* gdb.base/corefile.exp: Recognize the message saying that GDB
[deliverable/binutils-gdb.git] / gdb / arm-tdep.c
1 /* Common target dependent code for GDB on ARM systems.
2 Copyright 1988, 1989, 1991, 1992, 1993, 1995, 1996, 1998, 1999, 2000,
3 2001 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 2 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, write to the Free Software
19 Foundation, Inc., 59 Temple Place - Suite 330,
20 Boston, MA 02111-1307, USA. */
21
22 #include "defs.h"
23 #include "frame.h"
24 #include "inferior.h"
25 #include "gdbcmd.h"
26 #include "gdbcore.h"
27 #include "symfile.h"
28 #include "gdb_string.h"
29 #include "coff/internal.h" /* Internal format of COFF symbols in BFD */
30 #include "dis-asm.h" /* For register flavors. */
31 #include <ctype.h> /* for isupper () */
32 #include "regcache.h"
33 #include "doublest.h"
34 #include "value.h"
35 #include "solib-svr4.h"
36
37 /* Each OS has a different mechanism for accessing the various
38 registers stored in the sigcontext structure.
39
40 SIGCONTEXT_REGISTER_ADDRESS should be defined to the name (or
41 function pointer) which may be used to determine the addresses
42 of the various saved registers in the sigcontext structure.
43
44 For the ARM target, there are three parameters to this function.
45 The first is the pc value of the frame under consideration, the
46 second the stack pointer of this frame, and the last is the
47 register number to fetch.
48
49 If the tm.h file does not define this macro, then it's assumed that
50 no mechanism is needed and we define SIGCONTEXT_REGISTER_ADDRESS to
51 be 0.
52
53 When it comes time to multi-arching this code, see the identically
54 named machinery in ia64-tdep.c for an example of how it could be
55 done. It should not be necessary to modify the code below where
56 this macro is used. */
57
58 #ifdef SIGCONTEXT_REGISTER_ADDRESS
59 #ifndef SIGCONTEXT_REGISTER_ADDRESS_P
60 #define SIGCONTEXT_REGISTER_ADDRESS_P() 1
61 #endif
62 #else
63 #define SIGCONTEXT_REGISTER_ADDRESS(SP,PC,REG) 0
64 #define SIGCONTEXT_REGISTER_ADDRESS_P() 0
65 #endif
66
67 extern void _initialize_arm_tdep (void);
68
69 /* Number of different reg name sets (options). */
70 static int num_flavor_options;
71
72 /* We have more registers than the disassembler as gdb can print the value
73 of special registers as well.
74 The general register names are overwritten by whatever is being used by
75 the disassembler at the moment. We also adjust the case of cpsr and fps. */
76
77 /* Initial value: Register names used in ARM's ISA documentation. */
78 static char * arm_register_name_strings[] =
79 {"r0", "r1", "r2", "r3", /* 0 1 2 3 */
80 "r4", "r5", "r6", "r7", /* 4 5 6 7 */
81 "r8", "r9", "r10", "r11", /* 8 9 10 11 */
82 "r12", "sp", "lr", "pc", /* 12 13 14 15 */
83 "f0", "f1", "f2", "f3", /* 16 17 18 19 */
84 "f4", "f5", "f6", "f7", /* 20 21 22 23 */
85 "fps", "cpsr" }; /* 24 25 */
86 char **arm_register_names = arm_register_name_strings;
87
88 /* Valid register name flavors. */
89 static const char **valid_flavors;
90
91 /* Disassembly flavor to use. Default to "std" register names. */
92 static const char *disassembly_flavor;
93 static int current_option; /* Index to that option in the opcodes table. */
94
95 /* This is used to keep the bfd arch_info in sync with the disassembly
96 flavor. */
97 static void set_disassembly_flavor_sfunc(char *, int,
98 struct cmd_list_element *);
99 static void set_disassembly_flavor (void);
100
101 static void convert_from_extended (void *ptr, void *dbl);
102
103 /* Define other aspects of the stack frame. We keep the offsets of
104 all saved registers, 'cause we need 'em a lot! We also keep the
105 current size of the stack frame, and the offset of the frame
106 pointer from the stack pointer (for frameless functions, and when
107 we're still in the prologue of a function with a frame) */
108
109 struct frame_extra_info
110 {
111 struct frame_saved_regs fsr;
112 int framesize;
113 int frameoffset;
114 int framereg;
115 };
116
117 /* Addresses for calling Thumb functions have the bit 0 set.
118 Here are some macros to test, set, or clear bit 0 of addresses. */
119 #define IS_THUMB_ADDR(addr) ((addr) & 1)
120 #define MAKE_THUMB_ADDR(addr) ((addr) | 1)
121 #define UNMAKE_THUMB_ADDR(addr) ((addr) & ~1)
122
123 /* Will a function return an aggregate type in memory or in a
124 register? Return 0 if an aggregate type can be returned in a
125 register, 1 if it must be returned in memory. */
126
127 int
128 arm_use_struct_convention (int gcc_p, struct type *type)
129 {
130 int nRc;
131 register enum type_code code;
132
133 /* In the ARM ABI, "integer" like aggregate types are returned in
134 registers. For an aggregate type to be integer like, its size
135 must be less than or equal to REGISTER_SIZE and the offset of
136 each addressable subfield must be zero. Note that bit fields are
137 not addressable, and all addressable subfields of unions always
138 start at offset zero.
139
140 This function is based on the behaviour of GCC 2.95.1.
141 See: gcc/arm.c: arm_return_in_memory() for details.
142
143 Note: All versions of GCC before GCC 2.95.2 do not set up the
144 parameters correctly for a function returning the following
145 structure: struct { float f;}; This should be returned in memory,
146 not a register. Richard Earnshaw sent me a patch, but I do not
147 know of any way to detect if a function like the above has been
148 compiled with the correct calling convention. */
149
150 /* All aggregate types that won't fit in a register must be returned
151 in memory. */
152 if (TYPE_LENGTH (type) > REGISTER_SIZE)
153 {
154 return 1;
155 }
156
157 /* The only aggregate types that can be returned in a register are
158 structs and unions. Arrays must be returned in memory. */
159 code = TYPE_CODE (type);
160 if ((TYPE_CODE_STRUCT != code) && (TYPE_CODE_UNION != code))
161 {
162 return 1;
163 }
164
165 /* Assume all other aggregate types can be returned in a register.
166 Run a check for structures, unions and arrays. */
167 nRc = 0;
168
169 if ((TYPE_CODE_STRUCT == code) || (TYPE_CODE_UNION == code))
170 {
171 int i;
172 /* Need to check if this struct/union is "integer" like. For
173 this to be true, its size must be less than or equal to
174 REGISTER_SIZE and the offset of each addressable subfield
175 must be zero. Note that bit fields are not addressable, and
176 unions always start at offset zero. If any of the subfields
177 is a floating point type, the struct/union cannot be an
178 integer type. */
179
180 /* For each field in the object, check:
181 1) Is it FP? --> yes, nRc = 1;
182 2) Is it addressable (bitpos != 0) and
183 not packed (bitsize == 0)?
184 --> yes, nRc = 1
185 */
186
187 for (i = 0; i < TYPE_NFIELDS (type); i++)
188 {
189 enum type_code field_type_code;
190 field_type_code = TYPE_CODE (TYPE_FIELD_TYPE (type, i));
191
192 /* Is it a floating point type field? */
193 if (field_type_code == TYPE_CODE_FLT)
194 {
195 nRc = 1;
196 break;
197 }
198
199 /* If bitpos != 0, then we have to care about it. */
200 if (TYPE_FIELD_BITPOS (type, i) != 0)
201 {
202 /* Bitfields are not addressable. If the field bitsize is
203 zero, then the field is not packed. Hence it cannot be
204 a bitfield or any other packed type. */
205 if (TYPE_FIELD_BITSIZE (type, i) == 0)
206 {
207 nRc = 1;
208 break;
209 }
210 }
211 }
212 }
213
214 return nRc;
215 }
216
217 int
218 arm_frame_chain_valid (CORE_ADDR chain, struct frame_info *thisframe)
219 {
220 return (chain != 0 && (FRAME_SAVED_PC (thisframe) >= LOWEST_PC));
221 }
222
223 /* Set to true if the 32-bit mode is in use. */
224
225 int arm_apcs_32 = 1;
226
227 /* Flag set by arm_fix_call_dummy that tells whether the target
228 function is a Thumb function. This flag is checked by
229 arm_push_arguments. FIXME: Change the PUSH_ARGUMENTS macro (and
230 its use in valops.c) to pass the function address as an additional
231 parameter. */
232
233 static int target_is_thumb;
234
235 /* Flag set by arm_fix_call_dummy that tells whether the calling
236 function is a Thumb function. This flag is checked by
237 arm_pc_is_thumb and arm_call_dummy_breakpoint_offset. */
238
239 static int caller_is_thumb;
240
241 /* Determine if the program counter specified in MEMADDR is in a Thumb
242 function. */
243
244 int
245 arm_pc_is_thumb (CORE_ADDR memaddr)
246 {
247 struct minimal_symbol *sym;
248
249 /* If bit 0 of the address is set, assume this is a Thumb address. */
250 if (IS_THUMB_ADDR (memaddr))
251 return 1;
252
253 /* Thumb functions have a "special" bit set in minimal symbols. */
254 sym = lookup_minimal_symbol_by_pc (memaddr);
255 if (sym)
256 {
257 return (MSYMBOL_IS_SPECIAL (sym));
258 }
259 else
260 {
261 return 0;
262 }
263 }
264
265 /* Determine if the program counter specified in MEMADDR is in a call
266 dummy being called from a Thumb function. */
267
268 int
269 arm_pc_is_thumb_dummy (CORE_ADDR memaddr)
270 {
271 CORE_ADDR sp = read_sp ();
272
273 /* FIXME: Until we switch for the new call dummy macros, this heuristic
274 is the best we can do. We are trying to determine if the pc is on
275 the stack, which (hopefully) will only happen in a call dummy.
276 We hope the current stack pointer is not so far alway from the dummy
277 frame location (true if we have not pushed large data structures or
278 gone too many levels deep) and that our 1024 is not enough to consider
279 code regions as part of the stack (true for most practical purposes) */
280 if (PC_IN_CALL_DUMMY (memaddr, sp, sp + 1024))
281 return caller_is_thumb;
282 else
283 return 0;
284 }
285
286 CORE_ADDR
287 arm_addr_bits_remove (CORE_ADDR val)
288 {
289 if (arm_pc_is_thumb (val))
290 return (val & (arm_apcs_32 ? 0xfffffffe : 0x03fffffe));
291 else
292 return (val & (arm_apcs_32 ? 0xfffffffc : 0x03fffffc));
293 }
294
295 CORE_ADDR
296 arm_saved_pc_after_call (struct frame_info *frame)
297 {
298 return ADDR_BITS_REMOVE (read_register (LR_REGNUM));
299 }
300
301 int
302 arm_frameless_function_invocation (struct frame_info *fi)
303 {
304 CORE_ADDR func_start, after_prologue;
305 int frameless;
306
307 func_start = (get_pc_function_start ((fi)->pc) + FUNCTION_START_OFFSET);
308 after_prologue = SKIP_PROLOGUE (func_start);
309
310 /* There are some frameless functions whose first two instructions
311 follow the standard APCS form, in which case after_prologue will
312 be func_start + 8. */
313
314 frameless = (after_prologue < func_start + 12);
315 return frameless;
316 }
317
318 /* A typical Thumb prologue looks like this:
319 push {r7, lr}
320 add sp, sp, #-28
321 add r7, sp, #12
322 Sometimes the latter instruction may be replaced by:
323 mov r7, sp
324
325 or like this:
326 push {r7, lr}
327 mov r7, sp
328 sub sp, #12
329
330 or, on tpcs, like this:
331 sub sp,#16
332 push {r7, lr}
333 (many instructions)
334 mov r7, sp
335 sub sp, #12
336
337 There is always one instruction of three classes:
338 1 - push
339 2 - setting of r7
340 3 - adjusting of sp
341
342 When we have found at least one of each class we are done with the prolog.
343 Note that the "sub sp, #NN" before the push does not count.
344 */
345
346 static CORE_ADDR
347 thumb_skip_prologue (CORE_ADDR pc, CORE_ADDR func_end)
348 {
349 CORE_ADDR current_pc;
350 int findmask = 0; /* findmask:
351 bit 0 - push { rlist }
352 bit 1 - mov r7, sp OR add r7, sp, #imm (setting of r7)
353 bit 2 - sub sp, #simm OR add sp, #simm (adjusting of sp)
354 */
355
356 for (current_pc = pc; current_pc + 2 < func_end && current_pc < pc + 40; current_pc += 2)
357 {
358 unsigned short insn = read_memory_unsigned_integer (current_pc, 2);
359
360 if ((insn & 0xfe00) == 0xb400) /* push { rlist } */
361 {
362 findmask |= 1; /* push found */
363 }
364 else if ((insn & 0xff00) == 0xb000) /* add sp, #simm OR sub sp, #simm */
365 {
366 if ((findmask & 1) == 0) /* before push ? */
367 continue;
368 else
369 findmask |= 4; /* add/sub sp found */
370 }
371 else if ((insn & 0xff00) == 0xaf00) /* add r7, sp, #imm */
372 {
373 findmask |= 2; /* setting of r7 found */
374 }
375 else if (insn == 0x466f) /* mov r7, sp */
376 {
377 findmask |= 2; /* setting of r7 found */
378 }
379 else
380 continue; /* something in the prolog that we don't care about or some
381 instruction from outside the prolog scheduled here for optimization */
382 }
383
384 return current_pc;
385 }
386
387 /* The APCS (ARM Procedure Call Standard) defines the following
388 prologue:
389
390 mov ip, sp
391 [stmfd sp!, {a1,a2,a3,a4}]
392 stmfd sp!, {...,fp,ip,lr,pc}
393 [stfe f7, [sp, #-12]!]
394 [stfe f6, [sp, #-12]!]
395 [stfe f5, [sp, #-12]!]
396 [stfe f4, [sp, #-12]!]
397 sub fp, ip, #nn @@ nn == 20 or 4 depending on second insn */
398
399 CORE_ADDR
400 arm_skip_prologue (CORE_ADDR pc)
401 {
402 unsigned long inst;
403 CORE_ADDR skip_pc;
404 CORE_ADDR func_addr, func_end;
405 char *func_name;
406 struct symtab_and_line sal;
407
408 /* See what the symbol table says. */
409
410 if (find_pc_partial_function (pc, &func_name, &func_addr, &func_end))
411 {
412 struct symbol *sym;
413
414 /* Found a function. */
415 sym = lookup_symbol (func_name, NULL, VAR_NAMESPACE, NULL, NULL);
416 if (sym && SYMBOL_LANGUAGE (sym) != language_asm)
417 {
418 /* Don't use this trick for assembly source files. */
419 sal = find_pc_line (func_addr, 0);
420 if ((sal.line != 0) && (sal.end < func_end))
421 return sal.end;
422 }
423 }
424
425 /* Check if this is Thumb code. */
426 if (arm_pc_is_thumb (pc))
427 return thumb_skip_prologue (pc, func_end);
428
429 /* Can't find the prologue end in the symbol table, try it the hard way
430 by disassembling the instructions. */
431 skip_pc = pc;
432 inst = read_memory_integer (skip_pc, 4);
433 if (inst != 0xe1a0c00d) /* mov ip, sp */
434 return pc;
435
436 skip_pc += 4;
437 inst = read_memory_integer (skip_pc, 4);
438 if ((inst & 0xfffffff0) == 0xe92d0000) /* stmfd sp!,{a1,a2,a3,a4} */
439 {
440 skip_pc += 4;
441 inst = read_memory_integer (skip_pc, 4);
442 }
443
444 if ((inst & 0xfffff800) != 0xe92dd800) /* stmfd sp!,{...,fp,ip,lr,pc} */
445 return pc;
446
447 skip_pc += 4;
448 inst = read_memory_integer (skip_pc, 4);
449
450 /* Any insns after this point may float into the code, if it makes
451 for better instruction scheduling, so we skip them only if we
452 find them, but still consdier the function to be frame-ful. */
453
454 /* We may have either one sfmfd instruction here, or several stfe
455 insns, depending on the version of floating point code we
456 support. */
457 if ((inst & 0xffbf0fff) == 0xec2d0200) /* sfmfd fn, <cnt>, [sp]! */
458 {
459 skip_pc += 4;
460 inst = read_memory_integer (skip_pc, 4);
461 }
462 else
463 {
464 while ((inst & 0xffff8fff) == 0xed6d0103) /* stfe fn, [sp, #-12]! */
465 {
466 skip_pc += 4;
467 inst = read_memory_integer (skip_pc, 4);
468 }
469 }
470
471 if ((inst & 0xfffff000) == 0xe24cb000) /* sub fp, ip, #nn */
472 skip_pc += 4;
473
474 return skip_pc;
475 }
476 /* *INDENT-OFF* */
477 /* Function: thumb_scan_prologue (helper function for arm_scan_prologue)
478 This function decodes a Thumb function prologue to determine:
479 1) the size of the stack frame
480 2) which registers are saved on it
481 3) the offsets of saved regs
482 4) the offset from the stack pointer to the frame pointer
483 This information is stored in the "extra" fields of the frame_info.
484
485 A typical Thumb function prologue would create this stack frame
486 (offsets relative to FP)
487 old SP -> 24 stack parameters
488 20 LR
489 16 R7
490 R7 -> 0 local variables (16 bytes)
491 SP -> -12 additional stack space (12 bytes)
492 The frame size would thus be 36 bytes, and the frame offset would be
493 12 bytes. The frame register is R7.
494
495 The comments for thumb_skip_prolog() describe the algorithm we use to detect
496 the end of the prolog */
497 /* *INDENT-ON* */
498
499 static void
500 thumb_scan_prologue (struct frame_info *fi)
501 {
502 CORE_ADDR prologue_start;
503 CORE_ADDR prologue_end;
504 CORE_ADDR current_pc;
505 int saved_reg[16]; /* which register has been copied to register n? */
506 int findmask = 0; /* findmask:
507 bit 0 - push { rlist }
508 bit 1 - mov r7, sp OR add r7, sp, #imm (setting of r7)
509 bit 2 - sub sp, #simm OR add sp, #simm (adjusting of sp)
510 */
511 int i;
512
513 if (find_pc_partial_function (fi->pc, NULL, &prologue_start, &prologue_end))
514 {
515 struct symtab_and_line sal = find_pc_line (prologue_start, 0);
516
517 if (sal.line == 0) /* no line info, use current PC */
518 prologue_end = fi->pc;
519 else if (sal.end < prologue_end) /* next line begins after fn end */
520 prologue_end = sal.end; /* (probably means no prologue) */
521 }
522 else
523 prologue_end = prologue_start + 40; /* We're in the boondocks: allow for */
524 /* 16 pushes, an add, and "mv fp,sp" */
525
526 prologue_end = min (prologue_end, fi->pc);
527
528 /* Initialize the saved register map. When register H is copied to
529 register L, we will put H in saved_reg[L]. */
530 for (i = 0; i < 16; i++)
531 saved_reg[i] = i;
532
533 /* Search the prologue looking for instructions that set up the
534 frame pointer, adjust the stack pointer, and save registers.
535 Do this until all basic prolog instructions are found. */
536
537 fi->framesize = 0;
538 for (current_pc = prologue_start;
539 (current_pc < prologue_end) && ((findmask & 7) != 7);
540 current_pc += 2)
541 {
542 unsigned short insn;
543 int regno;
544 int offset;
545
546 insn = read_memory_unsigned_integer (current_pc, 2);
547
548 if ((insn & 0xfe00) == 0xb400) /* push { rlist } */
549 {
550 int mask;
551 findmask |= 1; /* push found */
552 /* Bits 0-7 contain a mask for registers R0-R7. Bit 8 says
553 whether to save LR (R14). */
554 mask = (insn & 0xff) | ((insn & 0x100) << 6);
555
556 /* Calculate offsets of saved R0-R7 and LR. */
557 for (regno = LR_REGNUM; regno >= 0; regno--)
558 if (mask & (1 << regno))
559 {
560 fi->framesize += 4;
561 fi->fsr.regs[saved_reg[regno]] = -(fi->framesize);
562 saved_reg[regno] = regno; /* reset saved register map */
563 }
564 }
565 else if ((insn & 0xff00) == 0xb000) /* add sp, #simm OR sub sp, #simm */
566 {
567 if ((findmask & 1) == 0) /* before push ? */
568 continue;
569 else
570 findmask |= 4; /* add/sub sp found */
571
572 offset = (insn & 0x7f) << 2; /* get scaled offset */
573 if (insn & 0x80) /* is it signed? (==subtracting) */
574 {
575 fi->frameoffset += offset;
576 offset = -offset;
577 }
578 fi->framesize -= offset;
579 }
580 else if ((insn & 0xff00) == 0xaf00) /* add r7, sp, #imm */
581 {
582 findmask |= 2; /* setting of r7 found */
583 fi->framereg = THUMB_FP_REGNUM;
584 fi->frameoffset = (insn & 0xff) << 2; /* get scaled offset */
585 }
586 else if (insn == 0x466f) /* mov r7, sp */
587 {
588 findmask |= 2; /* setting of r7 found */
589 fi->framereg = THUMB_FP_REGNUM;
590 fi->frameoffset = 0;
591 saved_reg[THUMB_FP_REGNUM] = SP_REGNUM;
592 }
593 else if ((insn & 0xffc0) == 0x4640) /* mov r0-r7, r8-r15 */
594 {
595 int lo_reg = insn & 7; /* dest. register (r0-r7) */
596 int hi_reg = ((insn >> 3) & 7) + 8; /* source register (r8-15) */
597 saved_reg[lo_reg] = hi_reg; /* remember hi reg was saved */
598 }
599 else
600 continue; /* something in the prolog that we don't care about or some
601 instruction from outside the prolog scheduled here for optimization */
602 }
603 }
604
605 /* Check if prologue for this frame's PC has already been scanned. If
606 it has, copy the relevant information about that prologue and
607 return non-zero. Otherwise do not copy anything and return zero.
608
609 The information saved in the cache includes:
610 * the frame register number;
611 * the size of the stack frame;
612 * the offsets of saved regs (relative to the old SP); and
613 * the offset from the stack pointer to the frame pointer
614
615 The cache contains only one entry, since this is adequate for the
616 typical sequence of prologue scan requests we get. When performing
617 a backtrace, GDB will usually ask to scan the same function twice
618 in a row (once to get the frame chain, and once to fill in the
619 extra frame information). */
620
621 static struct frame_info prologue_cache;
622
623 static int
624 check_prologue_cache (struct frame_info *fi)
625 {
626 int i;
627
628 if (fi->pc == prologue_cache.pc)
629 {
630 fi->framereg = prologue_cache.framereg;
631 fi->framesize = prologue_cache.framesize;
632 fi->frameoffset = prologue_cache.frameoffset;
633 for (i = 0; i < NUM_REGS; i++)
634 fi->fsr.regs[i] = prologue_cache.fsr.regs[i];
635 return 1;
636 }
637 else
638 return 0;
639 }
640
641
642 /* Copy the prologue information from fi to the prologue cache. */
643
644 static void
645 save_prologue_cache (struct frame_info *fi)
646 {
647 int i;
648
649 prologue_cache.pc = fi->pc;
650 prologue_cache.framereg = fi->framereg;
651 prologue_cache.framesize = fi->framesize;
652 prologue_cache.frameoffset = fi->frameoffset;
653
654 for (i = 0; i < NUM_REGS; i++)
655 prologue_cache.fsr.regs[i] = fi->fsr.regs[i];
656 }
657
658
659 /* This function decodes an ARM function prologue to determine:
660 1) the size of the stack frame
661 2) which registers are saved on it
662 3) the offsets of saved regs
663 4) the offset from the stack pointer to the frame pointer
664 This information is stored in the "extra" fields of the frame_info.
665
666 There are two basic forms for the ARM prologue. The fixed argument
667 function call will look like:
668
669 mov ip, sp
670 stmfd sp!, {fp, ip, lr, pc}
671 sub fp, ip, #4
672 [sub sp, sp, #4]
673
674 Which would create this stack frame (offsets relative to FP):
675 IP -> 4 (caller's stack)
676 FP -> 0 PC (points to address of stmfd instruction + 8 in callee)
677 -4 LR (return address in caller)
678 -8 IP (copy of caller's SP)
679 -12 FP (caller's FP)
680 SP -> -28 Local variables
681
682 The frame size would thus be 32 bytes, and the frame offset would be
683 28 bytes. The stmfd call can also save any of the vN registers it
684 plans to use, which increases the frame size accordingly.
685
686 Note: The stored PC is 8 off of the STMFD instruction that stored it
687 because the ARM Store instructions always store PC + 8 when you read
688 the PC register.
689
690 A variable argument function call will look like:
691
692 mov ip, sp
693 stmfd sp!, {a1, a2, a3, a4}
694 stmfd sp!, {fp, ip, lr, pc}
695 sub fp, ip, #20
696
697 Which would create this stack frame (offsets relative to FP):
698 IP -> 20 (caller's stack)
699 16 A4
700 12 A3
701 8 A2
702 4 A1
703 FP -> 0 PC (points to address of stmfd instruction + 8 in callee)
704 -4 LR (return address in caller)
705 -8 IP (copy of caller's SP)
706 -12 FP (caller's FP)
707 SP -> -28 Local variables
708
709 The frame size would thus be 48 bytes, and the frame offset would be
710 28 bytes.
711
712 There is another potential complication, which is that the optimizer
713 will try to separate the store of fp in the "stmfd" instruction from
714 the "sub fp, ip, #NN" instruction. Almost anything can be there, so
715 we just key on the stmfd, and then scan for the "sub fp, ip, #NN"...
716
717 Also, note, the original version of the ARM toolchain claimed that there
718 should be an
719
720 instruction at the end of the prologue. I have never seen GCC produce
721 this, and the ARM docs don't mention it. We still test for it below in
722 case it happens...
723
724 */
725
726 static void
727 arm_scan_prologue (struct frame_info *fi)
728 {
729 int regno, sp_offset, fp_offset;
730 CORE_ADDR prologue_start, prologue_end, current_pc;
731
732 /* Check if this function is already in the cache of frame information. */
733 if (check_prologue_cache (fi))
734 return;
735
736 /* Assume there is no frame until proven otherwise. */
737 fi->framereg = SP_REGNUM;
738 fi->framesize = 0;
739 fi->frameoffset = 0;
740
741 /* Check for Thumb prologue. */
742 if (arm_pc_is_thumb (fi->pc))
743 {
744 thumb_scan_prologue (fi);
745 save_prologue_cache (fi);
746 return;
747 }
748
749 /* Find the function prologue. If we can't find the function in
750 the symbol table, peek in the stack frame to find the PC. */
751 if (find_pc_partial_function (fi->pc, NULL, &prologue_start, &prologue_end))
752 {
753 /* One way to find the end of the prologue (which works well
754 for unoptimized code) is to do the following:
755
756 struct symtab_and_line sal = find_pc_line (prologue_start, 0);
757
758 if (sal.line == 0)
759 prologue_end = fi->pc;
760 else if (sal.end < prologue_end)
761 prologue_end = sal.end;
762
763 This mechanism is very accurate so long as the optimizer
764 doesn't move any instructions from the function body into the
765 prologue. If this happens, sal.end will be the last
766 instruction in the first hunk of prologue code just before
767 the first instruction that the scheduler has moved from
768 the body to the prologue.
769
770 In order to make sure that we scan all of the prologue
771 instructions, we use a slightly less accurate mechanism which
772 may scan more than necessary. To help compensate for this
773 lack of accuracy, the prologue scanning loop below contains
774 several clauses which'll cause the loop to terminate early if
775 an implausible prologue instruction is encountered.
776
777 The expression
778
779 prologue_start + 64
780
781 is a suitable endpoint since it accounts for the largest
782 possible prologue plus up to five instructions inserted by
783 the scheduler. */
784
785 if (prologue_end > prologue_start + 64)
786 {
787 prologue_end = prologue_start + 64; /* See above. */
788 }
789 }
790 else
791 {
792 /* Get address of the stmfd in the prologue of the callee; the saved
793 PC is the address of the stmfd + 8. */
794 prologue_start = ADDR_BITS_REMOVE (read_memory_integer (fi->frame, 4))
795 - 8;
796 prologue_end = prologue_start + 64; /* See above. */
797 }
798
799 /* Now search the prologue looking for instructions that set up the
800 frame pointer, adjust the stack pointer, and save registers.
801
802 Be careful, however, and if it doesn't look like a prologue,
803 don't try to scan it. If, for instance, a frameless function
804 begins with stmfd sp!, then we will tell ourselves there is
805 a frame, which will confuse stack traceback, as well ad"finish"
806 and other operations that rely on a knowledge of the stack
807 traceback.
808
809 In the APCS, the prologue should start with "mov ip, sp" so
810 if we don't see this as the first insn, we will stop. */
811
812 sp_offset = fp_offset = 0;
813
814 if (read_memory_unsigned_integer (prologue_start, 4)
815 == 0xe1a0c00d) /* mov ip, sp */
816 {
817 for (current_pc = prologue_start + 4; current_pc < prologue_end;
818 current_pc += 4)
819 {
820 unsigned int insn = read_memory_unsigned_integer (current_pc, 4);
821
822 if ((insn & 0xffff0000) == 0xe92d0000)
823 /* stmfd sp!, {..., fp, ip, lr, pc}
824 or
825 stmfd sp!, {a1, a2, a3, a4} */
826 {
827 int mask = insn & 0xffff;
828
829 /* Calculate offsets of saved registers. */
830 for (regno = PC_REGNUM; regno >= 0; regno--)
831 if (mask & (1 << regno))
832 {
833 sp_offset -= 4;
834 fi->fsr.regs[regno] = sp_offset;
835 }
836 }
837 else if ((insn & 0xfffff000) == 0xe24cb000) /* sub fp, ip #n */
838 {
839 unsigned imm = insn & 0xff; /* immediate value */
840 unsigned rot = (insn & 0xf00) >> 7; /* rotate amount */
841 imm = (imm >> rot) | (imm << (32 - rot));
842 fp_offset = -imm;
843 fi->framereg = FP_REGNUM;
844 }
845 else if ((insn & 0xfffff000) == 0xe24dd000) /* sub sp, sp #n */
846 {
847 unsigned imm = insn & 0xff; /* immediate value */
848 unsigned rot = (insn & 0xf00) >> 7; /* rotate amount */
849 imm = (imm >> rot) | (imm << (32 - rot));
850 sp_offset -= imm;
851 }
852 else if ((insn & 0xffff7fff) == 0xed6d0103) /* stfe f?, [sp, -#c]! */
853 {
854 sp_offset -= 12;
855 regno = F0_REGNUM + ((insn >> 12) & 0x07);
856 fi->fsr.regs[regno] = sp_offset;
857 }
858 else if ((insn & 0xffbf0fff) == 0xec2d0200) /* sfmfd f0, 4, [sp!] */
859 {
860 int n_saved_fp_regs;
861 unsigned int fp_start_reg, fp_bound_reg;
862
863 if ((insn & 0x800) == 0x800) /* N0 is set */
864 {
865 if ((insn & 0x40000) == 0x40000) /* N1 is set */
866 n_saved_fp_regs = 3;
867 else
868 n_saved_fp_regs = 1;
869 }
870 else
871 {
872 if ((insn & 0x40000) == 0x40000) /* N1 is set */
873 n_saved_fp_regs = 2;
874 else
875 n_saved_fp_regs = 4;
876 }
877
878 fp_start_reg = F0_REGNUM + ((insn >> 12) & 0x7);
879 fp_bound_reg = fp_start_reg + n_saved_fp_regs;
880 for (; fp_start_reg < fp_bound_reg; fp_start_reg++)
881 {
882 sp_offset -= 12;
883 fi->fsr.regs[fp_start_reg++] = sp_offset;
884 }
885 }
886 else if ((insn & 0xf0000000) != 0xe0000000)
887 break; /* Condition not true, exit early */
888 else if ((insn & 0xfe200000) == 0xe8200000) /* ldm? */
889 break; /* Don't scan past a block load */
890 else
891 /* The optimizer might shove anything into the prologue,
892 so we just skip what we don't recognize. */
893 continue;
894 }
895 }
896
897 /* The frame size is just the negative of the offset (from the original SP)
898 of the last thing thing we pushed on the stack. The frame offset is
899 [new FP] - [new SP]. */
900 fi->framesize = -sp_offset;
901 fi->frameoffset = fp_offset - sp_offset;
902
903 save_prologue_cache (fi);
904 }
905
906 /* Find REGNUM on the stack. Otherwise, it's in an active register.
907 One thing we might want to do here is to check REGNUM against the
908 clobber mask, and somehow flag it as invalid if it isn't saved on
909 the stack somewhere. This would provide a graceful failure mode
910 when trying to get the value of caller-saves registers for an inner
911 frame. */
912
913 static CORE_ADDR
914 arm_find_callers_reg (struct frame_info *fi, int regnum)
915 {
916 for (; fi; fi = fi->next)
917
918 #if 0 /* FIXME: enable this code if we convert to new call dummy scheme. */
919 if (PC_IN_CALL_DUMMY (fi->pc, fi->frame, fi->frame))
920 return generic_read_register_dummy (fi->pc, fi->frame, regnum);
921 else
922 #endif
923 if (fi->fsr.regs[regnum] != 0)
924 return read_memory_integer (fi->fsr.regs[regnum],
925 REGISTER_RAW_SIZE (regnum));
926 return read_register (regnum);
927 }
928 /* *INDENT-OFF* */
929 /* Function: frame_chain
930 Given a GDB frame, determine the address of the calling function's frame.
931 This will be used to create a new GDB frame struct, and then
932 INIT_EXTRA_FRAME_INFO and INIT_FRAME_PC will be called for the new frame.
933 For ARM, we save the frame size when we initialize the frame_info.
934
935 The original definition of this function was a macro in tm-arm.h:
936 { In the case of the ARM, the frame's nominal address is the FP value,
937 and 12 bytes before comes the saved previous FP value as a 4-byte word. }
938
939 #define FRAME_CHAIN(thisframe) \
940 ((thisframe)->pc >= LOWEST_PC ? \
941 read_memory_integer ((thisframe)->frame - 12, 4) :\
942 0)
943 */
944 /* *INDENT-ON* */
945
946 CORE_ADDR
947 arm_frame_chain (struct frame_info *fi)
948 {
949 #if 0 /* FIXME: enable this code if we convert to new call dummy scheme. */
950 CORE_ADDR fn_start, callers_pc, fp;
951
952 /* is this a dummy frame? */
953 if (PC_IN_CALL_DUMMY (fi->pc, fi->frame, fi->frame))
954 return fi->frame; /* dummy frame same as caller's frame */
955
956 /* is caller-of-this a dummy frame? */
957 callers_pc = FRAME_SAVED_PC (fi); /* find out who called us: */
958 fp = arm_find_callers_reg (fi, FP_REGNUM);
959 if (PC_IN_CALL_DUMMY (callers_pc, fp, fp))
960 return fp; /* dummy frame's frame may bear no relation to ours */
961
962 if (find_pc_partial_function (fi->pc, 0, &fn_start, 0))
963 if (fn_start == entry_point_address ())
964 return 0; /* in _start fn, don't chain further */
965 #endif
966 CORE_ADDR caller_pc, fn_start;
967 struct frame_info caller_fi;
968 int framereg = fi->framereg;
969
970 if (fi->pc < LOWEST_PC)
971 return 0;
972
973 /* If the caller is the startup code, we're at the end of the chain. */
974 caller_pc = FRAME_SAVED_PC (fi);
975 if (find_pc_partial_function (caller_pc, 0, &fn_start, 0))
976 if (fn_start == entry_point_address ())
977 return 0;
978
979 /* If the caller is Thumb and the caller is ARM, or vice versa,
980 the frame register of the caller is different from ours.
981 So we must scan the prologue of the caller to determine its
982 frame register number. */
983 if (arm_pc_is_thumb (caller_pc) != arm_pc_is_thumb (fi->pc))
984 {
985 memset (&caller_fi, 0, sizeof (caller_fi));
986 caller_fi.pc = caller_pc;
987 arm_scan_prologue (&caller_fi);
988 framereg = caller_fi.framereg;
989 }
990
991 /* If the caller used a frame register, return its value.
992 Otherwise, return the caller's stack pointer. */
993 if (framereg == FP_REGNUM || framereg == THUMB_FP_REGNUM)
994 return arm_find_callers_reg (fi, framereg);
995 else
996 return fi->frame + fi->framesize;
997 }
998
999 /* This function actually figures out the frame address for a given pc
1000 and sp. This is tricky because we sometimes don't use an explicit
1001 frame pointer, and the previous stack pointer isn't necessarily
1002 recorded on the stack. The only reliable way to get this info is
1003 to examine the prologue. FROMLEAF is a little confusing, it means
1004 this is the next frame up the chain AFTER a frameless function. If
1005 this is true, then the frame value for this frame is still in the
1006 fp register. */
1007
1008 void
1009 arm_init_extra_frame_info (int fromleaf, struct frame_info *fi)
1010 {
1011 int reg;
1012
1013 if (fi->next)
1014 fi->pc = FRAME_SAVED_PC (fi->next);
1015
1016 memset (fi->fsr.regs, '\000', sizeof fi->fsr.regs);
1017
1018 #if 0 /* FIXME: enable this code if we convert to new call dummy scheme. */
1019 if (PC_IN_CALL_DUMMY (fi->pc, fi->frame, fi->frame))
1020 {
1021 /* We need to setup fi->frame here because run_stack_dummy gets it wrong
1022 by assuming it's always FP. */
1023 fi->frame = generic_read_register_dummy (fi->pc, fi->frame, SP_REGNUM);
1024 fi->framesize = 0;
1025 fi->frameoffset = 0;
1026 return;
1027 }
1028 else
1029 #endif
1030
1031 /* Determine whether or not we're in a sigtramp frame.
1032 Unfortunately, it isn't sufficient to test
1033 fi->signal_handler_caller because this value is sometimes set
1034 after invoking INIT_EXTRA_FRAME_INFO. So we test *both*
1035 fi->signal_handler_caller and IN_SIGTRAMP to determine if we need
1036 to use the sigcontext addresses for the saved registers.
1037
1038 Note: If an ARM IN_SIGTRAMP method ever needs to compare against
1039 the name of the function, the code below will have to be changed
1040 to first fetch the name of the function and then pass this name
1041 to IN_SIGTRAMP. */
1042
1043 if (SIGCONTEXT_REGISTER_ADDRESS_P ()
1044 && (fi->signal_handler_caller || IN_SIGTRAMP (fi->pc, 0)))
1045 {
1046 CORE_ADDR sp;
1047
1048 if (!fi->next)
1049 sp = read_sp();
1050 else
1051 sp = fi->next->frame - fi->next->frameoffset + fi->next->framesize;
1052
1053 for (reg = 0; reg < NUM_REGS; reg++)
1054 fi->fsr.regs[reg] = SIGCONTEXT_REGISTER_ADDRESS (sp, fi->pc, reg);
1055
1056 /* FIXME: What about thumb mode? */
1057 fi->framereg = SP_REGNUM;
1058 fi->frame = read_memory_integer (fi->fsr.regs[fi->framereg], 4);
1059 fi->framesize = 0;
1060 fi->frameoffset = 0;
1061
1062 }
1063 else
1064 {
1065 arm_scan_prologue (fi);
1066
1067 if (!fi->next)
1068 /* this is the innermost frame? */
1069 fi->frame = read_register (fi->framereg);
1070 else if (fi->framereg == FP_REGNUM || fi->framereg == THUMB_FP_REGNUM)
1071 {
1072 /* not the innermost frame */
1073 /* If we have an FP, the callee saved it. */
1074 if (fi->next->fsr.regs[fi->framereg] != 0)
1075 fi->frame =
1076 read_memory_integer (fi->next->fsr.regs[fi->framereg], 4);
1077 else if (fromleaf)
1078 /* If we were called by a frameless fn. then our frame is
1079 still in the frame pointer register on the board... */
1080 fi->frame = read_fp ();
1081 }
1082
1083 /* Calculate actual addresses of saved registers using offsets
1084 determined by arm_scan_prologue. */
1085 for (reg = 0; reg < NUM_REGS; reg++)
1086 if (fi->fsr.regs[reg] != 0)
1087 fi->fsr.regs[reg] += fi->frame + fi->framesize - fi->frameoffset;
1088 }
1089 }
1090
1091
1092 /* Find the caller of this frame. We do this by seeing if LR_REGNUM
1093 is saved in the stack anywhere, otherwise we get it from the
1094 registers.
1095
1096 The old definition of this function was a macro:
1097 #define FRAME_SAVED_PC(FRAME) \
1098 ADDR_BITS_REMOVE (read_memory_integer ((FRAME)->frame - 4, 4)) */
1099
1100 CORE_ADDR
1101 arm_frame_saved_pc (struct frame_info *fi)
1102 {
1103 #if 0 /* FIXME: enable this code if we convert to new call dummy scheme. */
1104 if (PC_IN_CALL_DUMMY (fi->pc, fi->frame, fi->frame))
1105 return generic_read_register_dummy (fi->pc, fi->frame, PC_REGNUM);
1106 else
1107 #endif
1108 {
1109 CORE_ADDR pc = arm_find_callers_reg (fi, LR_REGNUM);
1110 return IS_THUMB_ADDR (pc) ? UNMAKE_THUMB_ADDR (pc) : pc;
1111 }
1112 }
1113
1114 /* Return the frame address. On ARM, it is R11; on Thumb it is R7.
1115 Examine the Program Status Register to decide which state we're in. */
1116
1117 CORE_ADDR
1118 arm_target_read_fp (void)
1119 {
1120 if (read_register (PS_REGNUM) & 0x20) /* Bit 5 is Thumb state bit */
1121 return read_register (THUMB_FP_REGNUM); /* R7 if Thumb */
1122 else
1123 return read_register (FP_REGNUM); /* R11 if ARM */
1124 }
1125
1126 /* Calculate the frame offsets of the saved registers (ARM version). */
1127
1128 void
1129 arm_frame_find_saved_regs (struct frame_info *fi,
1130 struct frame_saved_regs *regaddr)
1131 {
1132 memcpy (regaddr, &fi->fsr, sizeof (struct frame_saved_regs));
1133 }
1134
1135 void
1136 arm_push_dummy_frame (void)
1137 {
1138 CORE_ADDR old_sp = read_register (SP_REGNUM);
1139 CORE_ADDR sp = old_sp;
1140 CORE_ADDR fp, prologue_start;
1141 int regnum;
1142
1143 /* Push the two dummy prologue instructions in reverse order,
1144 so that they'll be in the correct low-to-high order in memory. */
1145 /* sub fp, ip, #4 */
1146 sp = push_word (sp, 0xe24cb004);
1147 /* stmdb sp!, {r0-r10, fp, ip, lr, pc} */
1148 prologue_start = sp = push_word (sp, 0xe92ddfff);
1149
1150 /* Push a pointer to the dummy prologue + 12, because when stm
1151 instruction stores the PC, it stores the address of the stm
1152 instruction itself plus 12. */
1153 fp = sp = push_word (sp, prologue_start + 12);
1154 sp = push_word (sp, read_register (PC_REGNUM)); /* FIXME: was PS_REGNUM */
1155 sp = push_word (sp, old_sp);
1156 sp = push_word (sp, read_register (FP_REGNUM));
1157
1158 for (regnum = 10; regnum >= 0; regnum--)
1159 sp = push_word (sp, read_register (regnum));
1160
1161 write_register (FP_REGNUM, fp);
1162 write_register (THUMB_FP_REGNUM, fp);
1163 write_register (SP_REGNUM, sp);
1164 }
1165
1166 /* Fix up the call dummy, based on whether the processor is currently
1167 in Thumb or ARM mode, and whether the target function is Thumb or
1168 ARM. There are three different situations requiring three
1169 different dummies:
1170
1171 * ARM calling ARM: uses the call dummy in tm-arm.h, which has already
1172 been copied into the dummy parameter to this function.
1173 * ARM calling Thumb: uses the call dummy in tm-arm.h, but with the
1174 "mov pc,r4" instruction patched to be a "bx r4" instead.
1175 * Thumb calling anything: uses the Thumb dummy defined below, which
1176 works for calling both ARM and Thumb functions.
1177
1178 All three call dummies expect to receive the target function
1179 address in R4, with the low bit set if it's a Thumb function. */
1180
1181 void
1182 arm_fix_call_dummy (char *dummy, CORE_ADDR pc, CORE_ADDR fun, int nargs,
1183 struct value **args, struct type *type, int gcc_p)
1184 {
1185 static short thumb_dummy[4] =
1186 {
1187 0xf000, 0xf801, /* bl label */
1188 0xdf18, /* swi 24 */
1189 0x4720, /* label: bx r4 */
1190 };
1191 static unsigned long arm_bx_r4 = 0xe12fff14; /* bx r4 instruction */
1192
1193 /* Set flag indicating whether the current PC is in a Thumb function. */
1194 caller_is_thumb = arm_pc_is_thumb (read_pc ());
1195
1196 /* If the target function is Thumb, set the low bit of the function
1197 address. And if the CPU is currently in ARM mode, patch the
1198 second instruction of call dummy to use a BX instruction to
1199 switch to Thumb mode. */
1200 target_is_thumb = arm_pc_is_thumb (fun);
1201 if (target_is_thumb)
1202 {
1203 fun |= 1;
1204 if (!caller_is_thumb)
1205 store_unsigned_integer (dummy + 4, sizeof (arm_bx_r4), arm_bx_r4);
1206 }
1207
1208 /* If the CPU is currently in Thumb mode, use the Thumb call dummy
1209 instead of the ARM one that's already been copied. This will
1210 work for both Thumb and ARM target functions. */
1211 if (caller_is_thumb)
1212 {
1213 int i;
1214 char *p = dummy;
1215 int len = sizeof (thumb_dummy) / sizeof (thumb_dummy[0]);
1216
1217 for (i = 0; i < len; i++)
1218 {
1219 store_unsigned_integer (p, sizeof (thumb_dummy[0]), thumb_dummy[i]);
1220 p += sizeof (thumb_dummy[0]);
1221 }
1222 }
1223
1224 /* Put the target address in r4; the call dummy will copy this to
1225 the PC. */
1226 write_register (4, fun);
1227 }
1228
1229 /* Return the offset in the call dummy of the instruction that needs
1230 to have a breakpoint placed on it. This is the offset of the 'swi
1231 24' instruction, which is no longer actually used, but simply acts
1232 as a place-holder now.
1233
1234 This implements the CALL_DUMMY_BREAK_OFFSET macro. */
1235
1236 int
1237 arm_call_dummy_breakpoint_offset (void)
1238 {
1239 if (caller_is_thumb)
1240 return 4;
1241 else
1242 return 8;
1243 }
1244
1245 /* Note: ScottB
1246
1247 This function does not support passing parameters using the FPA
1248 variant of the APCS. It passes any floating point arguments in the
1249 general registers and/or on the stack. */
1250
1251 CORE_ADDR
1252 arm_push_arguments (int nargs, struct value **args, CORE_ADDR sp,
1253 int struct_return, CORE_ADDR struct_addr)
1254 {
1255 char *fp;
1256 int argnum, argreg, nstack_size;
1257
1258 /* Walk through the list of args and determine how large a temporary
1259 stack is required. Need to take care here as structs may be
1260 passed on the stack, and we have to to push them. */
1261 nstack_size = -4 * REGISTER_SIZE; /* Some arguments go into A1-A4. */
1262 if (struct_return) /* The struct address goes in A1. */
1263 nstack_size += REGISTER_SIZE;
1264
1265 /* Walk through the arguments and add their size to nstack_size. */
1266 for (argnum = 0; argnum < nargs; argnum++)
1267 {
1268 int len;
1269 struct type *arg_type;
1270
1271 arg_type = check_typedef (VALUE_TYPE (args[argnum]));
1272 len = TYPE_LENGTH (arg_type);
1273
1274 /* ANSI C code passes float arguments as integers, K&R code
1275 passes float arguments as doubles. Correct for this here. */
1276 if (TYPE_CODE_FLT == TYPE_CODE (arg_type) && REGISTER_SIZE == len)
1277 nstack_size += FP_REGISTER_VIRTUAL_SIZE;
1278 else
1279 nstack_size += len;
1280 }
1281
1282 /* Allocate room on the stack, and initialize our stack frame
1283 pointer. */
1284 fp = NULL;
1285 if (nstack_size > 0)
1286 {
1287 sp -= nstack_size;
1288 fp = (char *) sp;
1289 }
1290
1291 /* Initialize the integer argument register pointer. */
1292 argreg = A1_REGNUM;
1293
1294 /* The struct_return pointer occupies the first parameter passing
1295 register. */
1296 if (struct_return)
1297 write_register (argreg++, struct_addr);
1298
1299 /* Process arguments from left to right. Store as many as allowed
1300 in the parameter passing registers (A1-A4), and save the rest on
1301 the temporary stack. */
1302 for (argnum = 0; argnum < nargs; argnum++)
1303 {
1304 int len;
1305 char *val;
1306 CORE_ADDR regval;
1307 enum type_code typecode;
1308 struct type *arg_type, *target_type;
1309
1310 arg_type = check_typedef (VALUE_TYPE (args[argnum]));
1311 target_type = TYPE_TARGET_TYPE (arg_type);
1312 len = TYPE_LENGTH (arg_type);
1313 typecode = TYPE_CODE (arg_type);
1314 val = (char *) VALUE_CONTENTS (args[argnum]);
1315
1316 /* ANSI C code passes float arguments as integers, K&R code
1317 passes float arguments as doubles. The .stabs record for
1318 for ANSI prototype floating point arguments records the
1319 type as FP_INTEGER, while a K&R style (no prototype)
1320 .stabs records the type as FP_FLOAT. In this latter case
1321 the compiler converts the float arguments to double before
1322 calling the function. */
1323 if (TYPE_CODE_FLT == typecode && REGISTER_SIZE == len)
1324 {
1325 DOUBLEST dblval;
1326 dblval = extract_floating (val, len);
1327 len = TARGET_DOUBLE_BIT / TARGET_CHAR_BIT;
1328 val = alloca (len);
1329 store_floating (val, len, dblval);
1330 }
1331 #if 1
1332 /* I don't know why this code was disable. The only logical use
1333 for a function pointer is to call that function, so setting
1334 the mode bit is perfectly fine. FN */
1335 /* If the argument is a pointer to a function, and it is a Thumb
1336 function, set the low bit of the pointer. */
1337 if (TYPE_CODE_PTR == typecode
1338 && NULL != target_type
1339 && TYPE_CODE_FUNC == TYPE_CODE (target_type))
1340 {
1341 CORE_ADDR regval = extract_address (val, len);
1342 if (arm_pc_is_thumb (regval))
1343 store_address (val, len, MAKE_THUMB_ADDR (regval));
1344 }
1345 #endif
1346 /* Copy the argument to general registers or the stack in
1347 register-sized pieces. Large arguments are split between
1348 registers and stack. */
1349 while (len > 0)
1350 {
1351 int partial_len = len < REGISTER_SIZE ? len : REGISTER_SIZE;
1352
1353 if (argreg <= ARM_LAST_ARG_REGNUM)
1354 {
1355 /* It's an argument being passed in a general register. */
1356 regval = extract_address (val, partial_len);
1357 write_register (argreg++, regval);
1358 }
1359 else
1360 {
1361 /* Push the arguments onto the stack. */
1362 write_memory ((CORE_ADDR) fp, val, REGISTER_SIZE);
1363 fp += REGISTER_SIZE;
1364 }
1365
1366 len -= partial_len;
1367 val += partial_len;
1368 }
1369 }
1370
1371 /* Return adjusted stack pointer. */
1372 return sp;
1373 }
1374
1375 void
1376 arm_pop_frame (void)
1377 {
1378 int regnum;
1379 struct frame_info *frame = get_current_frame ();
1380
1381 if (!PC_IN_CALL_DUMMY(frame->pc, frame->frame, read_fp()))
1382 {
1383 CORE_ADDR old_SP;
1384
1385 old_SP = read_register (frame->framereg);
1386 for (regnum = 0; regnum < NUM_REGS; regnum++)
1387 if (frame->fsr.regs[regnum] != 0)
1388 write_register (regnum,
1389 read_memory_integer (frame->fsr.regs[regnum], 4));
1390
1391 write_register (PC_REGNUM, FRAME_SAVED_PC (frame));
1392 write_register (SP_REGNUM, old_SP);
1393 }
1394 else
1395 {
1396 CORE_ADDR sp;
1397
1398 sp = read_register (FP_REGNUM);
1399 sp -= sizeof(CORE_ADDR); /* we don't care about this first word */
1400
1401 write_register (PC_REGNUM, read_memory_integer (sp, 4));
1402 sp -= sizeof(CORE_ADDR);
1403 write_register (SP_REGNUM, read_memory_integer (sp, 4));
1404 sp -= sizeof(CORE_ADDR);
1405 write_register (FP_REGNUM, read_memory_integer (sp, 4));
1406 sp -= sizeof(CORE_ADDR);
1407
1408 for (regnum = 10; regnum >= 0; regnum--)
1409 {
1410 write_register (regnum, read_memory_integer (sp, 4));
1411 sp -= sizeof(CORE_ADDR);
1412 }
1413 }
1414
1415 flush_cached_frames ();
1416 }
1417
1418 static void
1419 print_fpu_flags (int flags)
1420 {
1421 if (flags & (1 << 0))
1422 fputs ("IVO ", stdout);
1423 if (flags & (1 << 1))
1424 fputs ("DVZ ", stdout);
1425 if (flags & (1 << 2))
1426 fputs ("OFL ", stdout);
1427 if (flags & (1 << 3))
1428 fputs ("UFL ", stdout);
1429 if (flags & (1 << 4))
1430 fputs ("INX ", stdout);
1431 putchar ('\n');
1432 }
1433
1434 void
1435 arm_float_info (void)
1436 {
1437 register unsigned long status = read_register (FPS_REGNUM);
1438 int type;
1439
1440 type = (status >> 24) & 127;
1441 printf ("%s FPU type %d\n",
1442 (status & (1 << 31)) ? "Hardware" : "Software",
1443 type);
1444 fputs ("mask: ", stdout);
1445 print_fpu_flags (status >> 16);
1446 fputs ("flags: ", stdout);
1447 print_fpu_flags (status);
1448 }
1449
1450 struct type *
1451 arm_register_type (int regnum)
1452 {
1453 if (regnum >= F0_REGNUM && regnum < F0_REGNUM + NUM_FREGS)
1454 {
1455 if (TARGET_BYTE_ORDER == BIG_ENDIAN)
1456 return builtin_type_arm_ext_big;
1457 else
1458 return builtin_type_arm_ext_littlebyte_bigword;
1459 }
1460 else
1461 return builtin_type_int32;
1462 }
1463
1464 /* NOTE: cagney/2001-08-20: Both convert_from_extended() and
1465 convert_to_extended() use floatformat_arm_ext_littlebyte_bigword.
1466 It is thought that this is is the floating-point register format on
1467 little-endian systems. */
1468
1469 static void
1470 convert_from_extended (void *ptr, void *dbl)
1471 {
1472 DOUBLEST d;
1473 if (TARGET_BYTE_ORDER == BIG_ENDIAN)
1474 floatformat_to_doublest (&floatformat_arm_ext_big, ptr, &d);
1475 else
1476 floatformat_to_doublest (&floatformat_arm_ext_littlebyte_bigword,
1477 ptr, &d);
1478 floatformat_from_doublest (TARGET_DOUBLE_FORMAT, &d, dbl);
1479 }
1480
1481 void
1482 convert_to_extended (void *dbl, void *ptr)
1483 {
1484 DOUBLEST d;
1485 floatformat_to_doublest (TARGET_DOUBLE_FORMAT, ptr, &d);
1486 if (TARGET_BYTE_ORDER == BIG_ENDIAN)
1487 floatformat_from_doublest (&floatformat_arm_ext_big, &d, dbl);
1488 else
1489 floatformat_from_doublest (&floatformat_arm_ext_littlebyte_bigword,
1490 &d, dbl);
1491 }
1492
1493 static int
1494 condition_true (unsigned long cond, unsigned long status_reg)
1495 {
1496 if (cond == INST_AL || cond == INST_NV)
1497 return 1;
1498
1499 switch (cond)
1500 {
1501 case INST_EQ:
1502 return ((status_reg & FLAG_Z) != 0);
1503 case INST_NE:
1504 return ((status_reg & FLAG_Z) == 0);
1505 case INST_CS:
1506 return ((status_reg & FLAG_C) != 0);
1507 case INST_CC:
1508 return ((status_reg & FLAG_C) == 0);
1509 case INST_MI:
1510 return ((status_reg & FLAG_N) != 0);
1511 case INST_PL:
1512 return ((status_reg & FLAG_N) == 0);
1513 case INST_VS:
1514 return ((status_reg & FLAG_V) != 0);
1515 case INST_VC:
1516 return ((status_reg & FLAG_V) == 0);
1517 case INST_HI:
1518 return ((status_reg & (FLAG_C | FLAG_Z)) == FLAG_C);
1519 case INST_LS:
1520 return ((status_reg & (FLAG_C | FLAG_Z)) != FLAG_C);
1521 case INST_GE:
1522 return (((status_reg & FLAG_N) == 0) == ((status_reg & FLAG_V) == 0));
1523 case INST_LT:
1524 return (((status_reg & FLAG_N) == 0) != ((status_reg & FLAG_V) == 0));
1525 case INST_GT:
1526 return (((status_reg & FLAG_Z) == 0) &&
1527 (((status_reg & FLAG_N) == 0) == ((status_reg & FLAG_V) == 0)));
1528 case INST_LE:
1529 return (((status_reg & FLAG_Z) != 0) ||
1530 (((status_reg & FLAG_N) == 0) != ((status_reg & FLAG_V) == 0)));
1531 }
1532 return 1;
1533 }
1534
1535 #if SOFTWARE_SINGLE_STEP_P
1536 /* Support routines for single stepping. Calculate the next PC value. */
1537 #define submask(x) ((1L << ((x) + 1)) - 1)
1538 #define bit(obj,st) (((obj) >> (st)) & 1)
1539 #define bits(obj,st,fn) (((obj) >> (st)) & submask ((fn) - (st)))
1540 #define sbits(obj,st,fn) \
1541 ((long) (bits(obj,st,fn) | ((long) bit(obj,fn) * ~ submask (fn - st))))
1542 #define BranchDest(addr,instr) \
1543 ((CORE_ADDR) (((long) (addr)) + 8 + (sbits (instr, 0, 23) << 2)))
1544 #define ARM_PC_32 1
1545
1546 static unsigned long
1547 shifted_reg_val (unsigned long inst, int carry, unsigned long pc_val,
1548 unsigned long status_reg)
1549 {
1550 unsigned long res, shift;
1551 int rm = bits (inst, 0, 3);
1552 unsigned long shifttype = bits (inst, 5, 6);
1553
1554 if (bit (inst, 4))
1555 {
1556 int rs = bits (inst, 8, 11);
1557 shift = (rs == 15 ? pc_val + 8 : read_register (rs)) & 0xFF;
1558 }
1559 else
1560 shift = bits (inst, 7, 11);
1561
1562 res = (rm == 15
1563 ? ((pc_val | (ARM_PC_32 ? 0 : status_reg))
1564 + (bit (inst, 4) ? 12 : 8))
1565 : read_register (rm));
1566
1567 switch (shifttype)
1568 {
1569 case 0: /* LSL */
1570 res = shift >= 32 ? 0 : res << shift;
1571 break;
1572
1573 case 1: /* LSR */
1574 res = shift >= 32 ? 0 : res >> shift;
1575 break;
1576
1577 case 2: /* ASR */
1578 if (shift >= 32)
1579 shift = 31;
1580 res = ((res & 0x80000000L)
1581 ? ~((~res) >> shift) : res >> shift);
1582 break;
1583
1584 case 3: /* ROR/RRX */
1585 shift &= 31;
1586 if (shift == 0)
1587 res = (res >> 1) | (carry ? 0x80000000L : 0);
1588 else
1589 res = (res >> shift) | (res << (32 - shift));
1590 break;
1591 }
1592
1593 return res & 0xffffffff;
1594 }
1595
1596 /* Return number of 1-bits in VAL. */
1597
1598 static int
1599 bitcount (unsigned long val)
1600 {
1601 int nbits;
1602 for (nbits = 0; val != 0; nbits++)
1603 val &= val - 1; /* delete rightmost 1-bit in val */
1604 return nbits;
1605 }
1606
1607 static CORE_ADDR
1608 thumb_get_next_pc (CORE_ADDR pc)
1609 {
1610 unsigned long pc_val = ((unsigned long) pc) + 4; /* PC after prefetch */
1611 unsigned short inst1 = read_memory_integer (pc, 2);
1612 CORE_ADDR nextpc = pc + 2; /* default is next instruction */
1613 unsigned long offset;
1614
1615 if ((inst1 & 0xff00) == 0xbd00) /* pop {rlist, pc} */
1616 {
1617 CORE_ADDR sp;
1618
1619 /* Fetch the saved PC from the stack. It's stored above
1620 all of the other registers. */
1621 offset = bitcount (bits (inst1, 0, 7)) * REGISTER_SIZE;
1622 sp = read_register (SP_REGNUM);
1623 nextpc = (CORE_ADDR) read_memory_integer (sp + offset, 4);
1624 nextpc = ADDR_BITS_REMOVE (nextpc);
1625 if (nextpc == pc)
1626 error ("Infinite loop detected");
1627 }
1628 else if ((inst1 & 0xf000) == 0xd000) /* conditional branch */
1629 {
1630 unsigned long status = read_register (PS_REGNUM);
1631 unsigned long cond = bits (inst1, 8, 11);
1632 if (cond != 0x0f && condition_true (cond, status)) /* 0x0f = SWI */
1633 nextpc = pc_val + (sbits (inst1, 0, 7) << 1);
1634 }
1635 else if ((inst1 & 0xf800) == 0xe000) /* unconditional branch */
1636 {
1637 nextpc = pc_val + (sbits (inst1, 0, 10) << 1);
1638 }
1639 else if ((inst1 & 0xf800) == 0xf000) /* long branch with link */
1640 {
1641 unsigned short inst2 = read_memory_integer (pc + 2, 2);
1642 offset = (sbits (inst1, 0, 10) << 12) + (bits (inst2, 0, 10) << 1);
1643 nextpc = pc_val + offset;
1644 }
1645
1646 return nextpc;
1647 }
1648
1649 CORE_ADDR
1650 arm_get_next_pc (CORE_ADDR pc)
1651 {
1652 unsigned long pc_val;
1653 unsigned long this_instr;
1654 unsigned long status;
1655 CORE_ADDR nextpc;
1656
1657 if (arm_pc_is_thumb (pc))
1658 return thumb_get_next_pc (pc);
1659
1660 pc_val = (unsigned long) pc;
1661 this_instr = read_memory_integer (pc, 4);
1662 status = read_register (PS_REGNUM);
1663 nextpc = (CORE_ADDR) (pc_val + 4); /* Default case */
1664
1665 if (condition_true (bits (this_instr, 28, 31), status))
1666 {
1667 switch (bits (this_instr, 24, 27))
1668 {
1669 case 0x0:
1670 case 0x1: /* data processing */
1671 case 0x2:
1672 case 0x3:
1673 {
1674 unsigned long operand1, operand2, result = 0;
1675 unsigned long rn;
1676 int c;
1677
1678 if (bits (this_instr, 12, 15) != 15)
1679 break;
1680
1681 if (bits (this_instr, 22, 25) == 0
1682 && bits (this_instr, 4, 7) == 9) /* multiply */
1683 error ("Illegal update to pc in instruction");
1684
1685 /* Multiply into PC */
1686 c = (status & FLAG_C) ? 1 : 0;
1687 rn = bits (this_instr, 16, 19);
1688 operand1 = (rn == 15) ? pc_val + 8 : read_register (rn);
1689
1690 if (bit (this_instr, 25))
1691 {
1692 unsigned long immval = bits (this_instr, 0, 7);
1693 unsigned long rotate = 2 * bits (this_instr, 8, 11);
1694 operand2 = ((immval >> rotate) | (immval << (32 - rotate)))
1695 & 0xffffffff;
1696 }
1697 else /* operand 2 is a shifted register */
1698 operand2 = shifted_reg_val (this_instr, c, pc_val, status);
1699
1700 switch (bits (this_instr, 21, 24))
1701 {
1702 case 0x0: /*and */
1703 result = operand1 & operand2;
1704 break;
1705
1706 case 0x1: /*eor */
1707 result = operand1 ^ operand2;
1708 break;
1709
1710 case 0x2: /*sub */
1711 result = operand1 - operand2;
1712 break;
1713
1714 case 0x3: /*rsb */
1715 result = operand2 - operand1;
1716 break;
1717
1718 case 0x4: /*add */
1719 result = operand1 + operand2;
1720 break;
1721
1722 case 0x5: /*adc */
1723 result = operand1 + operand2 + c;
1724 break;
1725
1726 case 0x6: /*sbc */
1727 result = operand1 - operand2 + c;
1728 break;
1729
1730 case 0x7: /*rsc */
1731 result = operand2 - operand1 + c;
1732 break;
1733
1734 case 0x8:
1735 case 0x9:
1736 case 0xa:
1737 case 0xb: /* tst, teq, cmp, cmn */
1738 result = (unsigned long) nextpc;
1739 break;
1740
1741 case 0xc: /*orr */
1742 result = operand1 | operand2;
1743 break;
1744
1745 case 0xd: /*mov */
1746 /* Always step into a function. */
1747 result = operand2;
1748 break;
1749
1750 case 0xe: /*bic */
1751 result = operand1 & ~operand2;
1752 break;
1753
1754 case 0xf: /*mvn */
1755 result = ~operand2;
1756 break;
1757 }
1758 nextpc = (CORE_ADDR) ADDR_BITS_REMOVE (result);
1759
1760 if (nextpc == pc)
1761 error ("Infinite loop detected");
1762 break;
1763 }
1764
1765 case 0x4:
1766 case 0x5: /* data transfer */
1767 case 0x6:
1768 case 0x7:
1769 if (bit (this_instr, 20))
1770 {
1771 /* load */
1772 if (bits (this_instr, 12, 15) == 15)
1773 {
1774 /* rd == pc */
1775 unsigned long rn;
1776 unsigned long base;
1777
1778 if (bit (this_instr, 22))
1779 error ("Illegal update to pc in instruction");
1780
1781 /* byte write to PC */
1782 rn = bits (this_instr, 16, 19);
1783 base = (rn == 15) ? pc_val + 8 : read_register (rn);
1784 if (bit (this_instr, 24))
1785 {
1786 /* pre-indexed */
1787 int c = (status & FLAG_C) ? 1 : 0;
1788 unsigned long offset =
1789 (bit (this_instr, 25)
1790 ? shifted_reg_val (this_instr, c, pc_val, status)
1791 : bits (this_instr, 0, 11));
1792
1793 if (bit (this_instr, 23))
1794 base += offset;
1795 else
1796 base -= offset;
1797 }
1798 nextpc = (CORE_ADDR) read_memory_integer ((CORE_ADDR) base,
1799 4);
1800
1801 nextpc = ADDR_BITS_REMOVE (nextpc);
1802
1803 if (nextpc == pc)
1804 error ("Infinite loop detected");
1805 }
1806 }
1807 break;
1808
1809 case 0x8:
1810 case 0x9: /* block transfer */
1811 if (bit (this_instr, 20))
1812 {
1813 /* LDM */
1814 if (bit (this_instr, 15))
1815 {
1816 /* loading pc */
1817 int offset = 0;
1818
1819 if (bit (this_instr, 23))
1820 {
1821 /* up */
1822 unsigned long reglist = bits (this_instr, 0, 14);
1823 offset = bitcount (reglist) * 4;
1824 if (bit (this_instr, 24)) /* pre */
1825 offset += 4;
1826 }
1827 else if (bit (this_instr, 24))
1828 offset = -4;
1829
1830 {
1831 unsigned long rn_val =
1832 read_register (bits (this_instr, 16, 19));
1833 nextpc =
1834 (CORE_ADDR) read_memory_integer ((CORE_ADDR) (rn_val
1835 + offset),
1836 4);
1837 }
1838 nextpc = ADDR_BITS_REMOVE (nextpc);
1839 if (nextpc == pc)
1840 error ("Infinite loop detected");
1841 }
1842 }
1843 break;
1844
1845 case 0xb: /* branch & link */
1846 case 0xa: /* branch */
1847 {
1848 nextpc = BranchDest (pc, this_instr);
1849
1850 nextpc = ADDR_BITS_REMOVE (nextpc);
1851 if (nextpc == pc)
1852 error ("Infinite loop detected");
1853 break;
1854 }
1855
1856 case 0xc:
1857 case 0xd:
1858 case 0xe: /* coproc ops */
1859 case 0xf: /* SWI */
1860 break;
1861
1862 default:
1863 fprintf (stderr, "Bad bit-field extraction\n");
1864 return (pc);
1865 }
1866 }
1867
1868 return nextpc;
1869 }
1870
1871 /* single_step() is called just before we want to resume the inferior,
1872 if we want to single-step it but there is no hardware or kernel
1873 single-step support. We find the target of the coming instruction
1874 and breakpoint it.
1875
1876 single_step is also called just after the inferior stops. If we had
1877 set up a simulated single-step, we undo our damage. */
1878
1879 void
1880 arm_software_single_step (ignore, insert_bpt)
1881 int ignore; /* Signal, not needed */
1882 int insert_bpt;
1883 {
1884 static int next_pc; /* State between setting and unsetting. */
1885 static char break_mem[BREAKPOINT_MAX]; /* Temporary storage for mem@bpt */
1886
1887 if (insert_bpt)
1888 {
1889 next_pc = arm_get_next_pc (read_register (PC_REGNUM));
1890 target_insert_breakpoint (next_pc, &break_mem);
1891 }
1892 else
1893 target_remove_breakpoint (next_pc, &break_mem);
1894 }
1895 #endif /* SOFTWARE_SINGLE_STEP_P */
1896
1897 #include "bfd-in2.h"
1898 #include "libcoff.h"
1899
1900 static int
1901 gdb_print_insn_arm (bfd_vma memaddr, disassemble_info *info)
1902 {
1903 if (arm_pc_is_thumb (memaddr))
1904 {
1905 static asymbol *asym;
1906 static combined_entry_type ce;
1907 static struct coff_symbol_struct csym;
1908 static struct _bfd fake_bfd;
1909 static bfd_target fake_target;
1910
1911 if (csym.native == NULL)
1912 {
1913 /* Create a fake symbol vector containing a Thumb symbol. This is
1914 solely so that the code in print_insn_little_arm() and
1915 print_insn_big_arm() in opcodes/arm-dis.c will detect the presence
1916 of a Thumb symbol and switch to decoding Thumb instructions. */
1917
1918 fake_target.flavour = bfd_target_coff_flavour;
1919 fake_bfd.xvec = &fake_target;
1920 ce.u.syment.n_sclass = C_THUMBEXTFUNC;
1921 csym.native = &ce;
1922 csym.symbol.the_bfd = &fake_bfd;
1923 csym.symbol.name = "fake";
1924 asym = (asymbol *) & csym;
1925 }
1926
1927 memaddr = UNMAKE_THUMB_ADDR (memaddr);
1928 info->symbols = &asym;
1929 }
1930 else
1931 info->symbols = NULL;
1932
1933 if (TARGET_BYTE_ORDER == BIG_ENDIAN)
1934 return print_insn_big_arm (memaddr, info);
1935 else
1936 return print_insn_little_arm (memaddr, info);
1937 }
1938
1939 /* This function implements the BREAKPOINT_FROM_PC macro. It uses the
1940 program counter value to determine whether a 16-bit or 32-bit
1941 breakpoint should be used. It returns a pointer to a string of
1942 bytes that encode a breakpoint instruction, stores the length of
1943 the string to *lenptr, and adjusts the program counter (if
1944 necessary) to point to the actual memory location where the
1945 breakpoint should be inserted. */
1946
1947 unsigned char *
1948 arm_breakpoint_from_pc (CORE_ADDR *pcptr, int *lenptr)
1949 {
1950 if (arm_pc_is_thumb (*pcptr) || arm_pc_is_thumb_dummy (*pcptr))
1951 {
1952 if (TARGET_BYTE_ORDER == BIG_ENDIAN)
1953 {
1954 static char thumb_breakpoint[] = THUMB_BE_BREAKPOINT;
1955 *pcptr = UNMAKE_THUMB_ADDR (*pcptr);
1956 *lenptr = sizeof (thumb_breakpoint);
1957 return thumb_breakpoint;
1958 }
1959 else
1960 {
1961 static char thumb_breakpoint[] = THUMB_LE_BREAKPOINT;
1962 *pcptr = UNMAKE_THUMB_ADDR (*pcptr);
1963 *lenptr = sizeof (thumb_breakpoint);
1964 return thumb_breakpoint;
1965 }
1966 }
1967 else
1968 {
1969 if (TARGET_BYTE_ORDER == BIG_ENDIAN)
1970 {
1971 static char arm_breakpoint[] = ARM_BE_BREAKPOINT;
1972 *lenptr = sizeof (arm_breakpoint);
1973 return arm_breakpoint;
1974 }
1975 else
1976 {
1977 static char arm_breakpoint[] = ARM_LE_BREAKPOINT;
1978 *lenptr = sizeof (arm_breakpoint);
1979 return arm_breakpoint;
1980 }
1981 }
1982 }
1983
1984 /* Extract from an array REGBUF containing the (raw) register state a
1985 function return value of type TYPE, and copy that, in virtual
1986 format, into VALBUF. */
1987
1988 void
1989 arm_extract_return_value (struct type *type,
1990 char regbuf[REGISTER_BYTES],
1991 char *valbuf)
1992 {
1993 if (TYPE_CODE_FLT == TYPE_CODE (type))
1994 convert_from_extended (&regbuf[REGISTER_BYTE (F0_REGNUM)], valbuf);
1995 else
1996 memcpy (valbuf, &regbuf[REGISTER_BYTE (A1_REGNUM)], TYPE_LENGTH (type));
1997 }
1998
1999 /* Return non-zero if the PC is inside a thumb call thunk. */
2000
2001 int
2002 arm_in_call_stub (CORE_ADDR pc, char *name)
2003 {
2004 CORE_ADDR start_addr;
2005
2006 /* Find the starting address of the function containing the PC. If
2007 the caller didn't give us a name, look it up at the same time. */
2008 if (find_pc_partial_function (pc, name ? NULL : &name, &start_addr, NULL) == 0)
2009 return 0;
2010
2011 return strncmp (name, "_call_via_r", 11) == 0;
2012 }
2013
2014 /* If PC is in a Thumb call or return stub, return the address of the
2015 target PC, which is in a register. The thunk functions are called
2016 _called_via_xx, where x is the register name. The possible names
2017 are r0-r9, sl, fp, ip, sp, and lr. */
2018
2019 CORE_ADDR
2020 arm_skip_stub (CORE_ADDR pc)
2021 {
2022 char *name;
2023 CORE_ADDR start_addr;
2024
2025 /* Find the starting address and name of the function containing the PC. */
2026 if (find_pc_partial_function (pc, &name, &start_addr, NULL) == 0)
2027 return 0;
2028
2029 /* Call thunks always start with "_call_via_". */
2030 if (strncmp (name, "_call_via_", 10) == 0)
2031 {
2032 /* Use the name suffix to determine which register contains the
2033 target PC. */
2034 static char *table[15] =
2035 {"r0", "r1", "r2", "r3", "r4", "r5", "r6", "r7",
2036 "r8", "r9", "sl", "fp", "ip", "sp", "lr"
2037 };
2038 int regno;
2039
2040 for (regno = 0; regno <= 14; regno++)
2041 if (strcmp (&name[10], table[regno]) == 0)
2042 return read_register (regno);
2043 }
2044
2045 return 0; /* not a stub */
2046 }
2047
2048 /* If the user changes the register disassembly flavor used for info register
2049 and other commands, we have to also switch the flavor used in opcodes
2050 for disassembly output.
2051 This function is run in the set disassembly_flavor command, and does that. */
2052
2053 static void
2054 set_disassembly_flavor_sfunc (char *args, int from_tty,
2055 struct cmd_list_element *c)
2056 {
2057 set_disassembly_flavor ();
2058 }
2059 \f
2060 static void
2061 set_disassembly_flavor (void)
2062 {
2063 const char *setname, *setdesc, **regnames;
2064 int numregs, j;
2065
2066 /* Find the flavor that the user wants in the opcodes table. */
2067 int current = 0;
2068 numregs = get_arm_regnames (current, &setname, &setdesc, &regnames);
2069 while ((disassembly_flavor != setname)
2070 && (current < num_flavor_options))
2071 get_arm_regnames (++current, &setname, &setdesc, &regnames);
2072 current_option = current;
2073
2074 /* Fill our copy. */
2075 for (j = 0; j < numregs; j++)
2076 arm_register_names[j] = (char *) regnames[j];
2077
2078 /* Adjust case. */
2079 if (isupper (*regnames[PC_REGNUM]))
2080 {
2081 arm_register_names[FPS_REGNUM] = "FPS";
2082 arm_register_names[PS_REGNUM] = "CPSR";
2083 }
2084 else
2085 {
2086 arm_register_names[FPS_REGNUM] = "fps";
2087 arm_register_names[PS_REGNUM] = "cpsr";
2088 }
2089
2090 /* Synchronize the disassembler. */
2091 set_arm_regname_option (current);
2092 }
2093
2094 /* arm_othernames implements the "othernames" command. This is kind
2095 of hacky, and I prefer the set-show disassembly-flavor which is
2096 also used for the x86 gdb. I will keep this around, however, in
2097 case anyone is actually using it. */
2098
2099 static void
2100 arm_othernames (char *names, int n)
2101 {
2102 /* Circle through the various flavors. */
2103 current_option = (current_option + 1) % num_flavor_options;
2104
2105 disassembly_flavor = valid_flavors[current_option];
2106 set_disassembly_flavor ();
2107 }
2108
2109 /* Fetch, and possibly build, an appropriate link_map_offsets structure
2110 for ARM linux targets using the struct offsets defined in <link.h>.
2111 Note, however, that link.h is not actually referred to in this file.
2112 Instead, the relevant structs offsets were obtained from examining
2113 link.h. (We can't refer to link.h from this file because the host
2114 system won't necessarily have it, or if it does, the structs which
2115 it defines will refer to the host system, not the target.) */
2116
2117 struct link_map_offsets *
2118 arm_linux_svr4_fetch_link_map_offsets (void)
2119 {
2120 static struct link_map_offsets lmo;
2121 static struct link_map_offsets *lmp = 0;
2122
2123 if (lmp == 0)
2124 {
2125 lmp = &lmo;
2126
2127 lmo.r_debug_size = 8; /* Actual size is 20, but this is all we
2128 need. */
2129
2130 lmo.r_map_offset = 4;
2131 lmo.r_map_size = 4;
2132
2133 lmo.link_map_size = 20; /* Actual size is 552, but this is all we
2134 need. */
2135
2136 lmo.l_addr_offset = 0;
2137 lmo.l_addr_size = 4;
2138
2139 lmo.l_name_offset = 4;
2140 lmo.l_name_size = 4;
2141
2142 lmo.l_next_offset = 12;
2143 lmo.l_next_size = 4;
2144
2145 lmo.l_prev_offset = 16;
2146 lmo.l_prev_size = 4;
2147 }
2148
2149 return lmp;
2150 }
2151
2152 void
2153 _initialize_arm_tdep (void)
2154 {
2155 struct ui_file *stb;
2156 long length;
2157 struct cmd_list_element *new_cmd;
2158 const char *setname;
2159 const char *setdesc;
2160 const char **regnames;
2161 int numregs, i, j;
2162 static char *helptext;
2163
2164 tm_print_insn = gdb_print_insn_arm;
2165
2166 /* Get the number of possible sets of register names defined in opcodes. */
2167 num_flavor_options = get_arm_regname_num_options ();
2168
2169 /* Sync the opcode insn printer with our register viewer: */
2170 parse_arm_disassembler_option ("reg-names-std");
2171
2172 /* Begin creating the help text. */
2173 stb = mem_fileopen ();
2174 fprintf_unfiltered (stb, "Set the disassembly flavor.\n\
2175 The valid values are:\n");
2176
2177 /* Initialize the array that will be passed to add_set_enum_cmd(). */
2178 valid_flavors = xmalloc ((num_flavor_options + 1) * sizeof (char *));
2179 for (i = 0; i < num_flavor_options; i++)
2180 {
2181 numregs = get_arm_regnames (i, &setname, &setdesc, &regnames);
2182 valid_flavors[i] = setname;
2183 fprintf_unfiltered (stb, "%s - %s\n", setname,
2184 setdesc);
2185 /* Copy the default names (if found) and synchronize disassembler. */
2186 if (!strcmp (setname, "std"))
2187 {
2188 disassembly_flavor = setname;
2189 current_option = i;
2190 for (j = 0; j < numregs; j++)
2191 arm_register_names[j] = (char *) regnames[j];
2192 set_arm_regname_option (i);
2193 }
2194 }
2195 /* Mark the end of valid options. */
2196 valid_flavors[num_flavor_options] = NULL;
2197
2198 /* Finish the creation of the help text. */
2199 fprintf_unfiltered (stb, "The default is \"std\".");
2200 helptext = ui_file_xstrdup (stb, &length);
2201 ui_file_delete (stb);
2202
2203 /* Add the disassembly-flavor command */
2204 new_cmd = add_set_enum_cmd ("disassembly-flavor", no_class,
2205 valid_flavors,
2206 &disassembly_flavor,
2207 helptext,
2208 &setlist);
2209 new_cmd->function.sfunc = set_disassembly_flavor_sfunc;
2210 add_show_from_set (new_cmd, &showlist);
2211
2212 /* ??? Maybe this should be a boolean. */
2213 add_show_from_set (add_set_cmd ("apcs32", no_class,
2214 var_zinteger, (char *) &arm_apcs_32,
2215 "Set usage of ARM 32-bit mode.\n", &setlist),
2216 &showlist);
2217
2218 /* Add the deprecated "othernames" command */
2219
2220 add_com ("othernames", class_obscure, arm_othernames,
2221 "Switch to the next set of register names.");
2222 }
2223
2224 /* Test whether the coff symbol specific value corresponds to a Thumb
2225 function. */
2226
2227 int
2228 coff_sym_is_thumb (int val)
2229 {
2230 return (val == C_THUMBEXT ||
2231 val == C_THUMBSTAT ||
2232 val == C_THUMBEXTFUNC ||
2233 val == C_THUMBSTATFUNC ||
2234 val == C_THUMBLABEL);
2235 }
This page took 0.118033 seconds and 4 git commands to generate.