1 /* Target-dependent code for Atmel AVR, for GDB.
2 Copyright 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003
3 Free Software Foundation, Inc.
5 This file is part of GDB.
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.
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.
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. */
22 /* Contributed by Theodore A. Roth, troth@openavr.org */
24 /* Portions of this file were taken from the original gdb-4.18 patch developed
25 by Denis Chertykov, denisc@overta.ru */
32 #include "arch-utils.h"
34 #include "gdb_string.h"
38 (AVR micros are pure Harvard Architecture processors.)
40 The AVR family of microcontrollers have three distinctly different memory
41 spaces: flash, sram and eeprom. The flash is 16 bits wide and is used for
42 the most part to store program instructions. The sram is 8 bits wide and is
43 used for the stack and the heap. Some devices lack sram and some can have
44 an additional external sram added on as a peripheral.
46 The eeprom is 8 bits wide and is used to store data when the device is
47 powered down. Eeprom is not directly accessible, it can only be accessed
48 via io-registers using a special algorithm. Accessing eeprom via gdb's
49 remote serial protocol ('m' or 'M' packets) looks difficult to do and is
50 not included at this time.
52 [The eeprom could be read manually via ``x/b <eaddr + AVR_EMEM_START>'' or
53 written using ``set {unsigned char}<eaddr + AVR_EMEM_START>''. For this to
54 work, the remote target must be able to handle eeprom accesses and perform
55 the address translation.]
57 All three memory spaces have physical addresses beginning at 0x0. In
58 addition, the flash is addressed by gcc/binutils/gdb with respect to 8 bit
59 bytes instead of the 16 bit wide words used by the real device for the
62 In order for remote targets to work correctly, extra bits must be added to
63 addresses before they are send to the target or received from the target
64 via the remote serial protocol. The extra bits are the MSBs and are used to
65 decode which memory space the address is referring to. */
68 #define XMALLOC(TYPE) ((TYPE*) xmalloc (sizeof (TYPE)))
71 #define EXTRACT_INSN(addr) extract_unsigned_integer(addr,2)
73 /* Constants: prefixed with AVR_ to avoid name space clashes */
87 AVR_NUM_REGS
= 32 + 1 /*SREG*/ + 1 /*SP*/ + 1 /*PC*/,
88 AVR_NUM_REG_BYTES
= 32 + 1 /*SREG*/ + 2 /*SP*/ + 4 /*PC*/,
90 AVR_PC_REG_INDEX
= 35, /* index into array of registers */
92 AVR_MAX_PROLOGUE_SIZE
= 56, /* bytes */
94 /* Count of pushed registers. From r2 to r17 (inclusively), r28, r29 */
97 /* Number of the last pushed register. r17 for current avr-gcc */
98 AVR_LAST_PUSHED_REGNUM
= 17,
100 /* FIXME: TRoth/2002-01-??: Can we shift all these memory masks left 8
101 bits? Do these have to match the bfd vma values?. It sure would make
102 things easier in the future if they didn't need to match.
104 Note: I chose these values so as to be consistent with bfd vma
107 TRoth/2002-04-08: There is already a conflict with very large programs
108 in the mega128. The mega128 has 128K instruction bytes (64K words),
109 thus the Most Significant Bit is 0x10000 which gets masked off my
112 The problem manifests itself when trying to set a breakpoint in a
113 function which resides in the upper half of the instruction space and
114 thus requires a 17-bit address.
116 For now, I've just removed the EEPROM mask and changed AVR_MEM_MASK
117 from 0x00ff0000 to 0x00f00000. Eeprom is not accessible from gdb yet,
118 but could be for some remote targets by just adding the correct offset
119 to the address and letting the remote target handle the low-level
120 details of actually accessing the eeprom. */
122 AVR_IMEM_START
= 0x00000000, /* INSN memory */
123 AVR_SMEM_START
= 0x00800000, /* SRAM memory */
125 /* No eeprom mask defined */
126 AVR_MEM_MASK
= 0x00f00000, /* mask to determine memory space */
128 AVR_EMEM_START
= 0x00810000, /* EEPROM memory */
129 AVR_MEM_MASK
= 0x00ff0000, /* mask to determine memory space */
133 /* Any function with a frame looks like this
134 ....... <-SP POINTS HERE
135 LOCALS1 <-FP POINTS HERE
144 struct frame_extra_info
147 CORE_ADDR args_pointer
;
156 /* FIXME: TRoth: is there anything to put here? */
160 /* Lookup the name of a register given it's number. */
163 avr_register_name (int regnum
)
165 static char *register_names
[] = {
166 "r0", "r1", "r2", "r3", "r4", "r5", "r6", "r7",
167 "r8", "r9", "r10", "r11", "r12", "r13", "r14", "r15",
168 "r16", "r17", "r18", "r19", "r20", "r21", "r22", "r23",
169 "r24", "r25", "r26", "r27", "r28", "r29", "r30", "r31",
174 if (regnum
>= (sizeof (register_names
) / sizeof (*register_names
)))
176 return register_names
[regnum
];
179 /* Index within `registers' of the first byte of the space for
183 avr_register_byte (int regnum
)
185 if (regnum
< AVR_PC_REGNUM
)
188 return AVR_PC_REG_INDEX
;
191 /* Number of bytes of storage in the actual machine representation for
195 avr_register_raw_size (int regnum
)
209 /* Number of bytes of storage in the program's representation
213 avr_register_virtual_size (int regnum
)
215 return TYPE_LENGTH (REGISTER_VIRTUAL_TYPE (regnum
));
218 /* Return the GDB type object for the "standard" data type
219 of data in register N. */
222 avr_register_virtual_type (int regnum
)
227 return builtin_type_unsigned_long
;
229 return builtin_type_unsigned_short
;
231 return builtin_type_unsigned_char
;
235 /* Instruction address checks and convertions. */
238 avr_make_iaddr (CORE_ADDR x
)
240 return ((x
) | AVR_IMEM_START
);
244 avr_iaddr_p (CORE_ADDR x
)
246 return (((x
) & AVR_MEM_MASK
) == AVR_IMEM_START
);
249 /* FIXME: TRoth: Really need to use a larger mask for instructions. Some
250 devices are already up to 128KBytes of flash space.
252 TRoth/2002-04-8: See comment above where AVR_IMEM_START is defined. */
255 avr_convert_iaddr_to_raw (CORE_ADDR x
)
257 return ((x
) & 0xffffffff);
260 /* SRAM address checks and convertions. */
263 avr_make_saddr (CORE_ADDR x
)
265 return ((x
) | AVR_SMEM_START
);
269 avr_saddr_p (CORE_ADDR x
)
271 return (((x
) & AVR_MEM_MASK
) == AVR_SMEM_START
);
275 avr_convert_saddr_to_raw (CORE_ADDR x
)
277 return ((x
) & 0xffffffff);
280 /* EEPROM address checks and convertions. I don't know if these will ever
281 actually be used, but I've added them just the same. TRoth */
283 /* TRoth/2002-04-08: Commented out for now to allow fix for problem with large
284 programs in the mega128. */
286 /* static CORE_ADDR */
287 /* avr_make_eaddr (CORE_ADDR x) */
289 /* return ((x) | AVR_EMEM_START); */
293 /* avr_eaddr_p (CORE_ADDR x) */
295 /* return (((x) & AVR_MEM_MASK) == AVR_EMEM_START); */
298 /* static CORE_ADDR */
299 /* avr_convert_eaddr_to_raw (CORE_ADDR x) */
301 /* return ((x) & 0xffffffff); */
304 /* Convert from address to pointer and vice-versa. */
307 avr_address_to_pointer (struct type
*type
, void *buf
, CORE_ADDR addr
)
309 /* Is it a code address? */
310 if (TYPE_CODE (TYPE_TARGET_TYPE (type
)) == TYPE_CODE_FUNC
311 || TYPE_CODE (TYPE_TARGET_TYPE (type
)) == TYPE_CODE_METHOD
)
313 store_unsigned_integer (buf
, TYPE_LENGTH (type
),
314 avr_convert_iaddr_to_raw (addr
>> 1));
318 /* Strip off any upper segment bits. */
319 store_unsigned_integer (buf
, TYPE_LENGTH (type
),
320 avr_convert_saddr_to_raw (addr
));
325 avr_pointer_to_address (struct type
*type
, const void *buf
)
327 CORE_ADDR addr
= extract_unsigned_integer (buf
, TYPE_LENGTH (type
));
329 if (TYPE_CODE_SPACE (TYPE_TARGET_TYPE (type
)))
331 fprintf_unfiltered (gdb_stderr
, "CODE_SPACE ---->> ptr->addr: 0x%lx\n",
333 fprintf_unfiltered (gdb_stderr
,
334 "+++ If you see this, please send me an email <troth@openavr.org>\n");
337 /* Is it a code address? */
338 if (TYPE_CODE (TYPE_TARGET_TYPE (type
)) == TYPE_CODE_FUNC
339 || TYPE_CODE (TYPE_TARGET_TYPE (type
)) == TYPE_CODE_METHOD
340 || TYPE_CODE_SPACE (TYPE_TARGET_TYPE (type
)))
341 return avr_make_iaddr (addr
<< 1);
343 return avr_make_saddr (addr
);
347 avr_read_pc (ptid_t ptid
)
353 save_ptid
= inferior_ptid
;
354 inferior_ptid
= ptid
;
355 pc
= (int) read_register (AVR_PC_REGNUM
);
356 inferior_ptid
= save_ptid
;
357 retval
= avr_make_iaddr (pc
);
362 avr_write_pc (CORE_ADDR val
, ptid_t ptid
)
366 save_ptid
= inferior_ptid
;
367 inferior_ptid
= ptid
;
368 write_register (AVR_PC_REGNUM
, avr_convert_iaddr_to_raw (val
));
369 inferior_ptid
= save_ptid
;
375 return (avr_make_saddr (read_register (AVR_SP_REGNUM
)));
379 avr_write_sp (CORE_ADDR val
)
381 write_register (AVR_SP_REGNUM
, avr_convert_saddr_to_raw (val
));
387 return (avr_make_saddr (read_register (AVR_FP_REGNUM
)));
390 /* Translate a GDB virtual ADDR/LEN into a format the remote target
391 understands. Returns number of bytes that can be transfered
392 starting at TARG_ADDR. Return ZERO if no bytes can be transfered
393 (segmentation fault).
395 TRoth/2002-04-08: Could this be used to check for dereferencing an invalid
399 avr_remote_translate_xfer_address (struct gdbarch
*gdbarch
,
400 struct regcache
*regcache
,
401 CORE_ADDR memaddr
, int nr_bytes
,
402 CORE_ADDR
*targ_addr
, int *targ_len
)
407 /* FIXME: TRoth: Do nothing for now. Will need to examine memaddr at this
408 point and see if the high bit are set with the masks that we want. */
410 *targ_addr
= memaddr
;
411 *targ_len
= nr_bytes
;
414 /* avr_scan_prologue is also used as the
415 deprecated_frame_init_saved_regs().
417 Put here the code to store, into fi->saved_regs, the addresses of
418 the saved registers of frame described by FRAME_INFO. This
419 includes special registers such as pc and fp saved in special ways
420 in the stack frame. sp is even more special: the address we return
421 for it IS the sp for the next frame. */
423 /* Function: avr_scan_prologue (helper function for avr_init_extra_frame_info)
424 This function decodes a AVR function prologue to determine:
425 1) the size of the stack frame
426 2) which registers are saved on it
427 3) the offsets of saved regs
428 This information is stored in the "extra_info" field of the frame_info.
430 A typical AVR function prologue might look like this:
436 sbiw r28,<LOCALS_SIZE>
437 in __tmp_reg__,__SREG__
440 out __SREG__,__tmp_reg__
443 A `-mcall-prologues' prologue look like this:
444 ldi r26,<LOCALS_SIZE>
445 ldi r27,<LOCALS_SIZE>/265
446 ldi r30,pm_lo8(.L_foo_body)
447 ldi r31,pm_hi8(.L_foo_body)
448 rjmp __prologue_saves__+RRR
452 avr_scan_prologue (struct frame_info
*fi
)
454 CORE_ADDR prologue_start
;
455 CORE_ADDR prologue_end
;
461 struct minimal_symbol
*msymbol
;
463 unsigned char prologue
[AVR_MAX_PROLOGUE_SIZE
];
466 get_frame_extra_info (fi
)->framereg
= AVR_SP_REGNUM
;
468 if (find_pc_partial_function
469 (get_frame_pc (fi
), &name
, &prologue_start
, &prologue_end
))
471 struct symtab_and_line sal
= find_pc_line (prologue_start
, 0);
473 if (sal
.line
== 0) /* no line info, use current PC */
474 prologue_end
= get_frame_pc (fi
);
475 else if (sal
.end
< prologue_end
) /* next line begins after fn end */
476 prologue_end
= sal
.end
; /* (probably means no prologue) */
479 /* We're in the boondocks: allow for */
480 /* 19 pushes, an add, and "mv fp,sp" */
481 prologue_end
= prologue_start
+ AVR_MAX_PROLOGUE_SIZE
;
483 prologue_end
= min (prologue_end
, get_frame_pc (fi
));
485 /* Search the prologue looking for instructions that set up the
486 frame pointer, adjust the stack pointer, and save registers. */
488 get_frame_extra_info (fi
)->framesize
= 0;
489 prologue_len
= prologue_end
- prologue_start
;
490 read_memory (prologue_start
, prologue
, prologue_len
);
492 /* Scanning main()'s prologue
493 ldi r28,lo8(<RAM_ADDR> - <LOCALS_SIZE>)
494 ldi r29,hi8(<RAM_ADDR> - <LOCALS_SIZE>)
498 if (name
&& strcmp ("main", name
) == 0 && prologue_len
== 8)
501 unsigned char img
[] = {
502 0xde, 0xbf, /* out __SP_H__,r29 */
503 0xcd, 0xbf /* out __SP_L__,r28 */
506 get_frame_extra_info (fi
)->framereg
= AVR_FP_REGNUM
;
507 insn
= EXTRACT_INSN (&prologue
[vpc
]);
508 /* ldi r28,lo8(<RAM_ADDR> - <LOCALS_SIZE>) */
509 if ((insn
& 0xf0f0) == 0xe0c0)
511 locals
= (insn
& 0xf) | ((insn
& 0x0f00) >> 4);
512 insn
= EXTRACT_INSN (&prologue
[vpc
+ 2]);
513 /* ldi r29,hi8(<RAM_ADDR> - <LOCALS_SIZE>) */
514 if ((insn
& 0xf0f0) == 0xe0d0)
516 locals
|= ((insn
& 0xf) | ((insn
& 0x0f00) >> 4)) << 8;
517 if (memcmp (prologue
+ vpc
+ 4, img
, sizeof (img
)) == 0)
519 deprecated_update_frame_base_hack (fi
, locals
);
521 get_frame_extra_info (fi
)->is_main
= 1;
528 /* Scanning `-mcall-prologues' prologue
529 FIXME: mega prologue have a 12 bytes long */
531 while (prologue_len
<= 12) /* I'm use while to avoit many goto's */
537 insn
= EXTRACT_INSN (&prologue
[vpc
]);
538 /* ldi r26,<LOCALS_SIZE> */
539 if ((insn
& 0xf0f0) != 0xe0a0)
541 loc_size
= (insn
& 0xf) | ((insn
& 0x0f00) >> 4);
543 insn
= EXTRACT_INSN (&prologue
[vpc
+ 2]);
544 /* ldi r27,<LOCALS_SIZE> / 256 */
545 if ((insn
& 0xf0f0) != 0xe0b0)
547 loc_size
|= ((insn
& 0xf) | ((insn
& 0x0f00) >> 4)) << 8;
549 insn
= EXTRACT_INSN (&prologue
[vpc
+ 4]);
550 /* ldi r30,pm_lo8(.L_foo_body) */
551 if ((insn
& 0xf0f0) != 0xe0e0)
553 body_addr
= (insn
& 0xf) | ((insn
& 0x0f00) >> 4);
555 insn
= EXTRACT_INSN (&prologue
[vpc
+ 6]);
556 /* ldi r31,pm_hi8(.L_foo_body) */
557 if ((insn
& 0xf0f0) != 0xe0f0)
559 body_addr
|= ((insn
& 0xf) | ((insn
& 0x0f00) >> 4)) << 8;
561 if (body_addr
!= (prologue_start
+ 10) / 2)
564 msymbol
= lookup_minimal_symbol ("__prologue_saves__", NULL
, NULL
);
568 /* FIXME: prologue for mega have a JMP instead of RJMP */
569 insn
= EXTRACT_INSN (&prologue
[vpc
+ 8]);
570 /* rjmp __prologue_saves__+RRR */
571 if ((insn
& 0xf000) != 0xc000)
574 /* Extract PC relative offset from RJMP */
575 i
= (insn
& 0xfff) | (insn
& 0x800 ? (-1 ^ 0xfff) : 0);
576 /* Convert offset to byte addressable mode */
578 /* Destination address */
579 i
+= vpc
+ prologue_start
+ 10;
580 /* Resovle offset (in words) from __prologue_saves__ symbol.
581 Which is a pushes count in `-mcall-prologues' mode */
582 num_pushes
= AVR_MAX_PUSHES
- (i
- SYMBOL_VALUE_ADDRESS (msymbol
)) / 2;
584 if (num_pushes
> AVR_MAX_PUSHES
)
590 get_frame_saved_regs (fi
)[AVR_FP_REGNUM
+ 1] = num_pushes
;
592 get_frame_saved_regs (fi
)[AVR_FP_REGNUM
] = num_pushes
- 1;
594 for (from
= AVR_LAST_PUSHED_REGNUM
+ 1 - (num_pushes
- 2);
595 from
<= AVR_LAST_PUSHED_REGNUM
; ++from
)
596 get_frame_saved_regs (fi
)[from
] = ++i
;
598 get_frame_extra_info (fi
)->locals_size
= loc_size
;
599 get_frame_extra_info (fi
)->framesize
= loc_size
+ num_pushes
;
600 get_frame_extra_info (fi
)->framereg
= AVR_FP_REGNUM
;
604 /* Scan interrupt or signal function */
606 if (prologue_len
>= 12)
608 unsigned char img
[] = {
609 0x78, 0x94, /* sei */
610 0x1f, 0x92, /* push r1 */
611 0x0f, 0x92, /* push r0 */
612 0x0f, 0xb6, /* in r0,0x3f SREG */
613 0x0f, 0x92, /* push r0 */
614 0x11, 0x24 /* clr r1 */
616 if (memcmp (prologue
, img
, sizeof (img
)) == 0)
619 get_frame_saved_regs (fi
)[0] = 2;
620 get_frame_saved_regs (fi
)[1] = 1;
621 get_frame_extra_info (fi
)->framesize
+= 3;
623 else if (memcmp (img
+ 1, prologue
, sizeof (img
) - 1) == 0)
625 vpc
+= sizeof (img
) - 1;
626 get_frame_saved_regs (fi
)[0] = 2;
627 get_frame_saved_regs (fi
)[1] = 1;
628 get_frame_extra_info (fi
)->framesize
+= 3;
632 /* First stage of the prologue scanning.
635 for (; vpc
<= prologue_len
; vpc
+= 2)
637 insn
= EXTRACT_INSN (&prologue
[vpc
]);
638 if ((insn
& 0xfe0f) == 0x920f) /* push rXX */
640 /* Bits 4-9 contain a mask for registers R0-R32. */
641 regno
= (insn
& 0x1f0) >> 4;
642 ++get_frame_extra_info (fi
)->framesize
;
643 get_frame_saved_regs (fi
)[regno
] = get_frame_extra_info (fi
)->framesize
;
650 /* Second stage of the prologue scanning.
655 if (scan_stage
== 1 && vpc
+ 4 <= prologue_len
)
657 unsigned char img
[] = {
658 0xcd, 0xb7, /* in r28,__SP_L__ */
659 0xde, 0xb7 /* in r29,__SP_H__ */
661 unsigned short insn1
;
663 if (memcmp (prologue
+ vpc
, img
, sizeof (img
)) == 0)
666 get_frame_extra_info (fi
)->framereg
= AVR_FP_REGNUM
;
671 /* Third stage of the prologue scanning. (Really two stages)
673 sbiw r28,XX or subi r28,lo8(XX)
675 in __tmp_reg__,__SREG__
678 out __SREG__,__tmp_reg__
681 if (scan_stage
== 2 && vpc
+ 12 <= prologue_len
)
684 unsigned char img
[] = {
685 0x0f, 0xb6, /* in r0,0x3f */
686 0xf8, 0x94, /* cli */
687 0xcd, 0xbf, /* out 0x3d,r28 ; SPL */
688 0x0f, 0xbe, /* out 0x3f,r0 ; SREG */
689 0xde, 0xbf /* out 0x3e,r29 ; SPH */
691 unsigned char img_sig
[] = {
692 0xcd, 0xbf, /* out 0x3d,r28 ; SPL */
693 0xde, 0xbf /* out 0x3e,r29 ; SPH */
695 unsigned char img_int
[] = {
696 0xf8, 0x94, /* cli */
697 0xcd, 0xbf, /* out 0x3d,r28 ; SPL */
698 0x78, 0x94, /* sei */
699 0xde, 0xbf /* out 0x3e,r29 ; SPH */
702 insn
= EXTRACT_INSN (&prologue
[vpc
]);
704 if ((insn
& 0xff30) == 0x9720) /* sbiw r28,XXX */
705 locals_size
= (insn
& 0xf) | ((insn
& 0xc0) >> 2);
706 else if ((insn
& 0xf0f0) == 0x50c0) /* subi r28,lo8(XX) */
708 locals_size
= (insn
& 0xf) | ((insn
& 0xf00) >> 4);
709 insn
= EXTRACT_INSN (&prologue
[vpc
]);
711 locals_size
+= ((insn
& 0xf) | ((insn
& 0xf00) >> 4) << 8);
715 get_frame_extra_info (fi
)->locals_size
= locals_size
;
716 get_frame_extra_info (fi
)->framesize
+= locals_size
;
720 /* This function actually figures out the frame address for a given pc and
721 sp. This is tricky because we sometimes don't use an explicit
722 frame pointer, and the previous stack pointer isn't necessarily recorded
723 on the stack. The only reliable way to get this info is to
724 examine the prologue. */
727 avr_init_extra_frame_info (int fromleaf
, struct frame_info
*fi
)
731 if (get_next_frame (fi
))
732 deprecated_update_frame_pc_hack (fi
, DEPRECATED_FRAME_SAVED_PC (get_next_frame (fi
)));
734 frame_extra_info_zalloc (fi
, sizeof (struct frame_extra_info
));
735 frame_saved_regs_zalloc (fi
);
737 get_frame_extra_info (fi
)->return_pc
= 0;
738 get_frame_extra_info (fi
)->args_pointer
= 0;
739 get_frame_extra_info (fi
)->locals_size
= 0;
740 get_frame_extra_info (fi
)->framereg
= 0;
741 get_frame_extra_info (fi
)->framesize
= 0;
742 get_frame_extra_info (fi
)->is_main
= 0;
744 avr_scan_prologue (fi
);
746 if (DEPRECATED_PC_IN_CALL_DUMMY (get_frame_pc (fi
), get_frame_base (fi
),
747 get_frame_base (fi
)))
749 /* We need to setup fi->frame here because call_function_by_hand
750 gets it wrong by assuming it's always FP. */
751 deprecated_update_frame_base_hack (fi
, deprecated_read_register_dummy (get_frame_pc (fi
), get_frame_base (fi
),
754 else if (!get_next_frame (fi
))
755 /* this is the innermost frame? */
756 deprecated_update_frame_base_hack (fi
, read_register (get_frame_extra_info (fi
)->framereg
));
757 else if (get_frame_extra_info (fi
)->is_main
!= 1)
758 /* not the innermost frame, not `main' */
759 /* If we have an next frame, the callee saved it. */
761 struct frame_info
*next_fi
= get_next_frame (fi
);
762 if (get_frame_extra_info (fi
)->framereg
== AVR_SP_REGNUM
)
763 deprecated_update_frame_base_hack (fi
, (get_frame_base (next_fi
)
765 + get_frame_extra_info (next_fi
)->framesize
));
766 /* FIXME: I don't analyse va_args functions */
771 unsigned int fp_low
, fp_high
;
773 /* Scan all frames */
774 for (; next_fi
; next_fi
= get_next_frame (next_fi
))
776 /* look for saved AVR_FP_REGNUM */
777 if (get_frame_saved_regs (next_fi
)[AVR_FP_REGNUM
] && !fp
)
778 fp
= get_frame_saved_regs (next_fi
)[AVR_FP_REGNUM
];
779 /* look for saved AVR_FP_REGNUM + 1 */
780 if (get_frame_saved_regs (next_fi
)[AVR_FP_REGNUM
+ 1] && !fp1
)
781 fp1
= get_frame_saved_regs (next_fi
)[AVR_FP_REGNUM
+ 1];
783 fp_low
= (fp
? read_memory_unsigned_integer (avr_make_saddr (fp
), 1)
784 : read_register (AVR_FP_REGNUM
)) & 0xff;
786 (fp1
? read_memory_unsigned_integer (avr_make_saddr (fp1
), 1) :
787 read_register (AVR_FP_REGNUM
+ 1)) & 0xff;
788 deprecated_update_frame_base_hack (fi
, fp_low
| (fp_high
<< 8));
792 /* TRoth: Do we want to do this if we are in main? I don't think we should
793 since return_pc makes no sense when we are in main. */
795 if ((get_frame_pc (fi
)) && (get_frame_extra_info (fi
)->is_main
== 0))
796 /* We are not in CALL_DUMMY */
801 addr
= get_frame_base (fi
) + get_frame_extra_info (fi
)->framesize
+ 1;
803 /* Return address in stack in different endianness */
805 get_frame_extra_info (fi
)->return_pc
=
806 read_memory_unsigned_integer (avr_make_saddr (addr
), 1) << 8;
807 get_frame_extra_info (fi
)->return_pc
|=
808 read_memory_unsigned_integer (avr_make_saddr (addr
+ 1), 1);
810 /* This return address in words,
811 must be converted to the bytes address */
812 get_frame_extra_info (fi
)->return_pc
*= 2;
814 /* Resolve a pushed registers addresses */
815 for (i
= 0; i
< NUM_REGS
; i
++)
817 if (get_frame_saved_regs (fi
)[i
])
818 get_frame_saved_regs (fi
)[i
] = addr
- get_frame_saved_regs (fi
)[i
];
823 /* Restore the machine to the state it had before the current frame was
824 created. Usually used either by the "RETURN" command, or by
825 call_function_by_hand after the dummy_frame is finished. */
832 struct frame_info
*frame
= get_current_frame ();
834 if (DEPRECATED_PC_IN_CALL_DUMMY (get_frame_pc (frame
),
835 get_frame_base (frame
),
836 get_frame_base (frame
)))
838 generic_pop_dummy_frame ();
842 /* TRoth: Why only loop over 8 registers? */
844 for (regnum
= 0; regnum
< 8; regnum
++)
846 /* Don't forget AVR_SP_REGNUM in a frame_saved_regs struct is the
847 actual value we want, not the address of the value we want. */
848 if (get_frame_saved_regs (frame
)[regnum
] && regnum
!= AVR_SP_REGNUM
)
850 saddr
= avr_make_saddr (get_frame_saved_regs (frame
)[regnum
]);
851 write_register (regnum
,
852 read_memory_unsigned_integer (saddr
, 1));
854 else if (get_frame_saved_regs (frame
)[regnum
] && regnum
== AVR_SP_REGNUM
)
855 write_register (regnum
, get_frame_base (frame
) + 2);
858 /* Don't forget the update the PC too! */
859 write_pc (get_frame_extra_info (frame
)->return_pc
);
861 flush_cached_frames ();
864 /* Return the saved PC from this frame. */
867 avr_frame_saved_pc (struct frame_info
*frame
)
869 if (DEPRECATED_PC_IN_CALL_DUMMY (get_frame_pc (frame
),
870 get_frame_base (frame
),
871 get_frame_base (frame
)))
872 return deprecated_read_register_dummy (get_frame_pc (frame
),
873 get_frame_base (frame
),
876 return get_frame_extra_info (frame
)->return_pc
;
880 avr_saved_pc_after_call (struct frame_info
*frame
)
882 unsigned char m1
, m2
;
883 unsigned int sp
= read_register (AVR_SP_REGNUM
);
884 m1
= read_memory_unsigned_integer (avr_make_saddr (sp
+ 1), 1);
885 m2
= read_memory_unsigned_integer (avr_make_saddr (sp
+ 2), 1);
886 return (m2
| (m1
<< 8)) * 2;
889 /* Returns the return address for a dummy. */
892 avr_call_dummy_address (void)
894 return entry_point_address ();
897 /* Setup the return address for a dummy frame, as called by
898 call_function_by_hand. Only necessary when you are using an empty
902 avr_push_return_address (CORE_ADDR pc
, CORE_ADDR sp
)
904 unsigned char buf
[2];
907 struct minimal_symbol
*msymbol
;
914 write_memory (sp
+ 1, buf
, 2);
917 /* FIXME: TRoth/2002-02-18: This should probably be removed since it's a
918 left-over from Denis' original patch which used avr-mon for the target
919 instead of the generic remote target. */
920 if ((strcmp (target_shortname
, "avr-mon") == 0)
921 && (msymbol
= lookup_minimal_symbol ("gdb_break", NULL
, NULL
)))
923 mon_brk
= SYMBOL_VALUE_ADDRESS (msymbol
);
924 store_unsigned_integer (buf
, wordsize
, mon_brk
/ 2);
926 write_memory (sp
+ 1, buf
+ 1, 1);
927 write_memory (sp
+ 2, buf
, 1);
934 avr_skip_prologue (CORE_ADDR pc
)
936 CORE_ADDR func_addr
, func_end
;
937 struct symtab_and_line sal
;
939 /* See what the symbol table says */
941 if (find_pc_partial_function (pc
, NULL
, &func_addr
, &func_end
))
943 sal
= find_pc_line (func_addr
, 0);
945 /* troth/2002-08-05: For some very simple functions, gcc doesn't
946 generate a prologue and the sal.end ends up being the 2-byte ``ret''
947 instruction at the end of the function, but func_end ends up being
948 the address of the first instruction of the _next_ function. By
949 adjusting func_end by 2 bytes, we can catch these functions and not
950 return sal.end if it is the ``ret'' instruction. */
952 if (sal
.line
!= 0 && sal
.end
< (func_end
-2))
956 /* Either we didn't find the start of this function (nothing we can do),
957 or there's no line info, or the line after the prologue is after
958 the end of the function (there probably isn't a prologue). */
964 avr_frame_address (struct frame_info
*fi
)
966 return avr_make_saddr (get_frame_base (fi
));
969 /* Given a GDB frame, determine the address of the calling function's
970 frame. This will be used to create a new GDB frame struct, and
971 then DEPRECATED_INIT_EXTRA_FRAME_INFO and DEPRECATED_INIT_FRAME_PC
972 will be called for the new frame.
974 For us, the frame address is its stack pointer value, so we look up
975 the function prologue to determine the caller's sp value, and return it. */
978 avr_frame_chain (struct frame_info
*frame
)
980 if (DEPRECATED_PC_IN_CALL_DUMMY (get_frame_pc (frame
),
981 get_frame_base (frame
),
982 get_frame_base (frame
)))
984 /* initialize the return_pc now */
985 get_frame_extra_info (frame
)->return_pc
986 = deprecated_read_register_dummy (get_frame_pc (frame
),
987 get_frame_base (frame
),
989 return get_frame_base (frame
);
991 return (get_frame_extra_info (frame
)->is_main
? 0
992 : get_frame_base (frame
) + get_frame_extra_info (frame
)->framesize
+ 2 /* ret addr */ );
995 /* Store the address of the place in which to copy the structure the
996 subroutine will return. This is called from call_function.
998 We store structs through a pointer passed in the first Argument
1002 avr_store_struct_return (CORE_ADDR addr
, CORE_ADDR sp
)
1004 write_register (0, addr
);
1007 /* Setup the function arguments for calling a function in the inferior.
1009 On the AVR architecture, there are 18 registers (R25 to R8) which are
1010 dedicated for passing function arguments. Up to the first 18 arguments
1011 (depending on size) may go into these registers. The rest go on the stack.
1013 Arguments that are larger than WORDSIZE bytes will be split between two or
1014 more registers as available, but will NOT be split between a register and
1017 An exceptional case exists for struct arguments (and possibly other
1018 aggregates such as arrays) -- if the size is larger than WORDSIZE bytes but
1019 not a multiple of WORDSIZE bytes. In this case the argument is never split
1020 between the registers and the stack, but instead is copied in its entirety
1021 onto the stack, AND also copied into as many registers as there is room
1022 for. In other words, space in registers permitting, two copies of the same
1023 argument are passed in. As far as I can tell, only the one on the stack is
1024 used, although that may be a function of the level of compiler
1025 optimization. I suspect this is a compiler bug. Arguments of these odd
1026 sizes are left-justified within the word (as opposed to arguments smaller
1027 than WORDSIZE bytes, which are right-justified).
1029 If the function is to return an aggregate type such as a struct, the caller
1030 must allocate space into which the callee will copy the return value. In
1031 this case, a pointer to the return value location is passed into the callee
1032 in register R0, which displaces one of the other arguments passed in via
1033 registers R0 to R2. */
1036 avr_push_arguments (int nargs
, struct value
**args
, CORE_ADDR sp
,
1037 int struct_return
, CORE_ADDR struct_addr
)
1039 int stack_alloc
, stack_offset
;
1051 /* Now make sure there's space on the stack */
1052 for (argnum
= 0, stack_alloc
= 0; argnum
< nargs
; argnum
++)
1053 stack_alloc
+= TYPE_LENGTH (VALUE_TYPE (args
[argnum
]));
1054 sp
-= stack_alloc
; /* make room on stack for args */
1055 /* we may over-allocate a little here, but that won't hurt anything */
1058 if (struct_return
) /* "struct return" pointer takes up one argreg */
1060 write_register (--argreg
, struct_addr
);
1063 /* Now load as many as possible of the first arguments into registers, and
1064 push the rest onto the stack. There are 3N bytes in three registers
1065 available. Loop thru args from first to last. */
1067 for (argnum
= 0, stack_offset
= 0; argnum
< nargs
; argnum
++)
1069 type
= VALUE_TYPE (args
[argnum
]);
1070 len
= TYPE_LENGTH (type
);
1071 val
= (char *) VALUE_CONTENTS (args
[argnum
]);
1073 /* NOTE WELL!!!!! This is not an "else if" clause!!! That's because
1074 some *&^%$ things get passed on the stack AND in the registers! */
1076 { /* there's room in registers */
1078 regval
= extract_unsigned_integer (val
+ len
, wordsize
);
1079 write_register (argreg
--, regval
);
1085 /* Not all avr devices support the BREAK insn. Those that don't should treat
1086 it as a NOP. Thus, it should be ok. Since the avr is currently a remote
1087 only target, this shouldn't be a problem (I hope). TRoth/2003-05-14 */
1089 static const unsigned char *
1090 avr_breakpoint_from_pc (CORE_ADDR
* pcptr
, int *lenptr
)
1092 static unsigned char avr_break_insn
[] = { 0x98, 0x95 };
1093 *lenptr
= sizeof (avr_break_insn
);
1094 return avr_break_insn
;
1097 /* Initialize the gdbarch structure for the AVR's. */
1099 static struct gdbarch
*
1100 avr_gdbarch_init (struct gdbarch_info info
, struct gdbarch_list
*arches
)
1102 /* FIXME: TRoth/2002-02-18: I have no idea if avr_call_dummy_words[] should
1103 be bigger or not. Initial testing seems to show that `call my_func()`
1104 works and backtrace from a breakpoint within the call looks correct.
1105 Admittedly, I haven't tested with more than a very simple program. */
1106 static LONGEST avr_call_dummy_words
[] = { 0 };
1108 struct gdbarch
*gdbarch
;
1109 struct gdbarch_tdep
*tdep
;
1111 /* Find a candidate among the list of pre-declared architectures. */
1112 arches
= gdbarch_list_lookup_by_info (arches
, &info
);
1114 return arches
->gdbarch
;
1116 /* None found, create a new architecture from the information provided. */
1117 tdep
= XMALLOC (struct gdbarch_tdep
);
1118 gdbarch
= gdbarch_alloc (&info
, tdep
);
1120 /* NOTE: cagney/2002-12-06: This can be deleted when this arch is
1121 ready to unwind the PC first (see frame.c:get_prev_frame()). */
1122 set_gdbarch_deprecated_init_frame_pc (gdbarch
, init_frame_pc_default
);
1124 /* If we ever need to differentiate the device types, do it here. */
1125 switch (info
.bfd_arch_info
->mach
)
1135 set_gdbarch_short_bit (gdbarch
, 2 * TARGET_CHAR_BIT
);
1136 set_gdbarch_int_bit (gdbarch
, 2 * TARGET_CHAR_BIT
);
1137 set_gdbarch_long_bit (gdbarch
, 4 * TARGET_CHAR_BIT
);
1138 set_gdbarch_long_long_bit (gdbarch
, 8 * TARGET_CHAR_BIT
);
1139 set_gdbarch_ptr_bit (gdbarch
, 2 * TARGET_CHAR_BIT
);
1140 set_gdbarch_addr_bit (gdbarch
, 32);
1141 set_gdbarch_bfd_vma_bit (gdbarch
, 32); /* FIXME: TRoth/2002-02-18: Is this needed? */
1143 set_gdbarch_float_bit (gdbarch
, 4 * TARGET_CHAR_BIT
);
1144 set_gdbarch_double_bit (gdbarch
, 4 * TARGET_CHAR_BIT
);
1145 set_gdbarch_long_double_bit (gdbarch
, 4 * TARGET_CHAR_BIT
);
1147 set_gdbarch_float_format (gdbarch
, &floatformat_ieee_single_little
);
1148 set_gdbarch_double_format (gdbarch
, &floatformat_ieee_single_little
);
1149 set_gdbarch_long_double_format (gdbarch
, &floatformat_ieee_single_little
);
1151 set_gdbarch_read_pc (gdbarch
, avr_read_pc
);
1152 set_gdbarch_write_pc (gdbarch
, avr_write_pc
);
1153 set_gdbarch_deprecated_target_read_fp (gdbarch
, avr_read_fp
);
1154 set_gdbarch_read_sp (gdbarch
, avr_read_sp
);
1155 set_gdbarch_deprecated_dummy_write_sp (gdbarch
, avr_write_sp
);
1157 set_gdbarch_num_regs (gdbarch
, AVR_NUM_REGS
);
1159 set_gdbarch_sp_regnum (gdbarch
, AVR_SP_REGNUM
);
1160 set_gdbarch_deprecated_fp_regnum (gdbarch
, AVR_FP_REGNUM
);
1161 set_gdbarch_pc_regnum (gdbarch
, AVR_PC_REGNUM
);
1163 set_gdbarch_register_name (gdbarch
, avr_register_name
);
1164 set_gdbarch_deprecated_register_size (gdbarch
, 1);
1165 set_gdbarch_deprecated_register_bytes (gdbarch
, AVR_NUM_REG_BYTES
);
1166 set_gdbarch_deprecated_register_byte (gdbarch
, avr_register_byte
);
1167 set_gdbarch_deprecated_register_raw_size (gdbarch
, avr_register_raw_size
);
1168 set_gdbarch_deprecated_max_register_raw_size (gdbarch
, 4);
1169 set_gdbarch_deprecated_register_virtual_size (gdbarch
, avr_register_virtual_size
);
1170 set_gdbarch_deprecated_max_register_virtual_size (gdbarch
, 4);
1171 set_gdbarch_deprecated_register_virtual_type (gdbarch
, avr_register_virtual_type
);
1173 set_gdbarch_print_insn (gdbarch
, print_insn_avr
);
1175 set_gdbarch_call_dummy_address (gdbarch
, avr_call_dummy_address
);
1176 set_gdbarch_deprecated_call_dummy_words (gdbarch
, avr_call_dummy_words
);
1178 /* set_gdbarch_believe_pcc_promotion (gdbarch, 1); // TRoth: should this be set? */
1180 set_gdbarch_address_to_pointer (gdbarch
, avr_address_to_pointer
);
1181 set_gdbarch_pointer_to_address (gdbarch
, avr_pointer_to_address
);
1182 set_gdbarch_deprecated_push_arguments (gdbarch
, avr_push_arguments
);
1183 set_gdbarch_deprecated_push_return_address (gdbarch
, avr_push_return_address
);
1184 set_gdbarch_deprecated_pop_frame (gdbarch
, avr_pop_frame
);
1186 set_gdbarch_use_struct_convention (gdbarch
, generic_use_struct_convention
);
1187 set_gdbarch_deprecated_store_struct_return (gdbarch
, avr_store_struct_return
);
1189 set_gdbarch_deprecated_frame_init_saved_regs (gdbarch
, avr_scan_prologue
);
1190 set_gdbarch_deprecated_init_extra_frame_info (gdbarch
, avr_init_extra_frame_info
);
1191 set_gdbarch_skip_prologue (gdbarch
, avr_skip_prologue
);
1192 set_gdbarch_inner_than (gdbarch
, core_addr_lessthan
);
1194 set_gdbarch_decr_pc_after_break (gdbarch
, 0);
1195 set_gdbarch_breakpoint_from_pc (gdbarch
, avr_breakpoint_from_pc
);
1197 set_gdbarch_function_start_offset (gdbarch
, 0);
1198 set_gdbarch_remote_translate_xfer_address (gdbarch
,
1199 avr_remote_translate_xfer_address
);
1200 set_gdbarch_frame_args_skip (gdbarch
, 0);
1201 set_gdbarch_frameless_function_invocation (gdbarch
, frameless_look_for_prologue
); /* ??? */
1202 set_gdbarch_deprecated_frame_chain (gdbarch
, avr_frame_chain
);
1203 set_gdbarch_deprecated_frame_saved_pc (gdbarch
, avr_frame_saved_pc
);
1204 set_gdbarch_frame_args_address (gdbarch
, avr_frame_address
);
1205 set_gdbarch_frame_locals_address (gdbarch
, avr_frame_address
);
1206 set_gdbarch_deprecated_saved_pc_after_call (gdbarch
, avr_saved_pc_after_call
);
1211 /* Send a query request to the avr remote target asking for values of the io
1212 registers. If args parameter is not NULL, then the user has requested info
1213 on a specific io register [This still needs implemented and is ignored for
1214 now]. The query string should be one of these forms:
1216 "Ravr.io_reg" -> reply is "NN" number of io registers
1218 "Ravr.io_reg:addr,len" where addr is first register and len is number of
1219 registers to be read. The reply should be "<NAME>,VV;" for each io register
1220 where, <NAME> is a string, and VV is the hex value of the register.
1222 All io registers are 8-bit. */
1225 avr_io_reg_read_command (char *args
, int from_tty
)
1231 unsigned int nreg
= 0;
1235 /* fprintf_unfiltered (gdb_stderr, "DEBUG: avr_io_reg_read_command (\"%s\", %d)\n", */
1236 /* args, from_tty); */
1238 if (!current_target
.to_query
)
1240 fprintf_unfiltered (gdb_stderr
,
1241 "ERR: info io_registers NOT supported by current target\n");
1245 /* Just get the maximum buffer size. */
1246 target_query ((int) 'R', 0, 0, &bufsiz
);
1247 if (bufsiz
> sizeof (buf
))
1248 bufsiz
= sizeof (buf
);
1250 /* Find out how many io registers the target has. */
1251 strcpy (query
, "avr.io_reg");
1252 target_query ((int) 'R', query
, buf
, &bufsiz
);
1254 if (strncmp (buf
, "", bufsiz
) == 0)
1256 fprintf_unfiltered (gdb_stderr
,
1257 "info io_registers NOT supported by target\n");
1261 if (sscanf (buf
, "%x", &nreg
) != 1)
1263 fprintf_unfiltered (gdb_stderr
,
1264 "Error fetching number of io registers\n");
1268 reinitialize_more_filter ();
1270 printf_unfiltered ("Target has %u io registers:\n\n", nreg
);
1272 /* only fetch up to 8 registers at a time to keep the buffer small */
1275 for (i
= 0; i
< nreg
; i
+= step
)
1277 /* how many registers this round? */
1280 j
= nreg
- i
; /* last block is less than 8 registers */
1282 snprintf (query
, sizeof (query
) - 1, "avr.io_reg:%x,%x", i
, j
);
1283 target_query ((int) 'R', query
, buf
, &bufsiz
);
1286 for (k
= i
; k
< (i
+ j
); k
++)
1288 if (sscanf (p
, "%[^,],%x;", query
, &val
) == 2)
1290 printf_filtered ("[%02x] %-15s : %02x\n", k
, query
, val
);
1291 while ((*p
!= ';') && (*p
!= '\0'))
1293 p
++; /* skip over ';' */
1301 extern initialize_file_ftype _initialize_avr_tdep
; /* -Wmissing-prototypes */
1304 _initialize_avr_tdep (void)
1306 register_gdbarch_init (bfd_arch_avr
, avr_gdbarch_init
);
1308 /* Add a new command to allow the user to query the avr remote target for
1309 the values of the io space registers in a saner way than just using
1312 /* FIXME: TRoth/2002-02-18: This should probably be changed to 'info avr
1313 io_registers' to signify it is not available on other platforms. */
1315 add_cmd ("io_registers", class_info
, avr_io_reg_read_command
,
1316 "query remote avr target for io space register values", &infolist
);