2004-02-15 Andrew Cagney <cagney@redhat.com>
[deliverable/binutils-gdb.git] / gdb / ns32k-tdep.c
1 /* Target dependent code for the NS32000, for GDB.
2
3 Copyright 1986, 1988, 1991, 1992, 1994, 1995, 1998, 1999, 2000,
4 2001, 2002, 2003, 2004 Free Software Foundation, Inc.
5
6 This file is part of GDB.
7
8 This program is free software; you can redistribute it and/or modify
9 it under the terms of the GNU General Public License as published by
10 the Free Software Foundation; either version 2 of the License, or
11 (at your option) any later version.
12
13 This program is distributed in the hope that it will be useful,
14 but WITHOUT ANY WARRANTY; without even the implied warranty of
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 GNU General Public License for more details.
17
18 You should have received a copy of the GNU General Public License
19 along with this program; if not, write to the Free Software
20 Foundation, Inc., 59 Temple Place - Suite 330,
21 Boston, MA 02111-1307, USA. */
22
23 #include "defs.h"
24 #include "frame.h"
25 #include "gdbtypes.h"
26 #include "gdbcore.h"
27 #include "inferior.h"
28 #include "regcache.h"
29 #include "target.h"
30 #include "arch-utils.h"
31 #include "osabi.h"
32 #include "dis-asm.h"
33
34 #include "ns32k-tdep.h"
35 #include "gdb_string.h"
36
37 static int sign_extend (int value, int bits);
38 static CORE_ADDR ns32k_get_enter_addr (CORE_ADDR);
39 static int ns32k_localcount (CORE_ADDR enter_pc);
40 static void flip_bytes (void *, int);
41
42 static const char *
43 ns32k_register_name_32082 (int regno)
44 {
45 static char *register_names[] =
46 {
47 "r0", "r1", "r2", "r3", "r4", "r5", "r6", "r7",
48 "f0", "f1", "f2", "f3", "f4", "f5", "f6", "f7",
49 "sp", "fp", "pc", "ps",
50 "l0", "l1", "l2", "l3", "xx",
51 };
52
53 if (regno < 0)
54 return NULL;
55 if (regno >= sizeof (register_names) / sizeof (*register_names))
56 return NULL;
57
58 return (register_names[regno]);
59 }
60
61 static const char *
62 ns32k_register_name_32382 (int regno)
63 {
64 static char *register_names[] =
65 {
66 "r0", "r1", "r2", "r3", "r4", "r5", "r6", "r7",
67 "f0", "f1", "f2", "f3", "f4", "f5", "f6", "f7",
68 "sp", "fp", "pc", "ps",
69 "fsr",
70 "l0", "l1", "l2", "l3", "l4", "l5", "l6", "l7", "xx",
71 };
72
73 if (regno < 0)
74 return NULL;
75 if (regno >= sizeof (register_names) / sizeof (*register_names))
76 return NULL;
77
78 return (register_names[regno]);
79 }
80
81 static int
82 ns32k_register_byte_32082 (int regno)
83 {
84 if (regno >= NS32K_LP0_REGNUM)
85 return (NS32K_LP0_REGNUM * 4) + ((regno - NS32K_LP0_REGNUM) * 8);
86
87 return (regno * 4);
88 }
89
90 static int
91 ns32k_register_byte_32382 (int regno)
92 {
93 /* This is a bit yuk. The even numbered double precision floating
94 point long registers occupy the same space as the even:odd numbered
95 single precision floating point registers, but the extra 32381 FPU
96 registers are at the end. Doing it this way is compatible for both
97 32081 and 32381 equipped machines. */
98
99 return ((regno < NS32K_LP0_REGNUM ? regno
100 : (regno - NS32K_LP0_REGNUM) & 1 ? regno - 1
101 : (regno - NS32K_LP0_REGNUM + FP0_REGNUM)) * 4);
102 }
103
104 static int
105 ns32k_register_raw_size (int regno)
106 {
107 /* All registers are 4 bytes, except for the doubled floating
108 registers. */
109
110 return ((regno >= NS32K_LP0_REGNUM) ? 8 : 4);
111 }
112
113 static int
114 ns32k_register_virtual_size (int regno)
115 {
116 return ((regno >= NS32K_LP0_REGNUM) ? 8 : 4);
117 }
118
119 static struct type *
120 ns32k_register_virtual_type (int regno)
121 {
122 if (regno < FP0_REGNUM)
123 return (builtin_type_int);
124
125 if (regno < FP0_REGNUM + 8)
126 return (builtin_type_float);
127
128 if (regno < NS32K_LP0_REGNUM)
129 return (builtin_type_int);
130
131 return (builtin_type_double);
132 }
133
134 /* Immediately after a function call, return the saved PC. Can't
135 always go through the frames for this because on some systems,
136 the new frame is not set up until the new function executes some
137 instructions. */
138
139 static CORE_ADDR
140 ns32k_saved_pc_after_call (struct frame_info *frame)
141 {
142 return (read_memory_integer (read_register (SP_REGNUM), 4));
143 }
144
145 /* Advance PC across any function entry prologue instructions
146 to reach some "real" code. */
147
148 static CORE_ADDR
149 umax_skip_prologue (CORE_ADDR pc)
150 {
151 unsigned char op = read_memory_integer (pc, 1);
152 if (op == 0x82)
153 {
154 op = read_memory_integer (pc + 2, 1);
155 if ((op & 0x80) == 0)
156 pc += 3;
157 else if ((op & 0xc0) == 0x80)
158 pc += 4;
159 else
160 pc += 6;
161 }
162 return pc;
163 }
164 \f
165 static const unsigned char *
166 ns32k_breakpoint_from_pc (CORE_ADDR *pcp, int *lenp)
167 {
168 static const unsigned char breakpoint_insn[] = { 0xf2 };
169
170 *lenp = sizeof (breakpoint_insn);
171 return breakpoint_insn;
172 }
173
174 /* Return number of args passed to a frame.
175 Can return -1, meaning no way to tell.
176 Encore's C compiler often reuses same area on stack for args,
177 so this will often not work properly. If the arg names
178 are known, it's likely most of them will be printed. */
179
180 static int
181 umax_frame_num_args (struct frame_info *fi)
182 {
183 int numargs;
184 CORE_ADDR pc;
185 CORE_ADDR enter_addr;
186 unsigned int insn;
187 unsigned int addr_mode;
188 int width;
189
190 numargs = -1;
191 enter_addr = ns32k_get_enter_addr (get_frame_pc (fi));
192 if (enter_addr > 0)
193 {
194 pc = ((enter_addr == 1)
195 ? DEPRECATED_SAVED_PC_AFTER_CALL (fi)
196 : DEPRECATED_FRAME_SAVED_PC (fi));
197 insn = read_memory_integer (pc, 2);
198 addr_mode = (insn >> 11) & 0x1f;
199 insn = insn & 0x7ff;
200 if ((insn & 0x7fc) == 0x57c
201 && addr_mode == 0x14) /* immediate */
202 {
203 if (insn == 0x57c) /* adjspb */
204 width = 1;
205 else if (insn == 0x57d) /* adjspw */
206 width = 2;
207 else if (insn == 0x57f) /* adjspd */
208 width = 4;
209 else
210 internal_error (__FILE__, __LINE__, "bad else");
211 numargs = read_memory_integer (pc + 2, width);
212 if (width > 1)
213 flip_bytes (&numargs, width);
214 numargs = -sign_extend (numargs, width * 8) / 4;
215 }
216 }
217 return numargs;
218 }
219
220 static int
221 sign_extend (int value, int bits)
222 {
223 value = value & ((1 << bits) - 1);
224 return (value & (1 << (bits - 1))
225 ? value | (~((1 << bits) - 1))
226 : value);
227 }
228
229 static void
230 flip_bytes (void *p, int count)
231 {
232 char tmp;
233 char *ptr = 0;
234
235 while (count > 0)
236 {
237 tmp = *ptr;
238 ptr[0] = ptr[count - 1];
239 ptr[count - 1] = tmp;
240 ptr++;
241 count -= 2;
242 }
243 }
244
245 /* Return the number of locals in the current frame given a
246 pc pointing to the enter instruction. This is used by
247 ns32k_frame_init_saved_regs. */
248
249 static int
250 ns32k_localcount (CORE_ADDR enter_pc)
251 {
252 unsigned char localtype;
253 int localcount;
254
255 localtype = read_memory_integer (enter_pc + 2, 1);
256 if ((localtype & 0x80) == 0)
257 localcount = localtype;
258 else if ((localtype & 0xc0) == 0x80)
259 localcount = (((localtype & 0x3f) << 8)
260 | (read_memory_integer (enter_pc + 3, 1) & 0xff));
261 else
262 localcount = (((localtype & 0x3f) << 24)
263 | ((read_memory_integer (enter_pc + 3, 1) & 0xff) << 16)
264 | ((read_memory_integer (enter_pc + 4, 1) & 0xff) << 8)
265 | (read_memory_integer (enter_pc + 5, 1) & 0xff));
266 return localcount;
267 }
268
269
270 /* Nonzero if instruction at PC is a return instruction. */
271
272 static int
273 ns32k_about_to_return (CORE_ADDR pc)
274 {
275 return (read_memory_integer (pc, 1) == 0x12);
276 }
277
278 /* Get the address of the enter opcode for this function, if it is active.
279 Returns positive address > 1 if pc is between enter/exit,
280 1 if pc before enter or after exit, 0 otherwise. */
281 static CORE_ADDR
282 ns32k_get_enter_addr (CORE_ADDR pc)
283 {
284 CORE_ADDR enter_addr;
285 unsigned char op;
286
287 if (pc == 0)
288 return 0;
289
290 if (ns32k_about_to_return (pc))
291 return 1; /* after exit */
292
293 enter_addr = get_pc_function_start (pc);
294
295 if (pc == enter_addr)
296 return 1; /* before enter */
297
298 op = read_memory_integer (enter_addr, 1);
299
300 if (op != 0x82)
301 return 0; /* function has no enter/exit */
302
303 return enter_addr; /* pc is between enter and exit */
304 }
305
306 static CORE_ADDR
307 ns32k_frame_chain (struct frame_info *frame)
308 {
309 /* In the case of the NS32000 series, the frame's nominal address is the
310 FP value, and that address is saved at the previous FP value as a
311 4-byte word. */
312 return (read_memory_integer (get_frame_base (frame), 4));
313 }
314
315
316 static CORE_ADDR
317 ns32k_sigtramp_saved_pc (struct frame_info *frame)
318 {
319 CORE_ADDR sigcontext_addr;
320 char *buf;
321 int ptrbytes = TYPE_LENGTH (builtin_type_void_func_ptr);
322 int sigcontext_offs = (2 * TARGET_INT_BIT) / TARGET_CHAR_BIT;
323
324 buf = alloca (ptrbytes);
325 /* Get sigcontext address, it is the third parameter on the stack. */
326 if (get_next_frame (frame))
327 sigcontext_addr = read_memory_typed_address
328 (DEPRECATED_FRAME_ARGS_ADDRESS (get_next_frame (frame)) + FRAME_ARGS_SKIP + sigcontext_offs,
329 builtin_type_void_data_ptr);
330 else
331 sigcontext_addr = read_memory_typed_address
332 (read_register (SP_REGNUM) + sigcontext_offs, builtin_type_void_data_ptr);
333
334 /* Offset to saved PC in sigcontext, from <machine/signal.h>. Don't
335 cause a memory_error when accessing sigcontext in case the stack
336 layout has changed or the stack is corrupt. */
337 target_read_memory (sigcontext_addr + 20, buf, ptrbytes);
338 return extract_typed_address (buf, builtin_type_void_func_ptr);
339 }
340
341 static CORE_ADDR
342 ns32k_frame_saved_pc (struct frame_info *frame)
343 {
344 if ((get_frame_type (frame) == SIGTRAMP_FRAME))
345 return (ns32k_sigtramp_saved_pc (frame)); /* XXXJRT */
346
347 return (read_memory_integer (get_frame_base (frame) + 4, 4));
348 }
349
350 static CORE_ADDR
351 ns32k_frame_args_address (struct frame_info *frame)
352 {
353 if (ns32k_get_enter_addr (get_frame_pc (frame)) > 1)
354 return (get_frame_base (frame));
355
356 return (read_register (SP_REGNUM) - 4);
357 }
358
359 /* Code to initialize the addresses of the saved registers of frame described
360 by FRAME_INFO. This includes special registers such as pc and fp saved in
361 special ways in the stack frame. sp is even more special: the address we
362 return for it IS the sp for the next frame. */
363
364 static void
365 ns32k_frame_init_saved_regs (struct frame_info *frame)
366 {
367 int regmask, regnum;
368 int localcount;
369 CORE_ADDR enter_addr, next_addr;
370
371 if (deprecated_get_frame_saved_regs (frame))
372 return;
373
374 frame_saved_regs_zalloc (frame);
375
376 enter_addr = ns32k_get_enter_addr (get_frame_pc (frame));
377 if (enter_addr > 1)
378 {
379 regmask = read_memory_integer (enter_addr + 1, 1) & 0xff;
380 localcount = ns32k_localcount (enter_addr);
381 next_addr = get_frame_base (frame) + localcount;
382
383 for (regnum = 0; regnum < 8; regnum++)
384 {
385 if (regmask & (1 << regnum))
386 deprecated_get_frame_saved_regs (frame)[regnum] = next_addr -= 4;
387 }
388
389 deprecated_get_frame_saved_regs (frame)[SP_REGNUM] = get_frame_base (frame) + 4;
390 deprecated_get_frame_saved_regs (frame)[PC_REGNUM] = get_frame_base (frame) + 4;
391 deprecated_get_frame_saved_regs (frame)[DEPRECATED_FP_REGNUM] = read_memory_integer (get_frame_base (frame), 4);
392 }
393 else if (enter_addr == 1)
394 {
395 CORE_ADDR sp = read_register (SP_REGNUM);
396 deprecated_get_frame_saved_regs (frame)[PC_REGNUM] = sp;
397 deprecated_get_frame_saved_regs (frame)[SP_REGNUM] = sp + 4;
398 }
399 }
400
401 static void
402 ns32k_push_dummy_frame (void)
403 {
404 CORE_ADDR sp = read_register (SP_REGNUM);
405 int regnum;
406
407 sp = push_word (sp, read_register (PC_REGNUM));
408 sp = push_word (sp, read_register (DEPRECATED_FP_REGNUM));
409 write_register (DEPRECATED_FP_REGNUM, sp);
410
411 for (regnum = 0; regnum < 8; regnum++)
412 sp = push_word (sp, read_register (regnum));
413
414 write_register (SP_REGNUM, sp);
415 }
416
417 static void
418 ns32k_pop_frame (void)
419 {
420 struct frame_info *frame = get_current_frame ();
421 CORE_ADDR fp;
422 int regnum;
423
424 fp = get_frame_base (frame);
425 DEPRECATED_FRAME_INIT_SAVED_REGS (frame);
426
427 for (regnum = 0; regnum < 8; regnum++)
428 if (deprecated_get_frame_saved_regs (frame)[regnum])
429 write_register (regnum,
430 read_memory_integer (deprecated_get_frame_saved_regs (frame)[regnum], 4));
431
432 write_register (DEPRECATED_FP_REGNUM, read_memory_integer (fp, 4));
433 write_register (PC_REGNUM, read_memory_integer (fp + 4, 4));
434 write_register (SP_REGNUM, fp + 8);
435 flush_cached_frames ();
436 }
437 \f
438 /* The NS32000 call dummy sequence:
439
440 enter 0xff,0 82 ff 00
441 jsr @0x00010203 7f ae c0 01 02 03
442 adjspd 0x69696969 7f a5 01 02 03 04
443 bpt f2
444
445 It is 16 bytes long. */
446
447 static LONGEST ns32k_call_dummy_words[] =
448 {
449 0x7f00ff82,
450 0x0201c0ae,
451 0x01a57f03,
452 0xf2040302
453 };
454 static int sizeof_ns32k_call_dummy_words = sizeof (ns32k_call_dummy_words);
455
456 #define NS32K_CALL_DUMMY_ADDR 5
457 #define NS32K_CALL_DUMMY_NARGS 11
458
459 static void
460 ns32k_fix_call_dummy (char *dummy, CORE_ADDR pc, CORE_ADDR fun, int nargs,
461 struct value **args, struct type *type, int gcc_p)
462 {
463 int flipped;
464
465 flipped = fun | 0xc0000000;
466 flip_bytes (&flipped, 4);
467 store_unsigned_integer (dummy + NS32K_CALL_DUMMY_ADDR, 4, flipped);
468
469 flipped = - nargs * 4;
470 flip_bytes (&flipped, 4);
471 store_unsigned_integer (dummy + NS32K_CALL_DUMMY_NARGS, 4, flipped);
472 }
473 \f
474 static void
475 ns32k_store_struct_return (CORE_ADDR addr, CORE_ADDR sp)
476 {
477 /* On this machine, this is a no-op (Encore Umax didn't use GCC). */
478 }
479
480 static void
481 ns32k_extract_return_value (struct type *valtype, char *regbuf, char *valbuf)
482 {
483 memcpy (valbuf,
484 regbuf + DEPRECATED_REGISTER_BYTE (TYPE_CODE (valtype) == TYPE_CODE_FLT ?
485 FP0_REGNUM : 0), TYPE_LENGTH (valtype));
486 }
487
488 static void
489 ns32k_store_return_value (struct type *valtype, char *valbuf)
490 {
491 deprecated_write_register_bytes (TYPE_CODE (valtype) == TYPE_CODE_FLT
492 ? FP0_REGNUM : 0, valbuf,
493 TYPE_LENGTH (valtype));
494 }
495
496 void
497 ns32k_gdbarch_init_32082 (struct gdbarch *gdbarch)
498 {
499 set_gdbarch_num_regs (gdbarch, NS32K_NUM_REGS_32082);
500
501 set_gdbarch_register_name (gdbarch, ns32k_register_name_32082);
502 set_gdbarch_deprecated_register_bytes (gdbarch, NS32K_REGISTER_BYTES_32082);
503 set_gdbarch_deprecated_register_byte (gdbarch, ns32k_register_byte_32082);
504 }
505
506 void
507 ns32k_gdbarch_init_32382 (struct gdbarch *gdbarch)
508 {
509 set_gdbarch_num_regs (gdbarch, NS32K_NUM_REGS_32382);
510
511 set_gdbarch_register_name (gdbarch, ns32k_register_name_32382);
512 set_gdbarch_deprecated_register_bytes (gdbarch, NS32K_REGISTER_BYTES_32382);
513 set_gdbarch_deprecated_register_byte (gdbarch, ns32k_register_byte_32382);
514 }
515
516 /* Initialize the current architecture based on INFO. If possible, re-use an
517 architecture from ARCHES, which is a list of architectures already created
518 during this debugging session.
519
520 Called e.g. at program startup, when reading a core file, and when reading
521 a binary file. */
522
523 static struct gdbarch *
524 ns32k_gdbarch_init (struct gdbarch_info info, struct gdbarch_list *arches)
525 {
526 struct gdbarch *gdbarch;
527
528 /* If there is already a candidate, use it. */
529 arches = gdbarch_list_lookup_by_info (arches, &info);
530 if (arches != NULL)
531 return arches->gdbarch;
532
533 gdbarch = gdbarch_alloc (&info, NULL);
534
535 /* NOTE: cagney/2002-12-06: This can be deleted when this arch is
536 ready to unwind the PC first (see frame.c:get_prev_frame()). */
537 set_gdbarch_deprecated_init_frame_pc (gdbarch, deprecated_init_frame_pc_default);
538
539 /* Register info */
540 ns32k_gdbarch_init_32082 (gdbarch);
541 set_gdbarch_num_regs (gdbarch, NS32K_SP_REGNUM);
542 set_gdbarch_num_regs (gdbarch, NS32K_FP_REGNUM);
543 set_gdbarch_num_regs (gdbarch, NS32K_PC_REGNUM);
544 set_gdbarch_num_regs (gdbarch, NS32K_PS_REGNUM);
545
546 set_gdbarch_deprecated_register_size (gdbarch, NS32K_REGISTER_SIZE);
547 set_gdbarch_deprecated_register_raw_size (gdbarch, ns32k_register_raw_size);
548 set_gdbarch_deprecated_max_register_raw_size (gdbarch, NS32K_MAX_REGISTER_RAW_SIZE);
549 set_gdbarch_deprecated_register_virtual_size (gdbarch, ns32k_register_virtual_size);
550 set_gdbarch_deprecated_max_register_virtual_size (gdbarch,
551 NS32K_MAX_REGISTER_VIRTUAL_SIZE);
552 set_gdbarch_deprecated_register_virtual_type (gdbarch, ns32k_register_virtual_type);
553
554 /* Frame and stack info */
555 set_gdbarch_skip_prologue (gdbarch, umax_skip_prologue);
556 set_gdbarch_deprecated_saved_pc_after_call (gdbarch, ns32k_saved_pc_after_call);
557
558 set_gdbarch_frame_num_args (gdbarch, umax_frame_num_args);
559 set_gdbarch_frameless_function_invocation (gdbarch,
560 generic_frameless_function_invocation_not);
561
562 set_gdbarch_deprecated_frame_chain (gdbarch, ns32k_frame_chain);
563 set_gdbarch_deprecated_frame_saved_pc (gdbarch, ns32k_frame_saved_pc);
564
565 set_gdbarch_deprecated_frame_args_address (gdbarch, ns32k_frame_args_address);
566
567 set_gdbarch_deprecated_frame_init_saved_regs (gdbarch, ns32k_frame_init_saved_regs);
568
569 set_gdbarch_frame_args_skip (gdbarch, 8);
570
571 set_gdbarch_inner_than (gdbarch, core_addr_lessthan);
572
573 /* Return value info */
574 set_gdbarch_deprecated_store_struct_return (gdbarch, ns32k_store_struct_return);
575 set_gdbarch_deprecated_extract_return_value (gdbarch, ns32k_extract_return_value);
576 set_gdbarch_deprecated_store_return_value (gdbarch, ns32k_store_return_value);
577
578 /* Call dummy info */
579 set_gdbarch_deprecated_push_dummy_frame (gdbarch, ns32k_push_dummy_frame);
580 set_gdbarch_deprecated_pop_frame (gdbarch, ns32k_pop_frame);
581 set_gdbarch_call_dummy_location (gdbarch, ON_STACK);
582 set_gdbarch_deprecated_call_dummy_words (gdbarch, ns32k_call_dummy_words);
583 set_gdbarch_deprecated_sizeof_call_dummy_words (gdbarch, sizeof_ns32k_call_dummy_words);
584 set_gdbarch_deprecated_fix_call_dummy (gdbarch, ns32k_fix_call_dummy);
585 set_gdbarch_deprecated_call_dummy_start_offset (gdbarch, 3);
586 set_gdbarch_deprecated_call_dummy_breakpoint_offset (gdbarch, 15);
587 set_gdbarch_deprecated_use_generic_dummy_frames (gdbarch, 0);
588 set_gdbarch_deprecated_pc_in_call_dummy (gdbarch, deprecated_pc_in_call_dummy_on_stack);
589
590 /* Breakpoint info */
591 set_gdbarch_breakpoint_from_pc (gdbarch, ns32k_breakpoint_from_pc);
592
593 /* Should be using push_dummy_call. */
594 set_gdbarch_deprecated_dummy_write_sp (gdbarch, deprecated_write_sp);
595
596 set_gdbarch_print_insn (gdbarch, print_insn_ns32k);
597
598 /* Hook in OS ABI-specific overrides, if they have been registered. */
599 gdbarch_init_osabi (info, gdbarch);
600
601 return (gdbarch);
602 }
603
604 extern initialize_file_ftype _initialize_ns32k_tdep; /* -Wmissing-prototypes */
605
606 void
607 _initialize_ns32k_tdep (void)
608 {
609 gdbarch_register (bfd_arch_ns32k, ns32k_gdbarch_init, NULL);
610
611 }
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