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879b9398 GN |
1 | /* Target-dependent code for the Matsushita MN10200 for GDB, the GNU debugger. |
2 | Copyright 1997 Free Software Foundation, Inc. | |
3 | ||
4 | This file is part of GDB. | |
5 | ||
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. | |
10 | ||
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. | |
15 | ||
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, Boston, MA 02111-1307, USA. */ | |
19 | ||
20 | #include "defs.h" | |
21 | #include "frame.h" | |
22 | #include "inferior.h" | |
23 | #include "obstack.h" | |
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" | |
30 | ||
a698d0d0 JL |
31 | /* The main purpose of this file is dealing with prologues to extract |
32 | information about stack frames and saved registers. | |
33 | ||
34 | For reference here's how prologues look on the mn10200: | |
35 | ||
36 | With frame pointer: | |
37 | mov fp,a0 | |
38 | mov sp,fp | |
39 | add <size>,sp | |
fe380dcc | 40 | Register saves for d2, d3, a1, a2 as needed. Saves start |
4dbe5f8d JL |
41 | at fp - <size> + <outgoing_args_size> and work towards higher |
42 | addresses. Note that the saves are actually done off the stack | |
43 | pointer in the prologue! This makes for smaller code and easier | |
44 | prologue scanning as the displacement fields will unlikely | |
a698d0d0 JL |
45 | be more than 8 bits! |
46 | ||
47 | Without frame pointer: | |
48 | add <size>,sp | |
fe380dcc | 49 | Register saves for d2, d3, a1, a2 as needed. Saves start |
4dbe5f8d | 50 | at sp + <outgoing_args_size> and work towards higher addresses. |
a698d0d0 | 51 | |
4dbe5f8d JL |
52 | Out of line prologue: |
53 | add <local size>,sp -- optional | |
54 | jsr __prologue | |
55 | add <outgoing_size>,sp -- optional | |
56 | ||
57 | The stack pointer remains constant throughout the life of most | |
58 | functions. As a result the compiler will usually omit the | |
59 | frame pointer, so we must handle frame pointerless functions. */ | |
a698d0d0 | 60 | |
a698d0d0 JL |
61 | /* Analyze the prologue to determine where registers are saved, |
62 | the end of the prologue, etc etc. Return the end of the prologue | |
63 | scanned. | |
64 | ||
65 | We store into FI (if non-null) several tidbits of information: | |
66 | ||
67 | * stack_size -- size of this stack frame. Note that if we stop in | |
68 | certain parts of the prologue/epilogue we may claim the size of the | |
69 | current frame is zero. This happens when the current frame has | |
70 | not been allocated yet or has already been deallocated. | |
71 | ||
72 | * fsr -- Addresses of registers saved in the stack by this frame. | |
73 | ||
74 | * status -- A (relatively) generic status indicator. It's a bitmask | |
75 | with the following bits: | |
76 | ||
77 | MY_FRAME_IN_SP: The base of the current frame is actually in | |
78 | the stack pointer. This can happen for frame pointerless | |
79 | functions, or cases where we're stopped in the prologue/epilogue | |
80 | itself. For these cases mn10200_analyze_prologue will need up | |
81 | update fi->frame before returning or analyzing the register | |
82 | save instructions. | |
83 | ||
84 | MY_FRAME_IN_FP: The base of the current frame is in the | |
85 | frame pointer register ($a2). | |
86 | ||
87 | CALLER_A2_IN_A0: $a2 from the caller's frame is temporarily | |
88 | in $a0. This can happen if we're stopped in the prologue. | |
89 | ||
90 | NO_MORE_FRAMES: Set this if the current frame is "start" or | |
91 | if the first instruction looks like mov <imm>,sp. This tells | |
92 | frame chain to not bother trying to unwind past this frame. */ | |
93 | ||
94 | #define MY_FRAME_IN_SP 0x1 | |
95 | #define MY_FRAME_IN_FP 0x2 | |
96 | #define CALLER_A2_IN_A0 0x4 | |
97 | #define NO_MORE_FRAMES 0x8 | |
98 | ||
99 | static CORE_ADDR | |
100 | mn10200_analyze_prologue (fi, pc) | |
101 | struct frame_info *fi; | |
102 | CORE_ADDR pc; | |
879b9398 | 103 | { |
a698d0d0 JL |
104 | CORE_ADDR func_addr, func_end, addr, stop; |
105 | CORE_ADDR stack_size; | |
106 | unsigned char buf[4]; | |
107 | int status; | |
108 | char *name; | |
4dbe5f8d | 109 | int out_of_line_prologue = 0; |
a698d0d0 JL |
110 | |
111 | /* Use the PC in the frame if it's provided to look up the | |
112 | start of this function. */ | |
113 | pc = (fi ? fi->pc : pc); | |
114 | ||
115 | /* Find the start of this function. */ | |
116 | status = find_pc_partial_function (pc, &name, &func_addr, &func_end); | |
117 | ||
118 | /* Do nothing if we couldn't find the start of this function or if we're | |
119 | stopped at the first instruction in the prologue. */ | |
120 | if (status == 0) | |
121 | return pc; | |
122 | ||
123 | /* If we're in start, then give up. */ | |
124 | if (strcmp (name, "start") == 0) | |
125 | { | |
40fad493 MA |
126 | if (fi) |
127 | fi->status = NO_MORE_FRAMES; | |
a698d0d0 JL |
128 | return pc; |
129 | } | |
879b9398 | 130 | |
a698d0d0 JL |
131 | /* At the start of a function our frame is in the stack pointer. */ |
132 | if (fi) | |
133 | fi->status = MY_FRAME_IN_SP; | |
879b9398 | 134 | |
a698d0d0 JL |
135 | /* If we're physically on an RTS instruction, then our frame has already |
136 | been deallocated. | |
879b9398 | 137 | |
a698d0d0 JL |
138 | fi->frame is bogus, we need to fix it. */ |
139 | if (fi && fi->pc + 1 == func_end) | |
140 | { | |
141 | status = target_read_memory (fi->pc, buf, 1); | |
142 | if (status != 0) | |
143 | { | |
05f9155f JL |
144 | if (fi->next == NULL) |
145 | fi->frame = read_sp (); | |
a698d0d0 JL |
146 | return fi->pc; |
147 | } | |
879b9398 | 148 | |
a698d0d0 JL |
149 | if (buf[0] == 0xfe) |
150 | { | |
05f9155f JL |
151 | if (fi->next == NULL) |
152 | fi->frame = read_sp (); | |
a698d0d0 JL |
153 | return fi->pc; |
154 | } | |
155 | } | |
879b9398 | 156 | |
a698d0d0 JL |
157 | /* Similarly if we're stopped on the first insn of a prologue as our |
158 | frame hasn't been allocated yet. */ | |
159 | if (fi && fi->pc == func_addr) | |
160 | { | |
05f9155f JL |
161 | if (fi->next == NULL) |
162 | fi->frame = read_sp (); | |
a698d0d0 JL |
163 | return fi->pc; |
164 | } | |
165 | ||
166 | /* Figure out where to stop scanning. */ | |
167 | stop = fi ? fi->pc : func_end; | |
168 | ||
169 | /* Don't walk off the end of the function. */ | |
170 | stop = stop > func_end ? func_end : stop; | |
171 | ||
172 | /* Start scanning on the first instruction of this function. */ | |
173 | addr = func_addr; | |
174 | ||
175 | status = target_read_memory (addr, buf, 2); | |
176 | if (status != 0) | |
879b9398 | 177 | { |
05f9155f | 178 | if (fi && fi->next == NULL && fi->status & MY_FRAME_IN_SP) |
a698d0d0 JL |
179 | fi->frame = read_sp (); |
180 | return addr; | |
879b9398 GN |
181 | } |
182 | ||
a698d0d0 JL |
183 | /* First see if this insn sets the stack pointer; if so, it's something |
184 | we won't understand, so quit now. */ | |
185 | if (buf[0] == 0xdf | |
186 | || (buf[0] == 0xf4 && buf[1] == 0x77)) | |
187 | { | |
188 | if (fi) | |
189 | fi->status = NO_MORE_FRAMES; | |
190 | return addr; | |
191 | } | |
192 | ||
193 | /* Now see if we have a frame pointer. | |
194 | ||
195 | Search for mov a2,a0 (0xf278) | |
196 | then mov a3,a2 (0xf27e). */ | |
197 | ||
198 | if (buf[0] == 0xf2 && buf[1] == 0x78) | |
199 | { | |
200 | /* Our caller's $a2 will be found in $a0 now. Note it for | |
201 | our callers. */ | |
202 | if (fi) | |
203 | fi->status |= CALLER_A2_IN_A0; | |
204 | addr += 2; | |
205 | if (addr >= stop) | |
206 | { | |
207 | /* We still haven't allocated our local stack. Handle this | |
208 | as if we stopped on the first or last insn of a function. */ | |
05f9155f | 209 | if (fi && fi->next == NULL) |
a698d0d0 JL |
210 | fi->frame = read_sp (); |
211 | return addr; | |
212 | } | |
213 | ||
214 | status = target_read_memory (addr, buf, 2); | |
215 | if (status != 0) | |
216 | { | |
05f9155f | 217 | if (fi && fi->next == NULL) |
a698d0d0 JL |
218 | fi->frame = read_sp (); |
219 | return addr; | |
220 | } | |
221 | if (buf[0] == 0xf2 && buf[1] == 0x7e) | |
222 | { | |
223 | addr += 2; | |
224 | ||
225 | /* Our frame pointer is valid now. */ | |
226 | if (fi) | |
227 | { | |
228 | fi->status |= MY_FRAME_IN_FP; | |
229 | fi->status &= ~MY_FRAME_IN_SP; | |
230 | } | |
231 | if (addr >= stop) | |
232 | return addr; | |
233 | } | |
234 | else | |
235 | { | |
05f9155f | 236 | if (fi && fi->next == NULL) |
a698d0d0 JL |
237 | fi->frame = read_sp (); |
238 | return addr; | |
239 | } | |
240 | } | |
241 | ||
242 | /* Next we should allocate the local frame. | |
243 | ||
244 | Search for add imm8,a3 (0xd3XX) | |
245 | or add imm16,a3 (0xf70bXXXX) | |
246 | or add imm24,a3 (0xf467XXXXXX). | |
247 | ||
248 | If none of the above was found, then this prologue has | |
249 | no stack, and therefore can't have any register saves, | |
250 | so quit now. */ | |
251 | status = target_read_memory (addr, buf, 2); | |
252 | if (status != 0) | |
253 | { | |
05f9155f | 254 | if (fi && fi->next == NULL && (fi->status & MY_FRAME_IN_SP)) |
a698d0d0 JL |
255 | fi->frame = read_sp (); |
256 | return addr; | |
257 | } | |
258 | if (buf[0] == 0xd3) | |
259 | { | |
260 | stack_size = extract_signed_integer (&buf[1], 1); | |
261 | if (fi) | |
262 | fi->stack_size = stack_size; | |
263 | addr += 2; | |
264 | if (addr >= stop) | |
265 | { | |
05f9155f JL |
266 | if (fi && fi->next == NULL && (fi->status & MY_FRAME_IN_SP)) |
267 | fi->frame = read_sp () - stack_size; | |
a698d0d0 JL |
268 | return addr; |
269 | } | |
270 | } | |
271 | else if (buf[0] == 0xf7 && buf[1] == 0x0b) | |
272 | { | |
273 | status = target_read_memory (addr + 2, buf, 2); | |
274 | if (status != 0) | |
275 | { | |
05f9155f | 276 | if (fi && fi->next == NULL && (fi->status & MY_FRAME_IN_SP)) |
a698d0d0 JL |
277 | fi->frame = read_sp (); |
278 | return addr; | |
279 | } | |
280 | stack_size = extract_signed_integer (buf, 2); | |
281 | if (fi) | |
282 | fi->stack_size = stack_size; | |
283 | addr += 4; | |
284 | if (addr >= stop) | |
285 | { | |
05f9155f JL |
286 | if (fi && fi->next == NULL && (fi->status & MY_FRAME_IN_SP)) |
287 | fi->frame = read_sp () - stack_size; | |
a698d0d0 JL |
288 | return addr; |
289 | } | |
290 | } | |
291 | else if (buf[0] == 0xf4 && buf[1] == 0x67) | |
292 | { | |
293 | status = target_read_memory (addr + 2, buf, 3); | |
294 | if (status != 0) | |
295 | { | |
05f9155f | 296 | if (fi && fi->next == NULL && (fi->status & MY_FRAME_IN_SP)) |
a698d0d0 JL |
297 | fi->frame = read_sp (); |
298 | return addr; | |
299 | } | |
300 | stack_size = extract_signed_integer (buf, 3); | |
301 | if (fi) | |
302 | fi->stack_size = stack_size; | |
303 | addr += 5; | |
304 | if (addr >= stop) | |
305 | { | |
05f9155f JL |
306 | if (fi && fi->next == NULL && (fi->status & MY_FRAME_IN_SP)) |
307 | fi->frame = read_sp () - stack_size; | |
a698d0d0 JL |
308 | return addr; |
309 | } | |
310 | } | |
4dbe5f8d JL |
311 | |
312 | /* Now see if we have a call to __prologue for an out of line | |
313 | prologue. */ | |
314 | status = target_read_memory (addr, buf, 2); | |
315 | if (status != 0) | |
316 | return addr; | |
317 | ||
318 | /* First check for 16bit pc-relative call to __prologue. */ | |
319 | if (buf[0] == 0xfd) | |
879b9398 | 320 | { |
4dbe5f8d JL |
321 | CORE_ADDR temp; |
322 | status = target_read_memory (addr + 1, buf, 2); | |
323 | if (status != 0) | |
324 | { | |
325 | if (fi && fi->next == NULL && (fi->status & MY_FRAME_IN_SP)) | |
326 | fi->frame = read_sp (); | |
327 | return addr; | |
328 | } | |
329 | ||
330 | /* Get the PC this instruction will branch to. */ | |
9d4cd1e8 | 331 | temp = (extract_signed_integer (buf, 2) + addr + 3) & 0xffffff; |
4dbe5f8d JL |
332 | |
333 | /* Get the name of the function at the target address. */ | |
334 | status = find_pc_partial_function (temp, &name, NULL, NULL); | |
335 | if (status == 0) | |
336 | { | |
337 | if (fi && fi->next == NULL && (fi->status & MY_FRAME_IN_SP)) | |
338 | fi->frame = read_sp (); | |
339 | return addr; | |
340 | } | |
341 | ||
342 | /* Note if it is an out of line prologue. */ | |
343 | out_of_line_prologue = (strcmp (name, "__prologue") == 0); | |
344 | ||
345 | /* This sucks up 3 bytes of instruction space. */ | |
346 | if (out_of_line_prologue) | |
347 | addr += 3; | |
348 | ||
349 | if (addr >= stop) | |
350 | { | |
351 | if (fi && fi->next == NULL) | |
352 | { | |
353 | fi->stack_size -= 16; | |
354 | fi->frame = read_sp () - fi->stack_size; | |
355 | } | |
356 | return addr; | |
357 | } | |
358 | } | |
359 | /* Now check for the 24bit pc-relative call to __prologue. */ | |
360 | else if (buf[0] == 0xf4 && buf[1] == 0xe1) | |
361 | { | |
362 | CORE_ADDR temp; | |
363 | status = target_read_memory (addr + 2, buf, 3); | |
364 | if (status != 0) | |
365 | { | |
366 | if (fi && fi->next == NULL && (fi->status & MY_FRAME_IN_SP)) | |
367 | fi->frame = read_sp (); | |
368 | return addr; | |
369 | } | |
370 | ||
371 | /* Get the PC this instruction will branch to. */ | |
9d4cd1e8 | 372 | temp = (extract_signed_integer (buf, 3) + addr + 5) & 0xffffff; |
4dbe5f8d JL |
373 | |
374 | /* Get the name of the function at the target address. */ | |
375 | status = find_pc_partial_function (temp, &name, NULL, NULL); | |
376 | if (status == 0) | |
377 | { | |
378 | if (fi && fi->next == NULL && (fi->status & MY_FRAME_IN_SP)) | |
379 | fi->frame = read_sp (); | |
380 | return addr; | |
381 | } | |
382 | ||
383 | /* Note if it is an out of line prologue. */ | |
384 | out_of_line_prologue = (strcmp (name, "__prologue") == 0); | |
385 | ||
386 | /* This sucks up 5 bytes of instruction space. */ | |
387 | if (out_of_line_prologue) | |
388 | addr += 5; | |
389 | ||
390 | if (addr >= stop) | |
391 | { | |
392 | if (fi && fi->next == NULL && (fi->status & MY_FRAME_IN_SP)) | |
393 | { | |
394 | fi->stack_size -= 16; | |
395 | fi->frame = read_sp () - fi->stack_size; | |
396 | } | |
397 | return addr; | |
398 | } | |
399 | } | |
400 | ||
401 | /* Now actually handle the out of line prologue. */ | |
402 | if (out_of_line_prologue) | |
403 | { | |
404 | int outgoing_args_size = 0; | |
405 | ||
406 | /* First adjust the stack size for this function. The out of | |
407 | line prologue saves 4 registers (16bytes of data). */ | |
408 | if (fi) | |
409 | fi->stack_size -= 16; | |
410 | ||
411 | /* Update fi->frame if necessary. */ | |
412 | if (fi && fi->next == NULL) | |
413 | fi->frame = read_sp () - fi->stack_size; | |
414 | ||
415 | /* After the out of line prologue, there may be another | |
416 | stack adjustment for the outgoing arguments. | |
417 | ||
418 | Search for add imm8,a3 (0xd3XX) | |
419 | or add imm16,a3 (0xf70bXXXX) | |
420 | or add imm24,a3 (0xf467XXXXXX). */ | |
421 | ||
422 | status = target_read_memory (addr, buf, 2); | |
423 | if (status != 0) | |
424 | { | |
425 | if (fi) | |
426 | { | |
427 | fi->fsr.regs[2] = fi->frame + fi->stack_size + 4; | |
428 | fi->fsr.regs[3] = fi->frame + fi->stack_size + 8; | |
429 | fi->fsr.regs[5] = fi->frame + fi->stack_size + 12; | |
430 | fi->fsr.regs[6] = fi->frame + fi->stack_size + 16; | |
431 | } | |
432 | return addr; | |
433 | } | |
434 | ||
435 | if (buf[0] == 0xd3) | |
436 | { | |
437 | outgoing_args_size = extract_signed_integer (&buf[1], 1); | |
438 | addr += 2; | |
439 | } | |
440 | else if (buf[0] == 0xf7 && buf[1] == 0x0b) | |
441 | { | |
442 | status = target_read_memory (addr + 2, buf, 2); | |
443 | if (status != 0) | |
444 | { | |
445 | if (fi) | |
446 | { | |
447 | fi->fsr.regs[2] = fi->frame + fi->stack_size + 4; | |
448 | fi->fsr.regs[3] = fi->frame + fi->stack_size + 8; | |
449 | fi->fsr.regs[5] = fi->frame + fi->stack_size + 12; | |
450 | fi->fsr.regs[6] = fi->frame + fi->stack_size + 16; | |
451 | } | |
452 | return addr; | |
453 | } | |
454 | outgoing_args_size = extract_signed_integer (buf, 2); | |
455 | addr += 4; | |
456 | } | |
457 | else if (buf[0] == 0xf4 && buf[1] == 0x67) | |
458 | { | |
459 | status = target_read_memory (addr + 2, buf, 3); | |
460 | if (status != 0) | |
461 | { | |
462 | if (fi && fi->next == NULL) | |
463 | { | |
464 | fi->fsr.regs[2] = fi->frame + fi->stack_size + 4; | |
465 | fi->fsr.regs[3] = fi->frame + fi->stack_size + 8; | |
466 | fi->fsr.regs[5] = fi->frame + fi->stack_size + 12; | |
467 | fi->fsr.regs[6] = fi->frame + fi->stack_size + 16; | |
468 | } | |
469 | return addr; | |
470 | } | |
471 | outgoing_args_size = extract_signed_integer (buf, 3); | |
472 | addr += 5; | |
473 | } | |
474 | else | |
475 | outgoing_args_size = 0; | |
476 | ||
477 | /* Now that we know the size of the outgoing arguments, fix | |
478 | fi->frame again if this is the innermost frame. */ | |
479 | if (fi && fi->next == NULL) | |
480 | fi->frame -= outgoing_args_size; | |
481 | ||
482 | /* Note the register save information and update the stack | |
483 | size for this frame too. */ | |
484 | if (fi) | |
485 | { | |
486 | fi->fsr.regs[2] = fi->frame + fi->stack_size + 4; | |
487 | fi->fsr.regs[3] = fi->frame + fi->stack_size + 8; | |
488 | fi->fsr.regs[5] = fi->frame + fi->stack_size + 12; | |
489 | fi->fsr.regs[6] = fi->frame + fi->stack_size + 16; | |
490 | fi->stack_size += outgoing_args_size; | |
491 | } | |
492 | /* There can be no more prologue insns, so return now. */ | |
a698d0d0 | 493 | return addr; |
879b9398 GN |
494 | } |
495 | ||
a698d0d0 JL |
496 | /* At this point fi->frame needs to be correct. |
497 | ||
05f9155f JL |
498 | If MY_FRAME_IN_SP is set and we're the innermost frame, then we |
499 | need to fix fi->frame so that backtracing, find_frame_saved_regs, | |
500 | etc work correctly. */ | |
501 | if (fi && fi->next == NULL && (fi->status & MY_FRAME_IN_SP) != 0) | |
a698d0d0 JL |
502 | fi->frame = read_sp () - fi->stack_size; |
503 | ||
504 | /* And last we have the register saves. These are relatively | |
505 | simple because they're physically done off the stack pointer, | |
506 | and thus the number of different instructions we need to | |
507 | check is greatly reduced because we know the displacements | |
508 | will be small. | |
509 | ||
510 | Search for movx d2,(X,a3) (0xf55eXX) | |
511 | then movx d3,(X,a3) (0xf55fXX) | |
fe380dcc | 512 | then mov a1,(X,a3) (0x5dXX) No frame pointer case |
a698d0d0 JL |
513 | then mov a2,(X,a3) (0x5eXX) No frame pointer case |
514 | or mov a0,(X,a3) (0x5cXX) Frame pointer case. */ | |
515 | ||
516 | status = target_read_memory (addr, buf, 2); | |
517 | if (status != 0) | |
518 | return addr; | |
519 | if (buf[0] == 0xf5 && buf[1] == 0x5e) | |
520 | { | |
521 | if (fi) | |
522 | { | |
523 | status = target_read_memory (addr + 2, buf, 1); | |
524 | if (status != 0) | |
525 | return addr; | |
526 | fi->fsr.regs[2] = (fi->frame + stack_size | |
527 | + extract_signed_integer (buf, 1)); | |
528 | } | |
529 | addr += 3; | |
530 | if (addr >= stop) | |
531 | return addr; | |
532 | status = target_read_memory (addr, buf, 2); | |
533 | if (status != 0) | |
534 | return addr; | |
535 | } | |
536 | if (buf[0] == 0xf5 && buf[1] == 0x5f) | |
537 | { | |
538 | if (fi) | |
539 | { | |
540 | status = target_read_memory (addr + 2, buf, 1); | |
541 | if (status != 0) | |
542 | return addr; | |
543 | fi->fsr.regs[3] = (fi->frame + stack_size | |
544 | + extract_signed_integer (buf, 1)); | |
545 | } | |
546 | addr += 3; | |
547 | if (addr >= stop) | |
548 | return addr; | |
549 | status = target_read_memory (addr, buf, 2); | |
550 | if (status != 0) | |
551 | return addr; | |
552 | } | |
fe380dcc JL |
553 | if (buf[0] == 0x5d) |
554 | { | |
555 | if (fi) | |
556 | { | |
557 | status = target_read_memory (addr + 1, buf, 1); | |
558 | if (status != 0) | |
559 | return addr; | |
560 | fi->fsr.regs[5] = (fi->frame + stack_size | |
561 | + extract_signed_integer (buf, 1)); | |
562 | } | |
563 | addr += 2; | |
564 | if (addr >= stop) | |
565 | return addr; | |
566 | status = target_read_memory (addr, buf, 2); | |
567 | if (status != 0) | |
568 | return addr; | |
569 | } | |
a698d0d0 JL |
570 | if (buf[0] == 0x5e || buf[0] == 0x5c) |
571 | { | |
572 | if (fi) | |
573 | { | |
574 | status = target_read_memory (addr + 1, buf, 1); | |
575 | if (status != 0) | |
576 | return addr; | |
577 | fi->fsr.regs[6] = (fi->frame + stack_size | |
578 | + extract_signed_integer (buf, 1)); | |
579 | fi->status &= ~CALLER_A2_IN_A0; | |
580 | } | |
581 | addr += 2; | |
582 | if (addr >= stop) | |
583 | return addr; | |
584 | return addr; | |
585 | } | |
586 | return addr; | |
879b9398 | 587 | } |
a698d0d0 JL |
588 | |
589 | /* Function: frame_chain | |
590 | Figure out and return the caller's frame pointer given current | |
591 | frame_info struct. | |
879b9398 | 592 | |
a698d0d0 JL |
593 | We don't handle dummy frames yet but we would probably just return the |
594 | stack pointer that was in use at the time the function call was made? */ | |
879b9398 GN |
595 | |
596 | CORE_ADDR | |
a698d0d0 | 597 | mn10200_frame_chain (fi) |
879b9398 | 598 | struct frame_info *fi; |
879b9398 | 599 | { |
a698d0d0 JL |
600 | struct frame_info dummy_frame; |
601 | ||
602 | /* Walk through the prologue to determine the stack size, | |
603 | location of saved registers, end of the prologue, etc. */ | |
604 | if (fi->status == 0) | |
605 | mn10200_analyze_prologue (fi, (CORE_ADDR)0); | |
606 | ||
607 | /* Quit now if mn10200_analyze_prologue set NO_MORE_FRAMES. */ | |
608 | if (fi->status & NO_MORE_FRAMES) | |
609 | return 0; | |
610 | ||
611 | /* Now that we've analyzed our prologue, determine the frame | |
612 | pointer for our caller. | |
613 | ||
614 | If our caller has a frame pointer, then we need to | |
615 | find the entry value of $a2 to our function. | |
616 | ||
617 | If CALLER_A2_IN_A0, then the chain is in $a0. | |
618 | ||
619 | If fsr.regs[6] is nonzero, then it's at the memory | |
620 | location pointed to by fsr.regs[6]. | |
621 | ||
622 | Else it's still in $a2. | |
879b9398 | 623 | |
a698d0d0 | 624 | If our caller does not have a frame pointer, then his |
05f9155f | 625 | frame base is fi->frame + -caller's stack size + 4. */ |
a698d0d0 JL |
626 | |
627 | /* The easiest way to get that info is to analyze our caller's frame. | |
879b9398 | 628 | |
a698d0d0 JL |
629 | So we set up a dummy frame and call mn10200_analyze_prologue to |
630 | find stuff for us. */ | |
631 | dummy_frame.pc = FRAME_SAVED_PC (fi); | |
632 | dummy_frame.frame = fi->frame; | |
633 | memset (dummy_frame.fsr.regs, '\000', sizeof dummy_frame.fsr.regs); | |
634 | dummy_frame.status = 0; | |
635 | dummy_frame.stack_size = 0; | |
636 | mn10200_analyze_prologue (&dummy_frame); | |
637 | ||
638 | if (dummy_frame.status & MY_FRAME_IN_FP) | |
639 | { | |
640 | /* Our caller has a frame pointer. So find the frame in $a2, $a0, | |
641 | or in the stack. */ | |
642 | if (fi->fsr.regs[6]) | |
643 | return (read_memory_integer (fi->fsr.regs[FP_REGNUM], REGISTER_SIZE) | |
644 | & 0xffffff); | |
645 | else if (fi->status & CALLER_A2_IN_A0) | |
646 | return read_register (4); | |
647 | else | |
648 | return read_register (FP_REGNUM); | |
649 | } | |
650 | else | |
651 | { | |
652 | /* Our caller does not have a frame pointer. So his frame starts | |
653 | at the base of our frame (fi->frame) + <his size> + 4 (saved pc). */ | |
05f9155f | 654 | return fi->frame + -dummy_frame.stack_size + 4; |
a698d0d0 | 655 | } |
879b9398 GN |
656 | } |
657 | ||
658 | /* Function: skip_prologue | |
a698d0d0 | 659 | Return the address of the first inst past the prologue of the function. */ |
879b9398 GN |
660 | |
661 | CORE_ADDR | |
662 | mn10200_skip_prologue (pc) | |
663 | CORE_ADDR pc; | |
664 | { | |
c23cc10a JL |
665 | /* We used to check the debug symbols, but that can lose if |
666 | we have a null prologue. */ | |
667 | return mn10200_analyze_prologue (NULL, pc); | |
879b9398 GN |
668 | } |
669 | ||
670 | /* Function: pop_frame | |
671 | This routine gets called when either the user uses the `return' | |
672 | command, or the call dummy breakpoint gets hit. */ | |
673 | ||
674 | void | |
675 | mn10200_pop_frame (frame) | |
676 | struct frame_info *frame; | |
677 | { | |
678 | int regnum; | |
679 | ||
879b9398 GN |
680 | if (PC_IN_CALL_DUMMY(frame->pc, frame->frame, frame->frame)) |
681 | generic_pop_dummy_frame (); | |
682 | else | |
683 | { | |
684 | write_register (PC_REGNUM, FRAME_SAVED_PC (frame)); | |
685 | ||
a698d0d0 | 686 | /* Restore any saved registers. */ |
879b9398 GN |
687 | for (regnum = 0; regnum < NUM_REGS; regnum++) |
688 | if (frame->fsr.regs[regnum] != 0) | |
a698d0d0 JL |
689 | { |
690 | ULONGEST value; | |
691 | ||
692 | value = read_memory_unsigned_integer (frame->fsr.regs[regnum], | |
693 | REGISTER_RAW_SIZE (regnum)); | |
694 | write_register (regnum, value); | |
695 | } | |
879b9398 | 696 | |
a698d0d0 | 697 | /* Actually cut back the stack. */ |
879b9398 | 698 | write_register (SP_REGNUM, FRAME_FP (frame)); |
a698d0d0 JL |
699 | |
700 | /* Don't we need to set the PC?!? XXX FIXME. */ | |
879b9398 GN |
701 | } |
702 | ||
a698d0d0 | 703 | /* Throw away any cached frame information. */ |
879b9398 | 704 | flush_cached_frames (); |
879b9398 GN |
705 | } |
706 | ||
707 | /* Function: push_arguments | |
708 | Setup arguments for a call to the target. Arguments go in | |
a698d0d0 | 709 | order on the stack. */ |
879b9398 GN |
710 | |
711 | CORE_ADDR | |
712 | mn10200_push_arguments (nargs, args, sp, struct_return, struct_addr) | |
713 | int nargs; | |
714 | value_ptr *args; | |
715 | CORE_ADDR sp; | |
716 | unsigned char struct_return; | |
717 | CORE_ADDR struct_addr; | |
718 | { | |
719 | int argnum = 0; | |
720 | int len = 0; | |
a698d0d0 | 721 | int stack_offset = 0; |
fc5c7595 | 722 | int regsused = struct_return ? 1 : 0; |
879b9398 | 723 | |
a698d0d0 | 724 | /* This should be a nop, but align the stack just in case something |
25de138b JL |
725 | went wrong. Stacks are two byte aligned on the mn10200. */ |
726 | sp &= ~1; | |
879b9398 | 727 | |
a698d0d0 JL |
728 | /* Now make space on the stack for the args. |
729 | ||
730 | XXX This doesn't appear to handle pass-by-invisible reference | |
731 | arguments. */ | |
879b9398 | 732 | for (argnum = 0; argnum < nargs; argnum++) |
fc5c7595 JL |
733 | { |
734 | int arg_length = (TYPE_LENGTH (VALUE_TYPE (args[argnum])) + 1) & ~1; | |
735 | ||
736 | /* If we've used all argument registers, then this argument is | |
737 | pushed. */ | |
738 | if (regsused >= 2 || arg_length > 4) | |
739 | { | |
740 | regsused = 2; | |
741 | len += arg_length; | |
742 | } | |
743 | /* We know we've got some arg register space left. If this argument | |
744 | will fit entirely in regs, then put it there. */ | |
745 | else if (arg_length <= 2 | |
746 | || TYPE_CODE (VALUE_TYPE (args[argnum])) == TYPE_CODE_PTR) | |
747 | { | |
748 | regsused++; | |
749 | } | |
750 | else if (regsused == 0) | |
751 | { | |
752 | regsused = 2; | |
753 | } | |
754 | else | |
755 | { | |
756 | regsused = 2; | |
757 | len += arg_length; | |
758 | } | |
759 | } | |
879b9398 | 760 | |
a698d0d0 | 761 | /* Allocate stack space. */ |
879b9398 GN |
762 | sp -= len; |
763 | ||
fc5c7595 | 764 | regsused = struct_return ? 1 : 0; |
879b9398 GN |
765 | /* Push all arguments onto the stack. */ |
766 | for (argnum = 0; argnum < nargs; argnum++) | |
767 | { | |
768 | int len; | |
769 | char *val; | |
770 | ||
fc5c7595 | 771 | /* XXX Check this. What about UNIONS? */ |
879b9398 GN |
772 | if (TYPE_CODE (VALUE_TYPE (*args)) == TYPE_CODE_STRUCT |
773 | && TYPE_LENGTH (VALUE_TYPE (*args)) > 8) | |
774 | { | |
a698d0d0 | 775 | /* XXX Wrong, we want a pointer to this argument. */ |
879b9398 GN |
776 | len = TYPE_LENGTH (VALUE_TYPE (*args)); |
777 | val = (char *)VALUE_CONTENTS (*args); | |
778 | } | |
779 | else | |
780 | { | |
781 | len = TYPE_LENGTH (VALUE_TYPE (*args)); | |
782 | val = (char *)VALUE_CONTENTS (*args); | |
783 | } | |
784 | ||
fc5c7595 JL |
785 | if (regsused < 2 |
786 | && (len <= 2 | |
787 | || TYPE_CODE (VALUE_TYPE (*args)) == TYPE_CODE_PTR)) | |
879b9398 | 788 | { |
fc5c7595 JL |
789 | write_register (regsused, extract_unsigned_integer (val, 4)); |
790 | regsused++; | |
791 | } | |
792 | else if (regsused == 0 && len == 4) | |
793 | { | |
794 | write_register (regsused, extract_unsigned_integer (val, 2)); | |
795 | write_register (regsused + 1, extract_unsigned_integer (val + 2, 2)); | |
796 | regsused = 2; | |
797 | } | |
798 | else | |
799 | { | |
800 | regsused = 2; | |
801 | while (len > 0) | |
802 | { | |
803 | write_memory (sp + stack_offset, val, 2); | |
879b9398 | 804 | |
fc5c7595 JL |
805 | len -= 2; |
806 | val += 2; | |
807 | stack_offset += 2; | |
808 | } | |
879b9398 GN |
809 | } |
810 | args++; | |
811 | } | |
812 | ||
879b9398 GN |
813 | return sp; |
814 | } | |
815 | ||
816 | /* Function: push_return_address (pc) | |
817 | Set up the return address for the inferior function call. | |
818 | Needed for targets where we don't actually execute a JSR/BSR instruction */ | |
819 | ||
820 | CORE_ADDR | |
821 | mn10200_push_return_address (pc, sp) | |
822 | CORE_ADDR pc; | |
823 | CORE_ADDR sp; | |
824 | { | |
25de138b | 825 | unsigned char buf[4]; |
879b9398 | 826 | |
25de138b JL |
827 | store_unsigned_integer (buf, 4, CALL_DUMMY_ADDRESS ()); |
828 | write_memory (sp - 4, buf, 4); | |
829 | return sp - 4; | |
879b9398 | 830 | } |
d601a41f JL |
831 | |
832 | /* Function: store_struct_return (addr,sp) | |
833 | Store the structure value return address for an inferior function | |
834 | call. */ | |
835 | ||
836 | CORE_ADDR | |
837 | mn10200_store_struct_return (addr, sp) | |
838 | CORE_ADDR addr; | |
839 | CORE_ADDR sp; | |
840 | { | |
fc5c7595 JL |
841 | /* The structure return address is passed as the first argument. */ |
842 | write_register (0, addr); | |
843 | return sp; | |
d601a41f | 844 | } |
879b9398 GN |
845 | |
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 | |
854 | mn10200_frame_saved_pc (fi) | |
855 | struct frame_info *fi; | |
856 | { | |
a698d0d0 JL |
857 | /* The saved PC will always be at the base of the current frame. */ |
858 | return (read_memory_integer (fi->frame, REGISTER_SIZE) & 0xffffff); | |
879b9398 GN |
859 | } |
860 | ||
861 | void | |
862 | get_saved_register (raw_buffer, optimized, addrp, frame, regnum, lval) | |
863 | char *raw_buffer; | |
864 | int *optimized; | |
865 | CORE_ADDR *addrp; | |
866 | struct frame_info *frame; | |
867 | int regnum; | |
868 | enum lval_type *lval; | |
869 | { | |
879b9398 GN |
870 | generic_get_saved_register (raw_buffer, optimized, addrp, |
871 | frame, regnum, lval); | |
872 | } | |
873 | ||
874 | /* Function: init_extra_frame_info | |
875 | Setup the frame's frame pointer, pc, and frame addresses for saved | |
a698d0d0 | 876 | registers. Most of the work is done in mn10200_analyze_prologue(). |
879b9398 GN |
877 | |
878 | Note that when we are called for the last frame (currently active frame), | |
879 | that fi->pc and fi->frame will already be setup. However, fi->frame will | |
880 | be valid only if this routine uses FP. For previous frames, fi-frame will | |
a698d0d0 JL |
881 | always be correct. mn10200_analyze_prologue will fix fi->frame if |
882 | it's not valid. | |
879b9398 GN |
883 | |
884 | We can be called with the PC in the call dummy under two circumstances. | |
885 | First, during normal backtracing, second, while figuring out the frame | |
a698d0d0 | 886 | pointer just prior to calling the target function (see run_stack_dummy). */ |
879b9398 GN |
887 | |
888 | void | |
889 | mn10200_init_extra_frame_info (fi) | |
890 | struct frame_info *fi; | |
891 | { | |
879b9398 GN |
892 | if (fi->next) |
893 | fi->pc = FRAME_SAVED_PC (fi->next); | |
894 | ||
895 | memset (fi->fsr.regs, '\000', sizeof fi->fsr.regs); | |
a698d0d0 JL |
896 | fi->status = 0; |
897 | fi->stack_size = 0; | |
879b9398 | 898 | |
a698d0d0 | 899 | mn10200_analyze_prologue (fi, 0); |
879b9398 GN |
900 | } |
901 | ||
902 | void | |
903 | _initialize_mn10200_tdep () | |
904 | { | |
879b9398 GN |
905 | tm_print_insn = print_insn_mn10200; |
906 | } | |
907 |