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d7066cce AG |
1 | /* Target-dependent code for Moxie. |
2 | ||
3 | Copyright (C) 2009 Free Software Foundation, Inc. | |
4 | ||
5 | This file is part of GDB. | |
6 | ||
7 | This program is free software; you can redistribute it and/or modify | |
8 | it under the terms of the GNU General Public License as published by | |
9 | the Free Software Foundation; either version 3 of the License, or | |
10 | (at your option) any later version. | |
11 | ||
12 | This program is distributed in the hope that it will be useful, | |
13 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
14 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
15 | GNU General Public License for more details. | |
16 | ||
17 | You should have received a copy of the GNU General Public License | |
18 | along with this program. If not, see <http://www.gnu.org/licenses/>. */ | |
19 | ||
20 | #include "defs.h" | |
21 | #include "frame.h" | |
22 | #include "frame-unwind.h" | |
23 | #include "frame-base.h" | |
24 | #include "symtab.h" | |
25 | #include "gdbtypes.h" | |
26 | #include "gdbcmd.h" | |
27 | #include "gdbcore.h" | |
28 | #include "gdb_string.h" | |
29 | #include "value.h" | |
30 | #include "inferior.h" | |
31 | #include "symfile.h" | |
32 | #include "objfiles.h" | |
33 | #include "osabi.h" | |
34 | #include "language.h" | |
35 | #include "arch-utils.h" | |
36 | #include "regcache.h" | |
37 | #include "trad-frame.h" | |
38 | #include "dis-asm.h" | |
39 | ||
40 | #include "gdb_assert.h" | |
41 | ||
42 | #include "moxie-tdep.h" | |
43 | ||
44 | /* Local functions. */ | |
45 | ||
46 | extern void _initialize_moxie_tdep (void); | |
47 | ||
48 | /* Use an invalid address value as 'not available' marker. */ | |
49 | enum { REG_UNAVAIL = (CORE_ADDR) -1 }; | |
50 | ||
51 | struct moxie_frame_cache | |
52 | { | |
53 | /* Base address. */ | |
54 | CORE_ADDR base; | |
55 | CORE_ADDR pc; | |
56 | LONGEST framesize; | |
57 | CORE_ADDR saved_regs[MOXIE_NUM_REGS]; | |
58 | CORE_ADDR saved_sp; | |
59 | }; | |
60 | ||
61 | /* Implement the "frame_align" gdbarch method. */ | |
62 | ||
63 | static CORE_ADDR | |
64 | moxie_frame_align (struct gdbarch *gdbarch, CORE_ADDR sp) | |
65 | { | |
66 | /* Align to the size of an instruction (so that they can safely be | |
67 | pushed onto the stack. */ | |
68 | return sp & ~1; | |
69 | } | |
70 | ||
71 | /* Implement the "breakpoint_from_pc" gdbarch method. */ | |
72 | ||
73 | const static unsigned char * | |
74 | moxie_breakpoint_from_pc (struct gdbarch *gdbarch, | |
75 | CORE_ADDR *pcptr, int *lenptr) | |
76 | { | |
77 | static unsigned char breakpoint[] = { 0x35, 0x00 }; | |
78 | ||
79 | *lenptr = sizeof (breakpoint); | |
80 | return breakpoint; | |
81 | } | |
82 | ||
83 | /* Moxie register names. */ | |
84 | ||
85 | char *moxie_register_names[] = { | |
86 | "$fp", "$sp", "$r0", "$r1", "$r2", | |
87 | "$r3", "$r4", "$r5", "$r6", "$r7", | |
88 | "$r8", "$r9", "$r10", "$r11", "$r12", | |
89 | "$r13", "$pc", "$cc" }; | |
90 | ||
91 | /* Implement the "register_name" gdbarch method. */ | |
92 | ||
93 | static const char * | |
94 | moxie_register_name (struct gdbarch *gdbarch, int reg_nr) | |
95 | { | |
96 | if (reg_nr < 0) | |
97 | return NULL; | |
98 | if (reg_nr >= MOXIE_NUM_REGS) | |
99 | return NULL; | |
100 | return moxie_register_names[reg_nr]; | |
101 | } | |
102 | ||
103 | /* Implement the "register_type" gdbarch method. */ | |
104 | ||
105 | static struct type * | |
106 | moxie_register_type (struct gdbarch *gdbarch, int reg_nr) | |
107 | { | |
108 | if (reg_nr == MOXIE_PC_REGNUM) | |
109 | return builtin_type (gdbarch)->builtin_func_ptr; | |
110 | else if (reg_nr == MOXIE_SP_REGNUM || reg_nr == MOXIE_FP_REGNUM) | |
111 | return builtin_type (gdbarch)->builtin_data_ptr; | |
112 | else | |
df4df182 | 113 | return builtin_type (gdbarch)->builtin_int32; |
d7066cce AG |
114 | } |
115 | ||
116 | /* Write into appropriate registers a function return value | |
117 | of type TYPE, given in virtual format. */ | |
118 | ||
119 | static void | |
120 | moxie_store_return_value (struct type *type, struct regcache *regcache, | |
121 | const void *valbuf) | |
122 | { | |
e17a4113 UW |
123 | struct gdbarch *gdbarch = get_regcache_arch (regcache); |
124 | enum bfd_endian byte_order = gdbarch_byte_order (gdbarch); | |
d7066cce AG |
125 | CORE_ADDR regval; |
126 | int len = TYPE_LENGTH (type); | |
127 | ||
128 | /* Things always get returned in RET1_REGNUM, RET2_REGNUM. */ | |
e17a4113 | 129 | regval = extract_unsigned_integer (valbuf, len > 4 ? 4 : len, byte_order); |
d7066cce AG |
130 | regcache_cooked_write_unsigned (regcache, RET1_REGNUM, regval); |
131 | if (len > 4) | |
132 | { | |
e17a4113 UW |
133 | regval = extract_unsigned_integer ((gdb_byte *) valbuf + 4, |
134 | len - 4, byte_order); | |
d7066cce AG |
135 | regcache_cooked_write_unsigned (regcache, RET1_REGNUM + 1, regval); |
136 | } | |
137 | } | |
138 | ||
139 | /* Decode the instructions within the given address range. Decide | |
140 | when we must have reached the end of the function prologue. If a | |
141 | frame_info pointer is provided, fill in its saved_regs etc. | |
142 | ||
143 | Returns the address of the first instruction after the prologue. */ | |
144 | ||
145 | static CORE_ADDR | |
146 | moxie_analyze_prologue (CORE_ADDR start_addr, CORE_ADDR end_addr, | |
147 | struct moxie_frame_cache *cache, | |
148 | struct frame_info *this_frame) | |
149 | { | |
e17a4113 UW |
150 | struct gdbarch *gdbarch = get_frame_arch (this_frame); |
151 | enum bfd_endian byte_order = gdbarch_byte_order (gdbarch); | |
d7066cce AG |
152 | CORE_ADDR next_addr; |
153 | ULONGEST inst, inst2; | |
154 | LONGEST offset; | |
155 | int regnum; | |
156 | ||
157 | /* Record where the jsra instruction saves the PC and FP. */ | |
158 | cache->saved_regs[MOXIE_PC_REGNUM] = -4; | |
159 | cache->saved_regs[MOXIE_FP_REGNUM] = 0; | |
160 | cache->framesize = 0; | |
161 | ||
162 | if (start_addr >= end_addr) | |
163 | return end_addr; | |
164 | ||
165 | for (next_addr = start_addr; next_addr < end_addr; ) | |
166 | { | |
e17a4113 | 167 | inst = read_memory_unsigned_integer (next_addr, 2, byte_order); |
d7066cce AG |
168 | |
169 | /* Match "push $rN" where N is between 2 and 13 inclusive. */ | |
170 | if (inst >= 0x0614 && inst <= 0x061f) | |
171 | { | |
172 | regnum = inst & 0x000f; | |
173 | cache->framesize += 4; | |
174 | cache->saved_regs[regnum] = cache->framesize; | |
175 | next_addr += 2; | |
176 | } | |
177 | ||
178 | /* Optional stack allocation for args and local vars <= 4 | |
179 | byte. */ | |
180 | else if (inst == 0x01f0) /* ldi.l $r12, X */ | |
181 | { | |
e17a4113 UW |
182 | offset = read_memory_integer (next_addr + 2, 4, byte_order); |
183 | inst2 = read_memory_unsigned_integer (next_addr + 6, 2, byte_order); | |
d7066cce AG |
184 | |
185 | if (inst2 == 0x051f) /* add.l $sp, $r12 */ | |
186 | { | |
187 | cache->framesize += offset; | |
188 | } | |
189 | ||
190 | return (next_addr + 8); | |
191 | } | |
192 | else /* This is not a prologue instruction. */ | |
193 | break; | |
194 | } | |
195 | ||
196 | return next_addr; | |
197 | } | |
198 | ||
199 | /* Find the end of function prologue. */ | |
200 | ||
201 | static CORE_ADDR | |
202 | moxie_skip_prologue (struct gdbarch *gdbarch, CORE_ADDR pc) | |
203 | { | |
204 | CORE_ADDR func_addr = 0, func_end = 0; | |
205 | char *func_name; | |
206 | ||
207 | /* See if we can determine the end of the prologue via the symbol table. | |
208 | If so, then return either PC, or the PC after the prologue, whichever | |
209 | is greater. */ | |
210 | if (find_pc_partial_function (pc, &func_name, &func_addr, &func_end)) | |
211 | { | |
d80b854b UW |
212 | CORE_ADDR post_prologue_pc |
213 | = skip_prologue_using_sal (gdbarch, func_addr); | |
d7066cce AG |
214 | if (post_prologue_pc != 0) |
215 | return max (pc, post_prologue_pc); | |
216 | else | |
217 | { | |
218 | /* Can't determine prologue from the symbol table, need to examine | |
219 | instructions. */ | |
220 | struct symtab_and_line sal; | |
221 | struct symbol *sym; | |
222 | struct moxie_frame_cache cache; | |
223 | CORE_ADDR plg_end; | |
224 | ||
225 | memset (&cache, 0, sizeof cache); | |
226 | ||
227 | plg_end = moxie_analyze_prologue (func_addr, | |
228 | func_end, &cache, NULL); | |
229 | /* Found a function. */ | |
230 | sym = lookup_symbol (func_name, NULL, VAR_DOMAIN, NULL); | |
231 | /* Don't use line number debug info for assembly source | |
232 | files. */ | |
233 | if (sym && SYMBOL_LANGUAGE (sym) != language_asm) | |
234 | { | |
235 | sal = find_pc_line (func_addr, 0); | |
236 | if (sal.end && sal.end < func_end) | |
237 | { | |
238 | /* Found a line number, use it as end of | |
239 | prologue. */ | |
240 | return sal.end; | |
241 | } | |
242 | } | |
243 | /* No useable line symbol. Use result of prologue parsing | |
244 | method. */ | |
245 | return plg_end; | |
246 | } | |
247 | } | |
248 | ||
249 | /* No function symbol -- just return the PC. */ | |
250 | return (CORE_ADDR) pc; | |
251 | } | |
252 | ||
253 | struct moxie_unwind_cache | |
254 | { | |
255 | /* The previous frame's inner most stack address. Used as this | |
256 | frame ID's stack_addr. */ | |
257 | CORE_ADDR prev_sp; | |
258 | /* The frame's base, optionally used by the high-level debug info. */ | |
259 | CORE_ADDR base; | |
260 | int size; | |
261 | /* How far the SP and r13 (FP) have been offset from the start of | |
262 | the stack frame (as defined by the previous frame's stack | |
263 | pointer). */ | |
264 | LONGEST sp_offset; | |
265 | LONGEST r13_offset; | |
266 | int uses_frame; | |
267 | /* Table indicating the location of each and every register. */ | |
268 | struct trad_frame_saved_reg *saved_regs; | |
269 | }; | |
270 | ||
271 | /* Implement the "read_pc" gdbarch method. */ | |
272 | ||
273 | static CORE_ADDR | |
274 | moxie_read_pc (struct regcache *regcache) | |
275 | { | |
276 | ULONGEST pc; | |
277 | ||
278 | regcache_cooked_read_unsigned (regcache, MOXIE_PC_REGNUM, &pc); | |
279 | return pc; | |
280 | } | |
281 | ||
282 | /* Implement the "write_pc" gdbarch method. */ | |
283 | ||
284 | static void | |
285 | moxie_write_pc (struct regcache *regcache, CORE_ADDR val) | |
286 | { | |
287 | regcache_cooked_write_unsigned (regcache, MOXIE_PC_REGNUM, val); | |
288 | } | |
289 | ||
290 | /* Implement the "unwind_pc" gdbarch method. */ | |
291 | ||
292 | static CORE_ADDR | |
293 | moxie_unwind_sp (struct gdbarch *gdbarch, struct frame_info *next_frame) | |
294 | { | |
295 | return frame_unwind_register_unsigned (next_frame, MOXIE_SP_REGNUM); | |
296 | } | |
297 | ||
298 | /* Given a return value in `regbuf' with a type `valtype', | |
299 | extract and copy its value into `valbuf'. */ | |
300 | ||
301 | static void | |
302 | moxie_extract_return_value (struct type *type, struct regcache *regcache, | |
303 | void *dst) | |
304 | { | |
e17a4113 UW |
305 | struct gdbarch *gdbarch = get_regcache_arch (regcache); |
306 | enum bfd_endian byte_order = gdbarch_byte_order (gdbarch); | |
d7066cce AG |
307 | bfd_byte *valbuf = dst; |
308 | int len = TYPE_LENGTH (type); | |
309 | ULONGEST tmp; | |
310 | ||
311 | /* By using store_unsigned_integer we avoid having to do | |
312 | anything special for small big-endian values. */ | |
313 | regcache_cooked_read_unsigned (regcache, RET1_REGNUM, &tmp); | |
e17a4113 | 314 | store_unsigned_integer (valbuf, (len > 4 ? len - 4 : len), byte_order, tmp); |
d7066cce AG |
315 | |
316 | /* Ignore return values more than 8 bytes in size because the moxie | |
317 | returns anything more than 8 bytes in the stack. */ | |
318 | if (len > 4) | |
319 | { | |
320 | regcache_cooked_read_unsigned (regcache, RET1_REGNUM + 1, &tmp); | |
e17a4113 | 321 | store_unsigned_integer (valbuf + len - 4, 4, byte_order, tmp); |
d7066cce AG |
322 | } |
323 | } | |
324 | ||
325 | /* Implement the "return_value" gdbarch method. */ | |
326 | ||
327 | static enum return_value_convention | |
328 | moxie_return_value (struct gdbarch *gdbarch, struct type *func_type, | |
329 | struct type *valtype, struct regcache *regcache, | |
330 | gdb_byte *readbuf, const gdb_byte *writebuf) | |
331 | { | |
332 | if (TYPE_LENGTH (valtype) > 8) | |
333 | return RETURN_VALUE_STRUCT_CONVENTION; | |
334 | else | |
335 | { | |
336 | if (readbuf != NULL) | |
337 | moxie_extract_return_value (valtype, regcache, readbuf); | |
338 | if (writebuf != NULL) | |
339 | moxie_store_return_value (valtype, regcache, writebuf); | |
340 | return RETURN_VALUE_REGISTER_CONVENTION; | |
341 | } | |
342 | } | |
343 | ||
344 | /* Allocate and initialize a moxie_frame_cache object. */ | |
345 | ||
346 | static struct moxie_frame_cache * | |
347 | moxie_alloc_frame_cache (void) | |
348 | { | |
349 | struct moxie_frame_cache *cache; | |
350 | int i; | |
351 | ||
352 | cache = FRAME_OBSTACK_ZALLOC (struct moxie_frame_cache); | |
353 | ||
354 | cache->base = 0; | |
355 | cache->saved_sp = 0; | |
356 | cache->pc = 0; | |
357 | cache->framesize = 0; | |
358 | for (i = 0; i < MOXIE_NUM_REGS; ++i) | |
359 | cache->saved_regs[i] = REG_UNAVAIL; | |
360 | ||
361 | return cache; | |
362 | } | |
363 | ||
364 | /* Populate a moxie_frame_cache object for this_frame. */ | |
365 | ||
366 | static struct moxie_frame_cache * | |
367 | moxie_frame_cache (struct frame_info *this_frame, void **this_cache) | |
368 | { | |
369 | struct moxie_frame_cache *cache; | |
370 | CORE_ADDR current_pc; | |
371 | int i; | |
372 | ||
373 | if (*this_cache) | |
374 | return *this_cache; | |
375 | ||
376 | cache = moxie_alloc_frame_cache (); | |
377 | *this_cache = cache; | |
378 | ||
379 | cache->base = get_frame_register_unsigned (this_frame, MOXIE_FP_REGNUM); | |
380 | if (cache->base == 0) | |
381 | return cache; | |
382 | ||
383 | cache->pc = get_frame_func (this_frame); | |
384 | current_pc = get_frame_pc (this_frame); | |
385 | if (cache->pc) | |
386 | moxie_analyze_prologue (cache->pc, current_pc, cache, this_frame); | |
387 | ||
388 | cache->saved_sp = cache->base - cache->framesize; | |
389 | ||
390 | for (i = 0; i < MOXIE_NUM_REGS; ++i) | |
391 | if (cache->saved_regs[i] != REG_UNAVAIL) | |
392 | cache->saved_regs[i] = cache->base - cache->saved_regs[i]; | |
393 | ||
394 | return cache; | |
395 | } | |
396 | ||
397 | /* Implement the "unwind_pc" gdbarch method. */ | |
398 | ||
399 | static CORE_ADDR | |
400 | moxie_unwind_pc (struct gdbarch *gdbarch, struct frame_info *next_frame) | |
401 | { | |
402 | return frame_unwind_register_unsigned (next_frame, MOXIE_PC_REGNUM); | |
403 | } | |
404 | ||
405 | /* Given a GDB frame, determine the address of the calling function's | |
406 | frame. This will be used to create a new GDB frame struct. */ | |
407 | ||
408 | static void | |
409 | moxie_frame_this_id (struct frame_info *this_frame, | |
410 | void **this_prologue_cache, struct frame_id *this_id) | |
411 | { | |
412 | struct moxie_frame_cache *cache = moxie_frame_cache (this_frame, | |
413 | this_prologue_cache); | |
414 | ||
415 | /* This marks the outermost frame. */ | |
416 | if (cache->base == 0) | |
417 | return; | |
418 | ||
419 | *this_id = frame_id_build (cache->saved_sp, cache->pc); | |
420 | } | |
421 | ||
422 | /* Get the value of register regnum in the previous stack frame. */ | |
423 | ||
424 | static struct value * | |
425 | moxie_frame_prev_register (struct frame_info *this_frame, | |
426 | void **this_prologue_cache, int regnum) | |
427 | { | |
428 | struct moxie_frame_cache *cache = moxie_frame_cache (this_frame, | |
429 | this_prologue_cache); | |
430 | ||
431 | gdb_assert (regnum >= 0); | |
432 | ||
433 | if (regnum == MOXIE_SP_REGNUM && cache->saved_sp) | |
434 | return frame_unwind_got_constant (this_frame, regnum, cache->saved_sp); | |
435 | ||
436 | if (regnum < MOXIE_NUM_REGS && cache->saved_regs[regnum] != REG_UNAVAIL) | |
437 | return frame_unwind_got_memory (this_frame, regnum, | |
438 | cache->saved_regs[regnum]); | |
439 | ||
440 | return frame_unwind_got_register (this_frame, regnum, regnum); | |
441 | } | |
442 | ||
443 | static const struct frame_unwind moxie_frame_unwind = { | |
444 | NORMAL_FRAME, | |
445 | moxie_frame_this_id, | |
446 | moxie_frame_prev_register, | |
447 | NULL, | |
448 | default_frame_sniffer | |
449 | }; | |
450 | ||
451 | /* Return the base address of this_frame. */ | |
452 | ||
453 | static CORE_ADDR | |
454 | moxie_frame_base_address (struct frame_info *this_frame, void **this_cache) | |
455 | { | |
456 | struct moxie_frame_cache *cache = moxie_frame_cache (this_frame, | |
457 | this_cache); | |
458 | ||
459 | return cache->base; | |
460 | } | |
461 | ||
462 | static const struct frame_base moxie_frame_base = { | |
463 | &moxie_frame_unwind, | |
464 | moxie_frame_base_address, | |
465 | moxie_frame_base_address, | |
466 | moxie_frame_base_address | |
467 | }; | |
468 | ||
469 | static struct frame_id | |
470 | moxie_dummy_id (struct gdbarch *gdbarch, struct frame_info *this_frame) | |
471 | { | |
472 | CORE_ADDR sp = get_frame_register_unsigned (this_frame, MOXIE_SP_REGNUM); | |
473 | ||
474 | return frame_id_build (sp, get_frame_pc (this_frame)); | |
475 | } | |
476 | ||
477 | /* Allocate and initialize the moxie gdbarch object. */ | |
478 | ||
479 | static struct gdbarch * | |
480 | moxie_gdbarch_init (struct gdbarch_info info, struct gdbarch_list *arches) | |
481 | { | |
482 | struct gdbarch *gdbarch; | |
483 | struct gdbarch_tdep *tdep; | |
484 | ||
485 | /* If there is already a candidate, use it. */ | |
486 | arches = gdbarch_list_lookup_by_info (arches, &info); | |
487 | if (arches != NULL) | |
488 | return arches->gdbarch; | |
489 | ||
490 | /* Allocate space for the new architecture. */ | |
491 | tdep = XMALLOC (struct gdbarch_tdep); | |
492 | gdbarch = gdbarch_alloc (&info, tdep); | |
493 | ||
494 | set_gdbarch_read_pc (gdbarch, moxie_read_pc); | |
495 | set_gdbarch_write_pc (gdbarch, moxie_write_pc); | |
496 | set_gdbarch_unwind_sp (gdbarch, moxie_unwind_sp); | |
497 | ||
498 | set_gdbarch_num_regs (gdbarch, MOXIE_NUM_REGS); | |
499 | set_gdbarch_sp_regnum (gdbarch, MOXIE_SP_REGNUM); | |
500 | set_gdbarch_register_name (gdbarch, moxie_register_name); | |
501 | set_gdbarch_register_type (gdbarch, moxie_register_type); | |
502 | ||
503 | set_gdbarch_return_value (gdbarch, moxie_return_value); | |
504 | ||
505 | set_gdbarch_skip_prologue (gdbarch, moxie_skip_prologue); | |
506 | set_gdbarch_inner_than (gdbarch, core_addr_lessthan); | |
507 | set_gdbarch_breakpoint_from_pc (gdbarch, moxie_breakpoint_from_pc); | |
508 | set_gdbarch_frame_align (gdbarch, moxie_frame_align); | |
509 | ||
510 | frame_base_set_default (gdbarch, &moxie_frame_base); | |
511 | ||
512 | /* Methods for saving / extracting a dummy frame's ID. The ID's | |
513 | stack address must match the SP value returned by | |
514 | PUSH_DUMMY_CALL, and saved by generic_save_dummy_frame_tos. */ | |
515 | set_gdbarch_dummy_id (gdbarch, moxie_dummy_id); | |
516 | ||
517 | set_gdbarch_unwind_pc (gdbarch, moxie_unwind_pc); | |
518 | ||
519 | set_gdbarch_print_insn (gdbarch, print_insn_moxie); | |
520 | ||
521 | /* Hook in ABI-specific overrides, if they have been registered. */ | |
522 | gdbarch_init_osabi (info, gdbarch); | |
523 | ||
524 | /* Hook in the default unwinders. */ | |
525 | frame_unwind_append_unwinder (gdbarch, &moxie_frame_unwind); | |
526 | ||
527 | /* Support simple overlay manager. */ | |
528 | set_gdbarch_overlay_update (gdbarch, simple_overlay_update); | |
529 | ||
530 | return gdbarch; | |
531 | } | |
532 | ||
533 | /* Register this machine's init routine. */ | |
534 | ||
535 | void | |
536 | _initialize_moxie_tdep (void) | |
537 | { | |
538 | register_gdbarch_init (bfd_arch_moxie, moxie_gdbarch_init); | |
539 | } |