Commit | Line | Data |
---|---|---|
3de76938 GN |
1 | /* Target-dependent code for the Matsushita MN10300 for GDB, the GNU debugger. |
2 | Copyright 1996, 1997 Free Software Foundation, Inc. | |
ddc2888e GN |
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 | |
3de76938 | 18 | Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */ |
ddc2888e GN |
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 | ||
31 | /* Info gleaned from scanning a function's prologue. */ | |
32 | ||
33 | struct pifsr /* Info about one saved reg */ | |
34 | { | |
35 | int framereg; /* Frame reg (SP or FP) */ | |
36 | int offset; /* Offset from framereg */ | |
37 | int reg; /* Saved register number */ | |
38 | }; | |
39 | ||
40 | struct prologue_info | |
41 | { | |
42 | int framereg; | |
43 | int frameoffset; | |
44 | int start_function; | |
45 | struct pifsr *pifsrs; | |
46 | }; | |
47 | ||
3de76938 GN |
48 | static CORE_ADDR mn10300_scan_prologue PARAMS ((CORE_ADDR pc, |
49 | struct prologue_info *fs)); | |
50 | \f | |
51 | /* Function: scan_prologue | |
52 | Scan the prologue of the function that contains PC, and record what | |
53 | we find in PI. PI->fsr must be zeroed by the called. Returns the | |
54 | pc after the prologue. Note that the addresses saved in pi->fsr | |
55 | are actually just frame relative (negative offsets from the frame | |
56 | pointer). This is because we don't know the actual value of the | |
57 | frame pointer yet. In some circumstances, the frame pointer can't | |
58 | be determined till after we have scanned the prologue. */ | |
59 | ||
ddc2888e GN |
60 | static CORE_ADDR |
61 | mn10300_scan_prologue (pc, pi) | |
62 | CORE_ADDR pc; | |
63 | struct prologue_info *pi; | |
64 | { | |
3de76938 GN |
65 | CORE_ADDR func_addr, prologue_end, current_pc; |
66 | struct pifsr *pifsr; | |
67 | int fp_used; | |
68 | ||
69 | printf("mn10300_scan_prologue start\n"); | |
70 | ||
71 | /* First, figure out the bounds of the prologue so that we can limit the | |
72 | search to something reasonable. */ | |
73 | ||
74 | if (find_pc_partial_function (pc, NULL, &func_addr, NULL)) | |
75 | { | |
76 | struct symtab_and_line sal; | |
77 | ||
78 | sal = find_pc_line (func_addr, 0); | |
79 | ||
80 | if (func_addr == entry_point_address ()) | |
81 | pi->start_function = 1; | |
82 | else | |
83 | pi->start_function = 0; | |
84 | ||
85 | #if 0 | |
86 | if (sal.line == 0) | |
87 | prologue_end = pc; | |
88 | else | |
89 | prologue_end = sal.end; | |
90 | #else | |
91 | prologue_end = pc; | |
92 | #endif | |
93 | } | |
94 | else | |
95 | { /* We're in the boondocks */ | |
96 | func_addr = pc - 100; | |
97 | prologue_end = pc; | |
98 | } | |
99 | ||
100 | prologue_end = min (prologue_end, pc); | |
101 | ||
102 | /* Now, search the prologue looking for instructions that setup fp, save | |
103 | rp, adjust sp and such. We also record the frame offset of any saved | |
104 | registers. */ | |
105 | ||
106 | pi->frameoffset = 0; | |
107 | pi->framereg = SP_REGNUM; | |
108 | fp_used = 0; | |
109 | pifsr = pi->pifsrs; | |
110 | ||
111 | for (current_pc = func_addr; current_pc < prologue_end; current_pc += 2) | |
112 | { | |
113 | int insn; | |
114 | ||
115 | insn = read_memory_unsigned_integer (current_pc, 2); | |
116 | ||
117 | if ((insn & 0x07c0) == 0x0780 /* jarl or jr */ | |
118 | || (insn & 0xffe0) == 0x0060 /* jmp */ | |
119 | || (insn & 0x0780) == 0x0580) /* branch */ | |
120 | break; /* Ran into end of prologue */ | |
121 | if ((insn & 0xffe0) == ((SP_REGNUM << 11) | 0x0240)) /* add <imm>,sp */ | |
122 | pi->frameoffset = ((insn & 0x1f) ^ 0x10) - 0x10; | |
123 | else if (insn == ((SP_REGNUM << 11) | 0x0600 | SP_REGNUM)) /* addi <imm>,sp,sp */ | |
124 | pi->frameoffset = read_memory_integer (current_pc + 2, 2); | |
125 | else if (insn == ((FP_REGNUM << 11) | 0x0000 | 12)) /* mov r12,fp */ | |
126 | { | |
127 | fp_used = 1; | |
128 | pi->framereg = FP_REGNUM; | |
129 | } | |
130 | else if ((insn & 0x07ff) == (0x0760 | SP_REGNUM) /* st.w <reg>,<offset>[sp] */ | |
131 | || (fp_used | |
132 | && (insn & 0x07ff) == (0x0760 | FP_REGNUM))) /* st.w <reg>,<offset>[fp] */ | |
133 | if (pifsr) | |
134 | { | |
135 | pifsr->framereg = insn & 0x1f; | |
136 | pifsr->reg = (insn >> 11) & 0x1f; /* Extract <reg> */ | |
137 | ||
138 | pifsr->offset = read_memory_integer (current_pc + 2, 2) & ~1; | |
139 | ||
140 | pifsr++; | |
141 | } | |
142 | ||
143 | if ((insn & 0x0780) >= 0x0600) /* Four byte instruction? */ | |
144 | current_pc += 2; | |
145 | } | |
146 | ||
147 | if (pifsr) | |
148 | pifsr->framereg = 0; /* Tie off last entry */ | |
149 | ||
150 | printf("mn10300_scan_prologue end \n"); | |
151 | ||
152 | return current_pc; | |
ddc2888e GN |
153 | } |
154 | ||
3de76938 GN |
155 | /* Function: init_extra_frame_info |
156 | Setup the frame's frame pointer, pc, and frame addresses for saved | |
157 | registers. Most of the work is done in scan_prologue(). | |
158 | ||
159 | Note that when we are called for the last frame (currently active frame), | |
160 | that fi->pc and fi->frame will already be setup. However, fi->frame will | |
161 | be valid only if this routine uses FP. For previous frames, fi-frame will | |
162 | always be correct (since that is derived from mn10300_frame_chain ()). | |
163 | ||
164 | We can be called with the PC in the call dummy under two circumstances. | |
165 | First, during normal backtracing, second, while figuring out the frame | |
166 | pointer just prior to calling the target function (see run_stack_dummy). */ | |
167 | ||
ddc2888e GN |
168 | void |
169 | mn10300_init_extra_frame_info (fi) | |
170 | struct frame_info *fi; | |
171 | { | |
3de76938 GN |
172 | struct prologue_info pi; |
173 | struct pifsr pifsrs[NUM_REGS + 1], *pifsr; | |
174 | int reg; | |
175 | ||
176 | printf("mn10300_init_extra_frame_info start\n"); | |
177 | ||
178 | if (fi->next) | |
179 | fi->pc = FRAME_SAVED_PC (fi->next); | |
180 | ||
181 | memset (fi->fsr.regs, '\000', sizeof fi->fsr.regs); | |
182 | ||
183 | /* The call dummy doesn't save any registers on the stack, so we can return | |
184 | now. */ | |
185 | if (PC_IN_CALL_DUMMY (fi->pc, fi->frame, fi->frame)) | |
186 | return; | |
187 | ||
188 | pi.pifsrs = pifsrs; | |
189 | ||
190 | mn10300_scan_prologue (fi->pc, &pi); | |
191 | ||
192 | if (!fi->next && pi.framereg == SP_REGNUM) | |
193 | fi->frame = read_register (pi.framereg) - pi.frameoffset; | |
194 | ||
195 | for (pifsr = pifsrs; pifsr->framereg; pifsr++) | |
196 | { | |
197 | fi->fsr.regs[pifsr->reg] = pifsr->offset + fi->frame; | |
198 | ||
199 | if (pifsr->framereg == SP_REGNUM) | |
200 | fi->fsr.regs[pifsr->reg] += pi.frameoffset; | |
201 | } | |
202 | ||
203 | printf("mn10300_init_extra_frame_info end\n"); | |
ddc2888e GN |
204 | } |
205 | ||
3de76938 GN |
206 | /* Function: frame_chain |
207 | Figure out the frame prior to FI. Unfortunately, this involves | |
208 | scanning the prologue of the caller, which will also be done | |
209 | shortly by mn10300_init_extra_frame_info. For the dummy frame, we | |
210 | just return the stack pointer that was in use at the time the | |
211 | function call was made. */ | |
212 | ||
ddc2888e GN |
213 | CORE_ADDR |
214 | mn10300_frame_chain (fi) | |
215 | struct frame_info *fi; | |
216 | { | |
3de76938 GN |
217 | struct prologue_info pi; |
218 | CORE_ADDR callers_pc, fp; | |
219 | ||
220 | printf("mn10300_frame_chain start\n"); | |
221 | ||
222 | /* First, find out who called us */ | |
223 | callers_pc = FRAME_SAVED_PC (fi); | |
224 | /* If caller is a call-dummy, then our FP bears no relation to his FP! */ | |
225 | fp = mn10300_find_callers_reg (fi, FP_REGNUM); | |
226 | if (PC_IN_CALL_DUMMY(callers_pc, fp, fp)) | |
227 | return fp; /* caller is call-dummy: return oldest value of FP */ | |
228 | ||
229 | /* Caller is NOT a call-dummy, so everything else should just work. | |
230 | Even if THIS frame is a call-dummy! */ | |
231 | pi.pifsrs = NULL; | |
232 | ||
233 | mn10300_scan_prologue (callers_pc, &pi); | |
234 | ||
235 | printf("mn10300_frame_chain end\n"); | |
236 | ||
237 | if (pi.start_function) | |
238 | return 0; /* Don't chain beyond the start function */ | |
239 | ||
240 | if (pi.framereg == FP_REGNUM) | |
241 | return mn10300_find_callers_reg (fi, pi.framereg); | |
242 | ||
243 | return fi->frame - pi.frameoffset; | |
ddc2888e GN |
244 | } |
245 | ||
3de76938 GN |
246 | /* Function: find_callers_reg |
247 | Find REGNUM on the stack. Otherwise, it's in an active register. | |
248 | One thing we might want to do here is to check REGNUM against the | |
249 | clobber mask, and somehow flag it as invalid if it isn't saved on | |
250 | the stack somewhere. This would provide a graceful failure mode | |
251 | when trying to get the value of caller-saves registers for an inner | |
252 | frame. */ | |
253 | ||
ddc2888e GN |
254 | CORE_ADDR |
255 | mn10300_find_callers_reg (fi, regnum) | |
256 | struct frame_info *fi; | |
257 | int regnum; | |
258 | { | |
3de76938 GN |
259 | printf("mn10300_find_callers_reg\n"); |
260 | ||
261 | for (; fi; fi = fi->next) | |
262 | if (PC_IN_CALL_DUMMY (fi->pc, fi->frame, fi->frame)) | |
263 | return generic_read_register_dummy (fi->pc, fi->frame, regnum); | |
264 | else if (fi->fsr.regs[regnum] != 0) | |
265 | return read_memory_unsigned_integer (fi->fsr.regs[regnum], | |
266 | REGISTER_RAW_SIZE(regnum)); | |
267 | ||
268 | return read_register (regnum); | |
ddc2888e GN |
269 | } |
270 | ||
3de76938 GN |
271 | /* Function: skip_prologue |
272 | Return the address of the first code past the prologue of the function. */ | |
273 | ||
ddc2888e GN |
274 | CORE_ADDR |
275 | mn10300_skip_prologue (pc) | |
276 | CORE_ADDR pc; | |
277 | { | |
3de76938 GN |
278 | CORE_ADDR func_addr, func_end; |
279 | ||
280 | printf("mn10300_skip_prologue\n"); | |
281 | ||
282 | /* See what the symbol table says */ | |
283 | ||
284 | if (find_pc_partial_function (pc, NULL, &func_addr, &func_end)) | |
285 | { | |
286 | struct symtab_and_line sal; | |
287 | ||
288 | sal = find_pc_line (func_addr, 0); | |
289 | ||
290 | if (sal.line != 0 && sal.end < func_end) | |
291 | return sal.end; | |
292 | else | |
293 | /* Either there's no line info, or the line after the prologue is after | |
294 | the end of the function. In this case, there probably isn't a | |
295 | prologue. */ | |
296 | return pc; | |
297 | } | |
298 | ||
299 | /* We can't find the start of this function, so there's nothing we can do. */ | |
300 | return pc; | |
ddc2888e GN |
301 | } |
302 | ||
303 | /* Function: pop_frame | |
304 | This routine gets called when either the user uses the `return' | |
305 | command, or the call dummy breakpoint gets hit. */ | |
306 | ||
307 | void | |
308 | mn10300_pop_frame (frame) | |
309 | struct frame_info *frame; | |
310 | { | |
3de76938 GN |
311 | int regnum; |
312 | ||
313 | printf("mn10300_pop_frame start\n"); | |
314 | ||
315 | if (PC_IN_CALL_DUMMY(frame->pc, frame->frame, frame->frame)) | |
316 | generic_pop_dummy_frame (); | |
317 | else | |
318 | { | |
319 | write_register (PC_REGNUM, FRAME_SAVED_PC (frame)); | |
320 | ||
321 | for (regnum = 0; regnum < NUM_REGS; regnum++) | |
322 | if (frame->fsr.regs[regnum] != 0) | |
323 | write_register (regnum, | |
324 | read_memory_unsigned_integer (frame->fsr.regs[regnum], | |
325 | REGISTER_RAW_SIZE(regnum))); | |
326 | ||
327 | write_register (SP_REGNUM, FRAME_FP (frame)); | |
328 | } | |
329 | ||
330 | flush_cached_frames (); | |
331 | ||
332 | printf("mn10300_pop_frame end\n"); | |
ddc2888e GN |
333 | } |
334 | ||
3de76938 GN |
335 | /* Function: push_arguments |
336 | Setup arguments for a call to the target. Arguments go in | |
337 | order on the stack. | |
338 | */ | |
339 | ||
ddc2888e GN |
340 | CORE_ADDR |
341 | mn10300_push_arguments (nargs, args, sp, struct_return, struct_addr) | |
342 | int nargs; | |
343 | value_ptr *args; | |
344 | CORE_ADDR sp; | |
345 | unsigned char struct_return; | |
346 | CORE_ADDR struct_addr; | |
347 | { | |
3de76938 GN |
348 | int argnum = 0; |
349 | int len = 0; | |
350 | int stack_offset = 0; /* copy args to this offset onto stack */ | |
351 | ||
352 | printf("mn10300_push_arguments start\n"); | |
353 | ||
354 | /* First, just for safety, make sure stack is aligned */ | |
355 | sp &= ~3; | |
356 | ||
357 | /* Now make space on the stack for the args. */ | |
358 | for (argnum = 0; argnum < nargs; argnum++) | |
359 | len += ((TYPE_LENGTH(VALUE_TYPE(args[argnum])) + 3) & ~3); | |
360 | ||
361 | sp -= len; | |
362 | ||
363 | /* Push all arguments onto the stack. */ | |
364 | for (argnum = 0; argnum < nargs; argnum++) | |
365 | { | |
366 | int len; | |
367 | char *val; | |
368 | ||
369 | if (TYPE_CODE (VALUE_TYPE (*args)) == TYPE_CODE_STRUCT | |
370 | && TYPE_LENGTH (VALUE_TYPE (*args)) > 8) | |
371 | { | |
372 | /* for now, pretend structs aren't special */ | |
373 | len = TYPE_LENGTH (VALUE_TYPE (*args)); | |
374 | val = (char *)VALUE_CONTENTS (*args); | |
375 | } | |
376 | else | |
377 | { | |
378 | len = TYPE_LENGTH (VALUE_TYPE (*args)); | |
379 | val = (char *)VALUE_CONTENTS (*args); | |
380 | } | |
381 | ||
382 | while (len > 0) | |
383 | { | |
384 | write_memory (sp + stack_offset, val, 4); | |
385 | ||
386 | len -= 4; | |
387 | val += 4; | |
388 | stack_offset += 4; | |
389 | } | |
390 | args++; | |
391 | } | |
392 | ||
393 | printf("mn10300_push_arguments end\n"); | |
394 | ||
395 | return sp; | |
ddc2888e GN |
396 | } |
397 | ||
3de76938 GN |
398 | /* Function: push_return_address (pc) |
399 | Set up the return address for the inferior function call. | |
400 | Needed for targets where we don't actually execute a JSR/BSR instruction */ | |
401 | ||
ddc2888e GN |
402 | CORE_ADDR |
403 | mn10300_push_return_address (pc, sp) | |
404 | CORE_ADDR pc; | |
405 | CORE_ADDR sp; | |
406 | { | |
3de76938 GN |
407 | printf("mn10300_push_return_address\n"); |
408 | ||
409 | /* write_register (RP_REGNUM, CALL_DUMMY_ADDRESS ()); */ | |
410 | return sp; | |
ddc2888e GN |
411 | } |
412 | ||
3de76938 GN |
413 | /* Function: frame_saved_pc |
414 | Find the caller of this frame. We do this by seeing if RP_REGNUM | |
415 | is saved in the stack anywhere, otherwise we get it from the | |
416 | registers. If the inner frame is a dummy frame, return its PC | |
417 | instead of RP, because that's where "caller" of the dummy-frame | |
418 | will be found. */ | |
419 | ||
ddc2888e GN |
420 | CORE_ADDR |
421 | mn10300_frame_saved_pc (fi) | |
422 | struct frame_info *fi; | |
423 | { | |
3de76938 GN |
424 | printf("mn10300_frame_saved_pc\n"); |
425 | ||
426 | /* if (PC_IN_CALL_DUMMY(fi->pc, fi->frame, fi->frame)) */ | |
427 | return generic_read_register_dummy(fi->pc, fi->frame, PC_REGNUM); | |
428 | /* else | |
429 | return mn10300_find_callers_reg (fi, RP_REGNUM); | |
430 | */ | |
ddc2888e GN |
431 | } |
432 | ||
433 | void | |
434 | get_saved_register (raw_buffer, optimized, addrp, frame, regnum, lval) | |
435 | char *raw_buffer; | |
436 | int *optimized; | |
437 | CORE_ADDR *addrp; | |
438 | struct frame_info *frame; | |
439 | int regnum; | |
440 | enum lval_type *lval; | |
441 | { | |
3de76938 GN |
442 | printf("get_saved_register\n"); |
443 | ||
ddc2888e GN |
444 | generic_get_saved_register (raw_buffer, optimized, addrp, |
445 | frame, regnum, lval); | |
446 | } | |
447 | ||
3de76938 GN |
448 | /* Function: fix_call_dummy |
449 | Pokes the callee function's address into the CALL_DUMMY assembly stub. | |
450 | Assumes that the CALL_DUMMY looks like this: | |
451 | jarl <offset24>, r31 | |
452 | trap | |
453 | */ | |
454 | ||
ddc2888e GN |
455 | int |
456 | mn10300_fix_call_dummy (dummy, sp, fun, nargs, args, type, gcc_p) | |
457 | char *dummy; | |
458 | CORE_ADDR sp; | |
459 | CORE_ADDR fun; | |
460 | int nargs; | |
461 | value_ptr *args; | |
462 | struct type *type; | |
463 | int gcc_p; | |
464 | { | |
3de76938 GN |
465 | long offset24; |
466 | ||
467 | printf("mn10300_fix_call_dummy start\n"); | |
468 | ||
469 | offset24 = (long) fun - (long) entry_point_address (); | |
470 | offset24 &= 0x3fffff; | |
471 | offset24 |= 0xff800000; /* jarl <offset24>, r31 */ | |
472 | ||
473 | store_unsigned_integer ((unsigned int *)&dummy[2], 2, offset24 & 0xffff); | |
474 | store_unsigned_integer ((unsigned int *)&dummy[0], 2, offset24 >> 16); | |
475 | ||
476 | printf("mn10300_fix_call_dummy end\n"); | |
477 | ||
478 | return 0; | |
ddc2888e GN |
479 | } |
480 | ||
481 | void | |
482 | _initialize_mn10300_tdep () | |
483 | { | |
3de76938 GN |
484 | printf("_initialize_mn10300_tdep\n"); |
485 | ||
ddc2888e GN |
486 | tm_print_insn = print_insn_mn10300; |
487 | } |