Commit | Line | Data |
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c906108c | 1 | /* Target-dependent code for the Matsushita MN10200 for GDB, the GNU debugger. |
b6ba6518 | 2 | Copyright 1997, 1998, 1999, 2000, 2001 Free Software Foundation, Inc. |
c906108c | 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" | |
4e052eda | 31 | #include "regcache.h" |
c906108c | 32 | |
c5aa993b | 33 | |
c906108c SS |
34 | /* Should call_function allocate stack space for a struct return? */ |
35 | int | |
fba45db2 | 36 | mn10200_use_struct_convention (int gcc_p, struct type *type) |
c906108c SS |
37 | { |
38 | return (TYPE_NFIELDS (type) > 1 || TYPE_LENGTH (type) > 8); | |
39 | } | |
9846de1b | 40 | /* *INDENT-OFF* */ |
c906108c SS |
41 | /* The main purpose of this file is dealing with prologues to extract |
42 | information about stack frames and saved registers. | |
43 | ||
44 | For reference here's how prologues look on the mn10200: | |
45 | ||
46 | With frame pointer: | |
47 | mov fp,a0 | |
48 | mov sp,fp | |
49 | add <size>,sp | |
50 | Register saves for d2, d3, a1, a2 as needed. Saves start | |
51 | at fp - <size> + <outgoing_args_size> and work towards higher | |
52 | addresses. Note that the saves are actually done off the stack | |
53 | pointer in the prologue! This makes for smaller code and easier | |
54 | prologue scanning as the displacement fields will unlikely | |
55 | be more than 8 bits! | |
56 | ||
57 | Without frame pointer: | |
58 | add <size>,sp | |
59 | Register saves for d2, d3, a1, a2 as needed. Saves start | |
60 | at sp + <outgoing_args_size> and work towards higher addresses. | |
61 | ||
62 | Out of line prologue: | |
63 | add <local size>,sp -- optional | |
64 | jsr __prologue | |
65 | add <outgoing_size>,sp -- optional | |
66 | ||
67 | The stack pointer remains constant throughout the life of most | |
68 | functions. As a result the compiler will usually omit the | |
69 | frame pointer, so we must handle frame pointerless functions. */ | |
70 | ||
71 | /* Analyze the prologue to determine where registers are saved, | |
72 | the end of the prologue, etc etc. Return the end of the prologue | |
73 | scanned. | |
74 | ||
75 | We store into FI (if non-null) several tidbits of information: | |
76 | ||
77 | * stack_size -- size of this stack frame. Note that if we stop in | |
78 | certain parts of the prologue/epilogue we may claim the size of the | |
79 | current frame is zero. This happens when the current frame has | |
80 | not been allocated yet or has already been deallocated. | |
81 | ||
82 | * fsr -- Addresses of registers saved in the stack by this frame. | |
83 | ||
84 | * status -- A (relatively) generic status indicator. It's a bitmask | |
85 | with the following bits: | |
86 | ||
87 | MY_FRAME_IN_SP: The base of the current frame is actually in | |
88 | the stack pointer. This can happen for frame pointerless | |
89 | functions, or cases where we're stopped in the prologue/epilogue | |
90 | itself. For these cases mn10200_analyze_prologue will need up | |
91 | update fi->frame before returning or analyzing the register | |
92 | save instructions. | |
93 | ||
94 | MY_FRAME_IN_FP: The base of the current frame is in the | |
95 | frame pointer register ($a2). | |
96 | ||
97 | CALLER_A2_IN_A0: $a2 from the caller's frame is temporarily | |
98 | in $a0. This can happen if we're stopped in the prologue. | |
99 | ||
100 | NO_MORE_FRAMES: Set this if the current frame is "start" or | |
101 | if the first instruction looks like mov <imm>,sp. This tells | |
102 | frame chain to not bother trying to unwind past this frame. */ | |
9846de1b | 103 | /* *INDENT-ON* */ |
c906108c | 104 | |
c5aa993b JM |
105 | |
106 | ||
107 | ||
c906108c SS |
108 | #define MY_FRAME_IN_SP 0x1 |
109 | #define MY_FRAME_IN_FP 0x2 | |
110 | #define CALLER_A2_IN_A0 0x4 | |
111 | #define NO_MORE_FRAMES 0x8 | |
c5aa993b | 112 | |
c906108c | 113 | static CORE_ADDR |
fba45db2 | 114 | mn10200_analyze_prologue (struct frame_info *fi, CORE_ADDR pc) |
c906108c SS |
115 | { |
116 | CORE_ADDR func_addr, func_end, addr, stop; | |
93d56215 | 117 | CORE_ADDR stack_size = 0; |
c906108c SS |
118 | unsigned char buf[4]; |
119 | int status; | |
120 | char *name; | |
121 | int out_of_line_prologue = 0; | |
122 | ||
123 | /* Use the PC in the frame if it's provided to look up the | |
124 | start of this function. */ | |
125 | pc = (fi ? fi->pc : pc); | |
126 | ||
127 | /* Find the start of this function. */ | |
128 | status = find_pc_partial_function (pc, &name, &func_addr, &func_end); | |
129 | ||
130 | /* Do nothing if we couldn't find the start of this function or if we're | |
131 | stopped at the first instruction in the prologue. */ | |
132 | if (status == 0) | |
133 | return pc; | |
134 | ||
135 | /* If we're in start, then give up. */ | |
136 | if (strcmp (name, "start") == 0) | |
137 | { | |
138 | if (fi) | |
c5aa993b | 139 | fi->status = NO_MORE_FRAMES; |
c906108c SS |
140 | return pc; |
141 | } | |
142 | ||
143 | /* At the start of a function our frame is in the stack pointer. */ | |
144 | if (fi) | |
145 | fi->status = MY_FRAME_IN_SP; | |
146 | ||
147 | /* If we're physically on an RTS instruction, then our frame has already | |
148 | been deallocated. | |
149 | ||
150 | fi->frame is bogus, we need to fix it. */ | |
151 | if (fi && fi->pc + 1 == func_end) | |
152 | { | |
153 | status = target_read_memory (fi->pc, buf, 1); | |
154 | if (status != 0) | |
155 | { | |
156 | if (fi->next == NULL) | |
157 | fi->frame = read_sp (); | |
158 | return fi->pc; | |
159 | } | |
160 | ||
161 | if (buf[0] == 0xfe) | |
162 | { | |
163 | if (fi->next == NULL) | |
164 | fi->frame = read_sp (); | |
165 | return fi->pc; | |
166 | } | |
167 | } | |
168 | ||
169 | /* Similarly if we're stopped on the first insn of a prologue as our | |
170 | frame hasn't been allocated yet. */ | |
171 | if (fi && fi->pc == func_addr) | |
172 | { | |
173 | if (fi->next == NULL) | |
174 | fi->frame = read_sp (); | |
175 | return fi->pc; | |
176 | } | |
177 | ||
178 | /* Figure out where to stop scanning. */ | |
179 | stop = fi ? fi->pc : func_end; | |
180 | ||
181 | /* Don't walk off the end of the function. */ | |
182 | stop = stop > func_end ? func_end : stop; | |
183 | ||
184 | /* Start scanning on the first instruction of this function. */ | |
185 | addr = func_addr; | |
186 | ||
187 | status = target_read_memory (addr, buf, 2); | |
188 | if (status != 0) | |
189 | { | |
190 | if (fi && fi->next == NULL && fi->status & MY_FRAME_IN_SP) | |
191 | fi->frame = read_sp (); | |
192 | return addr; | |
193 | } | |
194 | ||
195 | /* First see if this insn sets the stack pointer; if so, it's something | |
196 | we won't understand, so quit now. */ | |
197 | if (buf[0] == 0xdf | |
198 | || (buf[0] == 0xf4 && buf[1] == 0x77)) | |
199 | { | |
200 | if (fi) | |
201 | fi->status = NO_MORE_FRAMES; | |
202 | return addr; | |
203 | } | |
204 | ||
205 | /* Now see if we have a frame pointer. | |
c5aa993b | 206 | |
c906108c | 207 | Search for mov a2,a0 (0xf278) |
c5aa993b | 208 | then mov a3,a2 (0xf27e). */ |
c906108c SS |
209 | |
210 | if (buf[0] == 0xf2 && buf[1] == 0x78) | |
211 | { | |
212 | /* Our caller's $a2 will be found in $a0 now. Note it for | |
c5aa993b | 213 | our callers. */ |
c906108c SS |
214 | if (fi) |
215 | fi->status |= CALLER_A2_IN_A0; | |
216 | addr += 2; | |
217 | if (addr >= stop) | |
218 | { | |
219 | /* We still haven't allocated our local stack. Handle this | |
220 | as if we stopped on the first or last insn of a function. */ | |
221 | if (fi && fi->next == NULL) | |
222 | fi->frame = read_sp (); | |
223 | return addr; | |
224 | } | |
225 | ||
226 | status = target_read_memory (addr, buf, 2); | |
227 | if (status != 0) | |
228 | { | |
229 | if (fi && fi->next == NULL) | |
230 | fi->frame = read_sp (); | |
231 | return addr; | |
232 | } | |
233 | if (buf[0] == 0xf2 && buf[1] == 0x7e) | |
234 | { | |
235 | addr += 2; | |
236 | ||
237 | /* Our frame pointer is valid now. */ | |
238 | if (fi) | |
239 | { | |
240 | fi->status |= MY_FRAME_IN_FP; | |
241 | fi->status &= ~MY_FRAME_IN_SP; | |
242 | } | |
243 | if (addr >= stop) | |
244 | return addr; | |
245 | } | |
246 | else | |
247 | { | |
248 | if (fi && fi->next == NULL) | |
249 | fi->frame = read_sp (); | |
250 | return addr; | |
251 | } | |
252 | } | |
253 | ||
254 | /* Next we should allocate the local frame. | |
c5aa993b | 255 | |
c906108c | 256 | Search for add imm8,a3 (0xd3XX) |
c5aa993b JM |
257 | or add imm16,a3 (0xf70bXXXX) |
258 | or add imm24,a3 (0xf467XXXXXX). | |
259 | ||
c906108c SS |
260 | If none of the above was found, then this prologue has |
261 | no stack, and therefore can't have any register saves, | |
262 | so quit now. */ | |
263 | status = target_read_memory (addr, buf, 2); | |
264 | if (status != 0) | |
265 | { | |
266 | if (fi && fi->next == NULL && (fi->status & MY_FRAME_IN_SP)) | |
267 | fi->frame = read_sp (); | |
268 | return addr; | |
269 | } | |
270 | if (buf[0] == 0xd3) | |
271 | { | |
272 | stack_size = extract_signed_integer (&buf[1], 1); | |
273 | if (fi) | |
274 | fi->stack_size = stack_size; | |
275 | addr += 2; | |
276 | if (addr >= stop) | |
277 | { | |
278 | if (fi && fi->next == NULL && (fi->status & MY_FRAME_IN_SP)) | |
279 | fi->frame = read_sp () - stack_size; | |
280 | return addr; | |
281 | } | |
282 | } | |
283 | else if (buf[0] == 0xf7 && buf[1] == 0x0b) | |
284 | { | |
285 | status = target_read_memory (addr + 2, buf, 2); | |
286 | if (status != 0) | |
287 | { | |
288 | if (fi && fi->next == NULL && (fi->status & MY_FRAME_IN_SP)) | |
289 | fi->frame = read_sp (); | |
290 | return addr; | |
291 | } | |
292 | stack_size = extract_signed_integer (buf, 2); | |
293 | if (fi) | |
294 | fi->stack_size = stack_size; | |
295 | addr += 4; | |
296 | if (addr >= stop) | |
297 | { | |
298 | if (fi && fi->next == NULL && (fi->status & MY_FRAME_IN_SP)) | |
299 | fi->frame = read_sp () - stack_size; | |
300 | return addr; | |
301 | } | |
302 | } | |
303 | else if (buf[0] == 0xf4 && buf[1] == 0x67) | |
304 | { | |
305 | status = target_read_memory (addr + 2, buf, 3); | |
306 | if (status != 0) | |
307 | { | |
308 | if (fi && fi->next == NULL && (fi->status & MY_FRAME_IN_SP)) | |
309 | fi->frame = read_sp (); | |
310 | return addr; | |
311 | } | |
312 | stack_size = extract_signed_integer (buf, 3); | |
313 | if (fi) | |
314 | fi->stack_size = stack_size; | |
315 | addr += 5; | |
316 | if (addr >= stop) | |
317 | { | |
318 | if (fi && fi->next == NULL && (fi->status & MY_FRAME_IN_SP)) | |
319 | fi->frame = read_sp () - stack_size; | |
320 | return addr; | |
321 | } | |
322 | } | |
323 | ||
324 | /* Now see if we have a call to __prologue for an out of line | |
325 | prologue. */ | |
326 | status = target_read_memory (addr, buf, 2); | |
327 | if (status != 0) | |
328 | return addr; | |
329 | ||
330 | /* First check for 16bit pc-relative call to __prologue. */ | |
331 | if (buf[0] == 0xfd) | |
332 | { | |
333 | CORE_ADDR temp; | |
334 | status = target_read_memory (addr + 1, buf, 2); | |
335 | if (status != 0) | |
336 | { | |
c5aa993b JM |
337 | if (fi && fi->next == NULL && (fi->status & MY_FRAME_IN_SP)) |
338 | fi->frame = read_sp (); | |
c906108c SS |
339 | return addr; |
340 | } | |
c5aa993b | 341 | |
c906108c SS |
342 | /* Get the PC this instruction will branch to. */ |
343 | temp = (extract_signed_integer (buf, 2) + addr + 3) & 0xffffff; | |
344 | ||
345 | /* Get the name of the function at the target address. */ | |
346 | status = find_pc_partial_function (temp, &name, NULL, NULL); | |
347 | if (status == 0) | |
348 | { | |
c5aa993b JM |
349 | if (fi && fi->next == NULL && (fi->status & MY_FRAME_IN_SP)) |
350 | fi->frame = read_sp (); | |
c906108c SS |
351 | return addr; |
352 | } | |
353 | ||
354 | /* Note if it is an out of line prologue. */ | |
355 | out_of_line_prologue = (strcmp (name, "__prologue") == 0); | |
356 | ||
357 | /* This sucks up 3 bytes of instruction space. */ | |
358 | if (out_of_line_prologue) | |
359 | addr += 3; | |
360 | ||
361 | if (addr >= stop) | |
362 | { | |
363 | if (fi && fi->next == NULL) | |
364 | { | |
365 | fi->stack_size -= 16; | |
366 | fi->frame = read_sp () - fi->stack_size; | |
367 | } | |
368 | return addr; | |
369 | } | |
370 | } | |
371 | /* Now check for the 24bit pc-relative call to __prologue. */ | |
372 | else if (buf[0] == 0xf4 && buf[1] == 0xe1) | |
373 | { | |
374 | CORE_ADDR temp; | |
375 | status = target_read_memory (addr + 2, buf, 3); | |
376 | if (status != 0) | |
377 | { | |
c5aa993b JM |
378 | if (fi && fi->next == NULL && (fi->status & MY_FRAME_IN_SP)) |
379 | fi->frame = read_sp (); | |
c906108c SS |
380 | return addr; |
381 | } | |
c5aa993b | 382 | |
c906108c SS |
383 | /* Get the PC this instruction will branch to. */ |
384 | temp = (extract_signed_integer (buf, 3) + addr + 5) & 0xffffff; | |
385 | ||
386 | /* Get the name of the function at the target address. */ | |
387 | status = find_pc_partial_function (temp, &name, NULL, NULL); | |
388 | if (status == 0) | |
389 | { | |
c5aa993b JM |
390 | if (fi && fi->next == NULL && (fi->status & MY_FRAME_IN_SP)) |
391 | fi->frame = read_sp (); | |
c906108c SS |
392 | return addr; |
393 | } | |
394 | ||
395 | /* Note if it is an out of line prologue. */ | |
396 | out_of_line_prologue = (strcmp (name, "__prologue") == 0); | |
397 | ||
398 | /* This sucks up 5 bytes of instruction space. */ | |
399 | if (out_of_line_prologue) | |
400 | addr += 5; | |
401 | ||
402 | if (addr >= stop) | |
403 | { | |
404 | if (fi && fi->next == NULL && (fi->status & MY_FRAME_IN_SP)) | |
405 | { | |
406 | fi->stack_size -= 16; | |
407 | fi->frame = read_sp () - fi->stack_size; | |
408 | } | |
409 | return addr; | |
410 | } | |
411 | } | |
412 | ||
413 | /* Now actually handle the out of line prologue. */ | |
414 | if (out_of_line_prologue) | |
415 | { | |
416 | int outgoing_args_size = 0; | |
417 | ||
418 | /* First adjust the stack size for this function. The out of | |
c5aa993b | 419 | line prologue saves 4 registers (16bytes of data). */ |
c906108c SS |
420 | if (fi) |
421 | fi->stack_size -= 16; | |
422 | ||
423 | /* Update fi->frame if necessary. */ | |
424 | if (fi && fi->next == NULL) | |
425 | fi->frame = read_sp () - fi->stack_size; | |
426 | ||
427 | /* After the out of line prologue, there may be another | |
c5aa993b JM |
428 | stack adjustment for the outgoing arguments. |
429 | ||
430 | Search for add imm8,a3 (0xd3XX) | |
431 | or add imm16,a3 (0xf70bXXXX) | |
432 | or add imm24,a3 (0xf467XXXXXX). */ | |
c906108c | 433 | |
c906108c SS |
434 | status = target_read_memory (addr, buf, 2); |
435 | if (status != 0) | |
436 | { | |
437 | if (fi) | |
438 | { | |
439 | fi->fsr.regs[2] = fi->frame + fi->stack_size + 4; | |
440 | fi->fsr.regs[3] = fi->frame + fi->stack_size + 8; | |
441 | fi->fsr.regs[5] = fi->frame + fi->stack_size + 12; | |
442 | fi->fsr.regs[6] = fi->frame + fi->stack_size + 16; | |
443 | } | |
444 | return addr; | |
445 | } | |
446 | ||
447 | if (buf[0] == 0xd3) | |
448 | { | |
449 | outgoing_args_size = extract_signed_integer (&buf[1], 1); | |
450 | addr += 2; | |
451 | } | |
452 | else if (buf[0] == 0xf7 && buf[1] == 0x0b) | |
453 | { | |
454 | status = target_read_memory (addr + 2, buf, 2); | |
455 | if (status != 0) | |
456 | { | |
457 | if (fi) | |
458 | { | |
459 | fi->fsr.regs[2] = fi->frame + fi->stack_size + 4; | |
460 | fi->fsr.regs[3] = fi->frame + fi->stack_size + 8; | |
461 | fi->fsr.regs[5] = fi->frame + fi->stack_size + 12; | |
462 | fi->fsr.regs[6] = fi->frame + fi->stack_size + 16; | |
463 | } | |
464 | return addr; | |
465 | } | |
466 | outgoing_args_size = extract_signed_integer (buf, 2); | |
467 | addr += 4; | |
468 | } | |
469 | else if (buf[0] == 0xf4 && buf[1] == 0x67) | |
470 | { | |
471 | status = target_read_memory (addr + 2, buf, 3); | |
472 | if (status != 0) | |
473 | { | |
474 | if (fi && fi->next == NULL) | |
475 | { | |
476 | fi->fsr.regs[2] = fi->frame + fi->stack_size + 4; | |
477 | fi->fsr.regs[3] = fi->frame + fi->stack_size + 8; | |
478 | fi->fsr.regs[5] = fi->frame + fi->stack_size + 12; | |
479 | fi->fsr.regs[6] = fi->frame + fi->stack_size + 16; | |
480 | } | |
481 | return addr; | |
482 | } | |
483 | outgoing_args_size = extract_signed_integer (buf, 3); | |
484 | addr += 5; | |
485 | } | |
486 | else | |
487 | outgoing_args_size = 0; | |
488 | ||
489 | /* Now that we know the size of the outgoing arguments, fix | |
c5aa993b | 490 | fi->frame again if this is the innermost frame. */ |
c906108c SS |
491 | if (fi && fi->next == NULL) |
492 | fi->frame -= outgoing_args_size; | |
493 | ||
494 | /* Note the register save information and update the stack | |
c5aa993b | 495 | size for this frame too. */ |
c906108c SS |
496 | if (fi) |
497 | { | |
498 | fi->fsr.regs[2] = fi->frame + fi->stack_size + 4; | |
499 | fi->fsr.regs[3] = fi->frame + fi->stack_size + 8; | |
500 | fi->fsr.regs[5] = fi->frame + fi->stack_size + 12; | |
501 | fi->fsr.regs[6] = fi->frame + fi->stack_size + 16; | |
502 | fi->stack_size += outgoing_args_size; | |
503 | } | |
504 | /* There can be no more prologue insns, so return now. */ | |
505 | return addr; | |
506 | } | |
507 | ||
508 | /* At this point fi->frame needs to be correct. | |
509 | ||
510 | If MY_FRAME_IN_SP is set and we're the innermost frame, then we | |
511 | need to fix fi->frame so that backtracing, find_frame_saved_regs, | |
512 | etc work correctly. */ | |
513 | if (fi && fi->next == NULL && (fi->status & MY_FRAME_IN_SP) != 0) | |
514 | fi->frame = read_sp () - fi->stack_size; | |
515 | ||
516 | /* And last we have the register saves. These are relatively | |
517 | simple because they're physically done off the stack pointer, | |
518 | and thus the number of different instructions we need to | |
519 | check is greatly reduced because we know the displacements | |
520 | will be small. | |
c5aa993b | 521 | |
c906108c | 522 | Search for movx d2,(X,a3) (0xf55eXX) |
c5aa993b JM |
523 | then movx d3,(X,a3) (0xf55fXX) |
524 | then mov a1,(X,a3) (0x5dXX) No frame pointer case | |
525 | then mov a2,(X,a3) (0x5eXX) No frame pointer case | |
526 | or mov a0,(X,a3) (0x5cXX) Frame pointer case. */ | |
c906108c SS |
527 | |
528 | status = target_read_memory (addr, buf, 2); | |
529 | if (status != 0) | |
530 | return addr; | |
531 | if (buf[0] == 0xf5 && buf[1] == 0x5e) | |
532 | { | |
533 | if (fi) | |
534 | { | |
535 | status = target_read_memory (addr + 2, buf, 1); | |
536 | if (status != 0) | |
537 | return addr; | |
538 | fi->fsr.regs[2] = (fi->frame + stack_size | |
539 | + extract_signed_integer (buf, 1)); | |
540 | } | |
541 | addr += 3; | |
542 | if (addr >= stop) | |
543 | return addr; | |
544 | status = target_read_memory (addr, buf, 2); | |
545 | if (status != 0) | |
546 | return addr; | |
547 | } | |
548 | if (buf[0] == 0xf5 && buf[1] == 0x5f) | |
549 | { | |
550 | if (fi) | |
551 | { | |
552 | status = target_read_memory (addr + 2, buf, 1); | |
553 | if (status != 0) | |
554 | return addr; | |
555 | fi->fsr.regs[3] = (fi->frame + stack_size | |
556 | + extract_signed_integer (buf, 1)); | |
557 | } | |
558 | addr += 3; | |
559 | if (addr >= stop) | |
560 | return addr; | |
561 | status = target_read_memory (addr, buf, 2); | |
562 | if (status != 0) | |
563 | return addr; | |
564 | } | |
565 | if (buf[0] == 0x5d) | |
566 | { | |
567 | if (fi) | |
568 | { | |
569 | status = target_read_memory (addr + 1, buf, 1); | |
570 | if (status != 0) | |
571 | return addr; | |
572 | fi->fsr.regs[5] = (fi->frame + stack_size | |
573 | + extract_signed_integer (buf, 1)); | |
574 | } | |
575 | addr += 2; | |
576 | if (addr >= stop) | |
577 | return addr; | |
578 | status = target_read_memory (addr, buf, 2); | |
579 | if (status != 0) | |
580 | return addr; | |
581 | } | |
582 | if (buf[0] == 0x5e || buf[0] == 0x5c) | |
583 | { | |
584 | if (fi) | |
585 | { | |
586 | status = target_read_memory (addr + 1, buf, 1); | |
587 | if (status != 0) | |
588 | return addr; | |
589 | fi->fsr.regs[6] = (fi->frame + stack_size | |
590 | + extract_signed_integer (buf, 1)); | |
591 | fi->status &= ~CALLER_A2_IN_A0; | |
592 | } | |
593 | addr += 2; | |
594 | if (addr >= stop) | |
595 | return addr; | |
596 | return addr; | |
597 | } | |
598 | return addr; | |
599 | } | |
c5aa993b | 600 | |
c906108c SS |
601 | /* Function: frame_chain |
602 | Figure out and return the caller's frame pointer given current | |
603 | frame_info struct. | |
604 | ||
605 | We don't handle dummy frames yet but we would probably just return the | |
606 | stack pointer that was in use at the time the function call was made? */ | |
607 | ||
608 | CORE_ADDR | |
fba45db2 | 609 | mn10200_frame_chain (struct frame_info *fi) |
c906108c SS |
610 | { |
611 | struct frame_info dummy_frame; | |
612 | ||
613 | /* Walk through the prologue to determine the stack size, | |
614 | location of saved registers, end of the prologue, etc. */ | |
615 | if (fi->status == 0) | |
c5aa993b | 616 | mn10200_analyze_prologue (fi, (CORE_ADDR) 0); |
c906108c SS |
617 | |
618 | /* Quit now if mn10200_analyze_prologue set NO_MORE_FRAMES. */ | |
619 | if (fi->status & NO_MORE_FRAMES) | |
620 | return 0; | |
621 | ||
622 | /* Now that we've analyzed our prologue, determine the frame | |
623 | pointer for our caller. | |
624 | ||
c5aa993b JM |
625 | If our caller has a frame pointer, then we need to |
626 | find the entry value of $a2 to our function. | |
c906108c | 627 | |
c5aa993b | 628 | If CALLER_A2_IN_A0, then the chain is in $a0. |
c906108c | 629 | |
c5aa993b JM |
630 | If fsr.regs[6] is nonzero, then it's at the memory |
631 | location pointed to by fsr.regs[6]. | |
c906108c | 632 | |
c5aa993b JM |
633 | Else it's still in $a2. |
634 | ||
635 | If our caller does not have a frame pointer, then his | |
636 | frame base is fi->frame + -caller's stack size + 4. */ | |
c906108c | 637 | |
c906108c SS |
638 | /* The easiest way to get that info is to analyze our caller's frame. |
639 | ||
640 | So we set up a dummy frame and call mn10200_analyze_prologue to | |
641 | find stuff for us. */ | |
642 | dummy_frame.pc = FRAME_SAVED_PC (fi); | |
643 | dummy_frame.frame = fi->frame; | |
644 | memset (dummy_frame.fsr.regs, '\000', sizeof dummy_frame.fsr.regs); | |
645 | dummy_frame.status = 0; | |
646 | dummy_frame.stack_size = 0; | |
c53efe6e | 647 | mn10200_analyze_prologue (&dummy_frame, 0); |
c906108c SS |
648 | |
649 | if (dummy_frame.status & MY_FRAME_IN_FP) | |
650 | { | |
651 | /* Our caller has a frame pointer. So find the frame in $a2, $a0, | |
c5aa993b | 652 | or in the stack. */ |
c906108c SS |
653 | if (fi->fsr.regs[6]) |
654 | return (read_memory_integer (fi->fsr.regs[FP_REGNUM], REGISTER_SIZE) | |
655 | & 0xffffff); | |
656 | else if (fi->status & CALLER_A2_IN_A0) | |
657 | return read_register (4); | |
658 | else | |
659 | return read_register (FP_REGNUM); | |
660 | } | |
661 | else | |
662 | { | |
663 | /* Our caller does not have a frame pointer. So his frame starts | |
c5aa993b | 664 | at the base of our frame (fi->frame) + <his size> + 4 (saved pc). */ |
c906108c SS |
665 | return fi->frame + -dummy_frame.stack_size + 4; |
666 | } | |
667 | } | |
668 | ||
669 | /* Function: skip_prologue | |
670 | Return the address of the first inst past the prologue of the function. */ | |
671 | ||
672 | CORE_ADDR | |
fba45db2 | 673 | mn10200_skip_prologue (CORE_ADDR pc) |
c906108c SS |
674 | { |
675 | /* We used to check the debug symbols, but that can lose if | |
676 | we have a null prologue. */ | |
677 | return mn10200_analyze_prologue (NULL, pc); | |
678 | } | |
679 | ||
680 | /* Function: pop_frame | |
681 | This routine gets called when either the user uses the `return' | |
682 | command, or the call dummy breakpoint gets hit. */ | |
683 | ||
684 | void | |
fba45db2 | 685 | mn10200_pop_frame (struct frame_info *frame) |
c906108c SS |
686 | { |
687 | int regnum; | |
688 | ||
c5aa993b | 689 | if (PC_IN_CALL_DUMMY (frame->pc, frame->frame, frame->frame)) |
c906108c SS |
690 | generic_pop_dummy_frame (); |
691 | else | |
692 | { | |
693 | write_register (PC_REGNUM, FRAME_SAVED_PC (frame)); | |
694 | ||
695 | /* Restore any saved registers. */ | |
696 | for (regnum = 0; regnum < NUM_REGS; regnum++) | |
697 | if (frame->fsr.regs[regnum] != 0) | |
698 | { | |
699 | ULONGEST value; | |
700 | ||
701 | value = read_memory_unsigned_integer (frame->fsr.regs[regnum], | |
c5aa993b | 702 | REGISTER_RAW_SIZE (regnum)); |
c906108c SS |
703 | write_register (regnum, value); |
704 | } | |
705 | ||
706 | /* Actually cut back the stack. */ | |
707 | write_register (SP_REGNUM, FRAME_FP (frame)); | |
708 | ||
709 | /* Don't we need to set the PC?!? XXX FIXME. */ | |
710 | } | |
711 | ||
712 | /* Throw away any cached frame information. */ | |
713 | flush_cached_frames (); | |
714 | } | |
715 | ||
716 | /* Function: push_arguments | |
717 | Setup arguments for a call to the target. Arguments go in | |
718 | order on the stack. */ | |
719 | ||
720 | CORE_ADDR | |
ea7c478f | 721 | mn10200_push_arguments (int nargs, struct value **args, CORE_ADDR sp, |
fba45db2 | 722 | unsigned char struct_return, CORE_ADDR struct_addr) |
c906108c SS |
723 | { |
724 | int argnum = 0; | |
725 | int len = 0; | |
726 | int stack_offset = 0; | |
727 | int regsused = struct_return ? 1 : 0; | |
728 | ||
729 | /* This should be a nop, but align the stack just in case something | |
730 | went wrong. Stacks are two byte aligned on the mn10200. */ | |
731 | sp &= ~1; | |
732 | ||
733 | /* Now make space on the stack for the args. | |
734 | ||
735 | XXX This doesn't appear to handle pass-by-invisible reference | |
736 | arguments. */ | |
737 | for (argnum = 0; argnum < nargs; argnum++) | |
738 | { | |
739 | int arg_length = (TYPE_LENGTH (VALUE_TYPE (args[argnum])) + 1) & ~1; | |
740 | ||
741 | /* If we've used all argument registers, then this argument is | |
c5aa993b | 742 | pushed. */ |
c906108c SS |
743 | if (regsused >= 2 || arg_length > 4) |
744 | { | |
745 | regsused = 2; | |
746 | len += arg_length; | |
747 | } | |
748 | /* We know we've got some arg register space left. If this argument | |
c5aa993b | 749 | will fit entirely in regs, then put it there. */ |
c906108c | 750 | else if (arg_length <= 2 |
c5aa993b | 751 | || TYPE_CODE (VALUE_TYPE (args[argnum])) == TYPE_CODE_PTR) |
c906108c SS |
752 | { |
753 | regsused++; | |
754 | } | |
755 | else if (regsused == 0) | |
756 | { | |
757 | regsused = 2; | |
758 | } | |
759 | else | |
760 | { | |
761 | regsused = 2; | |
762 | len += arg_length; | |
763 | } | |
764 | } | |
765 | ||
766 | /* Allocate stack space. */ | |
767 | sp -= len; | |
768 | ||
769 | regsused = struct_return ? 1 : 0; | |
770 | /* Push all arguments onto the stack. */ | |
771 | for (argnum = 0; argnum < nargs; argnum++) | |
772 | { | |
773 | int len; | |
774 | char *val; | |
775 | ||
776 | /* XXX Check this. What about UNIONS? */ | |
777 | if (TYPE_CODE (VALUE_TYPE (*args)) == TYPE_CODE_STRUCT | |
778 | && TYPE_LENGTH (VALUE_TYPE (*args)) > 8) | |
779 | { | |
780 | /* XXX Wrong, we want a pointer to this argument. */ | |
c5aa993b JM |
781 | len = TYPE_LENGTH (VALUE_TYPE (*args)); |
782 | val = (char *) VALUE_CONTENTS (*args); | |
c906108c SS |
783 | } |
784 | else | |
785 | { | |
786 | len = TYPE_LENGTH (VALUE_TYPE (*args)); | |
c5aa993b | 787 | val = (char *) VALUE_CONTENTS (*args); |
c906108c SS |
788 | } |
789 | ||
790 | if (regsused < 2 | |
791 | && (len <= 2 | |
792 | || TYPE_CODE (VALUE_TYPE (*args)) == TYPE_CODE_PTR)) | |
793 | { | |
794 | write_register (regsused, extract_unsigned_integer (val, 4)); | |
795 | regsused++; | |
796 | } | |
797 | else if (regsused == 0 && len == 4) | |
798 | { | |
799 | write_register (regsused, extract_unsigned_integer (val, 2)); | |
800 | write_register (regsused + 1, extract_unsigned_integer (val + 2, 2)); | |
801 | regsused = 2; | |
802 | } | |
803 | else | |
804 | { | |
805 | regsused = 2; | |
806 | while (len > 0) | |
807 | { | |
808 | write_memory (sp + stack_offset, val, 2); | |
809 | ||
810 | len -= 2; | |
811 | val += 2; | |
812 | stack_offset += 2; | |
813 | } | |
814 | } | |
815 | args++; | |
816 | } | |
817 | ||
818 | return sp; | |
819 | } | |
820 | ||
821 | /* Function: push_return_address (pc) | |
822 | Set up the return address for the inferior function call. | |
823 | Needed for targets where we don't actually execute a JSR/BSR instruction */ | |
c5aa993b | 824 | |
c906108c | 825 | CORE_ADDR |
fba45db2 | 826 | mn10200_push_return_address (CORE_ADDR pc, CORE_ADDR sp) |
c906108c SS |
827 | { |
828 | unsigned char buf[4]; | |
829 | ||
830 | store_unsigned_integer (buf, 4, CALL_DUMMY_ADDRESS ()); | |
831 | write_memory (sp - 4, buf, 4); | |
832 | return sp - 4; | |
833 | } | |
834 | ||
835 | /* Function: store_struct_return (addr,sp) | |
836 | Store the structure value return address for an inferior function | |
837 | call. */ | |
c5aa993b | 838 | |
c906108c | 839 | CORE_ADDR |
fba45db2 | 840 | mn10200_store_struct_return (CORE_ADDR addr, CORE_ADDR sp) |
c906108c SS |
841 | { |
842 | /* The structure return address is passed as the first argument. */ | |
843 | write_register (0, addr); | |
844 | return sp; | |
845 | } | |
c5aa993b | 846 | |
c906108c SS |
847 | /* Function: frame_saved_pc |
848 | Find the caller of this frame. We do this by seeing if RP_REGNUM | |
849 | is saved in the stack anywhere, otherwise we get it from the | |
850 | registers. If the inner frame is a dummy frame, return its PC | |
851 | instead of RP, because that's where "caller" of the dummy-frame | |
852 | will be found. */ | |
853 | ||
854 | CORE_ADDR | |
fba45db2 | 855 | mn10200_frame_saved_pc (struct frame_info *fi) |
c906108c SS |
856 | { |
857 | /* The saved PC will always be at the base of the current frame. */ | |
858 | return (read_memory_integer (fi->frame, REGISTER_SIZE) & 0xffffff); | |
859 | } | |
860 | ||
c906108c SS |
861 | /* Function: init_extra_frame_info |
862 | Setup the frame's frame pointer, pc, and frame addresses for saved | |
863 | registers. Most of the work is done in mn10200_analyze_prologue(). | |
864 | ||
865 | Note that when we are called for the last frame (currently active frame), | |
866 | that fi->pc and fi->frame will already be setup. However, fi->frame will | |
867 | be valid only if this routine uses FP. For previous frames, fi-frame will | |
868 | always be correct. mn10200_analyze_prologue will fix fi->frame if | |
869 | it's not valid. | |
870 | ||
871 | We can be called with the PC in the call dummy under two circumstances. | |
872 | First, during normal backtracing, second, while figuring out the frame | |
873 | pointer just prior to calling the target function (see run_stack_dummy). */ | |
874 | ||
875 | void | |
fba45db2 | 876 | mn10200_init_extra_frame_info (struct frame_info *fi) |
c906108c SS |
877 | { |
878 | if (fi->next) | |
879 | fi->pc = FRAME_SAVED_PC (fi->next); | |
880 | ||
881 | memset (fi->fsr.regs, '\000', sizeof fi->fsr.regs); | |
882 | fi->status = 0; | |
883 | fi->stack_size = 0; | |
884 | ||
885 | mn10200_analyze_prologue (fi, 0); | |
886 | } | |
887 | ||
888 | void | |
fba45db2 | 889 | _initialize_mn10200_tdep (void) |
c906108c SS |
890 | { |
891 | tm_print_insn = print_insn_mn10200; | |
892 | } |