* dwarf2read.c (dwarf2_get_pc_bounds): Complain if offset
[deliverable/binutils-gdb.git] / gdb / avr-tdep.c
CommitLineData
8818c391 1/* Target-dependent code for Atmel AVR, for GDB.
51603483 2 Copyright 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003
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3 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
de18ac1f 22/* Contributed by Theodore A. Roth, troth@openavr.org */
8818c391
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23
24/* Portions of this file were taken from the original gdb-4.18 patch developed
25 by Denis Chertykov, denisc@overta.ru */
26
27#include "defs.h"
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28#include "frame.h"
29#include "frame-unwind.h"
30#include "frame-base.h"
31#include "trad-frame.h"
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32#include "gdbcmd.h"
33#include "gdbcore.h"
34#include "inferior.h"
35#include "symfile.h"
36#include "arch-utils.h"
37#include "regcache.h"
5f8a3188 38#include "gdb_string.h"
a89aa300 39#include "dis-asm.h"
8818c391
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40
41/* AVR Background:
42
43 (AVR micros are pure Harvard Architecture processors.)
44
45 The AVR family of microcontrollers have three distinctly different memory
46 spaces: flash, sram and eeprom. The flash is 16 bits wide and is used for
47 the most part to store program instructions. The sram is 8 bits wide and is
48 used for the stack and the heap. Some devices lack sram and some can have
49 an additional external sram added on as a peripheral.
50
51 The eeprom is 8 bits wide and is used to store data when the device is
52 powered down. Eeprom is not directly accessible, it can only be accessed
53 via io-registers using a special algorithm. Accessing eeprom via gdb's
54 remote serial protocol ('m' or 'M' packets) looks difficult to do and is
55 not included at this time.
56
57 [The eeprom could be read manually via ``x/b <eaddr + AVR_EMEM_START>'' or
58 written using ``set {unsigned char}<eaddr + AVR_EMEM_START>''. For this to
59 work, the remote target must be able to handle eeprom accesses and perform
60 the address translation.]
61
62 All three memory spaces have physical addresses beginning at 0x0. In
63 addition, the flash is addressed by gcc/binutils/gdb with respect to 8 bit
64 bytes instead of the 16 bit wide words used by the real device for the
65 Program Counter.
66
67 In order for remote targets to work correctly, extra bits must be added to
68 addresses before they are send to the target or received from the target
69 via the remote serial protocol. The extra bits are the MSBs and are used to
70 decode which memory space the address is referring to. */
71
72#undef XMALLOC
73#define XMALLOC(TYPE) ((TYPE*) xmalloc (sizeof (TYPE)))
74
75#undef EXTRACT_INSN
76#define EXTRACT_INSN(addr) extract_unsigned_integer(addr,2)
77
78/* Constants: prefixed with AVR_ to avoid name space clashes */
79
80enum
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81{
82 AVR_REG_W = 24,
83 AVR_REG_X = 26,
84 AVR_REG_Y = 28,
85 AVR_FP_REGNUM = 28,
86 AVR_REG_Z = 30,
87
88 AVR_SREG_REGNUM = 32,
89 AVR_SP_REGNUM = 33,
90 AVR_PC_REGNUM = 34,
91
92 AVR_NUM_REGS = 32 + 1 /*SREG*/ + 1 /*SP*/ + 1 /*PC*/,
93 AVR_NUM_REG_BYTES = 32 + 1 /*SREG*/ + 2 /*SP*/ + 4 /*PC*/,
94
95 AVR_PC_REG_INDEX = 35, /* index into array of registers */
96
4add8633 97 AVR_MAX_PROLOGUE_SIZE = 64, /* bytes */
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98
99 /* Count of pushed registers. From r2 to r17 (inclusively), r28, r29 */
100 AVR_MAX_PUSHES = 18,
101
102 /* Number of the last pushed register. r17 for current avr-gcc */
103 AVR_LAST_PUSHED_REGNUM = 17,
104
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105 AVR_ARG1_REGNUM = 24, /* Single byte argument */
106 AVR_ARGN_REGNUM = 25, /* Multi byte argments */
107
108 AVR_RET1_REGNUM = 24, /* Single byte return value */
109 AVR_RETN_REGNUM = 25, /* Multi byte return value */
110
2e5ff58c
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111 /* FIXME: TRoth/2002-01-??: Can we shift all these memory masks left 8
112 bits? Do these have to match the bfd vma values?. It sure would make
113 things easier in the future if they didn't need to match.
114
115 Note: I chose these values so as to be consistent with bfd vma
116 addresses.
117
118 TRoth/2002-04-08: There is already a conflict with very large programs
119 in the mega128. The mega128 has 128K instruction bytes (64K words),
120 thus the Most Significant Bit is 0x10000 which gets masked off my
121 AVR_MEM_MASK.
122
123 The problem manifests itself when trying to set a breakpoint in a
124 function which resides in the upper half of the instruction space and
125 thus requires a 17-bit address.
126
127 For now, I've just removed the EEPROM mask and changed AVR_MEM_MASK
128 from 0x00ff0000 to 0x00f00000. Eeprom is not accessible from gdb yet,
129 but could be for some remote targets by just adding the correct offset
130 to the address and letting the remote target handle the low-level
131 details of actually accessing the eeprom. */
132
133 AVR_IMEM_START = 0x00000000, /* INSN memory */
134 AVR_SMEM_START = 0x00800000, /* SRAM memory */
8818c391 135#if 1
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136 /* No eeprom mask defined */
137 AVR_MEM_MASK = 0x00f00000, /* mask to determine memory space */
8818c391 138#else
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139 AVR_EMEM_START = 0x00810000, /* EEPROM memory */
140 AVR_MEM_MASK = 0x00ff0000, /* mask to determine memory space */
8818c391 141#endif
2e5ff58c 142};
8818c391 143
4add8633
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144/* Prologue types:
145
146 NORMAL and CALL are the typical types (the -mcall-prologues gcc option
147 causes the generation of the CALL type prologues). */
148
149enum {
150 AVR_PROLOGUE_NONE, /* No prologue */
151 AVR_PROLOGUE_NORMAL,
152 AVR_PROLOGUE_CALL, /* -mcall-prologues */
153 AVR_PROLOGUE_MAIN,
154 AVR_PROLOGUE_INTR, /* interrupt handler */
155 AVR_PROLOGUE_SIG, /* signal handler */
156};
157
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158/* Any function with a frame looks like this
159 ....... <-SP POINTS HERE
160 LOCALS1 <-FP POINTS HERE
161 LOCALS0
162 SAVED FP
163 SAVED R3
164 SAVED R2
165 RET PC
166 FIRST ARG
167 SECOND ARG */
168
4add8633 169struct avr_unwind_cache
2e5ff58c 170{
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171 /* The previous frame's inner most stack address. Used as this
172 frame ID's stack_addr. */
173 CORE_ADDR prev_sp;
174 /* The frame's base, optionally used by the high-level debug info. */
175 CORE_ADDR base;
176 int size;
177 int prologue_type;
178 /* Table indicating the location of each and every register. */
179 struct trad_frame_saved_reg *saved_regs;
2e5ff58c 180};
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181
182struct gdbarch_tdep
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183{
184 /* FIXME: TRoth: is there anything to put here? */
185 int foo;
186};
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187
188/* Lookup the name of a register given it's number. */
189
fa88f677 190static const char *
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191avr_register_name (int regnum)
192{
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193 static char *register_names[] = {
194 "r0", "r1", "r2", "r3", "r4", "r5", "r6", "r7",
195 "r8", "r9", "r10", "r11", "r12", "r13", "r14", "r15",
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196 "r16", "r17", "r18", "r19", "r20", "r21", "r22", "r23",
197 "r24", "r25", "r26", "r27", "r28", "r29", "r30", "r31",
198 "SREG", "SP", "PC"
199 };
200 if (regnum < 0)
201 return NULL;
202 if (regnum >= (sizeof (register_names) / sizeof (*register_names)))
203 return NULL;
204 return register_names[regnum];
205}
206
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207/* Return the GDB type object for the "standard" data type
208 of data in register N. */
209
210static struct type *
866b76ea 211avr_register_type (struct gdbarch *gdbarch, int reg_nr)
8818c391 212{
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213 if (reg_nr == AVR_PC_REGNUM)
214 return builtin_type_uint32;
866b76ea
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215 if (reg_nr == AVR_SP_REGNUM)
216 return builtin_type_void_data_ptr;
217 else
218 return builtin_type_uint8;
8818c391
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219}
220
221/* Instruction address checks and convertions. */
222
223static CORE_ADDR
224avr_make_iaddr (CORE_ADDR x)
225{
226 return ((x) | AVR_IMEM_START);
227}
228
229static int
230avr_iaddr_p (CORE_ADDR x)
231{
232 return (((x) & AVR_MEM_MASK) == AVR_IMEM_START);
233}
234
235/* FIXME: TRoth: Really need to use a larger mask for instructions. Some
236 devices are already up to 128KBytes of flash space.
237
238 TRoth/2002-04-8: See comment above where AVR_IMEM_START is defined. */
239
240static CORE_ADDR
241avr_convert_iaddr_to_raw (CORE_ADDR x)
242{
243 return ((x) & 0xffffffff);
244}
245
246/* SRAM address checks and convertions. */
247
248static CORE_ADDR
249avr_make_saddr (CORE_ADDR x)
250{
251 return ((x) | AVR_SMEM_START);
252}
253
254static int
255avr_saddr_p (CORE_ADDR x)
256{
257 return (((x) & AVR_MEM_MASK) == AVR_SMEM_START);
258}
259
260static CORE_ADDR
261avr_convert_saddr_to_raw (CORE_ADDR x)
262{
263 return ((x) & 0xffffffff);
264}
265
266/* EEPROM address checks and convertions. I don't know if these will ever
267 actually be used, but I've added them just the same. TRoth */
268
269/* TRoth/2002-04-08: Commented out for now to allow fix for problem with large
270 programs in the mega128. */
271
272/* static CORE_ADDR */
273/* avr_make_eaddr (CORE_ADDR x) */
274/* { */
275/* return ((x) | AVR_EMEM_START); */
276/* } */
277
278/* static int */
279/* avr_eaddr_p (CORE_ADDR x) */
280/* { */
281/* return (((x) & AVR_MEM_MASK) == AVR_EMEM_START); */
282/* } */
283
284/* static CORE_ADDR */
285/* avr_convert_eaddr_to_raw (CORE_ADDR x) */
286/* { */
287/* return ((x) & 0xffffffff); */
288/* } */
289
290/* Convert from address to pointer and vice-versa. */
291
292static void
293avr_address_to_pointer (struct type *type, void *buf, CORE_ADDR addr)
294{
295 /* Is it a code address? */
296 if (TYPE_CODE (TYPE_TARGET_TYPE (type)) == TYPE_CODE_FUNC
297 || TYPE_CODE (TYPE_TARGET_TYPE (type)) == TYPE_CODE_METHOD)
298 {
2e5ff58c 299 store_unsigned_integer (buf, TYPE_LENGTH (type),
4ea2465e 300 avr_convert_iaddr_to_raw (addr >> 1));
8818c391
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301 }
302 else
303 {
304 /* Strip off any upper segment bits. */
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305 store_unsigned_integer (buf, TYPE_LENGTH (type),
306 avr_convert_saddr_to_raw (addr));
8818c391
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307 }
308}
309
310static CORE_ADDR
66140c26 311avr_pointer_to_address (struct type *type, const void *buf)
8818c391 312{
7c0b4a20 313 CORE_ADDR addr = extract_unsigned_integer (buf, TYPE_LENGTH (type));
8818c391 314
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315 /* Is it a code address? */
316 if (TYPE_CODE (TYPE_TARGET_TYPE (type)) == TYPE_CODE_FUNC
317 || TYPE_CODE (TYPE_TARGET_TYPE (type)) == TYPE_CODE_METHOD
2e5ff58c 318 || TYPE_CODE_SPACE (TYPE_TARGET_TYPE (type)))
4ea2465e 319 return avr_make_iaddr (addr << 1);
8818c391
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320 else
321 return avr_make_saddr (addr);
322}
323
324static CORE_ADDR
325avr_read_pc (ptid_t ptid)
326{
327 ptid_t save_ptid;
8619218d 328 ULONGEST pc;
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329 CORE_ADDR retval;
330
331 save_ptid = inferior_ptid;
332 inferior_ptid = ptid;
8619218d 333 regcache_cooked_read_unsigned (current_regcache, AVR_PC_REGNUM, &pc);
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334 inferior_ptid = save_ptid;
335 retval = avr_make_iaddr (pc);
336 return retval;
337}
338
339static void
340avr_write_pc (CORE_ADDR val, ptid_t ptid)
341{
342 ptid_t save_ptid;
343
344 save_ptid = inferior_ptid;
345 inferior_ptid = ptid;
346 write_register (AVR_PC_REGNUM, avr_convert_iaddr_to_raw (val));
347 inferior_ptid = save_ptid;
348}
349
350static CORE_ADDR
351avr_read_sp (void)
352{
8619218d
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353 ULONGEST sp;
354
355 regcache_cooked_read_unsigned (current_regcache, AVR_SP_REGNUM, &sp);
356 return (avr_make_saddr (sp));
8818c391
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357}
358
4add8633
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359static int
360avr_scan_arg_moves (int vpc, unsigned char *prologue)
8818c391 361{
4add8633 362 unsigned short insn;
866b76ea 363
4add8633
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364 for (; vpc < AVR_MAX_PROLOGUE_SIZE; vpc += 2)
365 {
366 insn = EXTRACT_INSN (&prologue[vpc]);
367 if ((insn & 0xff00) == 0x0100) /* movw rXX, rYY */
368 continue;
369 else if ((insn & 0xfc00) == 0x2c00) /* mov rXX, rYY */
370 continue;
371 else
372 break;
373 }
374
375 return vpc;
8818c391
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376}
377
4add8633 378/* Function: avr_scan_prologue
8818c391 379
4add8633 380 This function decodes an AVR function prologue to determine:
8818c391
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381 1) the size of the stack frame
382 2) which registers are saved on it
383 3) the offsets of saved regs
4add8633 384 This information is stored in the avr_unwind_cache structure.
8818c391 385
e3d8b004
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386 Some devices lack the sbiw instruction, so on those replace this:
387 sbiw r28, XX
388 with this:
389 subi r28,lo8(XX)
390 sbci r29,hi8(XX)
391
392 A typical AVR function prologue with a frame pointer might look like this:
393 push rXX ; saved regs
394 ...
395 push r28
396 push r29
397 in r28,__SP_L__
398 in r29,__SP_H__
399 sbiw r28,<LOCALS_SIZE>
400 in __tmp_reg__,__SREG__
8818c391 401 cli
e3d8b004 402 out __SP_H__,r29
72fab697
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403 out __SREG__,__tmp_reg__
404 out __SP_L__,r28
e3d8b004
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405
406 A typical AVR function prologue without a frame pointer might look like
407 this:
408 push rXX ; saved regs
409 ...
410
411 A main function prologue looks like this:
412 ldi r28,lo8(<RAM_ADDR> - <LOCALS_SIZE>)
413 ldi r29,hi8(<RAM_ADDR> - <LOCALS_SIZE>)
414 out __SP_H__,r29
415 out __SP_L__,r28
416
417 A signal handler prologue looks like this:
418 push __zero_reg__
419 push __tmp_reg__
420 in __tmp_reg__, __SREG__
421 push __tmp_reg__
422 clr __zero_reg__
423 push rXX ; save registers r18:r27, r30:r31
424 ...
425 push r28 ; save frame pointer
426 push r29
427 in r28, __SP_L__
428 in r29, __SP_H__
429 sbiw r28, <LOCALS_SIZE>
430 out __SP_H__, r29
431 out __SP_L__, r28
432
433 A interrupt handler prologue looks like this:
434 sei
435 push __zero_reg__
436 push __tmp_reg__
437 in __tmp_reg__, __SREG__
438 push __tmp_reg__
439 clr __zero_reg__
440 push rXX ; save registers r18:r27, r30:r31
441 ...
442 push r28 ; save frame pointer
443 push r29
444 in r28, __SP_L__
445 in r29, __SP_H__
446 sbiw r28, <LOCALS_SIZE>
447 cli
448 out __SP_H__, r29
449 sei
450 out __SP_L__, r28
451
452 A `-mcall-prologues' prologue looks like this (Note that the megas use a
453 jmp instead of a rjmp, thus the prologue is one word larger since jmp is a
454 32 bit insn and rjmp is a 16 bit insn):
455 ldi r26,lo8(<LOCALS_SIZE>)
456 ldi r27,hi8(<LOCALS_SIZE>)
457 ldi r30,pm_lo8(.L_foo_body)
458 ldi r31,pm_hi8(.L_foo_body)
459 rjmp __prologue_saves__+RRR
460 .L_foo_body: */
8818c391 461
4add8633
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462/* Not really part of a prologue, but still need to scan for it, is when a
463 function prologue moves values passed via registers as arguments to new
464 registers. In this case, all local variables live in registers, so there
465 may be some register saves. This is what it looks like:
466 movw rMM, rNN
467 ...
468
469 There could be multiple movw's. If the target doesn't have a movw insn, it
470 will use two mov insns. This could be done after any of the above prologue
471 types. */
472
473static CORE_ADDR
474avr_scan_prologue (CORE_ADDR pc, struct avr_unwind_cache *info)
8818c391 475{
2e5ff58c
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476 int i;
477 unsigned short insn;
2e5ff58c 478 int scan_stage = 0;
8818c391 479 struct minimal_symbol *msymbol;
8818c391
TR
480 unsigned char prologue[AVR_MAX_PROLOGUE_SIZE];
481 int vpc = 0;
482
4add8633
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483 /* FIXME: TRoth/2003-06-11: This could be made more efficient by only
484 reading in the bytes of the prologue. The problem is that the figuring
485 out where the end of the prologue is is a bit difficult. The old code
486 tried to do that, but failed quite often. */
487 read_memory (pc, prologue, AVR_MAX_PROLOGUE_SIZE);
8818c391
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488
489 /* Scanning main()'s prologue
490 ldi r28,lo8(<RAM_ADDR> - <LOCALS_SIZE>)
491 ldi r29,hi8(<RAM_ADDR> - <LOCALS_SIZE>)
492 out __SP_H__,r29
493 out __SP_L__,r28 */
494
4add8633 495 if (1)
8818c391
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496 {
497 CORE_ADDR locals;
2e5ff58c
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498 unsigned char img[] = {
499 0xde, 0xbf, /* out __SP_H__,r29 */
500 0xcd, 0xbf /* out __SP_L__,r28 */
8818c391
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501 };
502
8818c391
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503 insn = EXTRACT_INSN (&prologue[vpc]);
504 /* ldi r28,lo8(<RAM_ADDR> - <LOCALS_SIZE>) */
2e5ff58c
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505 if ((insn & 0xf0f0) == 0xe0c0)
506 {
507 locals = (insn & 0xf) | ((insn & 0x0f00) >> 4);
508 insn = EXTRACT_INSN (&prologue[vpc + 2]);
509 /* ldi r29,hi8(<RAM_ADDR> - <LOCALS_SIZE>) */
510 if ((insn & 0xf0f0) == 0xe0d0)
511 {
512 locals |= ((insn & 0xf) | ((insn & 0x0f00) >> 4)) << 8;
513 if (memcmp (prologue + vpc + 4, img, sizeof (img)) == 0)
514 {
4add8633
TR
515 info->prologue_type = AVR_PROLOGUE_MAIN;
516 info->base = locals;
517 return pc + 4;
2e5ff58c
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518 }
519 }
520 }
8818c391 521 }
2e5ff58c 522
4add8633
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523 /* Scanning `-mcall-prologues' prologue
524 Classic prologue is 10 bytes, mega prologue is a 12 bytes long */
8818c391 525
e3d8b004 526 while (1) /* Using a while to avoid many goto's */
8818c391
TR
527 {
528 int loc_size;
529 int body_addr;
530 unsigned num_pushes;
4add8633 531 int pc_offset = 0;
2e5ff58c 532
8818c391
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533 insn = EXTRACT_INSN (&prologue[vpc]);
534 /* ldi r26,<LOCALS_SIZE> */
2e5ff58c
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535 if ((insn & 0xf0f0) != 0xe0a0)
536 break;
8818c391 537 loc_size = (insn & 0xf) | ((insn & 0x0f00) >> 4);
4add8633 538 pc_offset += 2;
2e5ff58c 539
8818c391
TR
540 insn = EXTRACT_INSN (&prologue[vpc + 2]);
541 /* ldi r27,<LOCALS_SIZE> / 256 */
542 if ((insn & 0xf0f0) != 0xe0b0)
2e5ff58c 543 break;
8818c391 544 loc_size |= ((insn & 0xf) | ((insn & 0x0f00) >> 4)) << 8;
4add8633 545 pc_offset += 2;
2e5ff58c 546
8818c391
TR
547 insn = EXTRACT_INSN (&prologue[vpc + 4]);
548 /* ldi r30,pm_lo8(.L_foo_body) */
549 if ((insn & 0xf0f0) != 0xe0e0)
2e5ff58c 550 break;
8818c391 551 body_addr = (insn & 0xf) | ((insn & 0x0f00) >> 4);
4add8633 552 pc_offset += 2;
8818c391
TR
553
554 insn = EXTRACT_INSN (&prologue[vpc + 6]);
555 /* ldi r31,pm_hi8(.L_foo_body) */
556 if ((insn & 0xf0f0) != 0xe0f0)
2e5ff58c 557 break;
8818c391 558 body_addr |= ((insn & 0xf) | ((insn & 0x0f00) >> 4)) << 8;
4add8633 559 pc_offset += 2;
8818c391 560
8818c391
TR
561 msymbol = lookup_minimal_symbol ("__prologue_saves__", NULL, NULL);
562 if (!msymbol)
2e5ff58c 563 break;
8818c391 564
8818c391
TR
565 insn = EXTRACT_INSN (&prologue[vpc + 8]);
566 /* rjmp __prologue_saves__+RRR */
e3d8b004
TR
567 if ((insn & 0xf000) == 0xc000)
568 {
569 /* Extract PC relative offset from RJMP */
570 i = (insn & 0xfff) | (insn & 0x800 ? (-1 ^ 0xfff) : 0);
571 /* Convert offset to byte addressable mode */
572 i *= 2;
573 /* Destination address */
4add8633 574 i += pc + 10;
e3d8b004 575
4add8633 576 if (body_addr != (pc + 10)/2)
e3d8b004 577 break;
4add8633
TR
578
579 pc_offset += 2;
e3d8b004 580 }
e3d8b004
TR
581 else if ((insn & 0xfe0e) == 0x940c)
582 {
583 /* Extract absolute PC address from JMP */
584 i = (((insn & 0x1) | ((insn & 0x1f0) >> 3) << 16)
585 | (EXTRACT_INSN (&prologue[vpc + 10]) & 0xffff));
586 /* Convert address to byte addressable mode */
587 i *= 2;
588
4add8633 589 if (body_addr != (pc + 12)/2)
e3d8b004 590 break;
4add8633
TR
591
592 pc_offset += 4;
e3d8b004
TR
593 }
594 else
595 break;
2e5ff58c 596
4add8633 597 /* Resolve offset (in words) from __prologue_saves__ symbol.
8818c391
TR
598 Which is a pushes count in `-mcall-prologues' mode */
599 num_pushes = AVR_MAX_PUSHES - (i - SYMBOL_VALUE_ADDRESS (msymbol)) / 2;
600
601 if (num_pushes > AVR_MAX_PUSHES)
4add8633
TR
602 {
603 fprintf_unfiltered (gdb_stderr, "Num pushes too large: %d\n",
604 num_pushes);
605 num_pushes = 0;
606 }
2e5ff58c 607
8818c391 608 if (num_pushes)
2e5ff58c
TR
609 {
610 int from;
4add8633
TR
611
612 info->saved_regs[AVR_FP_REGNUM + 1].addr = num_pushes;
2e5ff58c 613 if (num_pushes >= 2)
4add8633
TR
614 info->saved_regs[AVR_FP_REGNUM].addr = num_pushes - 1;
615
2e5ff58c
TR
616 i = 0;
617 for (from = AVR_LAST_PUSHED_REGNUM + 1 - (num_pushes - 2);
618 from <= AVR_LAST_PUSHED_REGNUM; ++from)
4add8633 619 info->saved_regs [from].addr = ++i;
2e5ff58c 620 }
4add8633
TR
621 info->size = loc_size + num_pushes;
622 info->prologue_type = AVR_PROLOGUE_CALL;
623
624 return pc + pc_offset;
8818c391
TR
625 }
626
4add8633
TR
627 /* Scan for the beginning of the prologue for an interrupt or signal
628 function. Note that we have to set the prologue type here since the
629 third stage of the prologue may not be present (e.g. no saved registered
630 or changing of the SP register). */
8818c391 631
4add8633 632 if (1)
8818c391 633 {
2e5ff58c
TR
634 unsigned char img[] = {
635 0x78, 0x94, /* sei */
636 0x1f, 0x92, /* push r1 */
637 0x0f, 0x92, /* push r0 */
638 0x0f, 0xb6, /* in r0,0x3f SREG */
639 0x0f, 0x92, /* push r0 */
640 0x11, 0x24 /* clr r1 */
8818c391
TR
641 };
642 if (memcmp (prologue, img, sizeof (img)) == 0)
2e5ff58c 643 {
4add8633 644 info->prologue_type = AVR_PROLOGUE_INTR;
2e5ff58c 645 vpc += sizeof (img);
4add8633
TR
646 info->saved_regs[AVR_SREG_REGNUM].addr = 3;
647 info->saved_regs[0].addr = 2;
648 info->saved_regs[1].addr = 1;
649 info->size += 3;
2e5ff58c 650 }
4add8633 651 else if (memcmp (img + 2, prologue, sizeof (img) - 2) == 0)
2e5ff58c 652 {
4add8633
TR
653 info->prologue_type = AVR_PROLOGUE_SIG;
654 vpc += sizeof (img) - 2;
655 info->saved_regs[AVR_SREG_REGNUM].addr = 3;
656 info->saved_regs[0].addr = 2;
657 info->saved_regs[1].addr = 1;
658 info->size += 3;
2e5ff58c 659 }
8818c391
TR
660 }
661
662 /* First stage of the prologue scanning.
4add8633 663 Scan pushes (saved registers) */
8818c391 664
4add8633 665 for (; vpc < AVR_MAX_PROLOGUE_SIZE; vpc += 2)
8818c391
TR
666 {
667 insn = EXTRACT_INSN (&prologue[vpc]);
2e5ff58c
TR
668 if ((insn & 0xfe0f) == 0x920f) /* push rXX */
669 {
670 /* Bits 4-9 contain a mask for registers R0-R32. */
4add8633
TR
671 int regno = (insn & 0x1f0) >> 4;
672 info->size++;
673 info->saved_regs[regno].addr = info->size;
2e5ff58c
TR
674 scan_stage = 1;
675 }
8818c391 676 else
2e5ff58c 677 break;
8818c391
TR
678 }
679
4add8633
TR
680 if (vpc >= AVR_MAX_PROLOGUE_SIZE)
681 fprintf_unfiltered (gdb_stderr,
682 "Hit end of prologue while scanning pushes\n");
683
8818c391
TR
684 /* Second stage of the prologue scanning.
685 Scan:
686 in r28,__SP_L__
687 in r29,__SP_H__ */
688
4add8633 689 if (scan_stage == 1 && vpc < AVR_MAX_PROLOGUE_SIZE)
8818c391 690 {
2e5ff58c
TR
691 unsigned char img[] = {
692 0xcd, 0xb7, /* in r28,__SP_L__ */
693 0xde, 0xb7 /* in r29,__SP_H__ */
8818c391
TR
694 };
695 unsigned short insn1;
2e5ff58c 696
8818c391 697 if (memcmp (prologue + vpc, img, sizeof (img)) == 0)
2e5ff58c
TR
698 {
699 vpc += 4;
2e5ff58c
TR
700 scan_stage = 2;
701 }
8818c391
TR
702 }
703
704 /* Third stage of the prologue scanning. (Really two stages)
705 Scan for:
706 sbiw r28,XX or subi r28,lo8(XX)
72fab697 707 sbci r29,hi8(XX)
8818c391
TR
708 in __tmp_reg__,__SREG__
709 cli
e3d8b004 710 out __SP_H__,r29
8818c391 711 out __SREG__,__tmp_reg__
e3d8b004 712 out __SP_L__,r28 */
8818c391 713
4add8633 714 if (scan_stage == 2 && vpc < AVR_MAX_PROLOGUE_SIZE)
8818c391
TR
715 {
716 int locals_size = 0;
2e5ff58c
TR
717 unsigned char img[] = {
718 0x0f, 0xb6, /* in r0,0x3f */
719 0xf8, 0x94, /* cli */
e3d8b004 720 0xde, 0xbf, /* out 0x3e,r29 ; SPH */
2e5ff58c 721 0x0f, 0xbe, /* out 0x3f,r0 ; SREG */
e3d8b004 722 0xcd, 0xbf /* out 0x3d,r28 ; SPL */
8818c391 723 };
2e5ff58c 724 unsigned char img_sig[] = {
e3d8b004
TR
725 0xde, 0xbf, /* out 0x3e,r29 ; SPH */
726 0xcd, 0xbf /* out 0x3d,r28 ; SPL */
8818c391 727 };
2e5ff58c
TR
728 unsigned char img_int[] = {
729 0xf8, 0x94, /* cli */
e3d8b004 730 0xde, 0xbf, /* out 0x3e,r29 ; SPH */
2e5ff58c 731 0x78, 0x94, /* sei */
e3d8b004 732 0xcd, 0xbf /* out 0x3d,r28 ; SPL */
8818c391 733 };
2e5ff58c 734
8818c391
TR
735 insn = EXTRACT_INSN (&prologue[vpc]);
736 vpc += 2;
2e5ff58c
TR
737 if ((insn & 0xff30) == 0x9720) /* sbiw r28,XXX */
738 locals_size = (insn & 0xf) | ((insn & 0xc0) >> 2);
739 else if ((insn & 0xf0f0) == 0x50c0) /* subi r28,lo8(XX) */
740 {
741 locals_size = (insn & 0xf) | ((insn & 0xf00) >> 4);
742 insn = EXTRACT_INSN (&prologue[vpc]);
743 vpc += 2;
744 locals_size += ((insn & 0xf) | ((insn & 0xf00) >> 4) << 8);
745 }
8818c391 746 else
4add8633
TR
747 return pc + vpc;
748
749 /* Scan the last part of the prologue. May not be present for interrupt
750 or signal handler functions, which is why we set the prologue type
751 when we saw the beginning of the prologue previously. */
752
753 if (memcmp (prologue + vpc, img_sig, sizeof (img_sig)) == 0)
754 {
755 vpc += sizeof (img_sig);
756 }
757 else if (memcmp (prologue + vpc, img_int, sizeof (img_int)) == 0)
758 {
759 vpc += sizeof (img_int);
760 }
761 if (memcmp (prologue + vpc, img, sizeof (img)) == 0)
762 {
763 info->prologue_type = AVR_PROLOGUE_NORMAL;
764 vpc += sizeof (img);
765 }
766
767 info->size += locals_size;
768
769 return pc + avr_scan_arg_moves (vpc, prologue);
8818c391 770 }
4add8633
TR
771
772 /* If we got this far, we could not scan the prologue, so just return the pc
773 of the frame plus an adjustment for argument move insns. */
774
775 return pc + avr_scan_arg_moves (vpc, prologue);;
8818c391
TR
776}
777
4add8633
TR
778static CORE_ADDR
779avr_skip_prologue (CORE_ADDR pc)
780{
781 CORE_ADDR func_addr, func_end;
782 CORE_ADDR prologue_end = pc;
8818c391 783
4add8633 784 /* See what the symbol table says */
8818c391 785
4add8633
TR
786 if (find_pc_partial_function (pc, NULL, &func_addr, &func_end))
787 {
788 struct symtab_and_line sal;
789 struct avr_unwind_cache info = {0};
790 struct trad_frame_saved_reg saved_regs[AVR_NUM_REGS];
2e5ff58c 791
4add8633 792 info.saved_regs = saved_regs;
8818c391 793
4add8633
TR
794 /* Need to run the prologue scanner to figure out if the function has a
795 prologue and possibly skip over moving arguments passed via registers
796 to other registers. */
2e5ff58c 797
4add8633 798 prologue_end = avr_scan_prologue (pc, &info);
8818c391 799
3b85b0f1
TR
800 if (info.prologue_type == AVR_PROLOGUE_NONE)
801 return pc;
802 else
4add8633
TR
803 {
804 sal = find_pc_line (func_addr, 0);
8818c391 805
4add8633
TR
806 if (sal.line != 0 && sal.end < func_end)
807 return sal.end;
808 }
809 }
2e5ff58c 810
4add8633
TR
811/* Either we didn't find the start of this function (nothing we can do),
812 or there's no line info, or the line after the prologue is after
813 the end of the function (there probably isn't a prologue). */
2e5ff58c 814
4add8633
TR
815 return prologue_end;
816}
8818c391 817
4add8633
TR
818/* Not all avr devices support the BREAK insn. Those that don't should treat
819 it as a NOP. Thus, it should be ok. Since the avr is currently a remote
820 only target, this shouldn't be a problem (I hope). TRoth/2003-05-14 */
8818c391 821
4add8633
TR
822static const unsigned char *
823avr_breakpoint_from_pc (CORE_ADDR * pcptr, int *lenptr)
824{
825 static unsigned char avr_break_insn [] = { 0x98, 0x95 };
826 *lenptr = sizeof (avr_break_insn);
827 return avr_break_insn;
8818c391
TR
828}
829
4add8633
TR
830/* Given a return value in `regbuf' with a type `valtype',
831 extract and copy its value into `valbuf'.
832
833 Return values are always passed via registers r25:r24:... */
8818c391
TR
834
835static void
4add8633
TR
836avr_extract_return_value (struct type *type, struct regcache *regcache,
837 void *valbuf)
8818c391 838{
4add8633
TR
839 ULONGEST r24, r25;
840 ULONGEST c;
841 int len;
842 if (TYPE_LENGTH (type) == 1)
8818c391 843 {
4add8633
TR
844 regcache_cooked_read_unsigned (regcache, 24, &c);
845 store_unsigned_integer (valbuf, 1, c);
8818c391
TR
846 }
847 else
848 {
4add8633
TR
849 int i;
850 /* The MSB of the return value is always in r25, calculate which
851 register holds the LSB. */
852 int lsb_reg = 25 - TYPE_LENGTH (type) + 1;
8818c391 853
4add8633
TR
854 for (i=0; i< TYPE_LENGTH (type); i++)
855 {
856 regcache_cooked_read (regcache, lsb_reg + i,
857 (bfd_byte *) valbuf + i);
4add8633
TR
858 }
859 }
860}
8818c391 861
4add8633
TR
862/* Put here the code to store, into fi->saved_regs, the addresses of
863 the saved registers of frame described by FRAME_INFO. This
864 includes special registers such as pc and fp saved in special ways
865 in the stack frame. sp is even more special: the address we return
866 for it IS the sp for the next frame. */
8818c391 867
4add8633
TR
868struct avr_unwind_cache *
869avr_frame_unwind_cache (struct frame_info *next_frame,
870 void **this_prologue_cache)
8818c391 871{
4add8633
TR
872 CORE_ADDR pc;
873 ULONGEST prev_sp;
874 ULONGEST this_base;
875 struct avr_unwind_cache *info;
876 int i;
877
878 if ((*this_prologue_cache))
879 return (*this_prologue_cache);
880
881 info = FRAME_OBSTACK_ZALLOC (struct avr_unwind_cache);
882 (*this_prologue_cache) = info;
883 info->saved_regs = trad_frame_alloc_saved_regs (next_frame);
884
885 info->size = 0;
886 info->prologue_type = AVR_PROLOGUE_NONE;
887
888 pc = frame_func_unwind (next_frame);
889
890 if ((pc > 0) && (pc < frame_pc_unwind (next_frame)))
891 avr_scan_prologue (pc, info);
892
3b85b0f1
TR
893 if ((info->prologue_type != AVR_PROLOGUE_NONE)
894 && (info->prologue_type != AVR_PROLOGUE_MAIN))
4add8633
TR
895 {
896 ULONGEST high_base; /* High byte of FP */
897
898 /* The SP was moved to the FP. This indicates that a new frame
899 was created. Get THIS frame's FP value by unwinding it from
900 the next frame. */
901 frame_unwind_unsigned_register (next_frame, AVR_FP_REGNUM, &this_base);
902 frame_unwind_unsigned_register (next_frame, AVR_FP_REGNUM+1, &high_base);
903 this_base += (high_base << 8);
904
905 /* The FP points at the last saved register. Adjust the FP back
906 to before the first saved register giving the SP. */
907 prev_sp = this_base + info->size;
908 }
8818c391 909 else
4add8633
TR
910 {
911 /* Assume that the FP is this frame's SP but with that pushed
912 stack space added back. */
913 frame_unwind_unsigned_register (next_frame, AVR_SP_REGNUM, &this_base);
914 prev_sp = this_base + info->size;
915 }
916
917 /* Add 1 here to adjust for the post-decrement nature of the push
918 instruction.*/
919 info->prev_sp = avr_make_saddr (prev_sp+1);
920
921 info->base = avr_make_saddr (this_base);
922
923 /* Adjust all the saved registers so that they contain addresses and not
3b85b0f1 924 offsets. */
4add8633
TR
925 for (i = 0; i < NUM_REGS - 1; i++)
926 if (info->saved_regs[i].addr)
927 {
928 info->saved_regs[i].addr = (info->prev_sp - info->saved_regs[i].addr);
929 }
930
931 /* Except for the main and startup code, the return PC is always saved on
932 the stack and is at the base of the frame. */
933
934 if (info->prologue_type != AVR_PROLOGUE_MAIN)
935 {
936 info->saved_regs[AVR_PC_REGNUM].addr = info->prev_sp;
937 }
938
3b85b0f1
TR
939 /* The previous frame's SP needed to be computed. Save the computed
940 value. */
941 trad_frame_set_value (info->saved_regs, AVR_SP_REGNUM, info->prev_sp+1);
942
4add8633 943 return info;
8818c391
TR
944}
945
946static CORE_ADDR
4add8633 947avr_unwind_pc (struct gdbarch *gdbarch, struct frame_info *next_frame)
8818c391 948{
4add8633
TR
949 ULONGEST pc;
950
951 frame_unwind_unsigned_register (next_frame, AVR_PC_REGNUM, &pc);
952
953 return avr_make_iaddr (pc);
8818c391
TR
954}
955
4add8633
TR
956/* Given a GDB frame, determine the address of the calling function's
957 frame. This will be used to create a new GDB frame struct. */
8818c391 958
4add8633
TR
959static void
960avr_frame_this_id (struct frame_info *next_frame,
961 void **this_prologue_cache,
962 struct frame_id *this_id)
8818c391 963{
4add8633
TR
964 struct avr_unwind_cache *info
965 = avr_frame_unwind_cache (next_frame, this_prologue_cache);
966 CORE_ADDR base;
967 CORE_ADDR func;
968 struct frame_id id;
969
970 /* The FUNC is easy. */
971 func = frame_func_unwind (next_frame);
972
973 /* This is meant to halt the backtrace at "_start". Make sure we
974 don't halt it at a generic dummy frame. */
627b3ba2 975 if (deprecated_inside_entry_file (func))
4add8633
TR
976 return;
977
978 /* Hopefully the prologue analysis either correctly determined the
979 frame's base (which is the SP from the previous frame), or set
980 that base to "NULL". */
981 base = info->prev_sp;
982 if (base == 0)
983 return;
984
985 id = frame_id_build (base, func);
986
987 /* Check that we're not going round in circles with the same frame
988 ID (but avoid applying the test to sentinel frames which do go
989 round in circles). Can't use frame_id_eq() as that doesn't yet
990 compare the frame's PC value. */
991 if (frame_relative_level (next_frame) >= 0
992 && get_frame_type (next_frame) != DUMMY_FRAME
993 && frame_id_eq (get_frame_id (next_frame), id))
994 return;
995
996 (*this_id) = id;
8818c391
TR
997}
998
4add8633
TR
999static void
1000avr_frame_prev_register (struct frame_info *next_frame,
1001 void **this_prologue_cache,
1002 int regnum, int *optimizedp,
1003 enum lval_type *lvalp, CORE_ADDR *addrp,
1004 int *realnump, void *bufferp)
8818c391 1005{
4add8633
TR
1006 struct avr_unwind_cache *info
1007 = avr_frame_unwind_cache (next_frame, this_prologue_cache);
8818c391 1008
3b85b0f1
TR
1009 if (regnum == AVR_PC_REGNUM)
1010 {
1011 if (trad_frame_addr_p (info->saved_regs, regnum))
1012 {
1013 *optimizedp = 0;
1014 *lvalp = lval_memory;
1015 *addrp = info->saved_regs[regnum].addr;
1016 *realnump = -1;
1017 if (bufferp != NULL)
1018 {
1019 /* Reading the return PC from the PC register is slightly
1020 abnormal. register_size(AVR_PC_REGNUM) says it is 4 bytes,
1021 but in reality, only two bytes (3 in upcoming mega256) are
1022 stored on the stack.
1023
1024 Also, note that the value on the stack is an addr to a word
1025 not a byte, so we will need to multiply it by two at some
1026 point.
1027
1028 And to confuse matters even more, the return address stored
1029 on the stack is in big endian byte order, even though most
1030 everything else about the avr is little endian. Ick! */
1031
1032 /* FIXME: number of bytes read here will need updated for the
1033 mega256 when it is available. */
1034
1035 ULONGEST pc;
1036 unsigned char tmp;
1037 unsigned char buf[2];
1038
1039 read_memory (info->saved_regs[regnum].addr, buf, 2);
1040
1041 /* Convert the PC read from memory as a big-endian to
1042 little-endian order. */
1043 tmp = buf[0];
1044 buf[0] = buf[1];
1045 buf[1] = tmp;
1046
1047 pc = (extract_unsigned_integer (buf, 2) * 2);
1048 store_unsigned_integer (bufferp,
1049 register_size (current_gdbarch, regnum),
1050 pc);
1051 }
1052 }
1053 }
1054 else
1055 trad_frame_prev_register (next_frame, info->saved_regs, regnum,
1056 optimizedp, lvalp, addrp, realnump, bufferp);
4add8633 1057}
8818c391 1058
4add8633
TR
1059static const struct frame_unwind avr_frame_unwind = {
1060 NORMAL_FRAME,
1061 avr_frame_this_id,
1062 avr_frame_prev_register
1063};
1064
1065const struct frame_unwind *
336d1bba 1066avr_frame_sniffer (struct frame_info *next_frame)
4add8633
TR
1067{
1068 return &avr_frame_unwind;
8818c391
TR
1069}
1070
1071static CORE_ADDR
4add8633 1072avr_frame_base_address (struct frame_info *next_frame, void **this_cache)
8818c391 1073{
4add8633
TR
1074 struct avr_unwind_cache *info
1075 = avr_frame_unwind_cache (next_frame, this_cache);
8818c391 1076
4add8633
TR
1077 return info->base;
1078}
8818c391 1079
4add8633
TR
1080static const struct frame_base avr_frame_base = {
1081 &avr_frame_unwind,
1082 avr_frame_base_address,
1083 avr_frame_base_address,
1084 avr_frame_base_address
1085};
ced15480 1086
4add8633
TR
1087/* Assuming NEXT_FRAME->prev is a dummy, return the frame ID of that
1088 dummy frame. The frame ID's base needs to match the TOS value
1089 saved by save_dummy_frame_tos(), and the PC match the dummy frame's
1090 breakpoint. */
8818c391 1091
4add8633
TR
1092static struct frame_id
1093avr_unwind_dummy_id (struct gdbarch *gdbarch, struct frame_info *next_frame)
1094{
1095 ULONGEST base;
8818c391 1096
4add8633
TR
1097 frame_unwind_unsigned_register (next_frame, AVR_SP_REGNUM, &base);
1098 return frame_id_build (avr_make_saddr (base), frame_pc_unwind (next_frame));
8818c391
TR
1099}
1100
4add8633
TR
1101/* When arguments must be pushed onto the stack, they go on in reverse
1102 order. The below implements a FILO (stack) to do this. */
8818c391 1103
4add8633
TR
1104struct stack_item
1105{
1106 int len;
1107 struct stack_item *prev;
1108 void *data;
1109};
8818c391 1110
4add8633
TR
1111static struct stack_item *push_stack_item (struct stack_item *prev,
1112 void *contents, int len);
1113static struct stack_item *
1114push_stack_item (struct stack_item *prev, void *contents, int len)
8818c391 1115{
4add8633
TR
1116 struct stack_item *si;
1117 si = xmalloc (sizeof (struct stack_item));
1118 si->data = xmalloc (len);
1119 si->len = len;
1120 si->prev = prev;
1121 memcpy (si->data, contents, len);
1122 return si;
8818c391
TR
1123}
1124
4add8633
TR
1125static struct stack_item *pop_stack_item (struct stack_item *si);
1126static struct stack_item *
1127pop_stack_item (struct stack_item *si)
8818c391 1128{
4add8633
TR
1129 struct stack_item *dead = si;
1130 si = si->prev;
1131 xfree (dead->data);
1132 xfree (dead);
1133 return si;
8818c391
TR
1134}
1135
8818c391
TR
1136/* Setup the function arguments for calling a function in the inferior.
1137
1138 On the AVR architecture, there are 18 registers (R25 to R8) which are
1139 dedicated for passing function arguments. Up to the first 18 arguments
1140 (depending on size) may go into these registers. The rest go on the stack.
1141
4add8633
TR
1142 All arguments are aligned to start in even-numbered registers (odd-sized
1143 arguments, including char, have one free register above them). For example,
1144 an int in arg1 and a char in arg2 would be passed as such:
1145
1146 arg1 -> r25:r24
1147 arg2 -> r22
1148
1149 Arguments that are larger than 2 bytes will be split between two or more
1150 registers as available, but will NOT be split between a register and the
1151 stack. Arguments that go onto the stack are pushed last arg first (this is
1152 similar to the d10v). */
1153
1154/* NOTE: TRoth/2003-06-17: The rest of this comment is old looks to be
1155 inaccurate.
8818c391
TR
1156
1157 An exceptional case exists for struct arguments (and possibly other
1158 aggregates such as arrays) -- if the size is larger than WORDSIZE bytes but
1159 not a multiple of WORDSIZE bytes. In this case the argument is never split
1160 between the registers and the stack, but instead is copied in its entirety
1161 onto the stack, AND also copied into as many registers as there is room
1162 for. In other words, space in registers permitting, two copies of the same
1163 argument are passed in. As far as I can tell, only the one on the stack is
1164 used, although that may be a function of the level of compiler
1165 optimization. I suspect this is a compiler bug. Arguments of these odd
1166 sizes are left-justified within the word (as opposed to arguments smaller
1167 than WORDSIZE bytes, which are right-justified).
1168
1169 If the function is to return an aggregate type such as a struct, the caller
1170 must allocate space into which the callee will copy the return value. In
1171 this case, a pointer to the return value location is passed into the callee
1172 in register R0, which displaces one of the other arguments passed in via
1173 registers R0 to R2. */
1174
1175static CORE_ADDR
4add8633
TR
1176avr_push_dummy_call (struct gdbarch *gdbarch, CORE_ADDR func_addr,
1177 struct regcache *regcache, CORE_ADDR bp_addr,
1178 int nargs, struct value **args, CORE_ADDR sp,
1179 int struct_return, CORE_ADDR struct_addr)
8818c391 1180{
4add8633
TR
1181 int i;
1182 unsigned char buf[2];
1183 CORE_ADDR return_pc = avr_convert_iaddr_to_raw (bp_addr);
1184 int regnum = AVR_ARGN_REGNUM;
1185 struct stack_item *si = NULL;
8818c391 1186
8818c391 1187#if 0
4add8633
TR
1188 /* FIXME: TRoth/2003-06-18: Not sure what to do when returning a struct. */
1189 if (struct_return)
8818c391 1190 {
4add8633
TR
1191 fprintf_unfiltered (gdb_stderr, "struct_return: 0x%lx\n", struct_addr);
1192 write_register (argreg--, struct_addr & 0xff);
1193 write_register (argreg--, (struct_addr >>8) & 0xff);
8818c391 1194 }
4add8633 1195#endif
8818c391 1196
4add8633 1197 for (i = 0; i < nargs; i++)
8818c391 1198 {
4add8633
TR
1199 int last_regnum;
1200 int j;
1201 struct value *arg = args[i];
1202 struct type *type = check_typedef (VALUE_TYPE (arg));
1203 char *contents = VALUE_CONTENTS (arg);
1204 int len = TYPE_LENGTH (type);
1205
1206 /* Calculate the potential last register needed. */
1207 last_regnum = regnum - (len + (len & 1));
1208
1209 /* If there are registers available, use them. Once we start putting
1210 stuff on the stack, all subsequent args go on stack. */
1211 if ((si == NULL) && (last_regnum >= 8))
1212 {
1213 ULONGEST val;
1214
1215 /* Skip a register for odd length args. */
1216 if (len & 1)
1217 regnum--;
1218
1219 val = extract_unsigned_integer (contents, len);
1220 for (j=0; j<len; j++)
1221 {
1222 regcache_cooked_write_unsigned (regcache, regnum--,
1223 val >> (8*(len-j-1)));
1224 }
1225 }
1226 /* No registers available, push the args onto the stack. */
1227 else
1228 {
1229 /* From here on, we don't care about regnum. */
1230 si = push_stack_item (si, contents, len);
1231 }
8818c391 1232 }
909cd28e 1233
4add8633
TR
1234 /* Push args onto the stack. */
1235 while (si)
1236 {
1237 sp -= si->len;
1238 /* Add 1 to sp here to account for post decr nature of pushes. */
1239 write_memory (sp+1, si->data, si->len);
1240 si = pop_stack_item (si);
1241 }
3605c34a 1242
4add8633
TR
1243 /* Set the return address. For the avr, the return address is the BP_ADDR.
1244 Need to push the return address onto the stack noting that it needs to be
1245 in big-endian order on the stack. */
1246 buf[0] = (return_pc >> 8) & 0xff;
1247 buf[1] = return_pc & 0xff;
3605c34a 1248
4add8633
TR
1249 sp -= 2;
1250 write_memory (sp+1, buf, 2); /* Add one since pushes are post decr ops. */
3605c34a 1251
4add8633
TR
1252 /* Finally, update the SP register. */
1253 regcache_cooked_write_unsigned (regcache, AVR_SP_REGNUM,
1254 avr_convert_saddr_to_raw (sp));
3605c34a 1255
4add8633 1256 return sp;
3605c34a
TR
1257}
1258
8818c391
TR
1259/* Initialize the gdbarch structure for the AVR's. */
1260
1261static struct gdbarch *
2e5ff58c
TR
1262avr_gdbarch_init (struct gdbarch_info info, struct gdbarch_list *arches)
1263{
2e5ff58c
TR
1264 struct gdbarch *gdbarch;
1265 struct gdbarch_tdep *tdep;
8818c391
TR
1266
1267 /* Find a candidate among the list of pre-declared architectures. */
1268 arches = gdbarch_list_lookup_by_info (arches, &info);
1269 if (arches != NULL)
1270 return arches->gdbarch;
1271
1272 /* None found, create a new architecture from the information provided. */
1273 tdep = XMALLOC (struct gdbarch_tdep);
1274 gdbarch = gdbarch_alloc (&info, tdep);
1275
1276 /* If we ever need to differentiate the device types, do it here. */
1277 switch (info.bfd_arch_info->mach)
1278 {
1279 case bfd_mach_avr1:
1280 case bfd_mach_avr2:
1281 case bfd_mach_avr3:
1282 case bfd_mach_avr4:
1283 case bfd_mach_avr5:
1284 break;
1285 }
1286
1287 set_gdbarch_short_bit (gdbarch, 2 * TARGET_CHAR_BIT);
1288 set_gdbarch_int_bit (gdbarch, 2 * TARGET_CHAR_BIT);
1289 set_gdbarch_long_bit (gdbarch, 4 * TARGET_CHAR_BIT);
1290 set_gdbarch_long_long_bit (gdbarch, 8 * TARGET_CHAR_BIT);
1291 set_gdbarch_ptr_bit (gdbarch, 2 * TARGET_CHAR_BIT);
1292 set_gdbarch_addr_bit (gdbarch, 32);
8818c391
TR
1293
1294 set_gdbarch_float_bit (gdbarch, 4 * TARGET_CHAR_BIT);
1295 set_gdbarch_double_bit (gdbarch, 4 * TARGET_CHAR_BIT);
1296 set_gdbarch_long_double_bit (gdbarch, 4 * TARGET_CHAR_BIT);
1297
1298 set_gdbarch_float_format (gdbarch, &floatformat_ieee_single_little);
1299 set_gdbarch_double_format (gdbarch, &floatformat_ieee_single_little);
1300 set_gdbarch_long_double_format (gdbarch, &floatformat_ieee_single_little);
1301
1302 set_gdbarch_read_pc (gdbarch, avr_read_pc);
1303 set_gdbarch_write_pc (gdbarch, avr_write_pc);
8818c391 1304 set_gdbarch_read_sp (gdbarch, avr_read_sp);
8818c391
TR
1305
1306 set_gdbarch_num_regs (gdbarch, AVR_NUM_REGS);
1307
1308 set_gdbarch_sp_regnum (gdbarch, AVR_SP_REGNUM);
8818c391
TR
1309 set_gdbarch_pc_regnum (gdbarch, AVR_PC_REGNUM);
1310
1311 set_gdbarch_register_name (gdbarch, avr_register_name);
866b76ea 1312 set_gdbarch_register_type (gdbarch, avr_register_type);
8818c391 1313
3605c34a 1314 set_gdbarch_extract_return_value (gdbarch, avr_extract_return_value);
8818c391
TR
1315 set_gdbarch_print_insn (gdbarch, print_insn_avr);
1316
4add8633 1317 set_gdbarch_push_dummy_call (gdbarch, avr_push_dummy_call);
8818c391
TR
1318
1319 set_gdbarch_address_to_pointer (gdbarch, avr_address_to_pointer);
1320 set_gdbarch_pointer_to_address (gdbarch, avr_pointer_to_address);
8818c391 1321
8818c391 1322 set_gdbarch_use_struct_convention (gdbarch, generic_use_struct_convention);
8818c391 1323
8818c391 1324 set_gdbarch_skip_prologue (gdbarch, avr_skip_prologue);
8818c391
TR
1325 set_gdbarch_inner_than (gdbarch, core_addr_lessthan);
1326
1327 set_gdbarch_decr_pc_after_break (gdbarch, 0);
909cd28e 1328 set_gdbarch_breakpoint_from_pc (gdbarch, avr_breakpoint_from_pc);
8818c391
TR
1329
1330 set_gdbarch_function_start_offset (gdbarch, 0);
98be1e77 1331
8818c391 1332 set_gdbarch_frame_args_skip (gdbarch, 0);
4add8633
TR
1333 set_gdbarch_frameless_function_invocation (gdbarch,
1334 frameless_look_for_prologue);
4add8633 1335
336d1bba 1336 frame_unwind_append_sniffer (gdbarch, avr_frame_sniffer);
4add8633
TR
1337 frame_base_set_default (gdbarch, &avr_frame_base);
1338
1339 set_gdbarch_unwind_dummy_id (gdbarch, avr_unwind_dummy_id);
1340
1341 set_gdbarch_unwind_pc (gdbarch, avr_unwind_pc);
8818c391 1342
8818c391
TR
1343 return gdbarch;
1344}
1345
1346/* Send a query request to the avr remote target asking for values of the io
1347 registers. If args parameter is not NULL, then the user has requested info
1348 on a specific io register [This still needs implemented and is ignored for
1349 now]. The query string should be one of these forms:
1350
1351 "Ravr.io_reg" -> reply is "NN" number of io registers
1352
1353 "Ravr.io_reg:addr,len" where addr is first register and len is number of
1354 registers to be read. The reply should be "<NAME>,VV;" for each io register
1355 where, <NAME> is a string, and VV is the hex value of the register.
1356
1357 All io registers are 8-bit. */
1358
1359static void
1360avr_io_reg_read_command (char *args, int from_tty)
1361{
2e5ff58c
TR
1362 int bufsiz = 0;
1363 char buf[400];
1364 char query[400];
1365 char *p;
1366 unsigned int nreg = 0;
1367 unsigned int val;
1368 int i, j, k, step;
8818c391 1369
2e5ff58c 1370 if (!current_target.to_query)
8818c391 1371 {
2e5ff58c 1372 fprintf_unfiltered (gdb_stderr,
98be1e77
TR
1373 "ERR: info io_registers NOT supported by current "
1374 "target\n");
8818c391
TR
1375 return;
1376 }
1377
1378 /* Just get the maximum buffer size. */
1379 target_query ((int) 'R', 0, 0, &bufsiz);
2e5ff58c
TR
1380 if (bufsiz > sizeof (buf))
1381 bufsiz = sizeof (buf);
8818c391
TR
1382
1383 /* Find out how many io registers the target has. */
1384 strcpy (query, "avr.io_reg");
2e5ff58c 1385 target_query ((int) 'R', query, buf, &bufsiz);
8818c391
TR
1386
1387 if (strncmp (buf, "", bufsiz) == 0)
1388 {
2e5ff58c
TR
1389 fprintf_unfiltered (gdb_stderr,
1390 "info io_registers NOT supported by target\n");
8818c391
TR
1391 return;
1392 }
1393
2e5ff58c 1394 if (sscanf (buf, "%x", &nreg) != 1)
8818c391 1395 {
2e5ff58c
TR
1396 fprintf_unfiltered (gdb_stderr,
1397 "Error fetching number of io registers\n");
8818c391
TR
1398 return;
1399 }
1400
2e5ff58c 1401 reinitialize_more_filter ();
8818c391
TR
1402
1403 printf_unfiltered ("Target has %u io registers:\n\n", nreg);
1404
1405 /* only fetch up to 8 registers at a time to keep the buffer small */
1406 step = 8;
1407
2e5ff58c 1408 for (i = 0; i < nreg; i += step)
8818c391 1409 {
91ccbfc1
TR
1410 /* how many registers this round? */
1411 j = step;
1412 if ((i+j) >= nreg)
1413 j = nreg - i; /* last block is less than 8 registers */
8818c391 1414
2e5ff58c 1415 snprintf (query, sizeof (query) - 1, "avr.io_reg:%x,%x", i, j);
8818c391
TR
1416 target_query ((int) 'R', query, buf, &bufsiz);
1417
1418 p = buf;
2e5ff58c
TR
1419 for (k = i; k < (i + j); k++)
1420 {
1421 if (sscanf (p, "%[^,],%x;", query, &val) == 2)
1422 {
1423 printf_filtered ("[%02x] %-15s : %02x\n", k, query, val);
1424 while ((*p != ';') && (*p != '\0'))
1425 p++;
1426 p++; /* skip over ';' */
1427 if (*p == '\0')
1428 break;
1429 }
1430 }
8818c391
TR
1431 }
1432}
1433
a78f21af
AC
1434extern initialize_file_ftype _initialize_avr_tdep; /* -Wmissing-prototypes */
1435
8818c391
TR
1436void
1437_initialize_avr_tdep (void)
1438{
1439 register_gdbarch_init (bfd_arch_avr, avr_gdbarch_init);
1440
1441 /* Add a new command to allow the user to query the avr remote target for
1442 the values of the io space registers in a saner way than just using
1443 `x/NNNb ADDR`. */
1444
1445 /* FIXME: TRoth/2002-02-18: This should probably be changed to 'info avr
1446 io_registers' to signify it is not available on other platforms. */
1447
1448 add_cmd ("io_registers", class_info, avr_io_reg_read_command,
2e5ff58c 1449 "query remote avr target for io space register values", &infolist);
8818c391 1450}
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