS Rd,Rs */ | |
201 | }; | |
202 | *ainstr = subset[(tinstr & 0x03C0) >> 6].opcode; /* base */ | |
203 | switch (subset[(tinstr & 0x03C0) >> 6].otype) | |
204 | { | |
205 | case t_norm: | |
206 | *ainstr |= ((tinstr & 0x0007) << 16) /* Rn */ | |
207 | | ((tinstr & 0x0007) << 12) /* Rd */ | |
208 | | ((tinstr & 0x0038) >> 3); /* Rs */ | |
209 | break; | |
210 | case t_shift: | |
211 | *ainstr |= ((tinstr & 0x0007) << 12) /* Rd */ | |
212 | | ((tinstr & 0x0007) >> 0) /* Rm */ | |
213 | | ((tinstr & 0x0038) << (8 - 3)); /* Rs */ | |
214 | break; | |
215 | case t_neg: | |
216 | *ainstr |= ((tinstr & 0x0007) << 12) /* Rd */ | |
217 | | ((tinstr & 0x0038) << (16 - 3)); /* Rn */ | |
218 | break; | |
219 | case t_mul: | |
220 | *ainstr |= ((tinstr & 0x0007) << 16) /* Rd */ | |
221 | | ((tinstr & 0x0007) << 8) /* Rs */ | |
222 | | ((tinstr & 0x0038) >> 3); /* Rm */ | |
223 | break; | |
224 | } | |
225 | } | |
c906108c | 226 | else |
dfcd3bfb JM |
227 | { |
228 | /* Format 5 */ | |
229 | ARMword Rd = ((tinstr & 0x0007) >> 0); | |
230 | ARMword Rs = ((tinstr & 0x0038) >> 3); | |
231 | if (tinstr & (1 << 7)) | |
232 | Rd += 8; | |
233 | if (tinstr & (1 << 6)) | |
234 | Rs += 8; | |
235 | switch ((tinstr & 0x03C0) >> 6) | |
236 | { | |
237 | case 0x1: /* ADD Rd,Rd,Hs */ | |
238 | case 0x2: /* ADD Hd,Hd,Rs */ | |
239 | case 0x3: /* ADD Hd,Hd,Hs */ | |
240 | *ainstr = 0xE0800000 /* base */ | |
241 | | (Rd << 16) /* Rn */ | |
242 | | (Rd << 12) /* Rd */ | |
243 | | (Rs << 0); /* Rm */ | |
244 | break; | |
245 | case 0x5: /* CMP Rd,Hs */ | |
246 | case 0x6: /* CMP Hd,Rs */ | |
247 | case 0x7: /* CMP Hd,Hs */ | |
248 | *ainstr = 0xE1500000 /* base */ | |
249 | | (Rd << 16) /* Rn */ | |
250 | | (Rd << 12) /* Rd */ | |
251 | | (Rs << 0); /* Rm */ | |
252 | break; | |
253 | case 0x9: /* MOV Rd,Hs */ | |
254 | case 0xA: /* MOV Hd,Rs */ | |
255 | case 0xB: /* MOV Hd,Hs */ | |
256 | *ainstr = 0xE1A00000 /* base */ | |
257 | | (Rd << 16) /* Rn */ | |
258 | | (Rd << 12) /* Rd */ | |
259 | | (Rs << 0); /* Rm */ | |
260 | break; | |
261 | case 0xC: /* BX Rs */ | |
262 | case 0xD: /* BX Hs */ | |
263 | *ainstr = 0xE12FFF10 /* base */ | |
264 | | ((tinstr & 0x0078) >> 3); /* Rd */ | |
265 | break; | |
f1129fb8 NC |
266 | case 0xE: /* UNDEFINED */ |
267 | case 0xF: /* UNDEFINED */ | |
268 | if (state->is_v5) | |
269 | { | |
270 | /* BLX Rs; BLX Hs */ | |
271 | *ainstr = 0xE12FFF30 /* base */ | |
272 | | ((tinstr & 0x0078) >> 3); /* Rd */ | |
273 | break; | |
274 | } | |
275 | /* Drop through. */ | |
dfcd3bfb JM |
276 | case 0x0: /* UNDEFINED */ |
277 | case 0x4: /* UNDEFINED */ | |
278 | case 0x8: /* UNDEFINED */ | |
546aee7a | 279 | handle_v6_thumb_insn (state, tinstr, & valid); |
dfcd3bfb JM |
280 | break; |
281 | } | |
282 | } | |
c906108c | 283 | break; |
dfcd3bfb | 284 | case 9: /* LDR Rd,[PC,#imm8] */ |
c906108c | 285 | /* Format 6 */ |
dfcd3bfb JM |
286 | *ainstr = 0xE59F0000 /* base */ |
287 | | ((tinstr & 0x0700) << (12 - 8)) /* Rd */ | |
288 | | ((tinstr & 0x00FF) << (2 - 0)); /* off8 */ | |
c906108c SS |
289 | break; |
290 | case 10: | |
291 | case 11: | |
292 | /* TODO: Format 7 and Format 8 perform the same ARM encoding, so | |
293 | the following could be merged into a single subset, saving on | |
294 | the following boolean: */ | |
295 | if ((tinstr & (1 << 9)) == 0) | |
dfcd3bfb JM |
296 | { |
297 | /* Format 7 */ | |
298 | ARMword subset[4] = { | |
299 | 0xE7800000, /* STR Rd,[Rb,Ro] */ | |
300 | 0xE7C00000, /* STRB Rd,[Rb,Ro] */ | |
301 | 0xE7900000, /* LDR Rd,[Rb,Ro] */ | |
302 | 0xE7D00000 /* LDRB Rd,[Rb,Ro] */ | |
303 | }; | |
304 | *ainstr = subset[(tinstr & 0x0C00) >> 10] /* base */ | |
305 | | ((tinstr & 0x0007) << (12 - 0)) /* Rd */ | |
306 | | ((tinstr & 0x0038) << (16 - 3)) /* Rb */ | |
307 | | ((tinstr & 0x01C0) >> 6); /* Ro */ | |
308 | } | |
c906108c | 309 | else |
dfcd3bfb JM |
310 | { |
311 | /* Format 8 */ | |
312 | ARMword subset[4] = { | |
313 | 0xE18000B0, /* STRH Rd,[Rb,Ro] */ | |
314 | 0xE19000D0, /* LDRSB Rd,[Rb,Ro] */ | |
315 | 0xE19000B0, /* LDRH Rd,[Rb,Ro] */ | |
316 | 0xE19000F0 /* LDRSH Rd,[Rb,Ro] */ | |
317 | }; | |
318 | *ainstr = subset[(tinstr & 0x0C00) >> 10] /* base */ | |
319 | | ((tinstr & 0x0007) << (12 - 0)) /* Rd */ | |
320 | | ((tinstr & 0x0038) << (16 - 3)) /* Rb */ | |
321 | | ((tinstr & 0x01C0) >> 6); /* Ro */ | |
322 | } | |
c906108c | 323 | break; |
dfcd3bfb JM |
324 | case 12: /* STR Rd,[Rb,#imm5] */ |
325 | case 13: /* LDR Rd,[Rb,#imm5] */ | |
326 | case 14: /* STRB Rd,[Rb,#imm5] */ | |
327 | case 15: /* LDRB Rd,[Rb,#imm5] */ | |
c906108c SS |
328 | /* Format 9 */ |
329 | { | |
dfcd3bfb JM |
330 | ARMword subset[4] = { |
331 | 0xE5800000, /* STR Rd,[Rb,#imm5] */ | |
332 | 0xE5900000, /* LDR Rd,[Rb,#imm5] */ | |
333 | 0xE5C00000, /* STRB Rd,[Rb,#imm5] */ | |
334 | 0xE5D00000 /* LDRB Rd,[Rb,#imm5] */ | |
335 | }; | |
336 | /* The offset range defends on whether we are transferring a | |
337 | byte or word value: */ | |
338 | *ainstr = subset[(tinstr & 0x1800) >> 11] /* base */ | |
339 | | ((tinstr & 0x0007) << (12 - 0)) /* Rd */ | |
340 | | ((tinstr & 0x0038) << (16 - 3)) /* Rb */ | |
341 | | ((tinstr & 0x07C0) >> (6 - ((tinstr & (1 << 12)) ? 0 : 2))); /* off5 */ | |
c906108c SS |
342 | } |
343 | break; | |
dfcd3bfb JM |
344 | case 16: /* STRH Rd,[Rb,#imm5] */ |
345 | case 17: /* LDRH Rd,[Rb,#imm5] */ | |
c906108c | 346 | /* Format 10 */ |
dfcd3bfb JM |
347 | *ainstr = ((tinstr & (1 << 11)) /* base */ |
348 | ? 0xE1D000B0 /* LDRH */ | |
349 | : 0xE1C000B0) /* STRH */ | |
350 | | ((tinstr & 0x0007) << (12 - 0)) /* Rd */ | |
351 | | ((tinstr & 0x0038) << (16 - 3)) /* Rb */ | |
352 | | ((tinstr & 0x01C0) >> (6 - 1)) /* off5, low nibble */ | |
353 | | ((tinstr & 0x0600) >> (9 - 8)); /* off5, high nibble */ | |
c906108c | 354 | break; |
dfcd3bfb JM |
355 | case 18: /* STR Rd,[SP,#imm8] */ |
356 | case 19: /* LDR Rd,[SP,#imm8] */ | |
c906108c | 357 | /* Format 11 */ |
dfcd3bfb JM |
358 | *ainstr = ((tinstr & (1 << 11)) /* base */ |
359 | ? 0xE59D0000 /* LDR */ | |
360 | : 0xE58D0000) /* STR */ | |
361 | | ((tinstr & 0x0700) << (12 - 8)) /* Rd */ | |
362 | | ((tinstr & 0x00FF) << 2); /* off8 */ | |
c906108c | 363 | break; |
dfcd3bfb JM |
364 | case 20: /* ADD Rd,PC,#imm8 */ |
365 | case 21: /* ADD Rd,SP,#imm8 */ | |
c906108c SS |
366 | /* Format 12 */ |
367 | if ((tinstr & (1 << 11)) == 0) | |
dfcd3bfb JM |
368 | { |
369 | /* NOTE: The PC value used here should by word aligned */ | |
c906108c SS |
370 | /* We encode shift-left-by-2 in the rotate immediate field, |
371 | so no shift of off8 is needed. */ | |
dfcd3bfb JM |
372 | *ainstr = 0xE28F0F00 /* base */ |
373 | | ((tinstr & 0x0700) << (12 - 8)) /* Rd */ | |
374 | | (tinstr & 0x00FF); /* off8 */ | |
375 | } | |
c906108c | 376 | else |
dfcd3bfb | 377 | { |
c906108c SS |
378 | /* We encode shift-left-by-2 in the rotate immediate field, |
379 | so no shift of off8 is needed. */ | |
dfcd3bfb JM |
380 | *ainstr = 0xE28D0F00 /* base */ |
381 | | ((tinstr & 0x0700) << (12 - 8)) /* Rd */ | |
382 | | (tinstr & 0x00FF); /* off8 */ | |
383 | } | |
c906108c SS |
384 | break; |
385 | case 22: | |
386 | case 23: | |
f1129fb8 | 387 | switch (tinstr & 0x0F00) |
dfcd3bfb | 388 | { |
f1129fb8 | 389 | case 0x0000: |
dfcd3bfb JM |
390 | /* Format 13 */ |
391 | /* NOTE: The instruction contains a shift left of 2 | |
f1129fb8 | 392 | equivalent (implemented as ROR #30): */ |
dfcd3bfb JM |
393 | *ainstr = ((tinstr & (1 << 7)) /* base */ |
394 | ? 0xE24DDF00 /* SUB */ | |
395 | : 0xE28DDF00) /* ADD */ | |
396 | | (tinstr & 0x007F); /* off7 */ | |
f1129fb8 NC |
397 | break; |
398 | case 0x0400: | |
399 | /* Format 14 - Push */ | |
400 | * ainstr = 0xE92D0000 | (tinstr & 0x00FF); | |
401 | break; | |
402 | case 0x0500: | |
403 | /* Format 14 - Push + LR */ | |
404 | * ainstr = 0xE92D4000 | (tinstr & 0x00FF); | |
405 | break; | |
406 | case 0x0c00: | |
407 | /* Format 14 - Pop */ | |
408 | * ainstr = 0xE8BD0000 | (tinstr & 0x00FF); | |
409 | break; | |
410 | case 0x0d00: | |
411 | /* Format 14 - Pop + PC */ | |
412 | * ainstr = 0xE8BD8000 | (tinstr & 0x00FF); | |
413 | break; | |
414 | case 0x0e00: | |
415 | if (state->is_v5) | |
416 | { | |
417 | /* This is normally an undefined instruction. The v5t architecture | |
418 | defines this particular pattern as a BKPT instruction, for | |
419 | hardware assisted debugging. We map onto the arm BKPT | |
420 | instruction. */ | |
421 | * ainstr = 0xE1200070 | ((tinstr & 0xf0) << 4) | (tinstr & 0xf); | |
422 | break; | |
423 | } | |
424 | /* Drop through. */ | |
425 | default: | |
426 | /* Everything else is an undefined instruction. */ | |
546aee7a | 427 | handle_v6_thumb_insn (state, tinstr, & valid); |
f1129fb8 | 428 | break; |
dfcd3bfb | 429 | } |
c906108c | 430 | break; |
dfcd3bfb JM |
431 | case 24: /* STMIA */ |
432 | case 25: /* LDMIA */ | |
c906108c | 433 | /* Format 15 */ |
dfcd3bfb JM |
434 | *ainstr = ((tinstr & (1 << 11)) /* base */ |
435 | ? 0xE8B00000 /* LDMIA */ | |
436 | : 0xE8A00000) /* STMIA */ | |
437 | | ((tinstr & 0x0700) << (16 - 8)) /* Rb */ | |
438 | | (tinstr & 0x00FF); /* mask8 */ | |
c906108c | 439 | break; |
dfcd3bfb JM |
440 | case 26: /* Bcc */ |
441 | case 27: /* Bcc/SWI */ | |
c906108c | 442 | if ((tinstr & 0x0F00) == 0x0F00) |
dfcd3bfb JM |
443 | { |
444 | /* Format 17 : SWI */ | |
445 | *ainstr = 0xEF000000; | |
c906108c SS |
446 | /* Breakpoint must be handled specially. */ |
447 | if ((tinstr & 0x00FF) == 0x18) | |
448 | *ainstr |= ((tinstr & 0x00FF) << 16); | |
7a292a7a SS |
449 | /* New breakpoint value. See gdb/arm-tdep.c */ |
450 | else if ((tinstr & 0x00FF) == 0xFE) | |
dfcd3bfb | 451 | *ainstr |= SWI_Breakpoint; |
c906108c SS |
452 | else |
453 | *ainstr |= (tinstr & 0x00FF); | |
dfcd3bfb | 454 | } |
c906108c | 455 | else if ((tinstr & 0x0F00) != 0x0E00) |
dfcd3bfb JM |
456 | { |
457 | /* Format 16 */ | |
458 | int doit = FALSE; | |
459 | /* TODO: Since we are doing a switch here, we could just add | |
460 | the SWI and undefined instruction checks into this | |
461 | switch to same on a couple of conditionals: */ | |
462 | switch ((tinstr & 0x0F00) >> 8) | |
463 | { | |
464 | case EQ: | |
465 | doit = ZFLAG; | |
466 | break; | |
467 | case NE: | |
468 | doit = !ZFLAG; | |
469 | break; | |
470 | case VS: | |
471 | doit = VFLAG; | |
472 | break; | |
473 | case VC: | |
474 | doit = !VFLAG; | |
475 | break; | |
476 | case MI: | |
477 | doit = NFLAG; | |
478 | break; | |
479 | case PL: | |
480 | doit = !NFLAG; | |
481 | break; | |
482 | case CS: | |
483 | doit = CFLAG; | |
484 | break; | |
485 | case CC: | |
486 | doit = !CFLAG; | |
487 | break; | |
488 | case HI: | |
489 | doit = (CFLAG && !ZFLAG); | |
490 | break; | |
491 | case LS: | |
492 | doit = (!CFLAG || ZFLAG); | |
493 | break; | |
494 | case GE: | |
495 | doit = ((!NFLAG && !VFLAG) || (NFLAG && VFLAG)); | |
496 | break; | |
497 | case LT: | |
498 | doit = ((NFLAG && !VFLAG) || (!NFLAG && VFLAG)); | |
499 | break; | |
500 | case GT: | |
501 | doit = ((!NFLAG && !VFLAG && !ZFLAG) | |
502 | || (NFLAG && VFLAG && !ZFLAG)); | |
503 | break; | |
504 | case LE: | |
505 | doit = ((NFLAG && !VFLAG) || (!NFLAG && VFLAG)) || ZFLAG; | |
506 | break; | |
507 | } | |
508 | if (doit) | |
509 | { | |
510 | state->Reg[15] = (pc + 4 | |
511 | + (((tinstr & 0x7F) << 1) | |
512 | | ((tinstr & (1 << 7)) ? 0xFFFFFF00 : 0))); | |
513 | FLUSHPIPE; | |
514 | } | |
515 | valid = t_branch; | |
516 | } | |
546aee7a NC |
517 | else |
518 | /* UNDEFINED : cc=1110(AL) uses different format. */ | |
519 | handle_v6_thumb_insn (state, tinstr, & valid); | |
c906108c | 520 | break; |
dfcd3bfb | 521 | case 28: /* B */ |
c906108c | 522 | /* Format 18 */ |
dfcd3bfb JM |
523 | state->Reg[15] = (pc + 4 |
524 | + (((tinstr & 0x3FF) << 1) | |
525 | | ((tinstr & (1 << 10)) ? 0xFFFFF800 : 0))); | |
c906108c SS |
526 | FLUSHPIPE; |
527 | valid = t_branch; | |
528 | break; | |
dfcd3bfb | 529 | case 29: /* UNDEFINED */ |
f1129fb8 NC |
530 | if (state->is_v5) |
531 | { | |
532 | if (tinstr & 1) | |
533 | { | |
546aee7a | 534 | handle_v6_thumb_insn (state, tinstr, & valid); |
f1129fb8 NC |
535 | break; |
536 | } | |
537 | /* Drop through. */ | |
538 | ||
f1129fb8 NC |
539 | /* Format 19 */ |
540 | /* There is no single ARM instruction equivalent for this | |
541 | instruction. Also, it should only ever be matched with the | |
542 | fmt19 "BL/BLX instruction 1" instruction. However, we do | |
543 | allow the simulation of it on its own, with undefined results | |
544 | if r14 is not suitably initialised. */ | |
545 | { | |
546 | ARMword tmp = (pc + 2); | |
7378e198 | 547 | |
f1129fb8 NC |
548 | state->Reg[15] = ((state->Reg[14] + ((tinstr & 0x07FF) << 1)) |
549 | & 0xFFFFFFFC); | |
550 | CLEART; | |
551 | state->Reg[14] = (tmp | 1); | |
552 | valid = t_branch; | |
553 | FLUSHPIPE; | |
554 | break; | |
555 | } | |
556 | } | |
546aee7a NC |
557 | |
558 | handle_v6_thumb_insn (state, tinstr, & valid); | |
c906108c | 559 | break; |
546aee7a | 560 | |
dfcd3bfb | 561 | case 30: /* BL instruction 1 */ |
c906108c SS |
562 | /* Format 19 */ |
563 | /* There is no single ARM instruction equivalent for this Thumb | |
564 | instruction. To keep the simulation simple (from the user | |
565 | perspective) we check if the following instruction is the | |
566 | second half of this BL, and if it is we simulate it | |
dfcd3bfb | 567 | immediately. */ |
c906108c | 568 | state->Reg[14] = state->Reg[15] \ |
7378e198 NC |
569 | + (((tinstr & 0x07FF) << 12) \ |
570 | | ((tinstr & (1 << 10)) ? 0xFF800000 : 0)); | |
571 | ||
dfcd3bfb JM |
572 | valid = t_branch; /* in-case we don't have the 2nd half */ |
573 | tinstr = next_instr; /* move the instruction down */ | |
4f3c3dbb | 574 | pc += 2; /* point the pc at the 2nd half */ |
c906108c | 575 | if (((tinstr & 0xF800) >> 11) != 31) |
f1129fb8 NC |
576 | { |
577 | if (((tinstr & 0xF800) >> 11) == 29) | |
578 | { | |
4f3c3dbb NC |
579 | ARMword tmp = (pc + 2); |
580 | ||
4f3c3dbb | 581 | state->Reg[15] = ((state->Reg[14] |
2984e114 | 582 | + ((tinstr & 0x07FE) << 1)) |
4f3c3dbb NC |
583 | & 0xFFFFFFFC); |
584 | CLEART; | |
585 | state->Reg[14] = (tmp | 1); | |
586 | valid = t_branch; | |
587 | FLUSHPIPE; | |
f1129fb8 | 588 | } |
4f3c3dbb NC |
589 | else |
590 | /* Exit, since not correct instruction. */ | |
591 | pc -= 2; | |
592 | break; | |
f1129fb8 | 593 | } |
c906108c | 594 | /* else we fall through to process the second half of the BL */ |
2984e114 | 595 | pc += 2; /* point the pc at the 2nd half */ |
dfcd3bfb | 596 | case 31: /* BL instruction 2 */ |
c906108c SS |
597 | /* Format 19 */ |
598 | /* There is no single ARM instruction equivalent for this | |
599 | instruction. Also, it should only ever be matched with the | |
600 | fmt19 "BL instruction 1" instruction. However, we do allow | |
601 | the simulation of it on its own, with undefined results if | |
dfcd3bfb | 602 | r14 is not suitably initialised. */ |
c906108c | 603 | { |
7378e198 NC |
604 | ARMword tmp = pc; |
605 | ||
dfcd3bfb JM |
606 | state->Reg[15] = (state->Reg[14] + ((tinstr & 0x07FF) << 1)); |
607 | state->Reg[14] = (tmp | 1); | |
608 | valid = t_branch; | |
609 | FLUSHPIPE; | |
c906108c SS |
610 | } |
611 | break; | |
612 | } | |
613 | ||
614 | return valid; | |
615 | } |