| 1 | /* Target-dependent code for Atmel AVR, for GDB. |
| 2 | Copyright 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003 |
| 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 | |
| 22 | /* Contributed by Theodore A. Roth, troth@verinet.com */ |
| 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" |
| 28 | #include "gdbcmd.h" |
| 29 | #include "gdbcore.h" |
| 30 | #include "inferior.h" |
| 31 | #include "symfile.h" |
| 32 | #include "arch-utils.h" |
| 33 | #include "regcache.h" |
| 34 | #include "gdb_string.h" |
| 35 | |
| 36 | /* AVR Background: |
| 37 | |
| 38 | (AVR micros are pure Harvard Architecture processors.) |
| 39 | |
| 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. |
| 45 | |
| 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. |
| 51 | |
| 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.] |
| 56 | |
| 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 |
| 60 | Program Counter. |
| 61 | |
| 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. */ |
| 66 | |
| 67 | #undef XMALLOC |
| 68 | #define XMALLOC(TYPE) ((TYPE*) xmalloc (sizeof (TYPE))) |
| 69 | |
| 70 | #undef EXTRACT_INSN |
| 71 | #define EXTRACT_INSN(addr) extract_unsigned_integer(addr,2) |
| 72 | |
| 73 | /* Constants: prefixed with AVR_ to avoid name space clashes */ |
| 74 | |
| 75 | enum |
| 76 | { |
| 77 | AVR_REG_W = 24, |
| 78 | AVR_REG_X = 26, |
| 79 | AVR_REG_Y = 28, |
| 80 | AVR_FP_REGNUM = 28, |
| 81 | AVR_REG_Z = 30, |
| 82 | |
| 83 | AVR_SREG_REGNUM = 32, |
| 84 | AVR_SP_REGNUM = 33, |
| 85 | AVR_PC_REGNUM = 34, |
| 86 | |
| 87 | AVR_NUM_REGS = 32 + 1 /*SREG*/ + 1 /*SP*/ + 1 /*PC*/, |
| 88 | AVR_NUM_REG_BYTES = 32 + 1 /*SREG*/ + 2 /*SP*/ + 4 /*PC*/, |
| 89 | |
| 90 | AVR_PC_REG_INDEX = 35, /* index into array of registers */ |
| 91 | |
| 92 | AVR_MAX_PROLOGUE_SIZE = 56, /* bytes */ |
| 93 | |
| 94 | /* Count of pushed registers. From r2 to r17 (inclusively), r28, r29 */ |
| 95 | AVR_MAX_PUSHES = 18, |
| 96 | |
| 97 | /* Number of the last pushed register. r17 for current avr-gcc */ |
| 98 | AVR_LAST_PUSHED_REGNUM = 17, |
| 99 | |
| 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. |
| 103 | |
| 104 | Note: I chose these values so as to be consistent with bfd vma |
| 105 | addresses. |
| 106 | |
| 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 |
| 110 | AVR_MEM_MASK. |
| 111 | |
| 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. |
| 115 | |
| 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. */ |
| 121 | |
| 122 | AVR_IMEM_START = 0x00000000, /* INSN memory */ |
| 123 | AVR_SMEM_START = 0x00800000, /* SRAM memory */ |
| 124 | #if 1 |
| 125 | /* No eeprom mask defined */ |
| 126 | AVR_MEM_MASK = 0x00f00000, /* mask to determine memory space */ |
| 127 | #else |
| 128 | AVR_EMEM_START = 0x00810000, /* EEPROM memory */ |
| 129 | AVR_MEM_MASK = 0x00ff0000, /* mask to determine memory space */ |
| 130 | #endif |
| 131 | }; |
| 132 | |
| 133 | /* Any function with a frame looks like this |
| 134 | ....... <-SP POINTS HERE |
| 135 | LOCALS1 <-FP POINTS HERE |
| 136 | LOCALS0 |
| 137 | SAVED FP |
| 138 | SAVED R3 |
| 139 | SAVED R2 |
| 140 | RET PC |
| 141 | FIRST ARG |
| 142 | SECOND ARG */ |
| 143 | |
| 144 | struct frame_extra_info |
| 145 | { |
| 146 | CORE_ADDR return_pc; |
| 147 | CORE_ADDR args_pointer; |
| 148 | int locals_size; |
| 149 | int framereg; |
| 150 | int framesize; |
| 151 | int is_main; |
| 152 | }; |
| 153 | |
| 154 | struct gdbarch_tdep |
| 155 | { |
| 156 | /* FIXME: TRoth: is there anything to put here? */ |
| 157 | int foo; |
| 158 | }; |
| 159 | |
| 160 | /* Lookup the name of a register given it's number. */ |
| 161 | |
| 162 | static const char * |
| 163 | avr_register_name (int regnum) |
| 164 | { |
| 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", |
| 170 | "SREG", "SP", "PC" |
| 171 | }; |
| 172 | if (regnum < 0) |
| 173 | return NULL; |
| 174 | if (regnum >= (sizeof (register_names) / sizeof (*register_names))) |
| 175 | return NULL; |
| 176 | return register_names[regnum]; |
| 177 | } |
| 178 | |
| 179 | /* Index within `registers' of the first byte of the space for |
| 180 | register REGNUM. */ |
| 181 | |
| 182 | static int |
| 183 | avr_register_byte (int regnum) |
| 184 | { |
| 185 | if (regnum < AVR_PC_REGNUM) |
| 186 | return regnum; |
| 187 | else |
| 188 | return AVR_PC_REG_INDEX; |
| 189 | } |
| 190 | |
| 191 | /* Number of bytes of storage in the actual machine representation for |
| 192 | register REGNUM. */ |
| 193 | |
| 194 | static int |
| 195 | avr_register_raw_size (int regnum) |
| 196 | { |
| 197 | switch (regnum) |
| 198 | { |
| 199 | case AVR_PC_REGNUM: |
| 200 | return 4; |
| 201 | case AVR_SP_REGNUM: |
| 202 | case AVR_FP_REGNUM: |
| 203 | return 2; |
| 204 | default: |
| 205 | return 1; |
| 206 | } |
| 207 | } |
| 208 | |
| 209 | /* Number of bytes of storage in the program's representation |
| 210 | for register N. */ |
| 211 | |
| 212 | static int |
| 213 | avr_register_virtual_size (int regnum) |
| 214 | { |
| 215 | return TYPE_LENGTH (REGISTER_VIRTUAL_TYPE (regnum)); |
| 216 | } |
| 217 | |
| 218 | /* Return the GDB type object for the "standard" data type |
| 219 | of data in register N. */ |
| 220 | |
| 221 | static struct type * |
| 222 | avr_register_virtual_type (int regnum) |
| 223 | { |
| 224 | switch (regnum) |
| 225 | { |
| 226 | case AVR_PC_REGNUM: |
| 227 | return builtin_type_unsigned_long; |
| 228 | case AVR_SP_REGNUM: |
| 229 | return builtin_type_unsigned_short; |
| 230 | default: |
| 231 | return builtin_type_unsigned_char; |
| 232 | } |
| 233 | } |
| 234 | |
| 235 | /* Instruction address checks and convertions. */ |
| 236 | |
| 237 | static CORE_ADDR |
| 238 | avr_make_iaddr (CORE_ADDR x) |
| 239 | { |
| 240 | return ((x) | AVR_IMEM_START); |
| 241 | } |
| 242 | |
| 243 | static int |
| 244 | avr_iaddr_p (CORE_ADDR x) |
| 245 | { |
| 246 | return (((x) & AVR_MEM_MASK) == AVR_IMEM_START); |
| 247 | } |
| 248 | |
| 249 | /* FIXME: TRoth: Really need to use a larger mask for instructions. Some |
| 250 | devices are already up to 128KBytes of flash space. |
| 251 | |
| 252 | TRoth/2002-04-8: See comment above where AVR_IMEM_START is defined. */ |
| 253 | |
| 254 | static CORE_ADDR |
| 255 | avr_convert_iaddr_to_raw (CORE_ADDR x) |
| 256 | { |
| 257 | return ((x) & 0xffffffff); |
| 258 | } |
| 259 | |
| 260 | /* SRAM address checks and convertions. */ |
| 261 | |
| 262 | static CORE_ADDR |
| 263 | avr_make_saddr (CORE_ADDR x) |
| 264 | { |
| 265 | return ((x) | AVR_SMEM_START); |
| 266 | } |
| 267 | |
| 268 | static int |
| 269 | avr_saddr_p (CORE_ADDR x) |
| 270 | { |
| 271 | return (((x) & AVR_MEM_MASK) == AVR_SMEM_START); |
| 272 | } |
| 273 | |
| 274 | static CORE_ADDR |
| 275 | avr_convert_saddr_to_raw (CORE_ADDR x) |
| 276 | { |
| 277 | return ((x) & 0xffffffff); |
| 278 | } |
| 279 | |
| 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 */ |
| 282 | |
| 283 | /* TRoth/2002-04-08: Commented out for now to allow fix for problem with large |
| 284 | programs in the mega128. */ |
| 285 | |
| 286 | /* static CORE_ADDR */ |
| 287 | /* avr_make_eaddr (CORE_ADDR x) */ |
| 288 | /* { */ |
| 289 | /* return ((x) | AVR_EMEM_START); */ |
| 290 | /* } */ |
| 291 | |
| 292 | /* static int */ |
| 293 | /* avr_eaddr_p (CORE_ADDR x) */ |
| 294 | /* { */ |
| 295 | /* return (((x) & AVR_MEM_MASK) == AVR_EMEM_START); */ |
| 296 | /* } */ |
| 297 | |
| 298 | /* static CORE_ADDR */ |
| 299 | /* avr_convert_eaddr_to_raw (CORE_ADDR x) */ |
| 300 | /* { */ |
| 301 | /* return ((x) & 0xffffffff); */ |
| 302 | /* } */ |
| 303 | |
| 304 | /* Convert from address to pointer and vice-versa. */ |
| 305 | |
| 306 | static void |
| 307 | avr_address_to_pointer (struct type *type, void *buf, CORE_ADDR addr) |
| 308 | { |
| 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) |
| 312 | { |
| 313 | store_unsigned_integer (buf, TYPE_LENGTH (type), |
| 314 | avr_convert_iaddr_to_raw (addr)); |
| 315 | } |
| 316 | else |
| 317 | { |
| 318 | /* Strip off any upper segment bits. */ |
| 319 | store_unsigned_integer (buf, TYPE_LENGTH (type), |
| 320 | avr_convert_saddr_to_raw (addr)); |
| 321 | } |
| 322 | } |
| 323 | |
| 324 | static CORE_ADDR |
| 325 | avr_pointer_to_address (struct type *type, const void *buf) |
| 326 | { |
| 327 | CORE_ADDR addr = extract_address (buf, TYPE_LENGTH (type)); |
| 328 | |
| 329 | if (TYPE_CODE_SPACE (TYPE_TARGET_TYPE (type))) |
| 330 | { |
| 331 | fprintf_unfiltered (gdb_stderr, "CODE_SPACE ---->> ptr->addr: 0x%lx\n", |
| 332 | addr); |
| 333 | fprintf_unfiltered (gdb_stderr, |
| 334 | "+++ If you see this, please send me an email <troth@verinet.com>\n"); |
| 335 | } |
| 336 | |
| 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); |
| 342 | else |
| 343 | return avr_make_saddr (addr); |
| 344 | } |
| 345 | |
| 346 | static CORE_ADDR |
| 347 | avr_read_pc (ptid_t ptid) |
| 348 | { |
| 349 | ptid_t save_ptid; |
| 350 | CORE_ADDR pc; |
| 351 | CORE_ADDR retval; |
| 352 | |
| 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); |
| 358 | return retval; |
| 359 | } |
| 360 | |
| 361 | static void |
| 362 | avr_write_pc (CORE_ADDR val, ptid_t ptid) |
| 363 | { |
| 364 | ptid_t save_ptid; |
| 365 | |
| 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; |
| 370 | } |
| 371 | |
| 372 | static CORE_ADDR |
| 373 | avr_read_sp (void) |
| 374 | { |
| 375 | return (avr_make_saddr (read_register (AVR_SP_REGNUM))); |
| 376 | } |
| 377 | |
| 378 | static void |
| 379 | avr_write_sp (CORE_ADDR val) |
| 380 | { |
| 381 | write_register (AVR_SP_REGNUM, avr_convert_saddr_to_raw (val)); |
| 382 | } |
| 383 | |
| 384 | static CORE_ADDR |
| 385 | avr_read_fp (void) |
| 386 | { |
| 387 | return (avr_make_saddr (read_register (AVR_FP_REGNUM))); |
| 388 | } |
| 389 | |
| 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). |
| 394 | |
| 395 | TRoth/2002-04-08: Could this be used to check for dereferencing an invalid |
| 396 | pointer? */ |
| 397 | |
| 398 | static void |
| 399 | avr_remote_translate_xfer_address (CORE_ADDR memaddr, int nr_bytes, |
| 400 | CORE_ADDR *targ_addr, int *targ_len) |
| 401 | { |
| 402 | long out_addr; |
| 403 | long out_len; |
| 404 | |
| 405 | /* FIXME: TRoth: Do nothing for now. Will need to examine memaddr at this |
| 406 | point and see if the high bit are set with the masks that we want. */ |
| 407 | |
| 408 | *targ_addr = memaddr; |
| 409 | *targ_len = nr_bytes; |
| 410 | } |
| 411 | |
| 412 | /* Function pointers obtained from the target are half of what gdb expects so |
| 413 | multiply by 2. */ |
| 414 | |
| 415 | static CORE_ADDR |
| 416 | avr_convert_from_func_ptr_addr (CORE_ADDR addr) |
| 417 | { |
| 418 | return addr * 2; |
| 419 | } |
| 420 | |
| 421 | /* avr_scan_prologue is also used as the |
| 422 | deprecated_frame_init_saved_regs(). |
| 423 | |
| 424 | Put here the code to store, into fi->saved_regs, the addresses of |
| 425 | the saved registers of frame described by FRAME_INFO. This |
| 426 | includes special registers such as pc and fp saved in special ways |
| 427 | in the stack frame. sp is even more special: the address we return |
| 428 | for it IS the sp for the next frame. */ |
| 429 | |
| 430 | /* Function: avr_scan_prologue (helper function for avr_init_extra_frame_info) |
| 431 | This function decodes a AVR function prologue to determine: |
| 432 | 1) the size of the stack frame |
| 433 | 2) which registers are saved on it |
| 434 | 3) the offsets of saved regs |
| 435 | This information is stored in the "extra_info" field of the frame_info. |
| 436 | |
| 437 | A typical AVR function prologue might look like this: |
| 438 | push rXX |
| 439 | push r28 |
| 440 | push r29 |
| 441 | in r28,__SP_L__ |
| 442 | in r29,__SP_H__ |
| 443 | sbiw r28,<LOCALS_SIZE> |
| 444 | in __tmp_reg__,__SREG__ |
| 445 | cli |
| 446 | out __SP_L__,r28 |
| 447 | out __SREG__,__tmp_reg__ |
| 448 | out __SP_H__,r29 |
| 449 | |
| 450 | A `-mcall-prologues' prologue look like this: |
| 451 | ldi r26,<LOCALS_SIZE> |
| 452 | ldi r27,<LOCALS_SIZE>/265 |
| 453 | ldi r30,pm_lo8(.L_foo_body) |
| 454 | ldi r31,pm_hi8(.L_foo_body) |
| 455 | rjmp __prologue_saves__+RRR |
| 456 | .L_foo_body: */ |
| 457 | |
| 458 | static void |
| 459 | avr_scan_prologue (struct frame_info *fi) |
| 460 | { |
| 461 | CORE_ADDR prologue_start; |
| 462 | CORE_ADDR prologue_end; |
| 463 | int i; |
| 464 | unsigned short insn; |
| 465 | int regno; |
| 466 | int scan_stage = 0; |
| 467 | char *name; |
| 468 | struct minimal_symbol *msymbol; |
| 469 | int prologue_len; |
| 470 | unsigned char prologue[AVR_MAX_PROLOGUE_SIZE]; |
| 471 | int vpc = 0; |
| 472 | |
| 473 | get_frame_extra_info (fi)->framereg = AVR_SP_REGNUM; |
| 474 | |
| 475 | if (find_pc_partial_function |
| 476 | (get_frame_pc (fi), &name, &prologue_start, &prologue_end)) |
| 477 | { |
| 478 | struct symtab_and_line sal = find_pc_line (prologue_start, 0); |
| 479 | |
| 480 | if (sal.line == 0) /* no line info, use current PC */ |
| 481 | prologue_end = get_frame_pc (fi); |
| 482 | else if (sal.end < prologue_end) /* next line begins after fn end */ |
| 483 | prologue_end = sal.end; /* (probably means no prologue) */ |
| 484 | } |
| 485 | else |
| 486 | /* We're in the boondocks: allow for */ |
| 487 | /* 19 pushes, an add, and "mv fp,sp" */ |
| 488 | prologue_end = prologue_start + AVR_MAX_PROLOGUE_SIZE; |
| 489 | |
| 490 | prologue_end = min (prologue_end, get_frame_pc (fi)); |
| 491 | |
| 492 | /* Search the prologue looking for instructions that set up the |
| 493 | frame pointer, adjust the stack pointer, and save registers. */ |
| 494 | |
| 495 | get_frame_extra_info (fi)->framesize = 0; |
| 496 | prologue_len = prologue_end - prologue_start; |
| 497 | read_memory (prologue_start, prologue, prologue_len); |
| 498 | |
| 499 | /* Scanning main()'s prologue |
| 500 | ldi r28,lo8(<RAM_ADDR> - <LOCALS_SIZE>) |
| 501 | ldi r29,hi8(<RAM_ADDR> - <LOCALS_SIZE>) |
| 502 | out __SP_H__,r29 |
| 503 | out __SP_L__,r28 */ |
| 504 | |
| 505 | if (name && strcmp ("main", name) == 0 && prologue_len == 8) |
| 506 | { |
| 507 | CORE_ADDR locals; |
| 508 | unsigned char img[] = { |
| 509 | 0xde, 0xbf, /* out __SP_H__,r29 */ |
| 510 | 0xcd, 0xbf /* out __SP_L__,r28 */ |
| 511 | }; |
| 512 | |
| 513 | get_frame_extra_info (fi)->framereg = AVR_FP_REGNUM; |
| 514 | insn = EXTRACT_INSN (&prologue[vpc]); |
| 515 | /* ldi r28,lo8(<RAM_ADDR> - <LOCALS_SIZE>) */ |
| 516 | if ((insn & 0xf0f0) == 0xe0c0) |
| 517 | { |
| 518 | locals = (insn & 0xf) | ((insn & 0x0f00) >> 4); |
| 519 | insn = EXTRACT_INSN (&prologue[vpc + 2]); |
| 520 | /* ldi r29,hi8(<RAM_ADDR> - <LOCALS_SIZE>) */ |
| 521 | if ((insn & 0xf0f0) == 0xe0d0) |
| 522 | { |
| 523 | locals |= ((insn & 0xf) | ((insn & 0x0f00) >> 4)) << 8; |
| 524 | if (memcmp (prologue + vpc + 4, img, sizeof (img)) == 0) |
| 525 | { |
| 526 | deprecated_update_frame_base_hack (fi, locals); |
| 527 | |
| 528 | get_frame_extra_info (fi)->is_main = 1; |
| 529 | return; |
| 530 | } |
| 531 | } |
| 532 | } |
| 533 | } |
| 534 | |
| 535 | /* Scanning `-mcall-prologues' prologue |
| 536 | FIXME: mega prologue have a 12 bytes long */ |
| 537 | |
| 538 | while (prologue_len <= 12) /* I'm use while to avoit many goto's */ |
| 539 | { |
| 540 | int loc_size; |
| 541 | int body_addr; |
| 542 | unsigned num_pushes; |
| 543 | |
| 544 | insn = EXTRACT_INSN (&prologue[vpc]); |
| 545 | /* ldi r26,<LOCALS_SIZE> */ |
| 546 | if ((insn & 0xf0f0) != 0xe0a0) |
| 547 | break; |
| 548 | loc_size = (insn & 0xf) | ((insn & 0x0f00) >> 4); |
| 549 | |
| 550 | insn = EXTRACT_INSN (&prologue[vpc + 2]); |
| 551 | /* ldi r27,<LOCALS_SIZE> / 256 */ |
| 552 | if ((insn & 0xf0f0) != 0xe0b0) |
| 553 | break; |
| 554 | loc_size |= ((insn & 0xf) | ((insn & 0x0f00) >> 4)) << 8; |
| 555 | |
| 556 | insn = EXTRACT_INSN (&prologue[vpc + 4]); |
| 557 | /* ldi r30,pm_lo8(.L_foo_body) */ |
| 558 | if ((insn & 0xf0f0) != 0xe0e0) |
| 559 | break; |
| 560 | body_addr = (insn & 0xf) | ((insn & 0x0f00) >> 4); |
| 561 | |
| 562 | insn = EXTRACT_INSN (&prologue[vpc + 6]); |
| 563 | /* ldi r31,pm_hi8(.L_foo_body) */ |
| 564 | if ((insn & 0xf0f0) != 0xe0f0) |
| 565 | break; |
| 566 | body_addr |= ((insn & 0xf) | ((insn & 0x0f00) >> 4)) << 8; |
| 567 | |
| 568 | if (body_addr != (prologue_start + 10) / 2) |
| 569 | break; |
| 570 | |
| 571 | msymbol = lookup_minimal_symbol ("__prologue_saves__", NULL, NULL); |
| 572 | if (!msymbol) |
| 573 | break; |
| 574 | |
| 575 | /* FIXME: prologue for mega have a JMP instead of RJMP */ |
| 576 | insn = EXTRACT_INSN (&prologue[vpc + 8]); |
| 577 | /* rjmp __prologue_saves__+RRR */ |
| 578 | if ((insn & 0xf000) != 0xc000) |
| 579 | break; |
| 580 | |
| 581 | /* Extract PC relative offset from RJMP */ |
| 582 | i = (insn & 0xfff) | (insn & 0x800 ? (-1 ^ 0xfff) : 0); |
| 583 | /* Convert offset to byte addressable mode */ |
| 584 | i *= 2; |
| 585 | /* Destination address */ |
| 586 | i += vpc + prologue_start + 10; |
| 587 | /* Resovle offset (in words) from __prologue_saves__ symbol. |
| 588 | Which is a pushes count in `-mcall-prologues' mode */ |
| 589 | num_pushes = AVR_MAX_PUSHES - (i - SYMBOL_VALUE_ADDRESS (msymbol)) / 2; |
| 590 | |
| 591 | if (num_pushes > AVR_MAX_PUSHES) |
| 592 | num_pushes = 0; |
| 593 | |
| 594 | if (num_pushes) |
| 595 | { |
| 596 | int from; |
| 597 | get_frame_saved_regs (fi)[AVR_FP_REGNUM + 1] = num_pushes; |
| 598 | if (num_pushes >= 2) |
| 599 | get_frame_saved_regs (fi)[AVR_FP_REGNUM] = num_pushes - 1; |
| 600 | i = 0; |
| 601 | for (from = AVR_LAST_PUSHED_REGNUM + 1 - (num_pushes - 2); |
| 602 | from <= AVR_LAST_PUSHED_REGNUM; ++from) |
| 603 | get_frame_saved_regs (fi)[from] = ++i; |
| 604 | } |
| 605 | get_frame_extra_info (fi)->locals_size = loc_size; |
| 606 | get_frame_extra_info (fi)->framesize = loc_size + num_pushes; |
| 607 | get_frame_extra_info (fi)->framereg = AVR_FP_REGNUM; |
| 608 | return; |
| 609 | } |
| 610 | |
| 611 | /* Scan interrupt or signal function */ |
| 612 | |
| 613 | if (prologue_len >= 12) |
| 614 | { |
| 615 | unsigned char img[] = { |
| 616 | 0x78, 0x94, /* sei */ |
| 617 | 0x1f, 0x92, /* push r1 */ |
| 618 | 0x0f, 0x92, /* push r0 */ |
| 619 | 0x0f, 0xb6, /* in r0,0x3f SREG */ |
| 620 | 0x0f, 0x92, /* push r0 */ |
| 621 | 0x11, 0x24 /* clr r1 */ |
| 622 | }; |
| 623 | if (memcmp (prologue, img, sizeof (img)) == 0) |
| 624 | { |
| 625 | vpc += sizeof (img); |
| 626 | get_frame_saved_regs (fi)[0] = 2; |
| 627 | get_frame_saved_regs (fi)[1] = 1; |
| 628 | get_frame_extra_info (fi)->framesize += 3; |
| 629 | } |
| 630 | else if (memcmp (img + 1, prologue, sizeof (img) - 1) == 0) |
| 631 | { |
| 632 | vpc += sizeof (img) - 1; |
| 633 | get_frame_saved_regs (fi)[0] = 2; |
| 634 | get_frame_saved_regs (fi)[1] = 1; |
| 635 | get_frame_extra_info (fi)->framesize += 3; |
| 636 | } |
| 637 | } |
| 638 | |
| 639 | /* First stage of the prologue scanning. |
| 640 | Scan pushes */ |
| 641 | |
| 642 | for (; vpc <= prologue_len; vpc += 2) |
| 643 | { |
| 644 | insn = EXTRACT_INSN (&prologue[vpc]); |
| 645 | if ((insn & 0xfe0f) == 0x920f) /* push rXX */ |
| 646 | { |
| 647 | /* Bits 4-9 contain a mask for registers R0-R32. */ |
| 648 | regno = (insn & 0x1f0) >> 4; |
| 649 | ++get_frame_extra_info (fi)->framesize; |
| 650 | get_frame_saved_regs (fi)[regno] = get_frame_extra_info (fi)->framesize; |
| 651 | scan_stage = 1; |
| 652 | } |
| 653 | else |
| 654 | break; |
| 655 | } |
| 656 | |
| 657 | /* Second stage of the prologue scanning. |
| 658 | Scan: |
| 659 | in r28,__SP_L__ |
| 660 | in r29,__SP_H__ */ |
| 661 | |
| 662 | if (scan_stage == 1 && vpc + 4 <= prologue_len) |
| 663 | { |
| 664 | unsigned char img[] = { |
| 665 | 0xcd, 0xb7, /* in r28,__SP_L__ */ |
| 666 | 0xde, 0xb7 /* in r29,__SP_H__ */ |
| 667 | }; |
| 668 | unsigned short insn1; |
| 669 | |
| 670 | if (memcmp (prologue + vpc, img, sizeof (img)) == 0) |
| 671 | { |
| 672 | vpc += 4; |
| 673 | get_frame_extra_info (fi)->framereg = AVR_FP_REGNUM; |
| 674 | scan_stage = 2; |
| 675 | } |
| 676 | } |
| 677 | |
| 678 | /* Third stage of the prologue scanning. (Really two stages) |
| 679 | Scan for: |
| 680 | sbiw r28,XX or subi r28,lo8(XX) |
| 681 | sbci r29,hi8(XX) |
| 682 | in __tmp_reg__,__SREG__ |
| 683 | cli |
| 684 | out __SP_L__,r28 |
| 685 | out __SREG__,__tmp_reg__ |
| 686 | out __SP_H__,r29 */ |
| 687 | |
| 688 | if (scan_stage == 2 && vpc + 12 <= prologue_len) |
| 689 | { |
| 690 | int locals_size = 0; |
| 691 | unsigned char img[] = { |
| 692 | 0x0f, 0xb6, /* in r0,0x3f */ |
| 693 | 0xf8, 0x94, /* cli */ |
| 694 | 0xcd, 0xbf, /* out 0x3d,r28 ; SPL */ |
| 695 | 0x0f, 0xbe, /* out 0x3f,r0 ; SREG */ |
| 696 | 0xde, 0xbf /* out 0x3e,r29 ; SPH */ |
| 697 | }; |
| 698 | unsigned char img_sig[] = { |
| 699 | 0xcd, 0xbf, /* out 0x3d,r28 ; SPL */ |
| 700 | 0xde, 0xbf /* out 0x3e,r29 ; SPH */ |
| 701 | }; |
| 702 | unsigned char img_int[] = { |
| 703 | 0xf8, 0x94, /* cli */ |
| 704 | 0xcd, 0xbf, /* out 0x3d,r28 ; SPL */ |
| 705 | 0x78, 0x94, /* sei */ |
| 706 | 0xde, 0xbf /* out 0x3e,r29 ; SPH */ |
| 707 | }; |
| 708 | |
| 709 | insn = EXTRACT_INSN (&prologue[vpc]); |
| 710 | vpc += 2; |
| 711 | if ((insn & 0xff30) == 0x9720) /* sbiw r28,XXX */ |
| 712 | locals_size = (insn & 0xf) | ((insn & 0xc0) >> 2); |
| 713 | else if ((insn & 0xf0f0) == 0x50c0) /* subi r28,lo8(XX) */ |
| 714 | { |
| 715 | locals_size = (insn & 0xf) | ((insn & 0xf00) >> 4); |
| 716 | insn = EXTRACT_INSN (&prologue[vpc]); |
| 717 | vpc += 2; |
| 718 | locals_size += ((insn & 0xf) | ((insn & 0xf00) >> 4) << 8); |
| 719 | } |
| 720 | else |
| 721 | return; |
| 722 | get_frame_extra_info (fi)->locals_size = locals_size; |
| 723 | get_frame_extra_info (fi)->framesize += locals_size; |
| 724 | } |
| 725 | } |
| 726 | |
| 727 | /* This function actually figures out the frame address for a given pc and |
| 728 | sp. This is tricky because we sometimes don't use an explicit |
| 729 | frame pointer, and the previous stack pointer isn't necessarily recorded |
| 730 | on the stack. The only reliable way to get this info is to |
| 731 | examine the prologue. */ |
| 732 | |
| 733 | static void |
| 734 | avr_init_extra_frame_info (int fromleaf, struct frame_info *fi) |
| 735 | { |
| 736 | int reg; |
| 737 | |
| 738 | if (get_next_frame (fi)) |
| 739 | deprecated_update_frame_pc_hack (fi, DEPRECATED_FRAME_SAVED_PC (get_next_frame (fi))); |
| 740 | |
| 741 | frame_extra_info_zalloc (fi, sizeof (struct frame_extra_info)); |
| 742 | frame_saved_regs_zalloc (fi); |
| 743 | |
| 744 | get_frame_extra_info (fi)->return_pc = 0; |
| 745 | get_frame_extra_info (fi)->args_pointer = 0; |
| 746 | get_frame_extra_info (fi)->locals_size = 0; |
| 747 | get_frame_extra_info (fi)->framereg = 0; |
| 748 | get_frame_extra_info (fi)->framesize = 0; |
| 749 | get_frame_extra_info (fi)->is_main = 0; |
| 750 | |
| 751 | avr_scan_prologue (fi); |
| 752 | |
| 753 | if (DEPRECATED_PC_IN_CALL_DUMMY (get_frame_pc (fi), get_frame_base (fi), |
| 754 | get_frame_base (fi))) |
| 755 | { |
| 756 | /* We need to setup fi->frame here because run_stack_dummy gets it wrong |
| 757 | by assuming it's always FP. */ |
| 758 | deprecated_update_frame_base_hack (fi, deprecated_read_register_dummy (get_frame_pc (fi), get_frame_base (fi), |
| 759 | AVR_PC_REGNUM)); |
| 760 | } |
| 761 | else if (!get_next_frame (fi)) |
| 762 | /* this is the innermost frame? */ |
| 763 | deprecated_update_frame_base_hack (fi, read_register (get_frame_extra_info (fi)->framereg)); |
| 764 | else if (get_frame_extra_info (fi)->is_main != 1) |
| 765 | /* not the innermost frame, not `main' */ |
| 766 | /* If we have an next frame, the callee saved it. */ |
| 767 | { |
| 768 | struct frame_info *next_fi = get_next_frame (fi); |
| 769 | if (get_frame_extra_info (fi)->framereg == AVR_SP_REGNUM) |
| 770 | deprecated_update_frame_base_hack (fi, (get_frame_base (next_fi) |
| 771 | + 2 /* ret addr */ |
| 772 | + get_frame_extra_info (next_fi)->framesize)); |
| 773 | /* FIXME: I don't analyse va_args functions */ |
| 774 | else |
| 775 | { |
| 776 | CORE_ADDR fp = 0; |
| 777 | CORE_ADDR fp1 = 0; |
| 778 | unsigned int fp_low, fp_high; |
| 779 | |
| 780 | /* Scan all frames */ |
| 781 | for (; next_fi; next_fi = get_next_frame (next_fi)) |
| 782 | { |
| 783 | /* look for saved AVR_FP_REGNUM */ |
| 784 | if (get_frame_saved_regs (next_fi)[AVR_FP_REGNUM] && !fp) |
| 785 | fp = get_frame_saved_regs (next_fi)[AVR_FP_REGNUM]; |
| 786 | /* look for saved AVR_FP_REGNUM + 1 */ |
| 787 | if (get_frame_saved_regs (next_fi)[AVR_FP_REGNUM + 1] && !fp1) |
| 788 | fp1 = get_frame_saved_regs (next_fi)[AVR_FP_REGNUM + 1]; |
| 789 | } |
| 790 | fp_low = (fp ? read_memory_unsigned_integer (avr_make_saddr (fp), 1) |
| 791 | : read_register (AVR_FP_REGNUM)) & 0xff; |
| 792 | fp_high = |
| 793 | (fp1 ? read_memory_unsigned_integer (avr_make_saddr (fp1), 1) : |
| 794 | read_register (AVR_FP_REGNUM + 1)) & 0xff; |
| 795 | deprecated_update_frame_base_hack (fi, fp_low | (fp_high << 8)); |
| 796 | } |
| 797 | } |
| 798 | |
| 799 | /* TRoth: Do we want to do this if we are in main? I don't think we should |
| 800 | since return_pc makes no sense when we are in main. */ |
| 801 | |
| 802 | if ((get_frame_pc (fi)) && (get_frame_extra_info (fi)->is_main == 0)) |
| 803 | /* We are not in CALL_DUMMY */ |
| 804 | { |
| 805 | CORE_ADDR addr; |
| 806 | int i; |
| 807 | |
| 808 | addr = get_frame_base (fi) + get_frame_extra_info (fi)->framesize + 1; |
| 809 | |
| 810 | /* Return address in stack in different endianness */ |
| 811 | |
| 812 | get_frame_extra_info (fi)->return_pc = |
| 813 | read_memory_unsigned_integer (avr_make_saddr (addr), 1) << 8; |
| 814 | get_frame_extra_info (fi)->return_pc |= |
| 815 | read_memory_unsigned_integer (avr_make_saddr (addr + 1), 1); |
| 816 | |
| 817 | /* This return address in words, |
| 818 | must be converted to the bytes address */ |
| 819 | get_frame_extra_info (fi)->return_pc *= 2; |
| 820 | |
| 821 | /* Resolve a pushed registers addresses */ |
| 822 | for (i = 0; i < NUM_REGS; i++) |
| 823 | { |
| 824 | if (get_frame_saved_regs (fi)[i]) |
| 825 | get_frame_saved_regs (fi)[i] = addr - get_frame_saved_regs (fi)[i]; |
| 826 | } |
| 827 | } |
| 828 | } |
| 829 | |
| 830 | /* Restore the machine to the state it had before the current frame was |
| 831 | created. Usually used either by the "RETURN" command, or by |
| 832 | call_function_by_hand after the dummy_frame is finished. */ |
| 833 | |
| 834 | static void |
| 835 | avr_pop_frame (void) |
| 836 | { |
| 837 | unsigned regnum; |
| 838 | CORE_ADDR saddr; |
| 839 | struct frame_info *frame = get_current_frame (); |
| 840 | |
| 841 | if (DEPRECATED_PC_IN_CALL_DUMMY (get_frame_pc (frame), |
| 842 | get_frame_base (frame), |
| 843 | get_frame_base (frame))) |
| 844 | { |
| 845 | generic_pop_dummy_frame (); |
| 846 | } |
| 847 | else |
| 848 | { |
| 849 | /* TRoth: Why only loop over 8 registers? */ |
| 850 | |
| 851 | for (regnum = 0; regnum < 8; regnum++) |
| 852 | { |
| 853 | /* Don't forget AVR_SP_REGNUM in a frame_saved_regs struct is the |
| 854 | actual value we want, not the address of the value we want. */ |
| 855 | if (get_frame_saved_regs (frame)[regnum] && regnum != AVR_SP_REGNUM) |
| 856 | { |
| 857 | saddr = avr_make_saddr (get_frame_saved_regs (frame)[regnum]); |
| 858 | write_register (regnum, |
| 859 | read_memory_unsigned_integer (saddr, 1)); |
| 860 | } |
| 861 | else if (get_frame_saved_regs (frame)[regnum] && regnum == AVR_SP_REGNUM) |
| 862 | write_register (regnum, get_frame_base (frame) + 2); |
| 863 | } |
| 864 | |
| 865 | /* Don't forget the update the PC too! */ |
| 866 | write_pc (get_frame_extra_info (frame)->return_pc); |
| 867 | } |
| 868 | flush_cached_frames (); |
| 869 | } |
| 870 | |
| 871 | /* Return the saved PC from this frame. */ |
| 872 | |
| 873 | static CORE_ADDR |
| 874 | avr_frame_saved_pc (struct frame_info *frame) |
| 875 | { |
| 876 | if (DEPRECATED_PC_IN_CALL_DUMMY (get_frame_pc (frame), |
| 877 | get_frame_base (frame), |
| 878 | get_frame_base (frame))) |
| 879 | return deprecated_read_register_dummy (get_frame_pc (frame), |
| 880 | get_frame_base (frame), |
| 881 | AVR_PC_REGNUM); |
| 882 | else |
| 883 | return get_frame_extra_info (frame)->return_pc; |
| 884 | } |
| 885 | |
| 886 | static CORE_ADDR |
| 887 | avr_saved_pc_after_call (struct frame_info *frame) |
| 888 | { |
| 889 | unsigned char m1, m2; |
| 890 | unsigned int sp = read_register (AVR_SP_REGNUM); |
| 891 | m1 = read_memory_unsigned_integer (avr_make_saddr (sp + 1), 1); |
| 892 | m2 = read_memory_unsigned_integer (avr_make_saddr (sp + 2), 1); |
| 893 | return (m2 | (m1 << 8)) * 2; |
| 894 | } |
| 895 | |
| 896 | /* Returns the return address for a dummy. */ |
| 897 | |
| 898 | static CORE_ADDR |
| 899 | avr_call_dummy_address (void) |
| 900 | { |
| 901 | return entry_point_address (); |
| 902 | } |
| 903 | |
| 904 | /* Setup the return address for a dummy frame, as called by |
| 905 | call_function_by_hand. Only necessary when you are using an empty |
| 906 | CALL_DUMMY. */ |
| 907 | |
| 908 | static CORE_ADDR |
| 909 | avr_push_return_address (CORE_ADDR pc, CORE_ADDR sp) |
| 910 | { |
| 911 | unsigned char buf[2]; |
| 912 | int wordsize = 2; |
| 913 | #if 0 |
| 914 | struct minimal_symbol *msymbol; |
| 915 | CORE_ADDR mon_brk; |
| 916 | #endif |
| 917 | |
| 918 | buf[0] = 0; |
| 919 | buf[1] = 0; |
| 920 | sp -= wordsize; |
| 921 | write_memory (sp + 1, buf, 2); |
| 922 | |
| 923 | #if 0 |
| 924 | /* FIXME: TRoth/2002-02-18: This should probably be removed since it's a |
| 925 | left-over from Denis' original patch which used avr-mon for the target |
| 926 | instead of the generic remote target. */ |
| 927 | if ((strcmp (target_shortname, "avr-mon") == 0) |
| 928 | && (msymbol = lookup_minimal_symbol ("gdb_break", NULL, NULL))) |
| 929 | { |
| 930 | mon_brk = SYMBOL_VALUE_ADDRESS (msymbol); |
| 931 | store_unsigned_integer (buf, wordsize, mon_brk / 2); |
| 932 | sp -= wordsize; |
| 933 | write_memory (sp + 1, buf + 1, 1); |
| 934 | write_memory (sp + 2, buf, 1); |
| 935 | } |
| 936 | #endif |
| 937 | return sp; |
| 938 | } |
| 939 | |
| 940 | static CORE_ADDR |
| 941 | avr_skip_prologue (CORE_ADDR pc) |
| 942 | { |
| 943 | CORE_ADDR func_addr, func_end; |
| 944 | struct symtab_and_line sal; |
| 945 | |
| 946 | /* See what the symbol table says */ |
| 947 | |
| 948 | if (find_pc_partial_function (pc, NULL, &func_addr, &func_end)) |
| 949 | { |
| 950 | sal = find_pc_line (func_addr, 0); |
| 951 | |
| 952 | /* troth/2002-08-05: For some very simple functions, gcc doesn't |
| 953 | generate a prologue and the sal.end ends up being the 2-byte ``ret'' |
| 954 | instruction at the end of the function, but func_end ends up being |
| 955 | the address of the first instruction of the _next_ function. By |
| 956 | adjusting func_end by 2 bytes, we can catch these functions and not |
| 957 | return sal.end if it is the ``ret'' instruction. */ |
| 958 | |
| 959 | if (sal.line != 0 && sal.end < (func_end-2)) |
| 960 | return sal.end; |
| 961 | } |
| 962 | |
| 963 | /* Either we didn't find the start of this function (nothing we can do), |
| 964 | or there's no line info, or the line after the prologue is after |
| 965 | the end of the function (there probably isn't a prologue). */ |
| 966 | |
| 967 | return pc; |
| 968 | } |
| 969 | |
| 970 | static CORE_ADDR |
| 971 | avr_frame_address (struct frame_info *fi) |
| 972 | { |
| 973 | return avr_make_saddr (get_frame_base (fi)); |
| 974 | } |
| 975 | |
| 976 | /* Given a GDB frame, determine the address of the calling function's |
| 977 | frame. This will be used to create a new GDB frame struct, and |
| 978 | then DEPRECATED_INIT_EXTRA_FRAME_INFO and DEPRECATED_INIT_FRAME_PC |
| 979 | will be called for the new frame. |
| 980 | |
| 981 | For us, the frame address is its stack pointer value, so we look up |
| 982 | the function prologue to determine the caller's sp value, and return it. */ |
| 983 | |
| 984 | static CORE_ADDR |
| 985 | avr_frame_chain (struct frame_info *frame) |
| 986 | { |
| 987 | if (DEPRECATED_PC_IN_CALL_DUMMY (get_frame_pc (frame), |
| 988 | get_frame_base (frame), |
| 989 | get_frame_base (frame))) |
| 990 | { |
| 991 | /* initialize the return_pc now */ |
| 992 | get_frame_extra_info (frame)->return_pc |
| 993 | = deprecated_read_register_dummy (get_frame_pc (frame), |
| 994 | get_frame_base (frame), |
| 995 | AVR_PC_REGNUM); |
| 996 | return get_frame_base (frame); |
| 997 | } |
| 998 | return (get_frame_extra_info (frame)->is_main ? 0 |
| 999 | : get_frame_base (frame) + get_frame_extra_info (frame)->framesize + 2 /* ret addr */ ); |
| 1000 | } |
| 1001 | |
| 1002 | /* Store the address of the place in which to copy the structure the |
| 1003 | subroutine will return. This is called from call_function. |
| 1004 | |
| 1005 | We store structs through a pointer passed in the first Argument |
| 1006 | register. */ |
| 1007 | |
| 1008 | static void |
| 1009 | avr_store_struct_return (CORE_ADDR addr, CORE_ADDR sp) |
| 1010 | { |
| 1011 | write_register (0, addr); |
| 1012 | } |
| 1013 | |
| 1014 | /* Setup the function arguments for calling a function in the inferior. |
| 1015 | |
| 1016 | On the AVR architecture, there are 18 registers (R25 to R8) which are |
| 1017 | dedicated for passing function arguments. Up to the first 18 arguments |
| 1018 | (depending on size) may go into these registers. The rest go on the stack. |
| 1019 | |
| 1020 | Arguments that are larger than WORDSIZE bytes will be split between two or |
| 1021 | more registers as available, but will NOT be split between a register and |
| 1022 | the stack. |
| 1023 | |
| 1024 | An exceptional case exists for struct arguments (and possibly other |
| 1025 | aggregates such as arrays) -- if the size is larger than WORDSIZE bytes but |
| 1026 | not a multiple of WORDSIZE bytes. In this case the argument is never split |
| 1027 | between the registers and the stack, but instead is copied in its entirety |
| 1028 | onto the stack, AND also copied into as many registers as there is room |
| 1029 | for. In other words, space in registers permitting, two copies of the same |
| 1030 | argument are passed in. As far as I can tell, only the one on the stack is |
| 1031 | used, although that may be a function of the level of compiler |
| 1032 | optimization. I suspect this is a compiler bug. Arguments of these odd |
| 1033 | sizes are left-justified within the word (as opposed to arguments smaller |
| 1034 | than WORDSIZE bytes, which are right-justified). |
| 1035 | |
| 1036 | If the function is to return an aggregate type such as a struct, the caller |
| 1037 | must allocate space into which the callee will copy the return value. In |
| 1038 | this case, a pointer to the return value location is passed into the callee |
| 1039 | in register R0, which displaces one of the other arguments passed in via |
| 1040 | registers R0 to R2. */ |
| 1041 | |
| 1042 | static CORE_ADDR |
| 1043 | avr_push_arguments (int nargs, struct value **args, CORE_ADDR sp, |
| 1044 | int struct_return, CORE_ADDR struct_addr) |
| 1045 | { |
| 1046 | int stack_alloc, stack_offset; |
| 1047 | int wordsize; |
| 1048 | int argreg; |
| 1049 | int argnum; |
| 1050 | struct type *type; |
| 1051 | CORE_ADDR regval; |
| 1052 | char *val; |
| 1053 | char valbuf[4]; |
| 1054 | int len; |
| 1055 | |
| 1056 | wordsize = 1; |
| 1057 | #if 0 |
| 1058 | /* Now make sure there's space on the stack */ |
| 1059 | for (argnum = 0, stack_alloc = 0; argnum < nargs; argnum++) |
| 1060 | stack_alloc += TYPE_LENGTH (VALUE_TYPE (args[argnum])); |
| 1061 | sp -= stack_alloc; /* make room on stack for args */ |
| 1062 | /* we may over-allocate a little here, but that won't hurt anything */ |
| 1063 | #endif |
| 1064 | argreg = 25; |
| 1065 | if (struct_return) /* "struct return" pointer takes up one argreg */ |
| 1066 | { |
| 1067 | write_register (--argreg, struct_addr); |
| 1068 | } |
| 1069 | |
| 1070 | /* Now load as many as possible of the first arguments into registers, and |
| 1071 | push the rest onto the stack. There are 3N bytes in three registers |
| 1072 | available. Loop thru args from first to last. */ |
| 1073 | |
| 1074 | for (argnum = 0, stack_offset = 0; argnum < nargs; argnum++) |
| 1075 | { |
| 1076 | type = VALUE_TYPE (args[argnum]); |
| 1077 | len = TYPE_LENGTH (type); |
| 1078 | val = (char *) VALUE_CONTENTS (args[argnum]); |
| 1079 | |
| 1080 | /* NOTE WELL!!!!! This is not an "else if" clause!!! That's because |
| 1081 | some *&^%$ things get passed on the stack AND in the registers! */ |
| 1082 | while (len > 0) |
| 1083 | { /* there's room in registers */ |
| 1084 | len -= wordsize; |
| 1085 | regval = extract_address (val + len, wordsize); |
| 1086 | write_register (argreg--, regval); |
| 1087 | } |
| 1088 | } |
| 1089 | return sp; |
| 1090 | } |
| 1091 | |
| 1092 | /* Initialize the gdbarch structure for the AVR's. */ |
| 1093 | |
| 1094 | static struct gdbarch * |
| 1095 | avr_gdbarch_init (struct gdbarch_info info, struct gdbarch_list *arches) |
| 1096 | { |
| 1097 | /* FIXME: TRoth/2002-02-18: I have no idea if avr_call_dummy_words[] should |
| 1098 | be bigger or not. Initial testing seems to show that `call my_func()` |
| 1099 | works and backtrace from a breakpoint within the call looks correct. |
| 1100 | Admittedly, I haven't tested with more than a very simple program. */ |
| 1101 | static LONGEST avr_call_dummy_words[] = { 0 }; |
| 1102 | |
| 1103 | struct gdbarch *gdbarch; |
| 1104 | struct gdbarch_tdep *tdep; |
| 1105 | |
| 1106 | /* Find a candidate among the list of pre-declared architectures. */ |
| 1107 | arches = gdbarch_list_lookup_by_info (arches, &info); |
| 1108 | if (arches != NULL) |
| 1109 | return arches->gdbarch; |
| 1110 | |
| 1111 | /* None found, create a new architecture from the information provided. */ |
| 1112 | tdep = XMALLOC (struct gdbarch_tdep); |
| 1113 | gdbarch = gdbarch_alloc (&info, tdep); |
| 1114 | |
| 1115 | /* NOTE: cagney/2002-12-06: This can be deleted when this arch is |
| 1116 | ready to unwind the PC first (see frame.c:get_prev_frame()). */ |
| 1117 | set_gdbarch_deprecated_init_frame_pc (gdbarch, init_frame_pc_default); |
| 1118 | |
| 1119 | /* If we ever need to differentiate the device types, do it here. */ |
| 1120 | switch (info.bfd_arch_info->mach) |
| 1121 | { |
| 1122 | case bfd_mach_avr1: |
| 1123 | case bfd_mach_avr2: |
| 1124 | case bfd_mach_avr3: |
| 1125 | case bfd_mach_avr4: |
| 1126 | case bfd_mach_avr5: |
| 1127 | break; |
| 1128 | } |
| 1129 | |
| 1130 | set_gdbarch_short_bit (gdbarch, 2 * TARGET_CHAR_BIT); |
| 1131 | set_gdbarch_int_bit (gdbarch, 2 * TARGET_CHAR_BIT); |
| 1132 | set_gdbarch_long_bit (gdbarch, 4 * TARGET_CHAR_BIT); |
| 1133 | set_gdbarch_long_long_bit (gdbarch, 8 * TARGET_CHAR_BIT); |
| 1134 | set_gdbarch_ptr_bit (gdbarch, 2 * TARGET_CHAR_BIT); |
| 1135 | set_gdbarch_addr_bit (gdbarch, 32); |
| 1136 | set_gdbarch_bfd_vma_bit (gdbarch, 32); /* FIXME: TRoth/2002-02-18: Is this needed? */ |
| 1137 | |
| 1138 | set_gdbarch_float_bit (gdbarch, 4 * TARGET_CHAR_BIT); |
| 1139 | set_gdbarch_double_bit (gdbarch, 4 * TARGET_CHAR_BIT); |
| 1140 | set_gdbarch_long_double_bit (gdbarch, 4 * TARGET_CHAR_BIT); |
| 1141 | |
| 1142 | set_gdbarch_float_format (gdbarch, &floatformat_ieee_single_little); |
| 1143 | set_gdbarch_double_format (gdbarch, &floatformat_ieee_single_little); |
| 1144 | set_gdbarch_long_double_format (gdbarch, &floatformat_ieee_single_little); |
| 1145 | |
| 1146 | set_gdbarch_read_pc (gdbarch, avr_read_pc); |
| 1147 | set_gdbarch_write_pc (gdbarch, avr_write_pc); |
| 1148 | set_gdbarch_read_fp (gdbarch, avr_read_fp); |
| 1149 | set_gdbarch_read_sp (gdbarch, avr_read_sp); |
| 1150 | set_gdbarch_write_sp (gdbarch, avr_write_sp); |
| 1151 | |
| 1152 | set_gdbarch_num_regs (gdbarch, AVR_NUM_REGS); |
| 1153 | |
| 1154 | set_gdbarch_sp_regnum (gdbarch, AVR_SP_REGNUM); |
| 1155 | set_gdbarch_fp_regnum (gdbarch, AVR_FP_REGNUM); |
| 1156 | set_gdbarch_pc_regnum (gdbarch, AVR_PC_REGNUM); |
| 1157 | |
| 1158 | set_gdbarch_register_name (gdbarch, avr_register_name); |
| 1159 | set_gdbarch_register_size (gdbarch, 1); |
| 1160 | set_gdbarch_register_bytes (gdbarch, AVR_NUM_REG_BYTES); |
| 1161 | set_gdbarch_register_byte (gdbarch, avr_register_byte); |
| 1162 | set_gdbarch_register_raw_size (gdbarch, avr_register_raw_size); |
| 1163 | set_gdbarch_deprecated_max_register_raw_size (gdbarch, 4); |
| 1164 | set_gdbarch_register_virtual_size (gdbarch, avr_register_virtual_size); |
| 1165 | set_gdbarch_deprecated_max_register_virtual_size (gdbarch, 4); |
| 1166 | set_gdbarch_register_virtual_type (gdbarch, avr_register_virtual_type); |
| 1167 | |
| 1168 | set_gdbarch_print_insn (gdbarch, print_insn_avr); |
| 1169 | |
| 1170 | set_gdbarch_call_dummy_address (gdbarch, avr_call_dummy_address); |
| 1171 | set_gdbarch_call_dummy_start_offset (gdbarch, 0); |
| 1172 | set_gdbarch_call_dummy_breakpoint_offset_p (gdbarch, 1); |
| 1173 | set_gdbarch_call_dummy_breakpoint_offset (gdbarch, 0); |
| 1174 | set_gdbarch_call_dummy_length (gdbarch, 0); |
| 1175 | set_gdbarch_call_dummy_p (gdbarch, 1); |
| 1176 | set_gdbarch_call_dummy_words (gdbarch, avr_call_dummy_words); |
| 1177 | set_gdbarch_fix_call_dummy (gdbarch, generic_fix_call_dummy); |
| 1178 | |
| 1179 | /* set_gdbarch_believe_pcc_promotion (gdbarch, 1); // TRoth: should this be set? */ |
| 1180 | |
| 1181 | set_gdbarch_address_to_pointer (gdbarch, avr_address_to_pointer); |
| 1182 | set_gdbarch_pointer_to_address (gdbarch, avr_pointer_to_address); |
| 1183 | set_gdbarch_push_arguments (gdbarch, avr_push_arguments); |
| 1184 | set_gdbarch_push_return_address (gdbarch, avr_push_return_address); |
| 1185 | set_gdbarch_deprecated_pop_frame (gdbarch, avr_pop_frame); |
| 1186 | |
| 1187 | set_gdbarch_use_struct_convention (gdbarch, generic_use_struct_convention); |
| 1188 | set_gdbarch_deprecated_store_struct_return (gdbarch, avr_store_struct_return); |
| 1189 | |
| 1190 | set_gdbarch_deprecated_frame_init_saved_regs (gdbarch, avr_scan_prologue); |
| 1191 | set_gdbarch_deprecated_init_extra_frame_info (gdbarch, avr_init_extra_frame_info); |
| 1192 | set_gdbarch_skip_prologue (gdbarch, avr_skip_prologue); |
| 1193 | set_gdbarch_inner_than (gdbarch, core_addr_lessthan); |
| 1194 | |
| 1195 | set_gdbarch_decr_pc_after_break (gdbarch, 0); |
| 1196 | |
| 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_saved_pc_after_call (gdbarch, avr_saved_pc_after_call); |
| 1207 | set_gdbarch_frame_num_args (gdbarch, frame_num_args_unknown); |
| 1208 | |
| 1209 | set_gdbarch_convert_from_func_ptr_addr (gdbarch, |
| 1210 | avr_convert_from_func_ptr_addr); |
| 1211 | |
| 1212 | return gdbarch; |
| 1213 | } |
| 1214 | |
| 1215 | /* Send a query request to the avr remote target asking for values of the io |
| 1216 | registers. If args parameter is not NULL, then the user has requested info |
| 1217 | on a specific io register [This still needs implemented and is ignored for |
| 1218 | now]. The query string should be one of these forms: |
| 1219 | |
| 1220 | "Ravr.io_reg" -> reply is "NN" number of io registers |
| 1221 | |
| 1222 | "Ravr.io_reg:addr,len" where addr is first register and len is number of |
| 1223 | registers to be read. The reply should be "<NAME>,VV;" for each io register |
| 1224 | where, <NAME> is a string, and VV is the hex value of the register. |
| 1225 | |
| 1226 | All io registers are 8-bit. */ |
| 1227 | |
| 1228 | static void |
| 1229 | avr_io_reg_read_command (char *args, int from_tty) |
| 1230 | { |
| 1231 | int bufsiz = 0; |
| 1232 | char buf[400]; |
| 1233 | char query[400]; |
| 1234 | char *p; |
| 1235 | unsigned int nreg = 0; |
| 1236 | unsigned int val; |
| 1237 | int i, j, k, step; |
| 1238 | |
| 1239 | /* fprintf_unfiltered (gdb_stderr, "DEBUG: avr_io_reg_read_command (\"%s\", %d)\n", */ |
| 1240 | /* args, from_tty); */ |
| 1241 | |
| 1242 | if (!current_target.to_query) |
| 1243 | { |
| 1244 | fprintf_unfiltered (gdb_stderr, |
| 1245 | "ERR: info io_registers NOT supported by current target\n"); |
| 1246 | return; |
| 1247 | } |
| 1248 | |
| 1249 | /* Just get the maximum buffer size. */ |
| 1250 | target_query ((int) 'R', 0, 0, &bufsiz); |
| 1251 | if (bufsiz > sizeof (buf)) |
| 1252 | bufsiz = sizeof (buf); |
| 1253 | |
| 1254 | /* Find out how many io registers the target has. */ |
| 1255 | strcpy (query, "avr.io_reg"); |
| 1256 | target_query ((int) 'R', query, buf, &bufsiz); |
| 1257 | |
| 1258 | if (strncmp (buf, "", bufsiz) == 0) |
| 1259 | { |
| 1260 | fprintf_unfiltered (gdb_stderr, |
| 1261 | "info io_registers NOT supported by target\n"); |
| 1262 | return; |
| 1263 | } |
| 1264 | |
| 1265 | if (sscanf (buf, "%x", &nreg) != 1) |
| 1266 | { |
| 1267 | fprintf_unfiltered (gdb_stderr, |
| 1268 | "Error fetching number of io registers\n"); |
| 1269 | return; |
| 1270 | } |
| 1271 | |
| 1272 | reinitialize_more_filter (); |
| 1273 | |
| 1274 | printf_unfiltered ("Target has %u io registers:\n\n", nreg); |
| 1275 | |
| 1276 | /* only fetch up to 8 registers at a time to keep the buffer small */ |
| 1277 | step = 8; |
| 1278 | |
| 1279 | for (i = 0; i < nreg; i += step) |
| 1280 | { |
| 1281 | /* how many registers this round? */ |
| 1282 | j = step; |
| 1283 | if ((i+j) >= nreg) |
| 1284 | j = nreg - i; /* last block is less than 8 registers */ |
| 1285 | |
| 1286 | snprintf (query, sizeof (query) - 1, "avr.io_reg:%x,%x", i, j); |
| 1287 | target_query ((int) 'R', query, buf, &bufsiz); |
| 1288 | |
| 1289 | p = buf; |
| 1290 | for (k = i; k < (i + j); k++) |
| 1291 | { |
| 1292 | if (sscanf (p, "%[^,],%x;", query, &val) == 2) |
| 1293 | { |
| 1294 | printf_filtered ("[%02x] %-15s : %02x\n", k, query, val); |
| 1295 | while ((*p != ';') && (*p != '\0')) |
| 1296 | p++; |
| 1297 | p++; /* skip over ';' */ |
| 1298 | if (*p == '\0') |
| 1299 | break; |
| 1300 | } |
| 1301 | } |
| 1302 | } |
| 1303 | } |
| 1304 | |
| 1305 | void |
| 1306 | _initialize_avr_tdep (void) |
| 1307 | { |
| 1308 | register_gdbarch_init (bfd_arch_avr, avr_gdbarch_init); |
| 1309 | |
| 1310 | /* Add a new command to allow the user to query the avr remote target for |
| 1311 | the values of the io space registers in a saner way than just using |
| 1312 | `x/NNNb ADDR`. */ |
| 1313 | |
| 1314 | /* FIXME: TRoth/2002-02-18: This should probably be changed to 'info avr |
| 1315 | io_registers' to signify it is not available on other platforms. */ |
| 1316 | |
| 1317 | add_cmd ("io_registers", class_info, avr_io_reg_read_command, |
| 1318 | "query remote avr target for io space register values", &infolist); |
| 1319 | } |