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c906108c SS |
1 | /* Target-dependent code for the Matsushita MN10200 for GDB, the GNU debugger. |
2 | Copyright 1997 Free Software Foundation, Inc. | |
3 | ||
c5aa993b | 4 | This file is part of GDB. |
c906108c | 5 | |
c5aa993b JM |
6 | This program is free software; you can redistribute it and/or modify |
7 | it under the terms of the GNU General Public License as published by | |
8 | the Free Software Foundation; either version 2 of the License, or | |
9 | (at your option) any later version. | |
c906108c | 10 | |
c5aa993b JM |
11 | This program is distributed in the hope that it will be useful, |
12 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
13 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
14 | GNU General Public License for more details. | |
c906108c | 15 | |
c5aa993b JM |
16 | You should have received a copy of the GNU General Public License |
17 | along with this program; if not, write to the Free Software | |
18 | Foundation, Inc., 59 Temple Place - Suite 330, | |
19 | Boston, MA 02111-1307, USA. */ | |
c906108c SS |
20 | |
21 | #include "defs.h" | |
22 | #include "frame.h" | |
23 | #include "inferior.h" | |
24 | #include "obstack.h" | |
25 | #include "target.h" | |
26 | #include "value.h" | |
27 | #include "bfd.h" | |
28 | #include "gdb_string.h" | |
29 | #include "gdbcore.h" | |
30 | #include "symfile.h" | |
31 | ||
c5aa993b | 32 | |
c906108c SS |
33 | /* Should call_function allocate stack space for a struct return? */ |
34 | int | |
35 | mn10200_use_struct_convention (gcc_p, type) | |
36 | int gcc_p; | |
37 | struct type *type; | |
38 | { | |
39 | return (TYPE_NFIELDS (type) > 1 || TYPE_LENGTH (type) > 8); | |
40 | } | |
9846de1b | 41 | /* *INDENT-OFF* */ |
c906108c SS |
42 | /* The main purpose of this file is dealing with prologues to extract |
43 | information about stack frames and saved registers. | |
44 | ||
45 | For reference here's how prologues look on the mn10200: | |
46 | ||
47 | With frame pointer: | |
48 | mov fp,a0 | |
49 | mov sp,fp | |
50 | add <size>,sp | |
51 | Register saves for d2, d3, a1, a2 as needed. Saves start | |
52 | at fp - <size> + <outgoing_args_size> and work towards higher | |
53 | addresses. Note that the saves are actually done off the stack | |
54 | pointer in the prologue! This makes for smaller code and easier | |
55 | prologue scanning as the displacement fields will unlikely | |
56 | be more than 8 bits! | |
57 | ||
58 | Without frame pointer: | |
59 | add <size>,sp | |
60 | Register saves for d2, d3, a1, a2 as needed. Saves start | |
61 | at sp + <outgoing_args_size> and work towards higher addresses. | |
62 | ||
63 | Out of line prologue: | |
64 | add <local size>,sp -- optional | |
65 | jsr __prologue | |
66 | add <outgoing_size>,sp -- optional | |
67 | ||
68 | The stack pointer remains constant throughout the life of most | |
69 | functions. As a result the compiler will usually omit the | |
70 | frame pointer, so we must handle frame pointerless functions. */ | |
71 | ||
72 | /* Analyze the prologue to determine where registers are saved, | |
73 | the end of the prologue, etc etc. Return the end of the prologue | |
74 | scanned. | |
75 | ||
76 | We store into FI (if non-null) several tidbits of information: | |
77 | ||
78 | * stack_size -- size of this stack frame. Note that if we stop in | |
79 | certain parts of the prologue/epilogue we may claim the size of the | |
80 | current frame is zero. This happens when the current frame has | |
81 | not been allocated yet or has already been deallocated. | |
82 | ||
83 | * fsr -- Addresses of registers saved in the stack by this frame. | |
84 | ||
85 | * status -- A (relatively) generic status indicator. It's a bitmask | |
86 | with the following bits: | |
87 | ||
88 | MY_FRAME_IN_SP: The base of the current frame is actually in | |
89 | the stack pointer. This can happen for frame pointerless | |
90 | functions, or cases where we're stopped in the prologue/epilogue | |
91 | itself. For these cases mn10200_analyze_prologue will need up | |
92 | update fi->frame before returning or analyzing the register | |
93 | save instructions. | |
94 | ||
95 | MY_FRAME_IN_FP: The base of the current frame is in the | |
96 | frame pointer register ($a2). | |
97 | ||
98 | CALLER_A2_IN_A0: $a2 from the caller's frame is temporarily | |
99 | in $a0. This can happen if we're stopped in the prologue. | |
100 | ||
101 | NO_MORE_FRAMES: Set this if the current frame is "start" or | |
102 | if the first instruction looks like mov <imm>,sp. This tells | |
103 | frame chain to not bother trying to unwind past this frame. */ | |
9846de1b | 104 | /* *INDENT-ON* */ |
c906108c | 105 | |
c5aa993b JM |
106 | |
107 | ||
108 | ||
c906108c SS |
109 | #define MY_FRAME_IN_SP 0x1 |
110 | #define MY_FRAME_IN_FP 0x2 | |
111 | #define CALLER_A2_IN_A0 0x4 | |
112 | #define NO_MORE_FRAMES 0x8 | |
c5aa993b | 113 | |
c906108c SS |
114 | static CORE_ADDR |
115 | mn10200_analyze_prologue (fi, pc) | |
c5aa993b JM |
116 | struct frame_info *fi; |
117 | CORE_ADDR pc; | |
c906108c SS |
118 | { |
119 | CORE_ADDR func_addr, func_end, addr, stop; | |
120 | CORE_ADDR stack_size; | |
121 | unsigned char buf[4]; | |
122 | int status; | |
123 | char *name; | |
124 | int out_of_line_prologue = 0; | |
125 | ||
126 | /* Use the PC in the frame if it's provided to look up the | |
127 | start of this function. */ | |
128 | pc = (fi ? fi->pc : pc); | |
129 | ||
130 | /* Find the start of this function. */ | |
131 | status = find_pc_partial_function (pc, &name, &func_addr, &func_end); | |
132 | ||
133 | /* Do nothing if we couldn't find the start of this function or if we're | |
134 | stopped at the first instruction in the prologue. */ | |
135 | if (status == 0) | |
136 | return pc; | |
137 | ||
138 | /* If we're in start, then give up. */ | |
139 | if (strcmp (name, "start") == 0) | |
140 | { | |
141 | if (fi) | |
c5aa993b | 142 | fi->status = NO_MORE_FRAMES; |
c906108c SS |
143 | return pc; |
144 | } | |
145 | ||
146 | /* At the start of a function our frame is in the stack pointer. */ | |
147 | if (fi) | |
148 | fi->status = MY_FRAME_IN_SP; | |
149 | ||
150 | /* If we're physically on an RTS instruction, then our frame has already | |
151 | been deallocated. | |
152 | ||
153 | fi->frame is bogus, we need to fix it. */ | |
154 | if (fi && fi->pc + 1 == func_end) | |
155 | { | |
156 | status = target_read_memory (fi->pc, buf, 1); | |
157 | if (status != 0) | |
158 | { | |
159 | if (fi->next == NULL) | |
160 | fi->frame = read_sp (); | |
161 | return fi->pc; | |
162 | } | |
163 | ||
164 | if (buf[0] == 0xfe) | |
165 | { | |
166 | if (fi->next == NULL) | |
167 | fi->frame = read_sp (); | |
168 | return fi->pc; | |
169 | } | |
170 | } | |
171 | ||
172 | /* Similarly if we're stopped on the first insn of a prologue as our | |
173 | frame hasn't been allocated yet. */ | |
174 | if (fi && fi->pc == func_addr) | |
175 | { | |
176 | if (fi->next == NULL) | |
177 | fi->frame = read_sp (); | |
178 | return fi->pc; | |
179 | } | |
180 | ||
181 | /* Figure out where to stop scanning. */ | |
182 | stop = fi ? fi->pc : func_end; | |
183 | ||
184 | /* Don't walk off the end of the function. */ | |
185 | stop = stop > func_end ? func_end : stop; | |
186 | ||
187 | /* Start scanning on the first instruction of this function. */ | |
188 | addr = func_addr; | |
189 | ||
190 | status = target_read_memory (addr, buf, 2); | |
191 | if (status != 0) | |
192 | { | |
193 | if (fi && fi->next == NULL && fi->status & MY_FRAME_IN_SP) | |
194 | fi->frame = read_sp (); | |
195 | return addr; | |
196 | } | |
197 | ||
198 | /* First see if this insn sets the stack pointer; if so, it's something | |
199 | we won't understand, so quit now. */ | |
200 | if (buf[0] == 0xdf | |
201 | || (buf[0] == 0xf4 && buf[1] == 0x77)) | |
202 | { | |
203 | if (fi) | |
204 | fi->status = NO_MORE_FRAMES; | |
205 | return addr; | |
206 | } | |
207 | ||
208 | /* Now see if we have a frame pointer. | |
c5aa993b | 209 | |
c906108c | 210 | Search for mov a2,a0 (0xf278) |
c5aa993b | 211 | then mov a3,a2 (0xf27e). */ |
c906108c SS |
212 | |
213 | if (buf[0] == 0xf2 && buf[1] == 0x78) | |
214 | { | |
215 | /* Our caller's $a2 will be found in $a0 now. Note it for | |
c5aa993b | 216 | our callers. */ |
c906108c SS |
217 | if (fi) |
218 | fi->status |= CALLER_A2_IN_A0; | |
219 | addr += 2; | |
220 | if (addr >= stop) | |
221 | { | |
222 | /* We still haven't allocated our local stack. Handle this | |
223 | as if we stopped on the first or last insn of a function. */ | |
224 | if (fi && fi->next == NULL) | |
225 | fi->frame = read_sp (); | |
226 | return addr; | |
227 | } | |
228 | ||
229 | status = target_read_memory (addr, buf, 2); | |
230 | if (status != 0) | |
231 | { | |
232 | if (fi && fi->next == NULL) | |
233 | fi->frame = read_sp (); | |
234 | return addr; | |
235 | } | |
236 | if (buf[0] == 0xf2 && buf[1] == 0x7e) | |
237 | { | |
238 | addr += 2; | |
239 | ||
240 | /* Our frame pointer is valid now. */ | |
241 | if (fi) | |
242 | { | |
243 | fi->status |= MY_FRAME_IN_FP; | |
244 | fi->status &= ~MY_FRAME_IN_SP; | |
245 | } | |
246 | if (addr >= stop) | |
247 | return addr; | |
248 | } | |
249 | else | |
250 | { | |
251 | if (fi && fi->next == NULL) | |
252 | fi->frame = read_sp (); | |
253 | return addr; | |
254 | } | |
255 | } | |
256 | ||
257 | /* Next we should allocate the local frame. | |
c5aa993b | 258 | |
c906108c | 259 | Search for add imm8,a3 (0xd3XX) |
c5aa993b JM |
260 | or add imm16,a3 (0xf70bXXXX) |
261 | or add imm24,a3 (0xf467XXXXXX). | |
262 | ||
c906108c SS |
263 | If none of the above was found, then this prologue has |
264 | no stack, and therefore can't have any register saves, | |
265 | so quit now. */ | |
266 | status = target_read_memory (addr, buf, 2); | |
267 | if (status != 0) | |
268 | { | |
269 | if (fi && fi->next == NULL && (fi->status & MY_FRAME_IN_SP)) | |
270 | fi->frame = read_sp (); | |
271 | return addr; | |
272 | } | |
273 | if (buf[0] == 0xd3) | |
274 | { | |
275 | stack_size = extract_signed_integer (&buf[1], 1); | |
276 | if (fi) | |
277 | fi->stack_size = stack_size; | |
278 | addr += 2; | |
279 | if (addr >= stop) | |
280 | { | |
281 | if (fi && fi->next == NULL && (fi->status & MY_FRAME_IN_SP)) | |
282 | fi->frame = read_sp () - stack_size; | |
283 | return addr; | |
284 | } | |
285 | } | |
286 | else if (buf[0] == 0xf7 && buf[1] == 0x0b) | |
287 | { | |
288 | status = target_read_memory (addr + 2, buf, 2); | |
289 | if (status != 0) | |
290 | { | |
291 | if (fi && fi->next == NULL && (fi->status & MY_FRAME_IN_SP)) | |
292 | fi->frame = read_sp (); | |
293 | return addr; | |
294 | } | |
295 | stack_size = extract_signed_integer (buf, 2); | |
296 | if (fi) | |
297 | fi->stack_size = stack_size; | |
298 | addr += 4; | |
299 | if (addr >= stop) | |
300 | { | |
301 | if (fi && fi->next == NULL && (fi->status & MY_FRAME_IN_SP)) | |
302 | fi->frame = read_sp () - stack_size; | |
303 | return addr; | |
304 | } | |
305 | } | |
306 | else if (buf[0] == 0xf4 && buf[1] == 0x67) | |
307 | { | |
308 | status = target_read_memory (addr + 2, buf, 3); | |
309 | if (status != 0) | |
310 | { | |
311 | if (fi && fi->next == NULL && (fi->status & MY_FRAME_IN_SP)) | |
312 | fi->frame = read_sp (); | |
313 | return addr; | |
314 | } | |
315 | stack_size = extract_signed_integer (buf, 3); | |
316 | if (fi) | |
317 | fi->stack_size = stack_size; | |
318 | addr += 5; | |
319 | if (addr >= stop) | |
320 | { | |
321 | if (fi && fi->next == NULL && (fi->status & MY_FRAME_IN_SP)) | |
322 | fi->frame = read_sp () - stack_size; | |
323 | return addr; | |
324 | } | |
325 | } | |
326 | ||
327 | /* Now see if we have a call to __prologue for an out of line | |
328 | prologue. */ | |
329 | status = target_read_memory (addr, buf, 2); | |
330 | if (status != 0) | |
331 | return addr; | |
332 | ||
333 | /* First check for 16bit pc-relative call to __prologue. */ | |
334 | if (buf[0] == 0xfd) | |
335 | { | |
336 | CORE_ADDR temp; | |
337 | status = target_read_memory (addr + 1, buf, 2); | |
338 | if (status != 0) | |
339 | { | |
c5aa993b JM |
340 | if (fi && fi->next == NULL && (fi->status & MY_FRAME_IN_SP)) |
341 | fi->frame = read_sp (); | |
c906108c SS |
342 | return addr; |
343 | } | |
c5aa993b | 344 | |
c906108c SS |
345 | /* Get the PC this instruction will branch to. */ |
346 | temp = (extract_signed_integer (buf, 2) + addr + 3) & 0xffffff; | |
347 | ||
348 | /* Get the name of the function at the target address. */ | |
349 | status = find_pc_partial_function (temp, &name, NULL, NULL); | |
350 | if (status == 0) | |
351 | { | |
c5aa993b JM |
352 | if (fi && fi->next == NULL && (fi->status & MY_FRAME_IN_SP)) |
353 | fi->frame = read_sp (); | |
c906108c SS |
354 | return addr; |
355 | } | |
356 | ||
357 | /* Note if it is an out of line prologue. */ | |
358 | out_of_line_prologue = (strcmp (name, "__prologue") == 0); | |
359 | ||
360 | /* This sucks up 3 bytes of instruction space. */ | |
361 | if (out_of_line_prologue) | |
362 | addr += 3; | |
363 | ||
364 | if (addr >= stop) | |
365 | { | |
366 | if (fi && fi->next == NULL) | |
367 | { | |
368 | fi->stack_size -= 16; | |
369 | fi->frame = read_sp () - fi->stack_size; | |
370 | } | |
371 | return addr; | |
372 | } | |
373 | } | |
374 | /* Now check for the 24bit pc-relative call to __prologue. */ | |
375 | else if (buf[0] == 0xf4 && buf[1] == 0xe1) | |
376 | { | |
377 | CORE_ADDR temp; | |
378 | status = target_read_memory (addr + 2, buf, 3); | |
379 | if (status != 0) | |
380 | { | |
c5aa993b JM |
381 | if (fi && fi->next == NULL && (fi->status & MY_FRAME_IN_SP)) |
382 | fi->frame = read_sp (); | |
c906108c SS |
383 | return addr; |
384 | } | |
c5aa993b | 385 | |
c906108c SS |
386 | /* Get the PC this instruction will branch to. */ |
387 | temp = (extract_signed_integer (buf, 3) + addr + 5) & 0xffffff; | |
388 | ||
389 | /* Get the name of the function at the target address. */ | |
390 | status = find_pc_partial_function (temp, &name, NULL, NULL); | |
391 | if (status == 0) | |
392 | { | |
c5aa993b JM |
393 | if (fi && fi->next == NULL && (fi->status & MY_FRAME_IN_SP)) |
394 | fi->frame = read_sp (); | |
c906108c SS |
395 | return addr; |
396 | } | |
397 | ||
398 | /* Note if it is an out of line prologue. */ | |
399 | out_of_line_prologue = (strcmp (name, "__prologue") == 0); | |
400 | ||
401 | /* This sucks up 5 bytes of instruction space. */ | |
402 | if (out_of_line_prologue) | |
403 | addr += 5; | |
404 | ||
405 | if (addr >= stop) | |
406 | { | |
407 | if (fi && fi->next == NULL && (fi->status & MY_FRAME_IN_SP)) | |
408 | { | |
409 | fi->stack_size -= 16; | |
410 | fi->frame = read_sp () - fi->stack_size; | |
411 | } | |
412 | return addr; | |
413 | } | |
414 | } | |
415 | ||
416 | /* Now actually handle the out of line prologue. */ | |
417 | if (out_of_line_prologue) | |
418 | { | |
419 | int outgoing_args_size = 0; | |
420 | ||
421 | /* First adjust the stack size for this function. The out of | |
c5aa993b | 422 | line prologue saves 4 registers (16bytes of data). */ |
c906108c SS |
423 | if (fi) |
424 | fi->stack_size -= 16; | |
425 | ||
426 | /* Update fi->frame if necessary. */ | |
427 | if (fi && fi->next == NULL) | |
428 | fi->frame = read_sp () - fi->stack_size; | |
429 | ||
430 | /* After the out of line prologue, there may be another | |
c5aa993b JM |
431 | stack adjustment for the outgoing arguments. |
432 | ||
433 | Search for add imm8,a3 (0xd3XX) | |
434 | or add imm16,a3 (0xf70bXXXX) | |
435 | or add imm24,a3 (0xf467XXXXXX). */ | |
c906108c | 436 | |
c906108c SS |
437 | status = target_read_memory (addr, buf, 2); |
438 | if (status != 0) | |
439 | { | |
440 | if (fi) | |
441 | { | |
442 | fi->fsr.regs[2] = fi->frame + fi->stack_size + 4; | |
443 | fi->fsr.regs[3] = fi->frame + fi->stack_size + 8; | |
444 | fi->fsr.regs[5] = fi->frame + fi->stack_size + 12; | |
445 | fi->fsr.regs[6] = fi->frame + fi->stack_size + 16; | |
446 | } | |
447 | return addr; | |
448 | } | |
449 | ||
450 | if (buf[0] == 0xd3) | |
451 | { | |
452 | outgoing_args_size = extract_signed_integer (&buf[1], 1); | |
453 | addr += 2; | |
454 | } | |
455 | else if (buf[0] == 0xf7 && buf[1] == 0x0b) | |
456 | { | |
457 | status = target_read_memory (addr + 2, buf, 2); | |
458 | if (status != 0) | |
459 | { | |
460 | if (fi) | |
461 | { | |
462 | fi->fsr.regs[2] = fi->frame + fi->stack_size + 4; | |
463 | fi->fsr.regs[3] = fi->frame + fi->stack_size + 8; | |
464 | fi->fsr.regs[5] = fi->frame + fi->stack_size + 12; | |
465 | fi->fsr.regs[6] = fi->frame + fi->stack_size + 16; | |
466 | } | |
467 | return addr; | |
468 | } | |
469 | outgoing_args_size = extract_signed_integer (buf, 2); | |
470 | addr += 4; | |
471 | } | |
472 | else if (buf[0] == 0xf4 && buf[1] == 0x67) | |
473 | { | |
474 | status = target_read_memory (addr + 2, buf, 3); | |
475 | if (status != 0) | |
476 | { | |
477 | if (fi && fi->next == NULL) | |
478 | { | |
479 | fi->fsr.regs[2] = fi->frame + fi->stack_size + 4; | |
480 | fi->fsr.regs[3] = fi->frame + fi->stack_size + 8; | |
481 | fi->fsr.regs[5] = fi->frame + fi->stack_size + 12; | |
482 | fi->fsr.regs[6] = fi->frame + fi->stack_size + 16; | |
483 | } | |
484 | return addr; | |
485 | } | |
486 | outgoing_args_size = extract_signed_integer (buf, 3); | |
487 | addr += 5; | |
488 | } | |
489 | else | |
490 | outgoing_args_size = 0; | |
491 | ||
492 | /* Now that we know the size of the outgoing arguments, fix | |
c5aa993b | 493 | fi->frame again if this is the innermost frame. */ |
c906108c SS |
494 | if (fi && fi->next == NULL) |
495 | fi->frame -= outgoing_args_size; | |
496 | ||
497 | /* Note the register save information and update the stack | |
c5aa993b | 498 | size for this frame too. */ |
c906108c SS |
499 | if (fi) |
500 | { | |
501 | fi->fsr.regs[2] = fi->frame + fi->stack_size + 4; | |
502 | fi->fsr.regs[3] = fi->frame + fi->stack_size + 8; | |
503 | fi->fsr.regs[5] = fi->frame + fi->stack_size + 12; | |
504 | fi->fsr.regs[6] = fi->frame + fi->stack_size + 16; | |
505 | fi->stack_size += outgoing_args_size; | |
506 | } | |
507 | /* There can be no more prologue insns, so return now. */ | |
508 | return addr; | |
509 | } | |
510 | ||
511 | /* At this point fi->frame needs to be correct. | |
512 | ||
513 | If MY_FRAME_IN_SP is set and we're the innermost frame, then we | |
514 | need to fix fi->frame so that backtracing, find_frame_saved_regs, | |
515 | etc work correctly. */ | |
516 | if (fi && fi->next == NULL && (fi->status & MY_FRAME_IN_SP) != 0) | |
517 | fi->frame = read_sp () - fi->stack_size; | |
518 | ||
519 | /* And last we have the register saves. These are relatively | |
520 | simple because they're physically done off the stack pointer, | |
521 | and thus the number of different instructions we need to | |
522 | check is greatly reduced because we know the displacements | |
523 | will be small. | |
c5aa993b | 524 | |
c906108c | 525 | Search for movx d2,(X,a3) (0xf55eXX) |
c5aa993b JM |
526 | then movx d3,(X,a3) (0xf55fXX) |
527 | then mov a1,(X,a3) (0x5dXX) No frame pointer case | |
528 | then mov a2,(X,a3) (0x5eXX) No frame pointer case | |
529 | or mov a0,(X,a3) (0x5cXX) Frame pointer case. */ | |
c906108c SS |
530 | |
531 | status = target_read_memory (addr, buf, 2); | |
532 | if (status != 0) | |
533 | return addr; | |
534 | if (buf[0] == 0xf5 && buf[1] == 0x5e) | |
535 | { | |
536 | if (fi) | |
537 | { | |
538 | status = target_read_memory (addr + 2, buf, 1); | |
539 | if (status != 0) | |
540 | return addr; | |
541 | fi->fsr.regs[2] = (fi->frame + stack_size | |
542 | + extract_signed_integer (buf, 1)); | |
543 | } | |
544 | addr += 3; | |
545 | if (addr >= stop) | |
546 | return addr; | |
547 | status = target_read_memory (addr, buf, 2); | |
548 | if (status != 0) | |
549 | return addr; | |
550 | } | |
551 | if (buf[0] == 0xf5 && buf[1] == 0x5f) | |
552 | { | |
553 | if (fi) | |
554 | { | |
555 | status = target_read_memory (addr + 2, buf, 1); | |
556 | if (status != 0) | |
557 | return addr; | |
558 | fi->fsr.regs[3] = (fi->frame + stack_size | |
559 | + extract_signed_integer (buf, 1)); | |
560 | } | |
561 | addr += 3; | |
562 | if (addr >= stop) | |
563 | return addr; | |
564 | status = target_read_memory (addr, buf, 2); | |
565 | if (status != 0) | |
566 | return addr; | |
567 | } | |
568 | if (buf[0] == 0x5d) | |
569 | { | |
570 | if (fi) | |
571 | { | |
572 | status = target_read_memory (addr + 1, buf, 1); | |
573 | if (status != 0) | |
574 | return addr; | |
575 | fi->fsr.regs[5] = (fi->frame + stack_size | |
576 | + extract_signed_integer (buf, 1)); | |
577 | } | |
578 | addr += 2; | |
579 | if (addr >= stop) | |
580 | return addr; | |
581 | status = target_read_memory (addr, buf, 2); | |
582 | if (status != 0) | |
583 | return addr; | |
584 | } | |
585 | if (buf[0] == 0x5e || buf[0] == 0x5c) | |
586 | { | |
587 | if (fi) | |
588 | { | |
589 | status = target_read_memory (addr + 1, buf, 1); | |
590 | if (status != 0) | |
591 | return addr; | |
592 | fi->fsr.regs[6] = (fi->frame + stack_size | |
593 | + extract_signed_integer (buf, 1)); | |
594 | fi->status &= ~CALLER_A2_IN_A0; | |
595 | } | |
596 | addr += 2; | |
597 | if (addr >= stop) | |
598 | return addr; | |
599 | return addr; | |
600 | } | |
601 | return addr; | |
602 | } | |
c5aa993b | 603 | |
c906108c SS |
604 | /* Function: frame_chain |
605 | Figure out and return the caller's frame pointer given current | |
606 | frame_info struct. | |
607 | ||
608 | We don't handle dummy frames yet but we would probably just return the | |
609 | stack pointer that was in use at the time the function call was made? */ | |
610 | ||
611 | CORE_ADDR | |
612 | mn10200_frame_chain (fi) | |
613 | struct frame_info *fi; | |
614 | { | |
615 | struct frame_info dummy_frame; | |
616 | ||
617 | /* Walk through the prologue to determine the stack size, | |
618 | location of saved registers, end of the prologue, etc. */ | |
619 | if (fi->status == 0) | |
c5aa993b | 620 | mn10200_analyze_prologue (fi, (CORE_ADDR) 0); |
c906108c SS |
621 | |
622 | /* Quit now if mn10200_analyze_prologue set NO_MORE_FRAMES. */ | |
623 | if (fi->status & NO_MORE_FRAMES) | |
624 | return 0; | |
625 | ||
626 | /* Now that we've analyzed our prologue, determine the frame | |
627 | pointer for our caller. | |
628 | ||
c5aa993b JM |
629 | If our caller has a frame pointer, then we need to |
630 | find the entry value of $a2 to our function. | |
c906108c | 631 | |
c5aa993b | 632 | If CALLER_A2_IN_A0, then the chain is in $a0. |
c906108c | 633 | |
c5aa993b JM |
634 | If fsr.regs[6] is nonzero, then it's at the memory |
635 | location pointed to by fsr.regs[6]. | |
c906108c | 636 | |
c5aa993b JM |
637 | Else it's still in $a2. |
638 | ||
639 | If our caller does not have a frame pointer, then his | |
640 | frame base is fi->frame + -caller's stack size + 4. */ | |
c906108c | 641 | |
c906108c SS |
642 | /* The easiest way to get that info is to analyze our caller's frame. |
643 | ||
644 | So we set up a dummy frame and call mn10200_analyze_prologue to | |
645 | find stuff for us. */ | |
646 | dummy_frame.pc = FRAME_SAVED_PC (fi); | |
647 | dummy_frame.frame = fi->frame; | |
648 | memset (dummy_frame.fsr.regs, '\000', sizeof dummy_frame.fsr.regs); | |
649 | dummy_frame.status = 0; | |
650 | dummy_frame.stack_size = 0; | |
651 | mn10200_analyze_prologue (&dummy_frame); | |
652 | ||
653 | if (dummy_frame.status & MY_FRAME_IN_FP) | |
654 | { | |
655 | /* Our caller has a frame pointer. So find the frame in $a2, $a0, | |
c5aa993b | 656 | or in the stack. */ |
c906108c SS |
657 | if (fi->fsr.regs[6]) |
658 | return (read_memory_integer (fi->fsr.regs[FP_REGNUM], REGISTER_SIZE) | |
659 | & 0xffffff); | |
660 | else if (fi->status & CALLER_A2_IN_A0) | |
661 | return read_register (4); | |
662 | else | |
663 | return read_register (FP_REGNUM); | |
664 | } | |
665 | else | |
666 | { | |
667 | /* Our caller does not have a frame pointer. So his frame starts | |
c5aa993b | 668 | at the base of our frame (fi->frame) + <his size> + 4 (saved pc). */ |
c906108c SS |
669 | return fi->frame + -dummy_frame.stack_size + 4; |
670 | } | |
671 | } | |
672 | ||
673 | /* Function: skip_prologue | |
674 | Return the address of the first inst past the prologue of the function. */ | |
675 | ||
676 | CORE_ADDR | |
677 | mn10200_skip_prologue (pc) | |
678 | CORE_ADDR pc; | |
679 | { | |
680 | /* We used to check the debug symbols, but that can lose if | |
681 | we have a null prologue. */ | |
682 | return mn10200_analyze_prologue (NULL, pc); | |
683 | } | |
684 | ||
685 | /* Function: pop_frame | |
686 | This routine gets called when either the user uses the `return' | |
687 | command, or the call dummy breakpoint gets hit. */ | |
688 | ||
689 | void | |
690 | mn10200_pop_frame (frame) | |
691 | struct frame_info *frame; | |
692 | { | |
693 | int regnum; | |
694 | ||
c5aa993b | 695 | if (PC_IN_CALL_DUMMY (frame->pc, frame->frame, frame->frame)) |
c906108c SS |
696 | generic_pop_dummy_frame (); |
697 | else | |
698 | { | |
699 | write_register (PC_REGNUM, FRAME_SAVED_PC (frame)); | |
700 | ||
701 | /* Restore any saved registers. */ | |
702 | for (regnum = 0; regnum < NUM_REGS; regnum++) | |
703 | if (frame->fsr.regs[regnum] != 0) | |
704 | { | |
705 | ULONGEST value; | |
706 | ||
707 | value = read_memory_unsigned_integer (frame->fsr.regs[regnum], | |
c5aa993b | 708 | REGISTER_RAW_SIZE (regnum)); |
c906108c SS |
709 | write_register (regnum, value); |
710 | } | |
711 | ||
712 | /* Actually cut back the stack. */ | |
713 | write_register (SP_REGNUM, FRAME_FP (frame)); | |
714 | ||
715 | /* Don't we need to set the PC?!? XXX FIXME. */ | |
716 | } | |
717 | ||
718 | /* Throw away any cached frame information. */ | |
719 | flush_cached_frames (); | |
720 | } | |
721 | ||
722 | /* Function: push_arguments | |
723 | Setup arguments for a call to the target. Arguments go in | |
724 | order on the stack. */ | |
725 | ||
726 | CORE_ADDR | |
727 | mn10200_push_arguments (nargs, args, sp, struct_return, struct_addr) | |
728 | int nargs; | |
729 | value_ptr *args; | |
730 | CORE_ADDR sp; | |
731 | unsigned char struct_return; | |
732 | CORE_ADDR struct_addr; | |
733 | { | |
734 | int argnum = 0; | |
735 | int len = 0; | |
736 | int stack_offset = 0; | |
737 | int regsused = struct_return ? 1 : 0; | |
738 | ||
739 | /* This should be a nop, but align the stack just in case something | |
740 | went wrong. Stacks are two byte aligned on the mn10200. */ | |
741 | sp &= ~1; | |
742 | ||
743 | /* Now make space on the stack for the args. | |
744 | ||
745 | XXX This doesn't appear to handle pass-by-invisible reference | |
746 | arguments. */ | |
747 | for (argnum = 0; argnum < nargs; argnum++) | |
748 | { | |
749 | int arg_length = (TYPE_LENGTH (VALUE_TYPE (args[argnum])) + 1) & ~1; | |
750 | ||
751 | /* If we've used all argument registers, then this argument is | |
c5aa993b | 752 | pushed. */ |
c906108c SS |
753 | if (regsused >= 2 || arg_length > 4) |
754 | { | |
755 | regsused = 2; | |
756 | len += arg_length; | |
757 | } | |
758 | /* We know we've got some arg register space left. If this argument | |
c5aa993b | 759 | will fit entirely in regs, then put it there. */ |
c906108c | 760 | else if (arg_length <= 2 |
c5aa993b | 761 | || TYPE_CODE (VALUE_TYPE (args[argnum])) == TYPE_CODE_PTR) |
c906108c SS |
762 | { |
763 | regsused++; | |
764 | } | |
765 | else if (regsused == 0) | |
766 | { | |
767 | regsused = 2; | |
768 | } | |
769 | else | |
770 | { | |
771 | regsused = 2; | |
772 | len += arg_length; | |
773 | } | |
774 | } | |
775 | ||
776 | /* Allocate stack space. */ | |
777 | sp -= len; | |
778 | ||
779 | regsused = struct_return ? 1 : 0; | |
780 | /* Push all arguments onto the stack. */ | |
781 | for (argnum = 0; argnum < nargs; argnum++) | |
782 | { | |
783 | int len; | |
784 | char *val; | |
785 | ||
786 | /* XXX Check this. What about UNIONS? */ | |
787 | if (TYPE_CODE (VALUE_TYPE (*args)) == TYPE_CODE_STRUCT | |
788 | && TYPE_LENGTH (VALUE_TYPE (*args)) > 8) | |
789 | { | |
790 | /* XXX Wrong, we want a pointer to this argument. */ | |
c5aa993b JM |
791 | len = TYPE_LENGTH (VALUE_TYPE (*args)); |
792 | val = (char *) VALUE_CONTENTS (*args); | |
c906108c SS |
793 | } |
794 | else | |
795 | { | |
796 | len = TYPE_LENGTH (VALUE_TYPE (*args)); | |
c5aa993b | 797 | val = (char *) VALUE_CONTENTS (*args); |
c906108c SS |
798 | } |
799 | ||
800 | if (regsused < 2 | |
801 | && (len <= 2 | |
802 | || TYPE_CODE (VALUE_TYPE (*args)) == TYPE_CODE_PTR)) | |
803 | { | |
804 | write_register (regsused, extract_unsigned_integer (val, 4)); | |
805 | regsused++; | |
806 | } | |
807 | else if (regsused == 0 && len == 4) | |
808 | { | |
809 | write_register (regsused, extract_unsigned_integer (val, 2)); | |
810 | write_register (regsused + 1, extract_unsigned_integer (val + 2, 2)); | |
811 | regsused = 2; | |
812 | } | |
813 | else | |
814 | { | |
815 | regsused = 2; | |
816 | while (len > 0) | |
817 | { | |
818 | write_memory (sp + stack_offset, val, 2); | |
819 | ||
820 | len -= 2; | |
821 | val += 2; | |
822 | stack_offset += 2; | |
823 | } | |
824 | } | |
825 | args++; | |
826 | } | |
827 | ||
828 | return sp; | |
829 | } | |
830 | ||
831 | /* Function: push_return_address (pc) | |
832 | Set up the return address for the inferior function call. | |
833 | Needed for targets where we don't actually execute a JSR/BSR instruction */ | |
c5aa993b | 834 | |
c906108c SS |
835 | CORE_ADDR |
836 | mn10200_push_return_address (pc, sp) | |
837 | CORE_ADDR pc; | |
838 | CORE_ADDR sp; | |
839 | { | |
840 | unsigned char buf[4]; | |
841 | ||
842 | store_unsigned_integer (buf, 4, CALL_DUMMY_ADDRESS ()); | |
843 | write_memory (sp - 4, buf, 4); | |
844 | return sp - 4; | |
845 | } | |
846 | ||
847 | /* Function: store_struct_return (addr,sp) | |
848 | Store the structure value return address for an inferior function | |
849 | call. */ | |
c5aa993b | 850 | |
c906108c SS |
851 | CORE_ADDR |
852 | mn10200_store_struct_return (addr, sp) | |
853 | CORE_ADDR addr; | |
854 | CORE_ADDR sp; | |
855 | { | |
856 | /* The structure return address is passed as the first argument. */ | |
857 | write_register (0, addr); | |
858 | return sp; | |
859 | } | |
c5aa993b | 860 | |
c906108c SS |
861 | /* Function: frame_saved_pc |
862 | Find the caller of this frame. We do this by seeing if RP_REGNUM | |
863 | is saved in the stack anywhere, otherwise we get it from the | |
864 | registers. If the inner frame is a dummy frame, return its PC | |
865 | instead of RP, because that's where "caller" of the dummy-frame | |
866 | will be found. */ | |
867 | ||
868 | CORE_ADDR | |
869 | mn10200_frame_saved_pc (fi) | |
870 | struct frame_info *fi; | |
871 | { | |
872 | /* The saved PC will always be at the base of the current frame. */ | |
873 | return (read_memory_integer (fi->frame, REGISTER_SIZE) & 0xffffff); | |
874 | } | |
875 | ||
c906108c SS |
876 | /* Function: init_extra_frame_info |
877 | Setup the frame's frame pointer, pc, and frame addresses for saved | |
878 | registers. Most of the work is done in mn10200_analyze_prologue(). | |
879 | ||
880 | Note that when we are called for the last frame (currently active frame), | |
881 | that fi->pc and fi->frame will already be setup. However, fi->frame will | |
882 | be valid only if this routine uses FP. For previous frames, fi-frame will | |
883 | always be correct. mn10200_analyze_prologue will fix fi->frame if | |
884 | it's not valid. | |
885 | ||
886 | We can be called with the PC in the call dummy under two circumstances. | |
887 | First, during normal backtracing, second, while figuring out the frame | |
888 | pointer just prior to calling the target function (see run_stack_dummy). */ | |
889 | ||
890 | void | |
891 | mn10200_init_extra_frame_info (fi) | |
892 | struct frame_info *fi; | |
893 | { | |
894 | if (fi->next) | |
895 | fi->pc = FRAME_SAVED_PC (fi->next); | |
896 | ||
897 | memset (fi->fsr.regs, '\000', sizeof fi->fsr.regs); | |
898 | fi->status = 0; | |
899 | fi->stack_size = 0; | |
900 | ||
901 | mn10200_analyze_prologue (fi, 0); | |
902 | } | |
903 | ||
904 | void | |
905 | _initialize_mn10200_tdep () | |
906 | { | |
907 | tm_print_insn = print_insn_mn10200; | |
908 | } |