1 /* Target-dependent code for Atmel AVR, for GDB.
3 Copyright (C) 1996-2015 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 3 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, see <http://www.gnu.org/licenses/>. */
20 /* Contributed by Theodore A. Roth, troth@openavr.org */
22 /* Portions of this file were taken from the original gdb-4.18 patch developed
23 by Denis Chertykov, denisc@overta.ru */
27 #include "frame-unwind.h"
28 #include "frame-base.h"
29 #include "trad-frame.h"
35 #include "arch-utils.h"
42 (AVR micros are pure Harvard Architecture processors.)
44 The AVR family of microcontrollers have three distinctly different memory
45 spaces: flash, sram and eeprom. The flash is 16 bits wide and is used for
46 the most part to store program instructions. The sram is 8 bits wide and is
47 used for the stack and the heap. Some devices lack sram and some can have
48 an additional external sram added on as a peripheral.
50 The eeprom is 8 bits wide and is used to store data when the device is
51 powered down. Eeprom is not directly accessible, it can only be accessed
52 via io-registers using a special algorithm. Accessing eeprom via gdb's
53 remote serial protocol ('m' or 'M' packets) looks difficult to do and is
54 not included at this time.
56 [The eeprom could be read manually via ``x/b <eaddr + AVR_EMEM_START>'' or
57 written using ``set {unsigned char}<eaddr + AVR_EMEM_START>''. For this to
58 work, the remote target must be able to handle eeprom accesses and perform
59 the address translation.]
61 All three memory spaces have physical addresses beginning at 0x0. In
62 addition, the flash is addressed by gcc/binutils/gdb with respect to 8 bit
63 bytes instead of the 16 bit wide words used by the real device for the
66 In order for remote targets to work correctly, extra bits must be added to
67 addresses before they are send to the target or received from the target
68 via the remote serial protocol. The extra bits are the MSBs and are used to
69 decode which memory space the address is referring to. */
71 /* Constants: prefixed with AVR_ to avoid name space clashes */
73 /* Address space flags */
75 /* We are assigning the TYPE_INSTANCE_FLAG_ADDRESS_CLASS_1 to the flash address
78 #define AVR_TYPE_ADDRESS_CLASS_FLASH TYPE_ADDRESS_CLASS_1
79 #define AVR_TYPE_INSTANCE_FLAG_ADDRESS_CLASS_FLASH \
80 TYPE_INSTANCE_FLAG_ADDRESS_CLASS_1
95 AVR_NUM_REGS = 32 + 1 /*SREG*/ + 1 /*SP*/ + 1 /*PC*/,
96 AVR_NUM_REG_BYTES = 32 + 1 /*SREG*/ + 2 /*SP*/ + 4 /*PC*/,
98 /* Pseudo registers. */
99 AVR_PSEUDO_PC_REGNUM = 35,
100 AVR_NUM_PSEUDO_REGS = 1,
102 AVR_PC_REG_INDEX = 35, /* index into array of registers */
104 AVR_MAX_PROLOGUE_SIZE = 64, /* bytes */
106 /* Count of pushed registers. From r2 to r17 (inclusively), r28, r29 */
109 /* Number of the last pushed register. r17 for current avr-gcc */
110 AVR_LAST_PUSHED_REGNUM = 17,
112 AVR_ARG1_REGNUM = 24, /* Single byte argument */
113 AVR_ARGN_REGNUM = 25, /* Multi byte argments */
115 AVR_RET1_REGNUM = 24, /* Single byte return value */
116 AVR_RETN_REGNUM = 25, /* Multi byte return value */
118 /* FIXME: TRoth/2002-01-??: Can we shift all these memory masks left 8
119 bits? Do these have to match the bfd vma values? It sure would make
120 things easier in the future if they didn't need to match.
122 Note: I chose these values so as to be consistent with bfd vma
125 TRoth/2002-04-08: There is already a conflict with very large programs
126 in the mega128. The mega128 has 128K instruction bytes (64K words),
127 thus the Most Significant Bit is 0x10000 which gets masked off my
130 The problem manifests itself when trying to set a breakpoint in a
131 function which resides in the upper half of the instruction space and
132 thus requires a 17-bit address.
134 For now, I've just removed the EEPROM mask and changed AVR_MEM_MASK
135 from 0x00ff0000 to 0x00f00000. Eeprom is not accessible from gdb yet,
136 but could be for some remote targets by just adding the correct offset
137 to the address and letting the remote target handle the low-level
138 details of actually accessing the eeprom. */
140 AVR_IMEM_START = 0x00000000, /* INSN memory */
141 AVR_SMEM_START = 0x00800000, /* SRAM memory */
143 /* No eeprom mask defined */
144 AVR_MEM_MASK = 0x00f00000, /* mask to determine memory space */
146 AVR_EMEM_START = 0x00810000, /* EEPROM memory */
147 AVR_MEM_MASK = 0x00ff0000, /* mask to determine memory space */
153 NORMAL and CALL are the typical types (the -mcall-prologues gcc option
154 causes the generation of the CALL type prologues). */
157 AVR_PROLOGUE_NONE, /* No prologue */
159 AVR_PROLOGUE_CALL, /* -mcall-prologues */
161 AVR_PROLOGUE_INTR, /* interrupt handler */
162 AVR_PROLOGUE_SIG, /* signal handler */
165 /* Any function with a frame looks like this
166 ....... <-SP POINTS HERE
167 LOCALS1 <-FP POINTS HERE
176 struct avr_unwind_cache
178 /* The previous frame's inner most stack address. Used as this
179 frame ID's stack_addr. */
181 /* The frame's base, optionally used by the high-level debug info. */
185 /* Table indicating the location of each and every register. */
186 struct trad_frame_saved_reg *saved_regs;
191 /* Number of bytes stored to the stack by call instructions.
192 2 bytes for avr1-5 and avrxmega1-5, 3 bytes for avr6 and avrxmega6-7. */
196 struct type *void_type;
197 /* Type for a function returning void. */
198 struct type *func_void_type;
199 /* Type for a pointer to a function. Used for the type of PC. */
200 struct type *pc_type;
203 /* Lookup the name of a register given it's number. */
206 avr_register_name (struct gdbarch *gdbarch, int regnum)
208 static const char * const register_names[] = {
209 "r0", "r1", "r2", "r3", "r4", "r5", "r6", "r7",
210 "r8", "r9", "r10", "r11", "r12", "r13", "r14", "r15",
211 "r16", "r17", "r18", "r19", "r20", "r21", "r22", "r23",
212 "r24", "r25", "r26", "r27", "r28", "r29", "r30", "r31",
218 if (regnum >= (sizeof (register_names) / sizeof (*register_names)))
220 return register_names[regnum];
223 /* Return the GDB type object for the "standard" data type
224 of data in register N. */
227 avr_register_type (struct gdbarch *gdbarch, int reg_nr)
229 if (reg_nr == AVR_PC_REGNUM)
230 return builtin_type (gdbarch)->builtin_uint32;
231 if (reg_nr == AVR_PSEUDO_PC_REGNUM)
232 return gdbarch_tdep (gdbarch)->pc_type;
233 if (reg_nr == AVR_SP_REGNUM)
234 return builtin_type (gdbarch)->builtin_data_ptr;
235 return builtin_type (gdbarch)->builtin_uint8;
238 /* Instruction address checks and convertions. */
241 avr_make_iaddr (CORE_ADDR x)
243 return ((x) | AVR_IMEM_START);
246 /* FIXME: TRoth: Really need to use a larger mask for instructions. Some
247 devices are already up to 128KBytes of flash space.
249 TRoth/2002-04-8: See comment above where AVR_IMEM_START is defined. */
252 avr_convert_iaddr_to_raw (CORE_ADDR x)
254 return ((x) & 0xffffffff);
257 /* SRAM address checks and convertions. */
260 avr_make_saddr (CORE_ADDR x)
262 /* Return 0 for NULL. */
266 return ((x) | AVR_SMEM_START);
270 avr_convert_saddr_to_raw (CORE_ADDR x)
272 return ((x) & 0xffffffff);
275 /* EEPROM address checks and convertions. I don't know if these will ever
276 actually be used, but I've added them just the same. TRoth */
278 /* TRoth/2002-04-08: Commented out for now to allow fix for problem with large
279 programs in the mega128. */
281 /* static CORE_ADDR */
282 /* avr_make_eaddr (CORE_ADDR x) */
284 /* return ((x) | AVR_EMEM_START); */
288 /* avr_eaddr_p (CORE_ADDR x) */
290 /* return (((x) & AVR_MEM_MASK) == AVR_EMEM_START); */
293 /* static CORE_ADDR */
294 /* avr_convert_eaddr_to_raw (CORE_ADDR x) */
296 /* return ((x) & 0xffffffff); */
299 /* Convert from address to pointer and vice-versa. */
302 avr_address_to_pointer (struct gdbarch *gdbarch,
303 struct type *type, gdb_byte *buf, CORE_ADDR addr)
305 enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
307 /* Is it a data address in flash? */
308 if (AVR_TYPE_ADDRESS_CLASS_FLASH (type))
310 /* A data pointer in flash is byte addressed. */
311 store_unsigned_integer (buf, TYPE_LENGTH (type), byte_order,
312 avr_convert_iaddr_to_raw (addr));
314 /* Is it a code address? */
315 else if (TYPE_CODE (TYPE_TARGET_TYPE (type)) == TYPE_CODE_FUNC
316 || TYPE_CODE (TYPE_TARGET_TYPE (type)) == TYPE_CODE_METHOD)
318 /* A code pointer is word (16 bits) addressed. We shift the address down
319 by 1 bit to convert it to a pointer. */
320 store_unsigned_integer (buf, TYPE_LENGTH (type), byte_order,
321 avr_convert_iaddr_to_raw (addr >> 1));
325 /* Strip off any upper segment bits. */
326 store_unsigned_integer (buf, TYPE_LENGTH (type), byte_order,
327 avr_convert_saddr_to_raw (addr));
332 avr_pointer_to_address (struct gdbarch *gdbarch,
333 struct type *type, const gdb_byte *buf)
335 enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
337 = extract_unsigned_integer (buf, TYPE_LENGTH (type), byte_order);
339 /* Is it a data address in flash? */
340 if (AVR_TYPE_ADDRESS_CLASS_FLASH (type))
342 /* A data pointer in flash is already byte addressed. */
343 return avr_make_iaddr (addr);
345 /* Is it a code address? */
346 else if (TYPE_CODE (TYPE_TARGET_TYPE (type)) == TYPE_CODE_FUNC
347 || TYPE_CODE (TYPE_TARGET_TYPE (type)) == TYPE_CODE_METHOD
348 || TYPE_CODE_SPACE (TYPE_TARGET_TYPE (type)))
350 /* A code pointer is word (16 bits) addressed so we shift it up
351 by 1 bit to convert it to an address. */
352 return avr_make_iaddr (addr << 1);
355 return avr_make_saddr (addr);
359 avr_integer_to_address (struct gdbarch *gdbarch,
360 struct type *type, const gdb_byte *buf)
362 ULONGEST addr = unpack_long (type, buf);
364 return avr_make_saddr (addr);
368 avr_read_pc (struct regcache *regcache)
371 regcache_cooked_read_unsigned (regcache, AVR_PC_REGNUM, &pc);
372 return avr_make_iaddr (pc);
376 avr_write_pc (struct regcache *regcache, CORE_ADDR val)
378 regcache_cooked_write_unsigned (regcache, AVR_PC_REGNUM,
379 avr_convert_iaddr_to_raw (val));
382 static enum register_status
383 avr_pseudo_register_read (struct gdbarch *gdbarch, struct regcache *regcache,
384 int regnum, gdb_byte *buf)
387 enum register_status status;
391 case AVR_PSEUDO_PC_REGNUM:
392 status = regcache_raw_read_unsigned (regcache, AVR_PC_REGNUM, &val);
393 if (status != REG_VALID)
396 store_unsigned_integer (buf, 4, gdbarch_byte_order (gdbarch), val);
399 internal_error (__FILE__, __LINE__, _("invalid regnum"));
404 avr_pseudo_register_write (struct gdbarch *gdbarch, struct regcache *regcache,
405 int regnum, const gdb_byte *buf)
411 case AVR_PSEUDO_PC_REGNUM:
412 val = extract_unsigned_integer (buf, 4, gdbarch_byte_order (gdbarch));
414 regcache_raw_write_unsigned (regcache, AVR_PC_REGNUM, val);
417 internal_error (__FILE__, __LINE__, _("invalid regnum"));
421 /* Function: avr_scan_prologue
423 This function decodes an AVR function prologue to determine:
424 1) the size of the stack frame
425 2) which registers are saved on it
426 3) the offsets of saved regs
427 This information is stored in the avr_unwind_cache structure.
429 Some devices lack the sbiw instruction, so on those replace this:
435 A typical AVR function prologue with a frame pointer might look like this:
436 push rXX ; saved regs
442 sbiw r28,<LOCALS_SIZE>
443 in __tmp_reg__,__SREG__
446 out __SREG__,__tmp_reg__
449 A typical AVR function prologue without a frame pointer might look like
451 push rXX ; saved regs
454 A main function prologue looks like this:
455 ldi r28,lo8(<RAM_ADDR> - <LOCALS_SIZE>)
456 ldi r29,hi8(<RAM_ADDR> - <LOCALS_SIZE>)
460 A signal handler prologue looks like this:
463 in __tmp_reg__, __SREG__
466 push rXX ; save registers r18:r27, r30:r31
468 push r28 ; save frame pointer
472 sbiw r28, <LOCALS_SIZE>
476 A interrupt handler prologue looks like this:
480 in __tmp_reg__, __SREG__
483 push rXX ; save registers r18:r27, r30:r31
485 push r28 ; save frame pointer
489 sbiw r28, <LOCALS_SIZE>
495 A `-mcall-prologues' prologue looks like this (Note that the megas use a
496 jmp instead of a rjmp, thus the prologue is one word larger since jmp is a
497 32 bit insn and rjmp is a 16 bit insn):
498 ldi r26,lo8(<LOCALS_SIZE>)
499 ldi r27,hi8(<LOCALS_SIZE>)
500 ldi r30,pm_lo8(.L_foo_body)
501 ldi r31,pm_hi8(.L_foo_body)
502 rjmp __prologue_saves__+RRR
505 /* Not really part of a prologue, but still need to scan for it, is when a
506 function prologue moves values passed via registers as arguments to new
507 registers. In this case, all local variables live in registers, so there
508 may be some register saves. This is what it looks like:
512 There could be multiple movw's. If the target doesn't have a movw insn, it
513 will use two mov insns. This could be done after any of the above prologue
517 avr_scan_prologue (struct gdbarch *gdbarch, CORE_ADDR pc_beg, CORE_ADDR pc_end,
518 struct avr_unwind_cache *info)
520 enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
524 struct bound_minimal_symbol msymbol;
525 unsigned char prologue[AVR_MAX_PROLOGUE_SIZE];
529 len = pc_end - pc_beg;
530 if (len > AVR_MAX_PROLOGUE_SIZE)
531 len = AVR_MAX_PROLOGUE_SIZE;
533 /* FIXME: TRoth/2003-06-11: This could be made more efficient by only
534 reading in the bytes of the prologue. The problem is that the figuring
535 out where the end of the prologue is is a bit difficult. The old code
536 tried to do that, but failed quite often. */
537 read_memory (pc_beg, prologue, len);
539 /* Scanning main()'s prologue
540 ldi r28,lo8(<RAM_ADDR> - <LOCALS_SIZE>)
541 ldi r29,hi8(<RAM_ADDR> - <LOCALS_SIZE>)
548 static const unsigned char img[] = {
549 0xde, 0xbf, /* out __SP_H__,r29 */
550 0xcd, 0xbf /* out __SP_L__,r28 */
553 insn = extract_unsigned_integer (&prologue[vpc], 2, byte_order);
554 /* ldi r28,lo8(<RAM_ADDR> - <LOCALS_SIZE>) */
555 if ((insn & 0xf0f0) == 0xe0c0)
557 locals = (insn & 0xf) | ((insn & 0x0f00) >> 4);
558 insn = extract_unsigned_integer (&prologue[vpc + 2], 2, byte_order);
559 /* ldi r29,hi8(<RAM_ADDR> - <LOCALS_SIZE>) */
560 if ((insn & 0xf0f0) == 0xe0d0)
562 locals |= ((insn & 0xf) | ((insn & 0x0f00) >> 4)) << 8;
563 if (vpc + 4 + sizeof (img) < len
564 && memcmp (prologue + vpc + 4, img, sizeof (img)) == 0)
566 info->prologue_type = AVR_PROLOGUE_MAIN;
574 /* Scanning `-mcall-prologues' prologue
575 Classic prologue is 10 bytes, mega prologue is a 12 bytes long */
577 while (1) /* Using a while to avoid many goto's */
584 /* At least the fifth instruction must have been executed to
585 modify frame shape. */
589 insn = extract_unsigned_integer (&prologue[vpc], 2, byte_order);
590 /* ldi r26,<LOCALS_SIZE> */
591 if ((insn & 0xf0f0) != 0xe0a0)
593 loc_size = (insn & 0xf) | ((insn & 0x0f00) >> 4);
596 insn = extract_unsigned_integer (&prologue[vpc + 2], 2, byte_order);
597 /* ldi r27,<LOCALS_SIZE> / 256 */
598 if ((insn & 0xf0f0) != 0xe0b0)
600 loc_size |= ((insn & 0xf) | ((insn & 0x0f00) >> 4)) << 8;
603 insn = extract_unsigned_integer (&prologue[vpc + 4], 2, byte_order);
604 /* ldi r30,pm_lo8(.L_foo_body) */
605 if ((insn & 0xf0f0) != 0xe0e0)
607 body_addr = (insn & 0xf) | ((insn & 0x0f00) >> 4);
610 insn = extract_unsigned_integer (&prologue[vpc + 6], 2, byte_order);
611 /* ldi r31,pm_hi8(.L_foo_body) */
612 if ((insn & 0xf0f0) != 0xe0f0)
614 body_addr |= ((insn & 0xf) | ((insn & 0x0f00) >> 4)) << 8;
617 msymbol = lookup_minimal_symbol ("__prologue_saves__", NULL, NULL);
621 insn = extract_unsigned_integer (&prologue[vpc + 8], 2, byte_order);
622 /* rjmp __prologue_saves__+RRR */
623 if ((insn & 0xf000) == 0xc000)
625 /* Extract PC relative offset from RJMP */
626 i = (insn & 0xfff) | (insn & 0x800 ? (-1 ^ 0xfff) : 0);
627 /* Convert offset to byte addressable mode */
629 /* Destination address */
632 if (body_addr != (pc_beg + 10)/2)
637 else if ((insn & 0xfe0e) == 0x940c)
639 /* Extract absolute PC address from JMP */
640 i = (((insn & 0x1) | ((insn & 0x1f0) >> 3) << 16)
641 | (extract_unsigned_integer (&prologue[vpc + 10], 2, byte_order)
643 /* Convert address to byte addressable mode */
646 if (body_addr != (pc_beg + 12)/2)
654 /* Resolve offset (in words) from __prologue_saves__ symbol.
655 Which is a pushes count in `-mcall-prologues' mode */
656 num_pushes = AVR_MAX_PUSHES - (i - BMSYMBOL_VALUE_ADDRESS (msymbol)) / 2;
658 if (num_pushes > AVR_MAX_PUSHES)
660 fprintf_unfiltered (gdb_stderr, _("Num pushes too large: %d\n"),
669 info->saved_regs[AVR_FP_REGNUM + 1].addr = num_pushes;
671 info->saved_regs[AVR_FP_REGNUM].addr = num_pushes - 1;
674 for (from = AVR_LAST_PUSHED_REGNUM + 1 - (num_pushes - 2);
675 from <= AVR_LAST_PUSHED_REGNUM; ++from)
676 info->saved_regs [from].addr = ++i;
678 info->size = loc_size + num_pushes;
679 info->prologue_type = AVR_PROLOGUE_CALL;
681 return pc_beg + pc_offset;
684 /* Scan for the beginning of the prologue for an interrupt or signal
685 function. Note that we have to set the prologue type here since the
686 third stage of the prologue may not be present (e.g. no saved registered
687 or changing of the SP register). */
691 static const unsigned char img[] = {
692 0x78, 0x94, /* sei */
693 0x1f, 0x92, /* push r1 */
694 0x0f, 0x92, /* push r0 */
695 0x0f, 0xb6, /* in r0,0x3f SREG */
696 0x0f, 0x92, /* push r0 */
697 0x11, 0x24 /* clr r1 */
699 if (len >= sizeof (img)
700 && memcmp (prologue, img, sizeof (img)) == 0)
702 info->prologue_type = AVR_PROLOGUE_INTR;
704 info->saved_regs[AVR_SREG_REGNUM].addr = 3;
705 info->saved_regs[0].addr = 2;
706 info->saved_regs[1].addr = 1;
709 else if (len >= sizeof (img) - 2
710 && memcmp (img + 2, prologue, sizeof (img) - 2) == 0)
712 info->prologue_type = AVR_PROLOGUE_SIG;
713 vpc += sizeof (img) - 2;
714 info->saved_regs[AVR_SREG_REGNUM].addr = 3;
715 info->saved_regs[0].addr = 2;
716 info->saved_regs[1].addr = 1;
721 /* First stage of the prologue scanning.
722 Scan pushes (saved registers) */
724 for (; vpc < len; vpc += 2)
726 insn = extract_unsigned_integer (&prologue[vpc], 2, byte_order);
727 if ((insn & 0xfe0f) == 0x920f) /* push rXX */
729 /* Bits 4-9 contain a mask for registers R0-R32. */
730 int regno = (insn & 0x1f0) >> 4;
732 info->saved_regs[regno].addr = info->size;
739 gdb_assert (vpc < AVR_MAX_PROLOGUE_SIZE);
741 /* Handle static small stack allocation using rcall or push. */
743 while (scan_stage == 1 && vpc < len)
745 insn = extract_unsigned_integer (&prologue[vpc], 2, byte_order);
746 if (insn == 0xd000) /* rcall .+0 */
748 info->size += gdbarch_tdep (gdbarch)->call_length;
751 else if (insn == 0x920f || insn == 0x921f) /* push r0 or push r1 */
760 /* Second stage of the prologue scanning.
765 if (scan_stage == 1 && vpc < len)
767 static const unsigned char img[] = {
768 0xcd, 0xb7, /* in r28,__SP_L__ */
769 0xde, 0xb7 /* in r29,__SP_H__ */
772 if (vpc + sizeof (img) < len
773 && memcmp (prologue + vpc, img, sizeof (img)) == 0)
780 /* Third stage of the prologue scanning. (Really two stages).
782 sbiw r28,XX or subi r28,lo8(XX)
784 in __tmp_reg__,__SREG__
787 out __SREG__,__tmp_reg__
790 if (scan_stage == 2 && vpc < len)
793 static const unsigned char img[] = {
794 0x0f, 0xb6, /* in r0,0x3f */
795 0xf8, 0x94, /* cli */
796 0xde, 0xbf, /* out 0x3e,r29 ; SPH */
797 0x0f, 0xbe, /* out 0x3f,r0 ; SREG */
798 0xcd, 0xbf /* out 0x3d,r28 ; SPL */
800 static const unsigned char img_sig[] = {
801 0xde, 0xbf, /* out 0x3e,r29 ; SPH */
802 0xcd, 0xbf /* out 0x3d,r28 ; SPL */
804 static const unsigned char img_int[] = {
805 0xf8, 0x94, /* cli */
806 0xde, 0xbf, /* out 0x3e,r29 ; SPH */
807 0x78, 0x94, /* sei */
808 0xcd, 0xbf /* out 0x3d,r28 ; SPL */
811 insn = extract_unsigned_integer (&prologue[vpc], 2, byte_order);
812 if ((insn & 0xff30) == 0x9720) /* sbiw r28,XXX */
814 locals_size = (insn & 0xf) | ((insn & 0xc0) >> 2);
817 else if ((insn & 0xf0f0) == 0x50c0) /* subi r28,lo8(XX) */
819 locals_size = (insn & 0xf) | ((insn & 0xf00) >> 4);
821 insn = extract_unsigned_integer (&prologue[vpc], 2, byte_order);
823 locals_size += ((insn & 0xf) | ((insn & 0xf00) >> 4)) << 8;
828 /* Scan the last part of the prologue. May not be present for interrupt
829 or signal handler functions, which is why we set the prologue type
830 when we saw the beginning of the prologue previously. */
832 if (vpc + sizeof (img_sig) < len
833 && memcmp (prologue + vpc, img_sig, sizeof (img_sig)) == 0)
835 vpc += sizeof (img_sig);
837 else if (vpc + sizeof (img_int) < len
838 && memcmp (prologue + vpc, img_int, sizeof (img_int)) == 0)
840 vpc += sizeof (img_int);
842 if (vpc + sizeof (img) < len
843 && memcmp (prologue + vpc, img, sizeof (img)) == 0)
845 info->prologue_type = AVR_PROLOGUE_NORMAL;
849 info->size += locals_size;
854 /* If we got this far, we could not scan the prologue, so just return the pc
855 of the frame plus an adjustment for argument move insns. */
857 for (; vpc < len; vpc += 2)
859 insn = extract_unsigned_integer (&prologue[vpc], 2, byte_order);
860 if ((insn & 0xff00) == 0x0100) /* movw rXX, rYY */
862 else if ((insn & 0xfc00) == 0x2c00) /* mov rXX, rYY */
872 avr_skip_prologue (struct gdbarch *gdbarch, CORE_ADDR pc)
874 CORE_ADDR func_addr, func_end;
875 CORE_ADDR post_prologue_pc;
877 /* See what the symbol table says */
879 if (!find_pc_partial_function (pc, NULL, &func_addr, &func_end))
882 post_prologue_pc = skip_prologue_using_sal (gdbarch, func_addr);
883 if (post_prologue_pc != 0)
884 return max (pc, post_prologue_pc);
887 CORE_ADDR prologue_end = pc;
888 struct avr_unwind_cache info = {0};
889 struct trad_frame_saved_reg saved_regs[AVR_NUM_REGS];
891 info.saved_regs = saved_regs;
893 /* Need to run the prologue scanner to figure out if the function has a
894 prologue and possibly skip over moving arguments passed via registers
895 to other registers. */
897 prologue_end = avr_scan_prologue (gdbarch, func_addr, func_end, &info);
899 if (info.prologue_type != AVR_PROLOGUE_NONE)
903 /* Either we didn't find the start of this function (nothing we can do),
904 or there's no line info, or the line after the prologue is after
905 the end of the function (there probably isn't a prologue). */
910 /* Not all avr devices support the BREAK insn. Those that don't should treat
911 it as a NOP. Thus, it should be ok. Since the avr is currently a remote
912 only target, this shouldn't be a problem (I hope). TRoth/2003-05-14 */
914 static const unsigned char *
915 avr_breakpoint_from_pc (struct gdbarch *gdbarch,
916 CORE_ADDR *pcptr, int *lenptr)
918 static const unsigned char avr_break_insn [] = { 0x98, 0x95 };
919 *lenptr = sizeof (avr_break_insn);
920 return avr_break_insn;
923 /* Determine, for architecture GDBARCH, how a return value of TYPE
924 should be returned. If it is supposed to be returned in registers,
925 and READBUF is non-zero, read the appropriate value from REGCACHE,
926 and copy it into READBUF. If WRITEBUF is non-zero, write the value
927 from WRITEBUF into REGCACHE. */
929 static enum return_value_convention
930 avr_return_value (struct gdbarch *gdbarch, struct value *function,
931 struct type *valtype, struct regcache *regcache,
932 gdb_byte *readbuf, const gdb_byte *writebuf)
935 /* Single byte are returned in r24.
936 Otherwise, the MSB of the return value is always in r25, calculate which
937 register holds the LSB. */
940 if ((TYPE_CODE (valtype) == TYPE_CODE_STRUCT
941 || TYPE_CODE (valtype) == TYPE_CODE_UNION
942 || TYPE_CODE (valtype) == TYPE_CODE_ARRAY)
943 && TYPE_LENGTH (valtype) > 8)
944 return RETURN_VALUE_STRUCT_CONVENTION;
946 if (TYPE_LENGTH (valtype) <= 2)
948 else if (TYPE_LENGTH (valtype) <= 4)
950 else if (TYPE_LENGTH (valtype) <= 8)
953 gdb_assert_not_reached ("unexpected type length");
955 if (writebuf != NULL)
957 for (i = 0; i < TYPE_LENGTH (valtype); i++)
958 regcache_cooked_write (regcache, lsb_reg + i, writebuf + i);
963 for (i = 0; i < TYPE_LENGTH (valtype); i++)
964 regcache_cooked_read (regcache, lsb_reg + i, readbuf + i);
967 return RETURN_VALUE_REGISTER_CONVENTION;
971 /* Put here the code to store, into fi->saved_regs, the addresses of
972 the saved registers of frame described by FRAME_INFO. This
973 includes special registers such as pc and fp saved in special ways
974 in the stack frame. sp is even more special: the address we return
975 for it IS the sp for the next frame. */
977 static struct avr_unwind_cache *
978 avr_frame_unwind_cache (struct frame_info *this_frame,
979 void **this_prologue_cache)
981 CORE_ADDR start_pc, current_pc;
984 struct avr_unwind_cache *info;
985 struct gdbarch *gdbarch;
986 struct gdbarch_tdep *tdep;
989 if (*this_prologue_cache)
990 return (struct avr_unwind_cache *) *this_prologue_cache;
992 info = FRAME_OBSTACK_ZALLOC (struct avr_unwind_cache);
993 *this_prologue_cache = info;
994 info->saved_regs = trad_frame_alloc_saved_regs (this_frame);
997 info->prologue_type = AVR_PROLOGUE_NONE;
999 start_pc = get_frame_func (this_frame);
1000 current_pc = get_frame_pc (this_frame);
1001 if ((start_pc > 0) && (start_pc <= current_pc))
1002 avr_scan_prologue (get_frame_arch (this_frame),
1003 start_pc, current_pc, info);
1005 if ((info->prologue_type != AVR_PROLOGUE_NONE)
1006 && (info->prologue_type != AVR_PROLOGUE_MAIN))
1008 ULONGEST high_base; /* High byte of FP */
1010 /* The SP was moved to the FP. This indicates that a new frame
1011 was created. Get THIS frame's FP value by unwinding it from
1013 this_base = get_frame_register_unsigned (this_frame, AVR_FP_REGNUM);
1014 high_base = get_frame_register_unsigned (this_frame, AVR_FP_REGNUM + 1);
1015 this_base += (high_base << 8);
1017 /* The FP points at the last saved register. Adjust the FP back
1018 to before the first saved register giving the SP. */
1019 prev_sp = this_base + info->size;
1023 /* Assume that the FP is this frame's SP but with that pushed
1024 stack space added back. */
1025 this_base = get_frame_register_unsigned (this_frame, AVR_SP_REGNUM);
1026 prev_sp = this_base + info->size;
1029 /* Add 1 here to adjust for the post-decrement nature of the push
1031 info->prev_sp = avr_make_saddr (prev_sp + 1);
1032 info->base = avr_make_saddr (this_base);
1034 gdbarch = get_frame_arch (this_frame);
1036 /* Adjust all the saved registers so that they contain addresses and not
1038 for (i = 0; i < gdbarch_num_regs (gdbarch) - 1; i++)
1039 if (info->saved_regs[i].addr > 0)
1040 info->saved_regs[i].addr = info->prev_sp - info->saved_regs[i].addr;
1042 /* Except for the main and startup code, the return PC is always saved on
1043 the stack and is at the base of the frame. */
1045 if (info->prologue_type != AVR_PROLOGUE_MAIN)
1046 info->saved_regs[AVR_PC_REGNUM].addr = info->prev_sp;
1048 /* The previous frame's SP needed to be computed. Save the computed
1050 tdep = gdbarch_tdep (gdbarch);
1051 trad_frame_set_value (info->saved_regs, AVR_SP_REGNUM,
1052 info->prev_sp - 1 + tdep->call_length);
1058 avr_unwind_pc (struct gdbarch *gdbarch, struct frame_info *next_frame)
1062 pc = frame_unwind_register_unsigned (next_frame, AVR_PC_REGNUM);
1064 return avr_make_iaddr (pc);
1068 avr_unwind_sp (struct gdbarch *gdbarch, struct frame_info *next_frame)
1072 sp = frame_unwind_register_unsigned (next_frame, AVR_SP_REGNUM);
1074 return avr_make_saddr (sp);
1077 /* Given a GDB frame, determine the address of the calling function's
1078 frame. This will be used to create a new GDB frame struct. */
1081 avr_frame_this_id (struct frame_info *this_frame,
1082 void **this_prologue_cache,
1083 struct frame_id *this_id)
1085 struct avr_unwind_cache *info
1086 = avr_frame_unwind_cache (this_frame, this_prologue_cache);
1091 /* The FUNC is easy. */
1092 func = get_frame_func (this_frame);
1094 /* Hopefully the prologue analysis either correctly determined the
1095 frame's base (which is the SP from the previous frame), or set
1096 that base to "NULL". */
1097 base = info->prev_sp;
1101 id = frame_id_build (base, func);
1105 static struct value *
1106 avr_frame_prev_register (struct frame_info *this_frame,
1107 void **this_prologue_cache, int regnum)
1109 struct gdbarch *gdbarch = get_frame_arch (this_frame);
1110 enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
1111 struct avr_unwind_cache *info
1112 = avr_frame_unwind_cache (this_frame, this_prologue_cache);
1114 if (regnum == AVR_PC_REGNUM || regnum == AVR_PSEUDO_PC_REGNUM)
1116 if (trad_frame_addr_p (info->saved_regs, AVR_PC_REGNUM))
1118 /* Reading the return PC from the PC register is slightly
1119 abnormal. register_size(AVR_PC_REGNUM) says it is 4 bytes,
1120 but in reality, only two bytes (3 in upcoming mega256) are
1121 stored on the stack.
1123 Also, note that the value on the stack is an addr to a word
1124 not a byte, so we will need to multiply it by two at some
1127 And to confuse matters even more, the return address stored
1128 on the stack is in big endian byte order, even though most
1129 everything else about the avr is little endian. Ick! */
1133 struct gdbarch *gdbarch = get_frame_arch (this_frame);
1134 struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
1136 read_memory (info->saved_regs[AVR_PC_REGNUM].addr,
1137 buf, tdep->call_length);
1139 /* Extract the PC read from memory as a big-endian. */
1141 for (i = 0; i < tdep->call_length; i++)
1142 pc = (pc << 8) | buf[i];
1144 if (regnum == AVR_PC_REGNUM)
1147 return frame_unwind_got_constant (this_frame, regnum, pc);
1150 return frame_unwind_got_optimized (this_frame, regnum);
1153 return trad_frame_get_prev_register (this_frame, info->saved_regs, regnum);
1156 static const struct frame_unwind avr_frame_unwind = {
1158 default_frame_unwind_stop_reason,
1160 avr_frame_prev_register,
1162 default_frame_sniffer
1166 avr_frame_base_address (struct frame_info *this_frame, void **this_cache)
1168 struct avr_unwind_cache *info
1169 = avr_frame_unwind_cache (this_frame, this_cache);
1174 static const struct frame_base avr_frame_base = {
1176 avr_frame_base_address,
1177 avr_frame_base_address,
1178 avr_frame_base_address
1181 /* Assuming THIS_FRAME is a dummy, return the frame ID of that dummy
1182 frame. The frame ID's base needs to match the TOS value saved by
1183 save_dummy_frame_tos(), and the PC match the dummy frame's breakpoint. */
1185 static struct frame_id
1186 avr_dummy_id (struct gdbarch *gdbarch, struct frame_info *this_frame)
1190 base = get_frame_register_unsigned (this_frame, AVR_SP_REGNUM);
1191 return frame_id_build (avr_make_saddr (base), get_frame_pc (this_frame));
1194 /* When arguments must be pushed onto the stack, they go on in reverse
1195 order. The below implements a FILO (stack) to do this. */
1200 struct stack_item *prev;
1204 static struct stack_item *
1205 push_stack_item (struct stack_item *prev, const bfd_byte *contents, int len)
1207 struct stack_item *si;
1208 si = XNEW (struct stack_item);
1209 si->data = (gdb_byte *) xmalloc (len);
1212 memcpy (si->data, contents, len);
1216 static struct stack_item *pop_stack_item (struct stack_item *si);
1217 static struct stack_item *
1218 pop_stack_item (struct stack_item *si)
1220 struct stack_item *dead = si;
1227 /* Setup the function arguments for calling a function in the inferior.
1229 On the AVR architecture, there are 18 registers (R25 to R8) which are
1230 dedicated for passing function arguments. Up to the first 18 arguments
1231 (depending on size) may go into these registers. The rest go on the stack.
1233 All arguments are aligned to start in even-numbered registers (odd-sized
1234 arguments, including char, have one free register above them). For example,
1235 an int in arg1 and a char in arg2 would be passed as such:
1240 Arguments that are larger than 2 bytes will be split between two or more
1241 registers as available, but will NOT be split between a register and the
1242 stack. Arguments that go onto the stack are pushed last arg first (this is
1243 similar to the d10v). */
1245 /* NOTE: TRoth/2003-06-17: The rest of this comment is old looks to be
1248 An exceptional case exists for struct arguments (and possibly other
1249 aggregates such as arrays) -- if the size is larger than WORDSIZE bytes but
1250 not a multiple of WORDSIZE bytes. In this case the argument is never split
1251 between the registers and the stack, but instead is copied in its entirety
1252 onto the stack, AND also copied into as many registers as there is room
1253 for. In other words, space in registers permitting, two copies of the same
1254 argument are passed in. As far as I can tell, only the one on the stack is
1255 used, although that may be a function of the level of compiler
1256 optimization. I suspect this is a compiler bug. Arguments of these odd
1257 sizes are left-justified within the word (as opposed to arguments smaller
1258 than WORDSIZE bytes, which are right-justified).
1260 If the function is to return an aggregate type such as a struct, the caller
1261 must allocate space into which the callee will copy the return value. In
1262 this case, a pointer to the return value location is passed into the callee
1263 in register R0, which displaces one of the other arguments passed in via
1264 registers R0 to R2. */
1267 avr_push_dummy_call (struct gdbarch *gdbarch, struct value *function,
1268 struct regcache *regcache, CORE_ADDR bp_addr,
1269 int nargs, struct value **args, CORE_ADDR sp,
1270 int struct_return, CORE_ADDR struct_addr)
1272 enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
1275 int call_length = gdbarch_tdep (gdbarch)->call_length;
1276 CORE_ADDR return_pc = avr_convert_iaddr_to_raw (bp_addr);
1277 int regnum = AVR_ARGN_REGNUM;
1278 struct stack_item *si = NULL;
1282 regcache_cooked_write_unsigned
1283 (regcache, regnum--, (struct_addr >> 8) & 0xff);
1284 regcache_cooked_write_unsigned
1285 (regcache, regnum--, struct_addr & 0xff);
1286 /* SP being post decremented, we need to reserve one byte so that the
1287 return address won't overwrite the result (or vice-versa). */
1288 if (sp == struct_addr)
1292 for (i = 0; i < nargs; i++)
1296 struct value *arg = args[i];
1297 struct type *type = check_typedef (value_type (arg));
1298 const bfd_byte *contents = value_contents (arg);
1299 int len = TYPE_LENGTH (type);
1301 /* Calculate the potential last register needed. */
1302 last_regnum = regnum - (len + (len & 1));
1304 /* If there are registers available, use them. Once we start putting
1305 stuff on the stack, all subsequent args go on stack. */
1306 if ((si == NULL) && (last_regnum >= 8))
1310 /* Skip a register for odd length args. */
1314 val = extract_unsigned_integer (contents, len, byte_order);
1315 for (j = 0; j < len; j++)
1316 regcache_cooked_write_unsigned
1317 (regcache, regnum--, val >> (8 * (len - j - 1)));
1319 /* No registers available, push the args onto the stack. */
1322 /* From here on, we don't care about regnum. */
1323 si = push_stack_item (si, contents, len);
1327 /* Push args onto the stack. */
1331 /* Add 1 to sp here to account for post decr nature of pushes. */
1332 write_memory (sp + 1, si->data, si->len);
1333 si = pop_stack_item (si);
1336 /* Set the return address. For the avr, the return address is the BP_ADDR.
1337 Need to push the return address onto the stack noting that it needs to be
1338 in big-endian order on the stack. */
1339 for (i = 1; i <= call_length; i++)
1341 buf[call_length - i] = return_pc & 0xff;
1346 /* Use 'sp + 1' since pushes are post decr ops. */
1347 write_memory (sp + 1, buf, call_length);
1349 /* Finally, update the SP register. */
1350 regcache_cooked_write_unsigned (regcache, AVR_SP_REGNUM,
1351 avr_convert_saddr_to_raw (sp));
1353 /* Return SP value for the dummy frame, where the return address hasn't been
1355 return sp + call_length;
1358 /* Unfortunately dwarf2 register for SP is 32. */
1361 avr_dwarf_reg_to_regnum (struct gdbarch *gdbarch, int reg)
1363 if (reg >= 0 && reg < 32)
1366 return AVR_SP_REGNUM;
1370 /* Implementation of `address_class_type_flags' gdbarch method.
1372 This method maps DW_AT_address_class attributes to a
1373 type_instance_flag_value. */
1376 avr_address_class_type_flags (int byte_size, int dwarf2_addr_class)
1378 /* The value 1 of the DW_AT_address_class attribute corresponds to the
1379 __flash qualifier. Note that this attribute is only valid with
1380 pointer types and therefore the flag is set to the pointer type and
1381 not its target type. */
1382 if (dwarf2_addr_class == 1 && byte_size == 2)
1383 return AVR_TYPE_INSTANCE_FLAG_ADDRESS_CLASS_FLASH;
1387 /* Implementation of `address_class_type_flags_to_name' gdbarch method.
1389 Convert a type_instance_flag_value to an address space qualifier. */
1392 avr_address_class_type_flags_to_name (struct gdbarch *gdbarch, int type_flags)
1394 if (type_flags & AVR_TYPE_INSTANCE_FLAG_ADDRESS_CLASS_FLASH)
1400 /* Implementation of `address_class_name_to_type_flags' gdbarch method.
1402 Convert an address space qualifier to a type_instance_flag_value. */
1405 avr_address_class_name_to_type_flags (struct gdbarch *gdbarch,
1407 int *type_flags_ptr)
1409 if (strcmp (name, "flash") == 0)
1411 *type_flags_ptr = AVR_TYPE_INSTANCE_FLAG_ADDRESS_CLASS_FLASH;
1418 /* Initialize the gdbarch structure for the AVR's. */
1420 static struct gdbarch *
1421 avr_gdbarch_init (struct gdbarch_info info, struct gdbarch_list *arches)
1423 struct gdbarch *gdbarch;
1424 struct gdbarch_tdep *tdep;
1425 struct gdbarch_list *best_arch;
1428 /* Avr-6 call instructions save 3 bytes. */
1429 switch (info.bfd_arch_info->mach)
1432 case bfd_mach_avrxmega1:
1434 case bfd_mach_avrxmega2:
1436 case bfd_mach_avrxmega3:
1438 case bfd_mach_avrxmega4:
1440 case bfd_mach_avrxmega5:
1445 case bfd_mach_avrxmega6:
1446 case bfd_mach_avrxmega7:
1451 /* If there is already a candidate, use it. */
1452 for (best_arch = gdbarch_list_lookup_by_info (arches, &info);
1454 best_arch = gdbarch_list_lookup_by_info (best_arch->next, &info))
1456 if (gdbarch_tdep (best_arch->gdbarch)->call_length == call_length)
1457 return best_arch->gdbarch;
1460 /* None found, create a new architecture from the information provided. */
1461 tdep = XNEW (struct gdbarch_tdep);
1462 gdbarch = gdbarch_alloc (&info, tdep);
1464 tdep->call_length = call_length;
1466 /* Create a type for PC. We can't use builtin types here, as they may not
1468 tdep->void_type = arch_type (gdbarch, TYPE_CODE_VOID, 1, "void");
1469 tdep->func_void_type = make_function_type (tdep->void_type, NULL);
1470 tdep->pc_type = arch_type (gdbarch, TYPE_CODE_PTR, 4, NULL);
1471 TYPE_TARGET_TYPE (tdep->pc_type) = tdep->func_void_type;
1472 TYPE_UNSIGNED (tdep->pc_type) = 1;
1474 set_gdbarch_short_bit (gdbarch, 2 * TARGET_CHAR_BIT);
1475 set_gdbarch_int_bit (gdbarch, 2 * TARGET_CHAR_BIT);
1476 set_gdbarch_long_bit (gdbarch, 4 * TARGET_CHAR_BIT);
1477 set_gdbarch_long_long_bit (gdbarch, 8 * TARGET_CHAR_BIT);
1478 set_gdbarch_ptr_bit (gdbarch, 2 * TARGET_CHAR_BIT);
1479 set_gdbarch_addr_bit (gdbarch, 32);
1481 set_gdbarch_float_bit (gdbarch, 4 * TARGET_CHAR_BIT);
1482 set_gdbarch_double_bit (gdbarch, 4 * TARGET_CHAR_BIT);
1483 set_gdbarch_long_double_bit (gdbarch, 4 * TARGET_CHAR_BIT);
1485 set_gdbarch_float_format (gdbarch, floatformats_ieee_single);
1486 set_gdbarch_double_format (gdbarch, floatformats_ieee_single);
1487 set_gdbarch_long_double_format (gdbarch, floatformats_ieee_single);
1489 set_gdbarch_read_pc (gdbarch, avr_read_pc);
1490 set_gdbarch_write_pc (gdbarch, avr_write_pc);
1492 set_gdbarch_num_regs (gdbarch, AVR_NUM_REGS);
1494 set_gdbarch_sp_regnum (gdbarch, AVR_SP_REGNUM);
1495 set_gdbarch_pc_regnum (gdbarch, AVR_PC_REGNUM);
1497 set_gdbarch_register_name (gdbarch, avr_register_name);
1498 set_gdbarch_register_type (gdbarch, avr_register_type);
1500 set_gdbarch_num_pseudo_regs (gdbarch, AVR_NUM_PSEUDO_REGS);
1501 set_gdbarch_pseudo_register_read (gdbarch, avr_pseudo_register_read);
1502 set_gdbarch_pseudo_register_write (gdbarch, avr_pseudo_register_write);
1504 set_gdbarch_return_value (gdbarch, avr_return_value);
1505 set_gdbarch_print_insn (gdbarch, print_insn_avr);
1507 set_gdbarch_push_dummy_call (gdbarch, avr_push_dummy_call);
1509 set_gdbarch_dwarf2_reg_to_regnum (gdbarch, avr_dwarf_reg_to_regnum);
1511 set_gdbarch_address_to_pointer (gdbarch, avr_address_to_pointer);
1512 set_gdbarch_pointer_to_address (gdbarch, avr_pointer_to_address);
1513 set_gdbarch_integer_to_address (gdbarch, avr_integer_to_address);
1515 set_gdbarch_skip_prologue (gdbarch, avr_skip_prologue);
1516 set_gdbarch_inner_than (gdbarch, core_addr_lessthan);
1518 set_gdbarch_breakpoint_from_pc (gdbarch, avr_breakpoint_from_pc);
1520 frame_unwind_append_unwinder (gdbarch, &avr_frame_unwind);
1521 frame_base_set_default (gdbarch, &avr_frame_base);
1523 set_gdbarch_dummy_id (gdbarch, avr_dummy_id);
1525 set_gdbarch_unwind_pc (gdbarch, avr_unwind_pc);
1526 set_gdbarch_unwind_sp (gdbarch, avr_unwind_sp);
1528 set_gdbarch_address_class_type_flags (gdbarch, avr_address_class_type_flags);
1529 set_gdbarch_address_class_name_to_type_flags
1530 (gdbarch, avr_address_class_name_to_type_flags);
1531 set_gdbarch_address_class_type_flags_to_name
1532 (gdbarch, avr_address_class_type_flags_to_name);
1537 /* Send a query request to the avr remote target asking for values of the io
1538 registers. If args parameter is not NULL, then the user has requested info
1539 on a specific io register [This still needs implemented and is ignored for
1540 now]. The query string should be one of these forms:
1542 "Ravr.io_reg" -> reply is "NN" number of io registers
1544 "Ravr.io_reg:addr,len" where addr is first register and len is number of
1545 registers to be read. The reply should be "<NAME>,VV;" for each io register
1546 where, <NAME> is a string, and VV is the hex value of the register.
1548 All io registers are 8-bit. */
1551 avr_io_reg_read_command (char *args, int from_tty)
1558 unsigned int nreg = 0;
1562 /* Find out how many io registers the target has. */
1563 bufsiz = target_read_alloc (¤t_target, TARGET_OBJECT_AVR,
1564 "avr.io_reg", &buf);
1565 bufstr = (const char *) buf;
1569 fprintf_unfiltered (gdb_stderr,
1570 _("ERR: info io_registers NOT supported "
1571 "by current target\n"));
1575 if (sscanf (bufstr, "%x", &nreg) != 1)
1577 fprintf_unfiltered (gdb_stderr,
1578 _("Error fetching number of io registers\n"));
1585 reinitialize_more_filter ();
1587 printf_unfiltered (_("Target has %u io registers:\n\n"), nreg);
1589 /* only fetch up to 8 registers at a time to keep the buffer small */
1592 for (i = 0; i < nreg; i += step)
1594 /* how many registers this round? */
1597 j = nreg - i; /* last block is less than 8 registers */
1599 snprintf (query, sizeof (query) - 1, "avr.io_reg:%x,%x", i, j);
1600 bufsiz = target_read_alloc (¤t_target, TARGET_OBJECT_AVR,
1603 p = (const char *) buf;
1604 for (k = i; k < (i + j); k++)
1606 if (sscanf (p, "%[^,],%x;", query, &val) == 2)
1608 printf_filtered ("[%02x] %-15s : %02x\n", k, query, val);
1609 while ((*p != ';') && (*p != '\0'))
1611 p++; /* skip over ';' */
1621 extern initialize_file_ftype _initialize_avr_tdep; /* -Wmissing-prototypes */
1624 _initialize_avr_tdep (void)
1626 register_gdbarch_init (bfd_arch_avr, avr_gdbarch_init);
1628 /* Add a new command to allow the user to query the avr remote target for
1629 the values of the io space registers in a saner way than just using
1632 /* FIXME: TRoth/2002-02-18: This should probably be changed to 'info avr
1633 io_registers' to signify it is not available on other platforms. */
1635 add_info ("io_registers", avr_io_reg_read_command,
1636 _("query remote avr target for io space register values"));