Commit | Line | Data |
---|---|---|
e2810631 | 1 | /* Target-dependent code for the NEC V850 for GDB, the GNU debugger. |
ac954805 | 2 | Copyright 1996, Free Software Foundation, Inc. |
e2810631 SG |
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 | ||
e2810631 SG |
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" | |
e2810631 | 28 | #include "gdbcore.h" |
23da411a SG |
29 | #include "symfile.h" |
30 | ||
23da411a SG |
31 | /* Info gleaned from scanning a function's prologue. */ |
32 | ||
a638512f SG |
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 | ||
23da411a | 40 | struct prologue_info |
e5a2ac8b | 41 | { |
e5a2ac8b | 42 | int framereg; |
23da411a SG |
43 | int frameoffset; |
44 | int start_function; | |
a638512f | 45 | struct pifsr *pifsrs; |
23da411a | 46 | }; |
e5a2ac8b | 47 | |
dc1b349d MS |
48 | static CORE_ADDR v850_scan_prologue PARAMS ((CORE_ADDR pc, |
49 | struct prologue_info *fs)); | |
23da411a | 50 | \f |
dc1b349d MS |
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. */ | |
23da411a SG |
59 | |
60 | static CORE_ADDR | |
dc1b349d | 61 | v850_scan_prologue (pc, pi) |
23da411a SG |
62 | CORE_ADDR pc; |
63 | struct prologue_info *pi; | |
64 | { | |
65 | CORE_ADDR func_addr, prologue_end, current_pc; | |
a638512f | 66 | struct pifsr *pifsr; |
23da411a | 67 | int fp_used; |
b71f8719 | 68 | int ep_used; |
e5a2ac8b SG |
69 | |
70 | /* First, figure out the bounds of the prologue so that we can limit the | |
71 | search to something reasonable. */ | |
72 | ||
23da411a | 73 | if (find_pc_partial_function (pc, NULL, &func_addr, NULL)) |
e5a2ac8b | 74 | { |
23da411a SG |
75 | struct symtab_and_line sal; |
76 | ||
e5a2ac8b SG |
77 | sal = find_pc_line (func_addr, 0); |
78 | ||
23da411a SG |
79 | if (func_addr == entry_point_address ()) |
80 | pi->start_function = 1; | |
81 | else | |
82 | pi->start_function = 0; | |
83 | ||
a638512f | 84 | #if 0 |
ac954805 | 85 | if (sal.line == 0) |
23da411a | 86 | prologue_end = pc; |
ac954805 SG |
87 | else |
88 | prologue_end = sal.end; | |
a638512f SG |
89 | #else |
90 | prologue_end = pc; | |
91 | #endif | |
e5a2ac8b SG |
92 | } |
93 | else | |
23da411a SG |
94 | { /* We're in the boondocks */ |
95 | func_addr = pc - 100; | |
96 | prologue_end = pc; | |
97 | } | |
e5a2ac8b | 98 | |
23da411a | 99 | prologue_end = min (prologue_end, pc); |
e5a2ac8b SG |
100 | |
101 | /* Now, search the prologue looking for instructions that setup fp, save | |
23da411a SG |
102 | rp, adjust sp and such. We also record the frame offset of any saved |
103 | registers. */ | |
e5a2ac8b | 104 | |
23da411a SG |
105 | pi->frameoffset = 0; |
106 | pi->framereg = SP_REGNUM; | |
107 | fp_used = 0; | |
b71f8719 | 108 | ep_used = 0; |
a638512f | 109 | pifsr = pi->pifsrs; |
e5a2ac8b SG |
110 | |
111 | for (current_pc = func_addr; current_pc < prologue_end; current_pc += 2) | |
112 | { | |
113 | int insn; | |
114 | ||
6420594b | 115 | insn = read_memory_unsigned_integer (current_pc, 2); |
e5a2ac8b | 116 | |
a638512f SG |
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 */ | |
e5a2ac8b | 121 | if ((insn & 0xffe0) == ((SP_REGNUM << 11) | 0x0240)) /* add <imm>,sp */ |
23da411a | 122 | pi->frameoffset = ((insn & 0x1f) ^ 0x10) - 0x10; |
e5a2ac8b | 123 | else if (insn == ((SP_REGNUM << 11) | 0x0600 | SP_REGNUM)) /* addi <imm>,sp,sp */ |
23da411a SG |
124 | pi->frameoffset = read_memory_integer (current_pc + 2, 2); |
125 | else if (insn == ((FP_REGNUM << 11) | 0x0000 | 12)) /* mov r12,fp */ | |
e5a2ac8b | 126 | { |
23da411a SG |
127 | fp_used = 1; |
128 | pi->framereg = FP_REGNUM; | |
129 | } | |
b71f8719 MM |
130 | else if (insn == 0xf003) /* mov sp,ep */ |
131 | ep_used = 1; | |
132 | else if (insn == 0xf001) /* mov r1,ep */ | |
133 | ep_used = 0; | |
134 | else if (((insn & 0x07ff) == (0x0760 | SP_REGNUM) /* st.w <reg>,<offset>[sp] */ | |
135 | || (fp_used | |
136 | && (insn & 0x07ff) == (0x0760 | FP_REGNUM))) /* st.w <reg>,<offset>[fp] */ | |
137 | && pifsr) | |
138 | { | |
139 | pifsr->framereg = insn & 0x1f; | |
140 | pifsr->reg = (insn >> 11) & 0x1f; /* Extract <reg> */ | |
141 | pifsr->offset = read_memory_integer (current_pc + 2, 2) & ~1; | |
142 | pifsr++; | |
143 | } | |
144 | ||
145 | else if (ep_used /* sst.w <reg>,<offset>[ep] */ | |
146 | && ((insn & 0x0781) == 0x0501) | |
147 | && pifsr) | |
148 | { | |
149 | pifsr->framereg = 3; | |
150 | pifsr->reg = (insn >> 11) & 0x1f; /* Extract <reg> */ | |
151 | pifsr->offset = (insn & 0x007e) << 2; | |
152 | pifsr++; | |
153 | } | |
6420594b SG |
154 | |
155 | if ((insn & 0x0780) >= 0x0600) /* Four byte instruction? */ | |
156 | current_pc += 2; | |
e5a2ac8b SG |
157 | } |
158 | ||
a638512f SG |
159 | if (pifsr) |
160 | pifsr->framereg = 0; /* Tie off last entry */ | |
161 | ||
23da411a | 162 | return current_pc; |
e5a2ac8b SG |
163 | } |
164 | ||
dc1b349d MS |
165 | /* Function: init_extra_frame_info |
166 | Setup the frame's frame pointer, pc, and frame addresses for saved | |
167 | registers. Most of the work is done in scan_prologue(). | |
e5a2ac8b | 168 | |
23da411a SG |
169 | Note that when we are called for the last frame (currently active frame), |
170 | that fi->pc and fi->frame will already be setup. However, fi->frame will | |
171 | be valid only if this routine uses FP. For previous frames, fi-frame will | |
172 | always be correct (since that is derived from v850_frame_chain ()). | |
173 | ||
174 | We can be called with the PC in the call dummy under two circumstances. | |
175 | First, during normal backtracing, second, while figuring out the frame | |
dc1b349d | 176 | pointer just prior to calling the target function (see run_stack_dummy). */ |
23da411a SG |
177 | |
178 | void | |
179 | v850_init_extra_frame_info (fi) | |
e5a2ac8b | 180 | struct frame_info *fi; |
e5a2ac8b | 181 | { |
23da411a | 182 | struct prologue_info pi; |
a638512f | 183 | struct pifsr pifsrs[NUM_REGS + 1], *pifsr; |
23da411a SG |
184 | int reg; |
185 | ||
186 | if (fi->next) | |
187 | fi->pc = FRAME_SAVED_PC (fi->next); | |
188 | ||
189 | memset (fi->fsr.regs, '\000', sizeof fi->fsr.regs); | |
190 | ||
191 | /* The call dummy doesn't save any registers on the stack, so we can return | |
192 | now. */ | |
dc1b349d | 193 | if (PC_IN_CALL_DUMMY (fi->pc, fi->frame, fi->frame)) |
23da411a | 194 | return; |
ac954805 | 195 | |
a638512f | 196 | pi.pifsrs = pifsrs; |
e5a2ac8b | 197 | |
dc1b349d | 198 | v850_scan_prologue (fi->pc, &pi); |
23da411a | 199 | |
a638512f SG |
200 | if (!fi->next && pi.framereg == SP_REGNUM) |
201 | fi->frame = read_register (pi.framereg) - pi.frameoffset; | |
23da411a | 202 | |
a638512f SG |
203 | for (pifsr = pifsrs; pifsr->framereg; pifsr++) |
204 | { | |
205 | fi->fsr.regs[pifsr->reg] = pifsr->offset + fi->frame; | |
206 | ||
207 | if (pifsr->framereg == SP_REGNUM) | |
208 | fi->fsr.regs[pifsr->reg] += pi.frameoffset; | |
209 | } | |
e5a2ac8b SG |
210 | } |
211 | ||
dc1b349d MS |
212 | /* Function: frame_chain |
213 | Figure out the frame prior to FI. Unfortunately, this involves | |
214 | scanning the prologue of the caller, which will also be done | |
215 | shortly by v850_init_extra_frame_info. For the dummy frame, we | |
216 | just return the stack pointer that was in use at the time the | |
217 | function call was made. */ | |
23da411a | 218 | |
e5a2ac8b SG |
219 | CORE_ADDR |
220 | v850_frame_chain (fi) | |
221 | struct frame_info *fi; | |
222 | { | |
23da411a | 223 | struct prologue_info pi; |
dc1b349d | 224 | CORE_ADDR callers_pc, fp; |
e5a2ac8b SG |
225 | |
226 | /* First, find out who called us */ | |
ac954805 | 227 | callers_pc = FRAME_SAVED_PC (fi); |
dc1b349d MS |
228 | /* If caller is a call-dummy, then our FP bears no relation to his FP! */ |
229 | fp = v850_find_callers_reg (fi, FP_REGNUM); | |
230 | if (PC_IN_CALL_DUMMY(callers_pc, fp, fp)) | |
231 | return fp; /* caller is call-dummy: return oldest value of FP */ | |
ac954805 | 232 | |
dc1b349d MS |
233 | /* Caller is NOT a call-dummy, so everything else should just work. |
234 | Even if THIS frame is a call-dummy! */ | |
a638512f | 235 | pi.pifsrs = NULL; |
e5a2ac8b | 236 | |
dc1b349d | 237 | v850_scan_prologue (callers_pc, &pi); |
e5a2ac8b | 238 | |
23da411a SG |
239 | if (pi.start_function) |
240 | return 0; /* Don't chain beyond the start function */ | |
ac954805 | 241 | |
23da411a SG |
242 | if (pi.framereg == FP_REGNUM) |
243 | return v850_find_callers_reg (fi, pi.framereg); | |
e5a2ac8b | 244 | |
23da411a SG |
245 | return fi->frame - pi.frameoffset; |
246 | } | |
e5a2ac8b | 247 | |
dc1b349d MS |
248 | /* Function: find_callers_reg |
249 | Find REGNUM on the stack. Otherwise, it's in an active register. | |
250 | One thing we might want to do here is to check REGNUM against the | |
251 | clobber mask, and somehow flag it as invalid if it isn't saved on | |
252 | the stack somewhere. This would provide a graceful failure mode | |
253 | when trying to get the value of caller-saves registers for an inner | |
254 | frame. */ | |
e5a2ac8b | 255 | |
23da411a SG |
256 | CORE_ADDR |
257 | v850_find_callers_reg (fi, regnum) | |
258 | struct frame_info *fi; | |
259 | int regnum; | |
260 | { | |
23da411a | 261 | for (; fi; fi = fi->next) |
dc1b349d MS |
262 | if (PC_IN_CALL_DUMMY (fi->pc, fi->frame, fi->frame)) |
263 | return generic_read_register_dummy (fi->pc, fi->frame, regnum); | |
23da411a | 264 | else if (fi->fsr.regs[regnum] != 0) |
dc1b349d MS |
265 | return read_memory_unsigned_integer (fi->fsr.regs[regnum], |
266 | REGISTER_RAW_SIZE(regnum)); | |
e5a2ac8b | 267 | |
23da411a | 268 | return read_register (regnum); |
e5a2ac8b SG |
269 | } |
270 | ||
dc1b349d MS |
271 | /* Function: skip_prologue |
272 | Return the address of the first code past the prologue of the function. */ | |
273 | ||
e5a2ac8b SG |
274 | CORE_ADDR |
275 | v850_skip_prologue (pc) | |
276 | CORE_ADDR pc; | |
277 | { | |
278 | CORE_ADDR func_addr, func_end; | |
279 | ||
280 | /* See what the symbol table says */ | |
281 | ||
282 | if (find_pc_partial_function (pc, NULL, &func_addr, &func_end)) | |
283 | { | |
284 | struct symtab_and_line sal; | |
285 | ||
286 | sal = find_pc_line (func_addr, 0); | |
287 | ||
ac954805 | 288 | if (sal.line != 0 && sal.end < func_end) |
e5a2ac8b SG |
289 | return sal.end; |
290 | else | |
ac954805 SG |
291 | /* Either there's no line info, or the line after the prologue is after |
292 | the end of the function. In this case, there probably isn't a | |
293 | prologue. */ | |
e5a2ac8b SG |
294 | return pc; |
295 | } | |
296 | ||
297 | /* We can't find the start of this function, so there's nothing we can do. */ | |
298 | return pc; | |
299 | } | |
300 | ||
dc1b349d MS |
301 | /* Function: pop_frame |
302 | This routine gets called when either the user uses the `return' | |
303 | command, or the call dummy breakpoint gets hit. */ | |
ac954805 SG |
304 | |
305 | void | |
e5a2ac8b SG |
306 | v850_pop_frame (frame) |
307 | struct frame_info *frame; | |
308 | { | |
309 | int regnum; | |
310 | ||
dc1b349d MS |
311 | if (PC_IN_CALL_DUMMY(frame->pc, frame->frame, frame->frame)) |
312 | generic_pop_dummy_frame (); | |
23da411a SG |
313 | else |
314 | { | |
315 | write_register (PC_REGNUM, FRAME_SAVED_PC (frame)); | |
ac954805 | 316 | |
23da411a SG |
317 | for (regnum = 0; regnum < NUM_REGS; regnum++) |
318 | if (frame->fsr.regs[regnum] != 0) | |
319 | write_register (regnum, | |
dc1b349d MS |
320 | read_memory_unsigned_integer (frame->fsr.regs[regnum], |
321 | REGISTER_RAW_SIZE(regnum))); | |
e5a2ac8b | 322 | |
23da411a SG |
323 | write_register (SP_REGNUM, FRAME_FP (frame)); |
324 | } | |
e5a2ac8b | 325 | |
e5a2ac8b | 326 | flush_cached_frames (); |
e5a2ac8b | 327 | } |
ac954805 | 328 | |
dc1b349d MS |
329 | /* Function: push_arguments |
330 | Setup arguments and RP for a call to the target. First four args | |
331 | go in R6->R9, subsequent args go into sp + 16 -> sp + ... Structs | |
332 | are passed by reference. 64 bit quantities (doubles and long | |
333 | longs) may be split between the regs and the stack. When calling a | |
334 | function that returns a struct, a pointer to the struct is passed | |
335 | in as a secret first argument (always in R6). | |
ac954805 | 336 | |
dc1b349d MS |
337 | Stack space for the args has NOT been allocated: that job is up to us. |
338 | */ | |
ac954805 SG |
339 | |
340 | CORE_ADDR | |
341 | v850_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 | { | |
348 | int argreg; | |
349 | int argnum; | |
dc1b349d MS |
350 | int len = 0; |
351 | int stack_offset; | |
ac954805 | 352 | |
dc1b349d MS |
353 | /* First, just for safety, make sure stack is aligned */ |
354 | sp &= ~3; | |
355 | ||
356 | /* Now make space on the stack for the args. */ | |
357 | for (argnum = 0; argnum < nargs; argnum++) | |
358 | len += ((TYPE_LENGTH(VALUE_TYPE(args[argnum])) + 3) & ~3); | |
359 | sp -= len; /* possibly over-allocating, but it works... */ | |
360 | /* (you might think we could allocate 16 bytes */ | |
361 | /* less, but the ABI seems to use it all! ) */ | |
687f4e23 | 362 | argreg = ARG0_REGNUM; |
ac954805 | 363 | |
dc1b349d | 364 | /* the struct_return pointer occupies the first parameter-passing reg */ |
ac954805 | 365 | if (struct_return) |
ac954805 | 366 | write_register (argreg++, struct_addr); |
ac954805 | 367 | |
dc1b349d MS |
368 | stack_offset = 16; |
369 | /* The offset onto the stack at which we will start copying parameters | |
370 | (after the registers are used up) begins at 16 rather than at zero. | |
371 | I don't really know why, that's just the way it seems to work. */ | |
372 | ||
373 | /* Now load as many as possible of the first arguments into | |
374 | registers, and push the rest onto the stack. There are 16 bytes | |
375 | in four registers available. Loop thru args from first to last. */ | |
ac954805 SG |
376 | for (argnum = 0; argnum < nargs; argnum++) |
377 | { | |
378 | int len; | |
379 | char *val; | |
dc1b349d | 380 | char valbuf[REGISTER_RAW_SIZE(ARG0_REGNUM)]; |
ac954805 SG |
381 | |
382 | if (TYPE_CODE (VALUE_TYPE (*args)) == TYPE_CODE_STRUCT | |
383 | && TYPE_LENGTH (VALUE_TYPE (*args)) > 8) | |
384 | { | |
385 | store_address (valbuf, 4, VALUE_ADDRESS (*args)); | |
386 | len = 4; | |
387 | val = valbuf; | |
388 | } | |
389 | else | |
390 | { | |
391 | len = TYPE_LENGTH (VALUE_TYPE (*args)); | |
392 | val = (char *)VALUE_CONTENTS (*args); | |
393 | } | |
394 | ||
395 | while (len > 0) | |
687f4e23 | 396 | if (argreg <= ARGLAST_REGNUM) |
ac954805 SG |
397 | { |
398 | CORE_ADDR regval; | |
399 | ||
400 | regval = extract_address (val, REGISTER_RAW_SIZE (argreg)); | |
401 | write_register (argreg, regval); | |
402 | ||
403 | len -= REGISTER_RAW_SIZE (argreg); | |
404 | val += REGISTER_RAW_SIZE (argreg); | |
405 | argreg++; | |
406 | } | |
407 | else | |
408 | { | |
dc1b349d | 409 | write_memory (sp + stack_offset, val, 4); |
ac954805 SG |
410 | |
411 | len -= 4; | |
412 | val += 4; | |
dc1b349d | 413 | stack_offset += 4; |
ac954805 SG |
414 | } |
415 | args++; | |
416 | } | |
dc1b349d MS |
417 | return sp; |
418 | } | |
ac954805 | 419 | |
dc1b349d MS |
420 | /* Function: push_return_address (pc) |
421 | Set up the return address for the inferior function call. | |
422 | Needed for targets where we don't actually execute a JSR/BSR instruction */ | |
423 | ||
dc1b349d MS |
424 | CORE_ADDR |
425 | v850_push_return_address (pc, sp) | |
426 | CORE_ADDR pc; | |
427 | CORE_ADDR sp; | |
428 | { | |
409f64ae | 429 | write_register (RP_REGNUM, CALL_DUMMY_ADDRESS ()); |
ac954805 SG |
430 | return sp; |
431 | } | |
dc1b349d MS |
432 | |
433 | /* Function: frame_saved_pc | |
434 | Find the caller of this frame. We do this by seeing if RP_REGNUM | |
435 | is saved in the stack anywhere, otherwise we get it from the | |
436 | registers. If the inner frame is a dummy frame, return its PC | |
437 | instead of RP, because that's where "caller" of the dummy-frame | |
438 | will be found. */ | |
439 | ||
440 | CORE_ADDR | |
441 | v850_frame_saved_pc (fi) | |
442 | struct frame_info *fi; | |
443 | { | |
444 | if (PC_IN_CALL_DUMMY(fi->pc, fi->frame, fi->frame)) | |
445 | return generic_read_register_dummy(fi->pc, fi->frame, PC_REGNUM); | |
446 | else | |
447 | return v850_find_callers_reg (fi, RP_REGNUM); | |
448 | } | |
449 | ||
450 | void | |
451 | get_saved_register (raw_buffer, optimized, addrp, frame, regnum, lval) | |
452 | char *raw_buffer; | |
453 | int *optimized; | |
454 | CORE_ADDR *addrp; | |
455 | struct frame_info *frame; | |
456 | int regnum; | |
457 | enum lval_type *lval; | |
458 | { | |
459 | generic_get_saved_register (raw_buffer, optimized, addrp, | |
460 | frame, regnum, lval); | |
461 | } | |
462 | ||
463 | ||
464 | /* Function: fix_call_dummy | |
465 | Pokes the callee function's address into the CALL_DUMMY assembly stub. | |
466 | Assumes that the CALL_DUMMY looks like this: | |
467 | jarl <offset24>, r31 | |
468 | trap | |
469 | */ | |
470 | ||
471 | int | |
472 | v850_fix_call_dummy (dummy, sp, fun, nargs, args, type, gcc_p) | |
473 | char *dummy; | |
474 | CORE_ADDR sp; | |
475 | CORE_ADDR fun; | |
476 | int nargs; | |
477 | value_ptr *args; | |
478 | struct type *type; | |
479 | int gcc_p; | |
480 | { | |
481 | long offset24; | |
dc1b349d | 482 | |
409f64ae | 483 | offset24 = (long) fun - (long) entry_point_address (); |
dc1b349d MS |
484 | offset24 &= 0x3fffff; |
485 | offset24 |= 0xff800000; /* jarl <offset24>, r31 */ | |
486 | ||
487 | store_unsigned_integer ((unsigned int *)&dummy[2], 2, offset24 & 0xffff); | |
488 | store_unsigned_integer ((unsigned int *)&dummy[0], 2, offset24 >> 16); | |
489 | return 0; | |
490 | } | |
491 | ||
e2810631 | 492 | void |
dc1b349d | 493 | _initialize_v850_tdep () |
e2810631 SG |
494 | { |
495 | tm_print_insn = print_insn_v850; | |
496 | } |