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" | |
c906108c SS |
24 | #include "target.h" |
25 | #include "value.h" | |
26 | #include "bfd.h" | |
27 | #include "gdb_string.h" | |
28 | #include "gdbcore.h" | |
29 | #include "symfile.h" | |
4e052eda | 30 | #include "regcache.h" |
c906108c | 31 | |
c5aa993b | 32 | |
c906108c SS |
33 | /* Should call_function allocate stack space for a struct return? */ |
34 | int | |
fba45db2 | 35 | mn10200_use_struct_convention (int gcc_p, struct type *type) |
c906108c SS |
36 | { |
37 | return (TYPE_NFIELDS (type) > 1 || TYPE_LENGTH (type) > 8); | |
38 | } | |
9846de1b | 39 | /* *INDENT-OFF* */ |
c906108c SS |
40 | /* The main purpose of this file is dealing with prologues to extract |
41 | information about stack frames and saved registers. | |
42 | ||
43 | For reference here's how prologues look on the mn10200: | |
44 | ||
45 | With frame pointer: | |
46 | mov fp,a0 | |
47 | mov sp,fp | |
48 | add <size>,sp | |
49 | Register saves for d2, d3, a1, a2 as needed. Saves start | |
50 | at fp - <size> + <outgoing_args_size> and work towards higher | |
51 | addresses. Note that the saves are actually done off the stack | |
52 | pointer in the prologue! This makes for smaller code and easier | |
53 | prologue scanning as the displacement fields will unlikely | |
54 | be more than 8 bits! | |
55 | ||
56 | Without frame pointer: | |
57 | add <size>,sp | |
58 | Register saves for d2, d3, a1, a2 as needed. Saves start | |
59 | at sp + <outgoing_args_size> and work towards higher addresses. | |
60 | ||
61 | Out of line prologue: | |
62 | add <local size>,sp -- optional | |
63 | jsr __prologue | |
64 | add <outgoing_size>,sp -- optional | |
65 | ||
66 | The stack pointer remains constant throughout the life of most | |
67 | functions. As a result the compiler will usually omit the | |
68 | frame pointer, so we must handle frame pointerless functions. */ | |
69 | ||
70 | /* Analyze the prologue to determine where registers are saved, | |
71 | the end of the prologue, etc etc. Return the end of the prologue | |
72 | scanned. | |
73 | ||
74 | We store into FI (if non-null) several tidbits of information: | |
75 | ||
76 | * stack_size -- size of this stack frame. Note that if we stop in | |
77 | certain parts of the prologue/epilogue we may claim the size of the | |
78 | current frame is zero. This happens when the current frame has | |
79 | not been allocated yet or has already been deallocated. | |
80 | ||
81 | * fsr -- Addresses of registers saved in the stack by this frame. | |
82 | ||
83 | * status -- A (relatively) generic status indicator. It's a bitmask | |
84 | with the following bits: | |
85 | ||
86 | MY_FRAME_IN_SP: The base of the current frame is actually in | |
87 | the stack pointer. This can happen for frame pointerless | |
88 | functions, or cases where we're stopped in the prologue/epilogue | |
89 | itself. For these cases mn10200_analyze_prologue will need up | |
90 | update fi->frame before returning or analyzing the register | |
91 | save instructions. | |
92 | ||
93 | MY_FRAME_IN_FP: The base of the current frame is in the | |
94 | frame pointer register ($a2). | |
95 | ||
96 | CALLER_A2_IN_A0: $a2 from the caller's frame is temporarily | |
97 | in $a0. This can happen if we're stopped in the prologue. | |
98 | ||
99 | NO_MORE_FRAMES: Set this if the current frame is "start" or | |
100 | if the first instruction looks like mov <imm>,sp. This tells | |
101 | frame chain to not bother trying to unwind past this frame. */ | |
9846de1b | 102 | /* *INDENT-ON* */ |
c906108c | 103 | |
c5aa993b JM |
104 | |
105 | ||
106 | ||
c906108c SS |
107 | #define MY_FRAME_IN_SP 0x1 |
108 | #define MY_FRAME_IN_FP 0x2 | |
109 | #define CALLER_A2_IN_A0 0x4 | |
110 | #define NO_MORE_FRAMES 0x8 | |
c5aa993b | 111 | |
c906108c | 112 | static CORE_ADDR |
fba45db2 | 113 | mn10200_analyze_prologue (struct frame_info *fi, CORE_ADDR pc) |
c906108c SS |
114 | { |
115 | CORE_ADDR func_addr, func_end, addr, stop; | |
93d56215 | 116 | CORE_ADDR stack_size = 0; |
c906108c SS |
117 | unsigned char buf[4]; |
118 | int status; | |
119 | char *name; | |
120 | int out_of_line_prologue = 0; | |
121 | ||
122 | /* Use the PC in the frame if it's provided to look up the | |
123 | start of this function. */ | |
124 | pc = (fi ? fi->pc : pc); | |
125 | ||
126 | /* Find the start of this function. */ | |
127 | status = find_pc_partial_function (pc, &name, &func_addr, &func_end); | |
128 | ||
129 | /* Do nothing if we couldn't find the start of this function or if we're | |
130 | stopped at the first instruction in the prologue. */ | |
131 | if (status == 0) | |
132 | return pc; | |
133 | ||
134 | /* If we're in start, then give up. */ | |
135 | if (strcmp (name, "start") == 0) | |
136 | { | |
137 | if (fi) | |
c5aa993b | 138 | fi->status = NO_MORE_FRAMES; |
c906108c SS |
139 | return pc; |
140 | } | |
141 | ||
142 | /* At the start of a function our frame is in the stack pointer. */ | |
143 | if (fi) | |
144 | fi->status = MY_FRAME_IN_SP; | |
145 | ||
146 | /* If we're physically on an RTS instruction, then our frame has already | |
147 | been deallocated. | |
148 | ||
149 | fi->frame is bogus, we need to fix it. */ | |
150 | if (fi && fi->pc + 1 == func_end) | |
151 | { | |
152 | status = target_read_memory (fi->pc, buf, 1); | |
153 | if (status != 0) | |
154 | { | |
155 | if (fi->next == NULL) | |
156 | fi->frame = read_sp (); | |
157 | return fi->pc; | |
158 | } | |
159 | ||
160 | if (buf[0] == 0xfe) | |
161 | { | |
162 | if (fi->next == NULL) | |
163 | fi->frame = read_sp (); | |
164 | return fi->pc; | |
165 | } | |
166 | } | |
167 | ||
168 | /* Similarly if we're stopped on the first insn of a prologue as our | |
169 | frame hasn't been allocated yet. */ | |
170 | if (fi && fi->pc == func_addr) | |
171 | { | |
172 | if (fi->next == NULL) | |
173 | fi->frame = read_sp (); | |
174 | return fi->pc; | |
175 | } | |
176 | ||
177 | /* Figure out where to stop scanning. */ | |
178 | stop = fi ? fi->pc : func_end; | |
179 | ||
180 | /* Don't walk off the end of the function. */ | |
181 | stop = stop > func_end ? func_end : stop; | |
182 | ||
183 | /* Start scanning on the first instruction of this function. */ | |
184 | addr = func_addr; | |
185 | ||
186 | status = target_read_memory (addr, buf, 2); | |
187 | if (status != 0) | |
188 | { | |
189 | if (fi && fi->next == NULL && fi->status & MY_FRAME_IN_SP) | |
190 | fi->frame = read_sp (); | |
191 | return addr; | |
192 | } | |
193 | ||
194 | /* First see if this insn sets the stack pointer; if so, it's something | |
195 | we won't understand, so quit now. */ | |
196 | if (buf[0] == 0xdf | |
197 | || (buf[0] == 0xf4 && buf[1] == 0x77)) | |
198 | { | |
199 | if (fi) | |
200 | fi->status = NO_MORE_FRAMES; | |
201 | return addr; | |
202 | } | |
203 | ||
204 | /* Now see if we have a frame pointer. | |
c5aa993b | 205 | |
c906108c | 206 | Search for mov a2,a0 (0xf278) |
c5aa993b | 207 | then mov a3,a2 (0xf27e). */ |
c906108c SS |
208 | |
209 | if (buf[0] == 0xf2 && buf[1] == 0x78) | |
210 | { | |
211 | /* Our caller's $a2 will be found in $a0 now. Note it for | |
c5aa993b | 212 | our callers. */ |
c906108c SS |
213 | if (fi) |
214 | fi->status |= CALLER_A2_IN_A0; | |
215 | addr += 2; | |
216 | if (addr >= stop) | |
217 | { | |
218 | /* We still haven't allocated our local stack. Handle this | |
219 | as if we stopped on the first or last insn of a function. */ | |
220 | if (fi && fi->next == NULL) | |
221 | fi->frame = read_sp (); | |
222 | return addr; | |
223 | } | |
224 | ||
225 | status = target_read_memory (addr, buf, 2); | |
226 | if (status != 0) | |
227 | { | |
228 | if (fi && fi->next == NULL) | |
229 | fi->frame = read_sp (); | |
230 | return addr; | |
231 | } | |
232 | if (buf[0] == 0xf2 && buf[1] == 0x7e) | |
233 | { | |
234 | addr += 2; | |
235 | ||
236 | /* Our frame pointer is valid now. */ | |
237 | if (fi) | |
238 | { | |
239 | fi->status |= MY_FRAME_IN_FP; | |
240 | fi->status &= ~MY_FRAME_IN_SP; | |
241 | } | |
242 | if (addr >= stop) | |
243 | return addr; | |
244 | } | |
245 | else | |
246 | { | |
247 | if (fi && fi->next == NULL) | |
248 | fi->frame = read_sp (); | |
249 | return addr; | |
250 | } | |
251 | } | |
252 | ||
253 | /* Next we should allocate the local frame. | |
c5aa993b | 254 | |
c906108c | 255 | Search for add imm8,a3 (0xd3XX) |
c5aa993b JM |
256 | or add imm16,a3 (0xf70bXXXX) |
257 | or add imm24,a3 (0xf467XXXXXX). | |
258 | ||
c906108c SS |
259 | If none of the above was found, then this prologue has |
260 | no stack, and therefore can't have any register saves, | |
261 | so quit now. */ | |
262 | status = target_read_memory (addr, buf, 2); | |
263 | if (status != 0) | |
264 | { | |
265 | if (fi && fi->next == NULL && (fi->status & MY_FRAME_IN_SP)) | |
266 | fi->frame = read_sp (); | |
267 | return addr; | |
268 | } | |
269 | if (buf[0] == 0xd3) | |
270 | { | |
271 | stack_size = extract_signed_integer (&buf[1], 1); | |
272 | if (fi) | |
273 | fi->stack_size = stack_size; | |
274 | addr += 2; | |
275 | if (addr >= stop) | |
276 | { | |
277 | if (fi && fi->next == NULL && (fi->status & MY_FRAME_IN_SP)) | |
278 | fi->frame = read_sp () - stack_size; | |
279 | return addr; | |
280 | } | |
281 | } | |
282 | else if (buf[0] == 0xf7 && buf[1] == 0x0b) | |
283 | { | |
284 | status = target_read_memory (addr + 2, buf, 2); | |
285 | if (status != 0) | |
286 | { | |
287 | if (fi && fi->next == NULL && (fi->status & MY_FRAME_IN_SP)) | |
288 | fi->frame = read_sp (); | |
289 | return addr; | |
290 | } | |
291 | stack_size = extract_signed_integer (buf, 2); | |
292 | if (fi) | |
293 | fi->stack_size = stack_size; | |
294 | addr += 4; | |
295 | if (addr >= stop) | |
296 | { | |
297 | if (fi && fi->next == NULL && (fi->status & MY_FRAME_IN_SP)) | |
298 | fi->frame = read_sp () - stack_size; | |
299 | return addr; | |
300 | } | |
301 | } | |
302 | else if (buf[0] == 0xf4 && buf[1] == 0x67) | |
303 | { | |
304 | status = target_read_memory (addr + 2, buf, 3); | |
305 | if (status != 0) | |
306 | { | |
307 | if (fi && fi->next == NULL && (fi->status & MY_FRAME_IN_SP)) | |
308 | fi->frame = read_sp (); | |
309 | return addr; | |
310 | } | |
311 | stack_size = extract_signed_integer (buf, 3); | |
312 | if (fi) | |
313 | fi->stack_size = stack_size; | |
314 | addr += 5; | |
315 | if (addr >= stop) | |
316 | { | |
317 | if (fi && fi->next == NULL && (fi->status & MY_FRAME_IN_SP)) | |
318 | fi->frame = read_sp () - stack_size; | |
319 | return addr; | |
320 | } | |
321 | } | |
322 | ||
323 | /* Now see if we have a call to __prologue for an out of line | |
324 | prologue. */ | |
325 | status = target_read_memory (addr, buf, 2); | |
326 | if (status != 0) | |
327 | return addr; | |
328 | ||
329 | /* First check for 16bit pc-relative call to __prologue. */ | |
330 | if (buf[0] == 0xfd) | |
331 | { | |
332 | CORE_ADDR temp; | |
333 | status = target_read_memory (addr + 1, buf, 2); | |
334 | if (status != 0) | |
335 | { | |
c5aa993b JM |
336 | if (fi && fi->next == NULL && (fi->status & MY_FRAME_IN_SP)) |
337 | fi->frame = read_sp (); | |
c906108c SS |
338 | return addr; |
339 | } | |
c5aa993b | 340 | |
c906108c SS |
341 | /* Get the PC this instruction will branch to. */ |
342 | temp = (extract_signed_integer (buf, 2) + addr + 3) & 0xffffff; | |
343 | ||
344 | /* Get the name of the function at the target address. */ | |
345 | status = find_pc_partial_function (temp, &name, NULL, NULL); | |
346 | if (status == 0) | |
347 | { | |
c5aa993b JM |
348 | if (fi && fi->next == NULL && (fi->status & MY_FRAME_IN_SP)) |
349 | fi->frame = read_sp (); | |
c906108c SS |
350 | return addr; |
351 | } | |
352 | ||
353 | /* Note if it is an out of line prologue. */ | |
354 | out_of_line_prologue = (strcmp (name, "__prologue") == 0); | |
355 | ||
356 | /* This sucks up 3 bytes of instruction space. */ | |
357 | if (out_of_line_prologue) | |
358 | addr += 3; | |
359 | ||
360 | if (addr >= stop) | |
361 | { | |
362 | if (fi && fi->next == NULL) | |
363 | { | |
364 | fi->stack_size -= 16; | |
365 | fi->frame = read_sp () - fi->stack_size; | |
366 | } | |
367 | return addr; | |
368 | } | |
369 | } | |
370 | /* Now check for the 24bit pc-relative call to __prologue. */ | |
371 | else if (buf[0] == 0xf4 && buf[1] == 0xe1) | |
372 | { | |
373 | CORE_ADDR temp; | |
374 | status = target_read_memory (addr + 2, buf, 3); | |
375 | if (status != 0) | |
376 | { | |
c5aa993b JM |
377 | if (fi && fi->next == NULL && (fi->status & MY_FRAME_IN_SP)) |
378 | fi->frame = read_sp (); | |
c906108c SS |
379 | return addr; |
380 | } | |
c5aa993b | 381 | |
c906108c SS |
382 | /* Get the PC this instruction will branch to. */ |
383 | temp = (extract_signed_integer (buf, 3) + addr + 5) & 0xffffff; | |
384 | ||
385 | /* Get the name of the function at the target address. */ | |
386 | status = find_pc_partial_function (temp, &name, NULL, NULL); | |
387 | if (status == 0) | |
388 | { | |
c5aa993b JM |
389 | if (fi && fi->next == NULL && (fi->status & MY_FRAME_IN_SP)) |
390 | fi->frame = read_sp (); | |
c906108c SS |
391 | return addr; |
392 | } | |
393 | ||
394 | /* Note if it is an out of line prologue. */ | |
395 | out_of_line_prologue = (strcmp (name, "__prologue") == 0); | |
396 | ||
397 | /* This sucks up 5 bytes of instruction space. */ | |
398 | if (out_of_line_prologue) | |
399 | addr += 5; | |
400 | ||
401 | if (addr >= stop) | |
402 | { | |
403 | if (fi && fi->next == NULL && (fi->status & MY_FRAME_IN_SP)) | |
404 | { | |
405 | fi->stack_size -= 16; | |
406 | fi->frame = read_sp () - fi->stack_size; | |
407 | } | |
408 | return addr; | |
409 | } | |
410 | } | |
411 | ||
412 | /* Now actually handle the out of line prologue. */ | |
413 | if (out_of_line_prologue) | |
414 | { | |
415 | int outgoing_args_size = 0; | |
416 | ||
417 | /* First adjust the stack size for this function. The out of | |
c5aa993b | 418 | line prologue saves 4 registers (16bytes of data). */ |
c906108c SS |
419 | if (fi) |
420 | fi->stack_size -= 16; | |
421 | ||
422 | /* Update fi->frame if necessary. */ | |
423 | if (fi && fi->next == NULL) | |
424 | fi->frame = read_sp () - fi->stack_size; | |
425 | ||
426 | /* After the out of line prologue, there may be another | |
c5aa993b JM |
427 | stack adjustment for the outgoing arguments. |
428 | ||
429 | Search for add imm8,a3 (0xd3XX) | |
430 | or add imm16,a3 (0xf70bXXXX) | |
431 | or add imm24,a3 (0xf467XXXXXX). */ | |
c906108c | 432 | |
c906108c SS |
433 | status = target_read_memory (addr, buf, 2); |
434 | if (status != 0) | |
435 | { | |
436 | if (fi) | |
437 | { | |
438 | fi->fsr.regs[2] = fi->frame + fi->stack_size + 4; | |
439 | fi->fsr.regs[3] = fi->frame + fi->stack_size + 8; | |
440 | fi->fsr.regs[5] = fi->frame + fi->stack_size + 12; | |
441 | fi->fsr.regs[6] = fi->frame + fi->stack_size + 16; | |
442 | } | |
443 | return addr; | |
444 | } | |
445 | ||
446 | if (buf[0] == 0xd3) | |
447 | { | |
448 | outgoing_args_size = extract_signed_integer (&buf[1], 1); | |
449 | addr += 2; | |
450 | } | |
451 | else if (buf[0] == 0xf7 && buf[1] == 0x0b) | |
452 | { | |
453 | status = target_read_memory (addr + 2, buf, 2); | |
454 | if (status != 0) | |
455 | { | |
456 | if (fi) | |
457 | { | |
458 | fi->fsr.regs[2] = fi->frame + fi->stack_size + 4; | |
459 | fi->fsr.regs[3] = fi->frame + fi->stack_size + 8; | |
460 | fi->fsr.regs[5] = fi->frame + fi->stack_size + 12; | |
461 | fi->fsr.regs[6] = fi->frame + fi->stack_size + 16; | |
462 | } | |
463 | return addr; | |
464 | } | |
465 | outgoing_args_size = extract_signed_integer (buf, 2); | |
466 | addr += 4; | |
467 | } | |
468 | else if (buf[0] == 0xf4 && buf[1] == 0x67) | |
469 | { | |
470 | status = target_read_memory (addr + 2, buf, 3); | |
471 | if (status != 0) | |
472 | { | |
473 | if (fi && fi->next == NULL) | |
474 | { | |
475 | fi->fsr.regs[2] = fi->frame + fi->stack_size + 4; | |
476 | fi->fsr.regs[3] = fi->frame + fi->stack_size + 8; | |
477 | fi->fsr.regs[5] = fi->frame + fi->stack_size + 12; | |
478 | fi->fsr.regs[6] = fi->frame + fi->stack_size + 16; | |
479 | } | |
480 | return addr; | |
481 | } | |
482 | outgoing_args_size = extract_signed_integer (buf, 3); | |
483 | addr += 5; | |
484 | } | |
485 | else | |
486 | outgoing_args_size = 0; | |
487 | ||
488 | /* Now that we know the size of the outgoing arguments, fix | |
c5aa993b | 489 | fi->frame again if this is the innermost frame. */ |
c906108c SS |
490 | if (fi && fi->next == NULL) |
491 | fi->frame -= outgoing_args_size; | |
492 | ||
493 | /* Note the register save information and update the stack | |
c5aa993b | 494 | size for this frame too. */ |
c906108c SS |
495 | if (fi) |
496 | { | |
497 | fi->fsr.regs[2] = fi->frame + fi->stack_size + 4; | |
498 | fi->fsr.regs[3] = fi->frame + fi->stack_size + 8; | |
499 | fi->fsr.regs[5] = fi->frame + fi->stack_size + 12; | |
500 | fi->fsr.regs[6] = fi->frame + fi->stack_size + 16; | |
501 | fi->stack_size += outgoing_args_size; | |
502 | } | |
503 | /* There can be no more prologue insns, so return now. */ | |
504 | return addr; | |
505 | } | |
506 | ||
507 | /* At this point fi->frame needs to be correct. | |
508 | ||
509 | If MY_FRAME_IN_SP is set and we're the innermost frame, then we | |
510 | need to fix fi->frame so that backtracing, find_frame_saved_regs, | |
511 | etc work correctly. */ | |
512 | if (fi && fi->next == NULL && (fi->status & MY_FRAME_IN_SP) != 0) | |
513 | fi->frame = read_sp () - fi->stack_size; | |
514 | ||
515 | /* And last we have the register saves. These are relatively | |
516 | simple because they're physically done off the stack pointer, | |
517 | and thus the number of different instructions we need to | |
518 | check is greatly reduced because we know the displacements | |
519 | will be small. | |
c5aa993b | 520 | |
c906108c | 521 | Search for movx d2,(X,a3) (0xf55eXX) |
c5aa993b JM |
522 | then movx d3,(X,a3) (0xf55fXX) |
523 | then mov a1,(X,a3) (0x5dXX) No frame pointer case | |
524 | then mov a2,(X,a3) (0x5eXX) No frame pointer case | |
525 | or mov a0,(X,a3) (0x5cXX) Frame pointer case. */ | |
c906108c SS |
526 | |
527 | status = target_read_memory (addr, buf, 2); | |
528 | if (status != 0) | |
529 | return addr; | |
530 | if (buf[0] == 0xf5 && buf[1] == 0x5e) | |
531 | { | |
532 | if (fi) | |
533 | { | |
534 | status = target_read_memory (addr + 2, buf, 1); | |
535 | if (status != 0) | |
536 | return addr; | |
537 | fi->fsr.regs[2] = (fi->frame + stack_size | |
538 | + extract_signed_integer (buf, 1)); | |
539 | } | |
540 | addr += 3; | |
541 | if (addr >= stop) | |
542 | return addr; | |
543 | status = target_read_memory (addr, buf, 2); | |
544 | if (status != 0) | |
545 | return addr; | |
546 | } | |
547 | if (buf[0] == 0xf5 && buf[1] == 0x5f) | |
548 | { | |
549 | if (fi) | |
550 | { | |
551 | status = target_read_memory (addr + 2, buf, 1); | |
552 | if (status != 0) | |
553 | return addr; | |
554 | fi->fsr.regs[3] = (fi->frame + stack_size | |
555 | + extract_signed_integer (buf, 1)); | |
556 | } | |
557 | addr += 3; | |
558 | if (addr >= stop) | |
559 | return addr; | |
560 | status = target_read_memory (addr, buf, 2); | |
561 | if (status != 0) | |
562 | return addr; | |
563 | } | |
564 | if (buf[0] == 0x5d) | |
565 | { | |
566 | if (fi) | |
567 | { | |
568 | status = target_read_memory (addr + 1, buf, 1); | |
569 | if (status != 0) | |
570 | return addr; | |
571 | fi->fsr.regs[5] = (fi->frame + stack_size | |
572 | + extract_signed_integer (buf, 1)); | |
573 | } | |
574 | addr += 2; | |
575 | if (addr >= stop) | |
576 | return addr; | |
577 | status = target_read_memory (addr, buf, 2); | |
578 | if (status != 0) | |
579 | return addr; | |
580 | } | |
581 | if (buf[0] == 0x5e || buf[0] == 0x5c) | |
582 | { | |
583 | if (fi) | |
584 | { | |
585 | status = target_read_memory (addr + 1, buf, 1); | |
586 | if (status != 0) | |
587 | return addr; | |
588 | fi->fsr.regs[6] = (fi->frame + stack_size | |
589 | + extract_signed_integer (buf, 1)); | |
590 | fi->status &= ~CALLER_A2_IN_A0; | |
591 | } | |
592 | addr += 2; | |
593 | if (addr >= stop) | |
594 | return addr; | |
595 | return addr; | |
596 | } | |
597 | return addr; | |
598 | } | |
c5aa993b | 599 | |
c906108c SS |
600 | /* Function: frame_chain |
601 | Figure out and return the caller's frame pointer given current | |
602 | frame_info struct. | |
603 | ||
604 | We don't handle dummy frames yet but we would probably just return the | |
605 | stack pointer that was in use at the time the function call was made? */ | |
606 | ||
607 | CORE_ADDR | |
fba45db2 | 608 | mn10200_frame_chain (struct frame_info *fi) |
c906108c SS |
609 | { |
610 | struct frame_info dummy_frame; | |
611 | ||
612 | /* Walk through the prologue to determine the stack size, | |
613 | location of saved registers, end of the prologue, etc. */ | |
614 | if (fi->status == 0) | |
c5aa993b | 615 | mn10200_analyze_prologue (fi, (CORE_ADDR) 0); |
c906108c SS |
616 | |
617 | /* Quit now if mn10200_analyze_prologue set NO_MORE_FRAMES. */ | |
618 | if (fi->status & NO_MORE_FRAMES) | |
619 | return 0; | |
620 | ||
621 | /* Now that we've analyzed our prologue, determine the frame | |
622 | pointer for our caller. | |
623 | ||
c5aa993b JM |
624 | If our caller has a frame pointer, then we need to |
625 | find the entry value of $a2 to our function. | |
c906108c | 626 | |
c5aa993b | 627 | If CALLER_A2_IN_A0, then the chain is in $a0. |
c906108c | 628 | |
c5aa993b JM |
629 | If fsr.regs[6] is nonzero, then it's at the memory |
630 | location pointed to by fsr.regs[6]. | |
c906108c | 631 | |
c5aa993b JM |
632 | Else it's still in $a2. |
633 | ||
634 | If our caller does not have a frame pointer, then his | |
635 | frame base is fi->frame + -caller's stack size + 4. */ | |
c906108c | 636 | |
c906108c SS |
637 | /* The easiest way to get that info is to analyze our caller's frame. |
638 | ||
639 | So we set up a dummy frame and call mn10200_analyze_prologue to | |
640 | find stuff for us. */ | |
641 | dummy_frame.pc = FRAME_SAVED_PC (fi); | |
642 | dummy_frame.frame = fi->frame; | |
643 | memset (dummy_frame.fsr.regs, '\000', sizeof dummy_frame.fsr.regs); | |
644 | dummy_frame.status = 0; | |
645 | dummy_frame.stack_size = 0; | |
c53efe6e | 646 | mn10200_analyze_prologue (&dummy_frame, 0); |
c906108c SS |
647 | |
648 | if (dummy_frame.status & MY_FRAME_IN_FP) | |
649 | { | |
650 | /* Our caller has a frame pointer. So find the frame in $a2, $a0, | |
c5aa993b | 651 | or in the stack. */ |
c906108c SS |
652 | if (fi->fsr.regs[6]) |
653 | return (read_memory_integer (fi->fsr.regs[FP_REGNUM], REGISTER_SIZE) | |
654 | & 0xffffff); | |
655 | else if (fi->status & CALLER_A2_IN_A0) | |
656 | return read_register (4); | |
657 | else | |
658 | return read_register (FP_REGNUM); | |
659 | } | |
660 | else | |
661 | { | |
662 | /* Our caller does not have a frame pointer. So his frame starts | |
c5aa993b | 663 | at the base of our frame (fi->frame) + <his size> + 4 (saved pc). */ |
c906108c SS |
664 | return fi->frame + -dummy_frame.stack_size + 4; |
665 | } | |
666 | } | |
667 | ||
668 | /* Function: skip_prologue | |
669 | Return the address of the first inst past the prologue of the function. */ | |
670 | ||
671 | CORE_ADDR | |
fba45db2 | 672 | mn10200_skip_prologue (CORE_ADDR pc) |
c906108c SS |
673 | { |
674 | /* We used to check the debug symbols, but that can lose if | |
675 | we have a null prologue. */ | |
676 | return mn10200_analyze_prologue (NULL, pc); | |
677 | } | |
678 | ||
679 | /* Function: pop_frame | |
680 | This routine gets called when either the user uses the `return' | |
681 | command, or the call dummy breakpoint gets hit. */ | |
682 | ||
683 | void | |
fba45db2 | 684 | mn10200_pop_frame (struct frame_info *frame) |
c906108c SS |
685 | { |
686 | int regnum; | |
687 | ||
c5aa993b | 688 | if (PC_IN_CALL_DUMMY (frame->pc, frame->frame, frame->frame)) |
c906108c SS |
689 | generic_pop_dummy_frame (); |
690 | else | |
691 | { | |
692 | write_register (PC_REGNUM, FRAME_SAVED_PC (frame)); | |
693 | ||
694 | /* Restore any saved registers. */ | |
695 | for (regnum = 0; regnum < NUM_REGS; regnum++) | |
696 | if (frame->fsr.regs[regnum] != 0) | |
697 | { | |
698 | ULONGEST value; | |
699 | ||
700 | value = read_memory_unsigned_integer (frame->fsr.regs[regnum], | |
c5aa993b | 701 | REGISTER_RAW_SIZE (regnum)); |
c906108c SS |
702 | write_register (regnum, value); |
703 | } | |
704 | ||
705 | /* Actually cut back the stack. */ | |
706 | write_register (SP_REGNUM, FRAME_FP (frame)); | |
707 | ||
708 | /* Don't we need to set the PC?!? XXX FIXME. */ | |
709 | } | |
710 | ||
711 | /* Throw away any cached frame information. */ | |
712 | flush_cached_frames (); | |
713 | } | |
714 | ||
715 | /* Function: push_arguments | |
716 | Setup arguments for a call to the target. Arguments go in | |
717 | order on the stack. */ | |
718 | ||
719 | CORE_ADDR | |
ea7c478f | 720 | mn10200_push_arguments (int nargs, struct value **args, CORE_ADDR sp, |
fba45db2 | 721 | unsigned char struct_return, CORE_ADDR struct_addr) |
c906108c SS |
722 | { |
723 | int argnum = 0; | |
724 | int len = 0; | |
725 | int stack_offset = 0; | |
726 | int regsused = struct_return ? 1 : 0; | |
727 | ||
728 | /* This should be a nop, but align the stack just in case something | |
729 | went wrong. Stacks are two byte aligned on the mn10200. */ | |
730 | sp &= ~1; | |
731 | ||
732 | /* Now make space on the stack for the args. | |
733 | ||
734 | XXX This doesn't appear to handle pass-by-invisible reference | |
735 | arguments. */ | |
736 | for (argnum = 0; argnum < nargs; argnum++) | |
737 | { | |
738 | int arg_length = (TYPE_LENGTH (VALUE_TYPE (args[argnum])) + 1) & ~1; | |
739 | ||
740 | /* If we've used all argument registers, then this argument is | |
c5aa993b | 741 | pushed. */ |
c906108c SS |
742 | if (regsused >= 2 || arg_length > 4) |
743 | { | |
744 | regsused = 2; | |
745 | len += arg_length; | |
746 | } | |
747 | /* We know we've got some arg register space left. If this argument | |
c5aa993b | 748 | will fit entirely in regs, then put it there. */ |
c906108c | 749 | else if (arg_length <= 2 |
c5aa993b | 750 | || TYPE_CODE (VALUE_TYPE (args[argnum])) == TYPE_CODE_PTR) |
c906108c SS |
751 | { |
752 | regsused++; | |
753 | } | |
754 | else if (regsused == 0) | |
755 | { | |
756 | regsused = 2; | |
757 | } | |
758 | else | |
759 | { | |
760 | regsused = 2; | |
761 | len += arg_length; | |
762 | } | |
763 | } | |
764 | ||
765 | /* Allocate stack space. */ | |
766 | sp -= len; | |
767 | ||
768 | regsused = struct_return ? 1 : 0; | |
769 | /* Push all arguments onto the stack. */ | |
770 | for (argnum = 0; argnum < nargs; argnum++) | |
771 | { | |
772 | int len; | |
773 | char *val; | |
774 | ||
775 | /* XXX Check this. What about UNIONS? */ | |
776 | if (TYPE_CODE (VALUE_TYPE (*args)) == TYPE_CODE_STRUCT | |
777 | && TYPE_LENGTH (VALUE_TYPE (*args)) > 8) | |
778 | { | |
779 | /* XXX Wrong, we want a pointer to this argument. */ | |
c5aa993b JM |
780 | len = TYPE_LENGTH (VALUE_TYPE (*args)); |
781 | val = (char *) VALUE_CONTENTS (*args); | |
c906108c SS |
782 | } |
783 | else | |
784 | { | |
785 | len = TYPE_LENGTH (VALUE_TYPE (*args)); | |
c5aa993b | 786 | val = (char *) VALUE_CONTENTS (*args); |
c906108c SS |
787 | } |
788 | ||
789 | if (regsused < 2 | |
790 | && (len <= 2 | |
791 | || TYPE_CODE (VALUE_TYPE (*args)) == TYPE_CODE_PTR)) | |
792 | { | |
793 | write_register (regsused, extract_unsigned_integer (val, 4)); | |
794 | regsused++; | |
795 | } | |
796 | else if (regsused == 0 && len == 4) | |
797 | { | |
798 | write_register (regsused, extract_unsigned_integer (val, 2)); | |
799 | write_register (regsused + 1, extract_unsigned_integer (val + 2, 2)); | |
800 | regsused = 2; | |
801 | } | |
802 | else | |
803 | { | |
804 | regsused = 2; | |
805 | while (len > 0) | |
806 | { | |
807 | write_memory (sp + stack_offset, val, 2); | |
808 | ||
809 | len -= 2; | |
810 | val += 2; | |
811 | stack_offset += 2; | |
812 | } | |
813 | } | |
814 | args++; | |
815 | } | |
816 | ||
817 | return sp; | |
818 | } | |
819 | ||
820 | /* Function: push_return_address (pc) | |
821 | Set up the return address for the inferior function call. | |
822 | Needed for targets where we don't actually execute a JSR/BSR instruction */ | |
c5aa993b | 823 | |
c906108c | 824 | CORE_ADDR |
fba45db2 | 825 | mn10200_push_return_address (CORE_ADDR pc, CORE_ADDR sp) |
c906108c SS |
826 | { |
827 | unsigned char buf[4]; | |
828 | ||
829 | store_unsigned_integer (buf, 4, CALL_DUMMY_ADDRESS ()); | |
830 | write_memory (sp - 4, buf, 4); | |
831 | return sp - 4; | |
832 | } | |
833 | ||
834 | /* Function: store_struct_return (addr,sp) | |
835 | Store the structure value return address for an inferior function | |
836 | call. */ | |
c5aa993b | 837 | |
c906108c | 838 | CORE_ADDR |
fba45db2 | 839 | mn10200_store_struct_return (CORE_ADDR addr, CORE_ADDR sp) |
c906108c SS |
840 | { |
841 | /* The structure return address is passed as the first argument. */ | |
842 | write_register (0, addr); | |
843 | return sp; | |
844 | } | |
c5aa993b | 845 | |
c906108c SS |
846 | /* Function: frame_saved_pc |
847 | Find the caller of this frame. We do this by seeing if RP_REGNUM | |
848 | is saved in the stack anywhere, otherwise we get it from the | |
849 | registers. If the inner frame is a dummy frame, return its PC | |
850 | instead of RP, because that's where "caller" of the dummy-frame | |
851 | will be found. */ | |
852 | ||
853 | CORE_ADDR | |
fba45db2 | 854 | mn10200_frame_saved_pc (struct frame_info *fi) |
c906108c SS |
855 | { |
856 | /* The saved PC will always be at the base of the current frame. */ | |
857 | return (read_memory_integer (fi->frame, REGISTER_SIZE) & 0xffffff); | |
858 | } | |
859 | ||
c906108c SS |
860 | /* Function: init_extra_frame_info |
861 | Setup the frame's frame pointer, pc, and frame addresses for saved | |
862 | registers. Most of the work is done in mn10200_analyze_prologue(). | |
863 | ||
864 | Note that when we are called for the last frame (currently active frame), | |
865 | that fi->pc and fi->frame will already be setup. However, fi->frame will | |
866 | be valid only if this routine uses FP. For previous frames, fi-frame will | |
867 | always be correct. mn10200_analyze_prologue will fix fi->frame if | |
868 | it's not valid. | |
869 | ||
870 | We can be called with the PC in the call dummy under two circumstances. | |
871 | First, during normal backtracing, second, while figuring out the frame | |
872 | pointer just prior to calling the target function (see run_stack_dummy). */ | |
873 | ||
874 | void | |
fba45db2 | 875 | mn10200_init_extra_frame_info (struct frame_info *fi) |
c906108c SS |
876 | { |
877 | if (fi->next) | |
878 | fi->pc = FRAME_SAVED_PC (fi->next); | |
879 | ||
880 | memset (fi->fsr.regs, '\000', sizeof fi->fsr.regs); | |
881 | fi->status = 0; | |
882 | fi->stack_size = 0; | |
883 | ||
884 | mn10200_analyze_prologue (fi, 0); | |
885 | } | |
886 | ||
887 | void | |
fba45db2 | 888 | _initialize_mn10200_tdep (void) |
c906108c SS |
889 | { |
890 | tm_print_insn = print_insn_mn10200; | |
891 | } |