| 1 | /* Target-dependent code for Renesas M32R, for GDB. |
| 2 | |
| 3 | Copyright (C) 1996-2018 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 3 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, see <http://www.gnu.org/licenses/>. */ |
| 19 | |
| 20 | #include "defs.h" |
| 21 | #include "frame.h" |
| 22 | #include "frame-unwind.h" |
| 23 | #include "frame-base.h" |
| 24 | #include "symtab.h" |
| 25 | #include "gdbtypes.h" |
| 26 | #include "gdbcmd.h" |
| 27 | #include "gdbcore.h" |
| 28 | #include "value.h" |
| 29 | #include "inferior.h" |
| 30 | #include "symfile.h" |
| 31 | #include "objfiles.h" |
| 32 | #include "osabi.h" |
| 33 | #include "language.h" |
| 34 | #include "arch-utils.h" |
| 35 | #include "regcache.h" |
| 36 | #include "trad-frame.h" |
| 37 | #include "dis-asm.h" |
| 38 | #include "objfiles.h" |
| 39 | #include "m32r-tdep.h" |
| 40 | #include <algorithm> |
| 41 | |
| 42 | /* The size of the argument registers (r0 - r3) in bytes. */ |
| 43 | #define M32R_ARG_REGISTER_SIZE 4 |
| 44 | |
| 45 | /* Local functions */ |
| 46 | |
| 47 | static CORE_ADDR |
| 48 | m32r_frame_align (struct gdbarch *gdbarch, CORE_ADDR sp) |
| 49 | { |
| 50 | /* Align to the size of an instruction (so that they can safely be |
| 51 | pushed onto the stack. */ |
| 52 | return sp & ~3; |
| 53 | } |
| 54 | |
| 55 | |
| 56 | /* Breakpoints |
| 57 | |
| 58 | The little endian mode of M32R is unique. In most of architectures, |
| 59 | two 16-bit instructions, A and B, are placed as the following: |
| 60 | |
| 61 | Big endian: |
| 62 | A0 A1 B0 B1 |
| 63 | |
| 64 | Little endian: |
| 65 | A1 A0 B1 B0 |
| 66 | |
| 67 | In M32R, they are placed like this: |
| 68 | |
| 69 | Big endian: |
| 70 | A0 A1 B0 B1 |
| 71 | |
| 72 | Little endian: |
| 73 | B1 B0 A1 A0 |
| 74 | |
| 75 | This is because M32R always fetches instructions in 32-bit. |
| 76 | |
| 77 | The following functions take care of this behavior. */ |
| 78 | |
| 79 | static int |
| 80 | m32r_memory_insert_breakpoint (struct gdbarch *gdbarch, |
| 81 | struct bp_target_info *bp_tgt) |
| 82 | { |
| 83 | CORE_ADDR addr = bp_tgt->placed_address = bp_tgt->reqstd_address; |
| 84 | int val; |
| 85 | gdb_byte buf[4]; |
| 86 | gdb_byte contents_cache[4]; |
| 87 | gdb_byte bp_entry[] = { 0x10, 0xf1 }; /* dpt */ |
| 88 | |
| 89 | /* Save the memory contents. */ |
| 90 | val = target_read_memory (addr & 0xfffffffc, contents_cache, 4); |
| 91 | if (val != 0) |
| 92 | return val; /* return error */ |
| 93 | |
| 94 | memcpy (bp_tgt->shadow_contents, contents_cache, 4); |
| 95 | bp_tgt->shadow_len = 4; |
| 96 | |
| 97 | /* Determine appropriate breakpoint contents and size for this address. */ |
| 98 | if (gdbarch_byte_order (gdbarch) == BFD_ENDIAN_BIG) |
| 99 | { |
| 100 | if ((addr & 3) == 0) |
| 101 | { |
| 102 | buf[0] = bp_entry[0]; |
| 103 | buf[1] = bp_entry[1]; |
| 104 | buf[2] = contents_cache[2] & 0x7f; |
| 105 | buf[3] = contents_cache[3]; |
| 106 | } |
| 107 | else |
| 108 | { |
| 109 | buf[0] = contents_cache[0]; |
| 110 | buf[1] = contents_cache[1]; |
| 111 | buf[2] = bp_entry[0]; |
| 112 | buf[3] = bp_entry[1]; |
| 113 | } |
| 114 | } |
| 115 | else /* little-endian */ |
| 116 | { |
| 117 | if ((addr & 3) == 0) |
| 118 | { |
| 119 | buf[0] = contents_cache[0]; |
| 120 | buf[1] = contents_cache[1] & 0x7f; |
| 121 | buf[2] = bp_entry[1]; |
| 122 | buf[3] = bp_entry[0]; |
| 123 | } |
| 124 | else |
| 125 | { |
| 126 | buf[0] = bp_entry[1]; |
| 127 | buf[1] = bp_entry[0]; |
| 128 | buf[2] = contents_cache[2]; |
| 129 | buf[3] = contents_cache[3]; |
| 130 | } |
| 131 | } |
| 132 | |
| 133 | /* Write the breakpoint. */ |
| 134 | val = target_write_memory (addr & 0xfffffffc, buf, 4); |
| 135 | return val; |
| 136 | } |
| 137 | |
| 138 | static int |
| 139 | m32r_memory_remove_breakpoint (struct gdbarch *gdbarch, |
| 140 | struct bp_target_info *bp_tgt) |
| 141 | { |
| 142 | CORE_ADDR addr = bp_tgt->placed_address; |
| 143 | int val; |
| 144 | gdb_byte buf[4]; |
| 145 | gdb_byte *contents_cache = bp_tgt->shadow_contents; |
| 146 | |
| 147 | buf[0] = contents_cache[0]; |
| 148 | buf[1] = contents_cache[1]; |
| 149 | buf[2] = contents_cache[2]; |
| 150 | buf[3] = contents_cache[3]; |
| 151 | |
| 152 | /* Remove parallel bit. */ |
| 153 | if (gdbarch_byte_order (gdbarch) == BFD_ENDIAN_BIG) |
| 154 | { |
| 155 | if ((buf[0] & 0x80) == 0 && (buf[2] & 0x80) != 0) |
| 156 | buf[2] &= 0x7f; |
| 157 | } |
| 158 | else /* little-endian */ |
| 159 | { |
| 160 | if ((buf[3] & 0x80) == 0 && (buf[1] & 0x80) != 0) |
| 161 | buf[1] &= 0x7f; |
| 162 | } |
| 163 | |
| 164 | /* Write contents. */ |
| 165 | val = target_write_raw_memory (addr & 0xfffffffc, buf, 4); |
| 166 | return val; |
| 167 | } |
| 168 | |
| 169 | /* Implement the breakpoint_kind_from_pc gdbarch method. */ |
| 170 | |
| 171 | static int |
| 172 | m32r_breakpoint_kind_from_pc (struct gdbarch *gdbarch, CORE_ADDR *pcptr) |
| 173 | { |
| 174 | if ((*pcptr & 3) == 0) |
| 175 | return 4; |
| 176 | else |
| 177 | return 2; |
| 178 | } |
| 179 | |
| 180 | /* Implement the sw_breakpoint_from_kind gdbarch method. */ |
| 181 | |
| 182 | static const gdb_byte * |
| 183 | m32r_sw_breakpoint_from_kind (struct gdbarch *gdbarch, int kind, int *size) |
| 184 | { |
| 185 | static gdb_byte be_bp_entry[] = { |
| 186 | 0x10, 0xf1, 0x70, 0x00 |
| 187 | }; /* dpt -> nop */ |
| 188 | static gdb_byte le_bp_entry[] = { |
| 189 | 0x00, 0x70, 0xf1, 0x10 |
| 190 | }; /* dpt -> nop */ |
| 191 | |
| 192 | *size = kind; |
| 193 | |
| 194 | /* Determine appropriate breakpoint. */ |
| 195 | if (gdbarch_byte_order (gdbarch) == BFD_ENDIAN_BIG) |
| 196 | return be_bp_entry; |
| 197 | else |
| 198 | { |
| 199 | if (kind == 4) |
| 200 | return le_bp_entry; |
| 201 | else |
| 202 | return le_bp_entry + 2; |
| 203 | } |
| 204 | } |
| 205 | |
| 206 | static const char *m32r_register_names[] = { |
| 207 | "r0", "r1", "r2", "r3", "r4", "r5", "r6", "r7", |
| 208 | "r8", "r9", "r10", "r11", "r12", "fp", "lr", "sp", |
| 209 | "psw", "cbr", "spi", "spu", "bpc", "pc", "accl", "acch", |
| 210 | "evb" |
| 211 | }; |
| 212 | |
| 213 | static const char * |
| 214 | m32r_register_name (struct gdbarch *gdbarch, int reg_nr) |
| 215 | { |
| 216 | if (reg_nr < 0) |
| 217 | return NULL; |
| 218 | if (reg_nr >= M32R_NUM_REGS) |
| 219 | return NULL; |
| 220 | return m32r_register_names[reg_nr]; |
| 221 | } |
| 222 | |
| 223 | |
| 224 | /* Return the GDB type object for the "standard" data type |
| 225 | of data in register N. */ |
| 226 | |
| 227 | static struct type * |
| 228 | m32r_register_type (struct gdbarch *gdbarch, int reg_nr) |
| 229 | { |
| 230 | if (reg_nr == M32R_PC_REGNUM) |
| 231 | return builtin_type (gdbarch)->builtin_func_ptr; |
| 232 | else if (reg_nr == M32R_SP_REGNUM || reg_nr == M32R_FP_REGNUM) |
| 233 | return builtin_type (gdbarch)->builtin_data_ptr; |
| 234 | else |
| 235 | return builtin_type (gdbarch)->builtin_int32; |
| 236 | } |
| 237 | |
| 238 | |
| 239 | /* Write into appropriate registers a function return value |
| 240 | of type TYPE, given in virtual format. |
| 241 | |
| 242 | Things always get returned in RET1_REGNUM, RET2_REGNUM. */ |
| 243 | |
| 244 | static void |
| 245 | m32r_store_return_value (struct type *type, struct regcache *regcache, |
| 246 | const gdb_byte *valbuf) |
| 247 | { |
| 248 | struct gdbarch *gdbarch = regcache->arch (); |
| 249 | enum bfd_endian byte_order = gdbarch_byte_order (gdbarch); |
| 250 | CORE_ADDR regval; |
| 251 | int len = TYPE_LENGTH (type); |
| 252 | |
| 253 | regval = extract_unsigned_integer (valbuf, len > 4 ? 4 : len, byte_order); |
| 254 | regcache_cooked_write_unsigned (regcache, RET1_REGNUM, regval); |
| 255 | |
| 256 | if (len > 4) |
| 257 | { |
| 258 | regval = extract_unsigned_integer (valbuf + 4, |
| 259 | len - 4, byte_order); |
| 260 | regcache_cooked_write_unsigned (regcache, RET1_REGNUM + 1, regval); |
| 261 | } |
| 262 | } |
| 263 | |
| 264 | /* This is required by skip_prologue. The results of decoding a prologue |
| 265 | should be cached because this thrashing is getting nuts. */ |
| 266 | |
| 267 | static int |
| 268 | decode_prologue (struct gdbarch *gdbarch, |
| 269 | CORE_ADDR start_pc, CORE_ADDR scan_limit, |
| 270 | CORE_ADDR *pl_endptr, unsigned long *framelength) |
| 271 | { |
| 272 | enum bfd_endian byte_order = gdbarch_byte_order (gdbarch); |
| 273 | unsigned long framesize; |
| 274 | int insn; |
| 275 | int op1; |
| 276 | CORE_ADDR after_prologue = 0; |
| 277 | CORE_ADDR after_push = 0; |
| 278 | CORE_ADDR after_stack_adjust = 0; |
| 279 | CORE_ADDR current_pc; |
| 280 | LONGEST return_value; |
| 281 | |
| 282 | framesize = 0; |
| 283 | after_prologue = 0; |
| 284 | |
| 285 | for (current_pc = start_pc; current_pc < scan_limit; current_pc += 2) |
| 286 | { |
| 287 | /* Check if current pc's location is readable. */ |
| 288 | if (!safe_read_memory_integer (current_pc, 2, byte_order, &return_value)) |
| 289 | return -1; |
| 290 | |
| 291 | insn = read_memory_unsigned_integer (current_pc, 2, byte_order); |
| 292 | |
| 293 | if (insn == 0x0000) |
| 294 | break; |
| 295 | |
| 296 | /* If this is a 32 bit instruction, we dont want to examine its |
| 297 | immediate data as though it were an instruction. */ |
| 298 | if (current_pc & 0x02) |
| 299 | { |
| 300 | /* Decode this instruction further. */ |
| 301 | insn &= 0x7fff; |
| 302 | } |
| 303 | else |
| 304 | { |
| 305 | if (insn & 0x8000) |
| 306 | { |
| 307 | if (current_pc == scan_limit) |
| 308 | scan_limit += 2; /* extend the search */ |
| 309 | |
| 310 | current_pc += 2; /* skip the immediate data */ |
| 311 | |
| 312 | /* Check if current pc's location is readable. */ |
| 313 | if (!safe_read_memory_integer (current_pc, 2, byte_order, |
| 314 | &return_value)) |
| 315 | return -1; |
| 316 | |
| 317 | if (insn == 0x8faf) /* add3 sp, sp, xxxx */ |
| 318 | /* add 16 bit sign-extended offset */ |
| 319 | { |
| 320 | framesize += |
| 321 | -((short) read_memory_unsigned_integer (current_pc, |
| 322 | 2, byte_order)); |
| 323 | } |
| 324 | else |
| 325 | { |
| 326 | if (((insn >> 8) == 0xe4) /* ld24 r4, xxxxxx; sub sp, r4 */ |
| 327 | && safe_read_memory_integer (current_pc + 2, |
| 328 | 2, byte_order, |
| 329 | &return_value) |
| 330 | && read_memory_unsigned_integer (current_pc + 2, |
| 331 | 2, byte_order) |
| 332 | == 0x0f24) |
| 333 | { |
| 334 | /* Subtract 24 bit sign-extended negative-offset. */ |
| 335 | insn = read_memory_unsigned_integer (current_pc - 2, |
| 336 | 4, byte_order); |
| 337 | if (insn & 0x00800000) /* sign extend */ |
| 338 | insn |= 0xff000000; /* negative */ |
| 339 | else |
| 340 | insn &= 0x00ffffff; /* positive */ |
| 341 | framesize += insn; |
| 342 | } |
| 343 | } |
| 344 | after_push = current_pc + 2; |
| 345 | continue; |
| 346 | } |
| 347 | } |
| 348 | op1 = insn & 0xf000; /* Isolate just the first nibble. */ |
| 349 | |
| 350 | if ((insn & 0xf0ff) == 0x207f) |
| 351 | { /* st reg, @-sp */ |
| 352 | framesize += 4; |
| 353 | after_prologue = 0; |
| 354 | continue; |
| 355 | } |
| 356 | if ((insn >> 8) == 0x4f) /* addi sp, xx */ |
| 357 | /* Add 8 bit sign-extended offset. */ |
| 358 | { |
| 359 | int stack_adjust = (signed char) (insn & 0xff); |
| 360 | |
| 361 | /* there are probably two of these stack adjustments: |
| 362 | 1) A negative one in the prologue, and |
| 363 | 2) A positive one in the epilogue. |
| 364 | We are only interested in the first one. */ |
| 365 | |
| 366 | if (stack_adjust < 0) |
| 367 | { |
| 368 | framesize -= stack_adjust; |
| 369 | after_prologue = 0; |
| 370 | /* A frameless function may have no "mv fp, sp". |
| 371 | In that case, this is the end of the prologue. */ |
| 372 | after_stack_adjust = current_pc + 2; |
| 373 | } |
| 374 | continue; |
| 375 | } |
| 376 | if (insn == 0x1d8f) |
| 377 | { /* mv fp, sp */ |
| 378 | after_prologue = current_pc + 2; |
| 379 | break; /* end of stack adjustments */ |
| 380 | } |
| 381 | |
| 382 | /* Nop looks like a branch, continue explicitly. */ |
| 383 | if (insn == 0x7000) |
| 384 | { |
| 385 | after_prologue = current_pc + 2; |
| 386 | continue; /* nop occurs between pushes. */ |
| 387 | } |
| 388 | /* End of prolog if any of these are trap instructions. */ |
| 389 | if ((insn & 0xfff0) == 0x10f0) |
| 390 | { |
| 391 | after_prologue = current_pc; |
| 392 | break; |
| 393 | } |
| 394 | /* End of prolog if any of these are branch instructions. */ |
| 395 | if ((op1 == 0x7000) || (op1 == 0xb000) || (op1 == 0xf000)) |
| 396 | { |
| 397 | after_prologue = current_pc; |
| 398 | continue; |
| 399 | } |
| 400 | /* Some of the branch instructions are mixed with other types. */ |
| 401 | if (op1 == 0x1000) |
| 402 | { |
| 403 | int subop = insn & 0x0ff0; |
| 404 | if ((subop == 0x0ec0) || (subop == 0x0fc0)) |
| 405 | { |
| 406 | after_prologue = current_pc; |
| 407 | continue; /* jmp , jl */ |
| 408 | } |
| 409 | } |
| 410 | } |
| 411 | |
| 412 | if (framelength) |
| 413 | *framelength = framesize; |
| 414 | |
| 415 | if (current_pc >= scan_limit) |
| 416 | { |
| 417 | if (pl_endptr) |
| 418 | { |
| 419 | if (after_stack_adjust != 0) |
| 420 | /* We did not find a "mv fp,sp", but we DID find |
| 421 | a stack_adjust. Is it safe to use that as the |
| 422 | end of the prologue? I just don't know. */ |
| 423 | { |
| 424 | *pl_endptr = after_stack_adjust; |
| 425 | } |
| 426 | else if (after_push != 0) |
| 427 | /* We did not find a "mv fp,sp", but we DID find |
| 428 | a push. Is it safe to use that as the |
| 429 | end of the prologue? I just don't know. */ |
| 430 | { |
| 431 | *pl_endptr = after_push; |
| 432 | } |
| 433 | else |
| 434 | /* We reached the end of the loop without finding the end |
| 435 | of the prologue. No way to win -- we should report |
| 436 | failure. The way we do that is to return the original |
| 437 | start_pc. GDB will set a breakpoint at the start of |
| 438 | the function (etc.) */ |
| 439 | *pl_endptr = start_pc; |
| 440 | } |
| 441 | return 0; |
| 442 | } |
| 443 | |
| 444 | if (after_prologue == 0) |
| 445 | after_prologue = current_pc; |
| 446 | |
| 447 | if (pl_endptr) |
| 448 | *pl_endptr = after_prologue; |
| 449 | |
| 450 | return 0; |
| 451 | } /* decode_prologue */ |
| 452 | |
| 453 | /* Function: skip_prologue |
| 454 | Find end of function prologue. */ |
| 455 | |
| 456 | #define DEFAULT_SEARCH_LIMIT 128 |
| 457 | |
| 458 | static CORE_ADDR |
| 459 | m32r_skip_prologue (struct gdbarch *gdbarch, CORE_ADDR pc) |
| 460 | { |
| 461 | enum bfd_endian byte_order = gdbarch_byte_order (gdbarch); |
| 462 | CORE_ADDR func_addr, func_end; |
| 463 | struct symtab_and_line sal; |
| 464 | LONGEST return_value; |
| 465 | |
| 466 | /* See what the symbol table says. */ |
| 467 | |
| 468 | if (find_pc_partial_function (pc, NULL, &func_addr, &func_end)) |
| 469 | { |
| 470 | sal = find_pc_line (func_addr, 0); |
| 471 | |
| 472 | if (sal.line != 0 && sal.end <= func_end) |
| 473 | { |
| 474 | func_end = sal.end; |
| 475 | } |
| 476 | else |
| 477 | /* Either there's no line info, or the line after the prologue is after |
| 478 | the end of the function. In this case, there probably isn't a |
| 479 | prologue. */ |
| 480 | { |
| 481 | func_end = std::min (func_end, func_addr + DEFAULT_SEARCH_LIMIT); |
| 482 | } |
| 483 | } |
| 484 | else |
| 485 | func_end = pc + DEFAULT_SEARCH_LIMIT; |
| 486 | |
| 487 | /* If pc's location is not readable, just quit. */ |
| 488 | if (!safe_read_memory_integer (pc, 4, byte_order, &return_value)) |
| 489 | return pc; |
| 490 | |
| 491 | /* Find the end of prologue. */ |
| 492 | if (decode_prologue (gdbarch, pc, func_end, &sal.end, NULL) < 0) |
| 493 | return pc; |
| 494 | |
| 495 | return sal.end; |
| 496 | } |
| 497 | |
| 498 | struct m32r_unwind_cache |
| 499 | { |
| 500 | /* The previous frame's inner most stack address. Used as this |
| 501 | frame ID's stack_addr. */ |
| 502 | CORE_ADDR prev_sp; |
| 503 | /* The frame's base, optionally used by the high-level debug info. */ |
| 504 | CORE_ADDR base; |
| 505 | int size; |
| 506 | /* How far the SP and r13 (FP) have been offset from the start of |
| 507 | the stack frame (as defined by the previous frame's stack |
| 508 | pointer). */ |
| 509 | LONGEST sp_offset; |
| 510 | LONGEST r13_offset; |
| 511 | int uses_frame; |
| 512 | /* Table indicating the location of each and every register. */ |
| 513 | struct trad_frame_saved_reg *saved_regs; |
| 514 | }; |
| 515 | |
| 516 | /* Put here the code to store, into fi->saved_regs, the addresses of |
| 517 | the saved registers of frame described by FRAME_INFO. This |
| 518 | includes special registers such as pc and fp saved in special ways |
| 519 | in the stack frame. sp is even more special: the address we return |
| 520 | for it IS the sp for the next frame. */ |
| 521 | |
| 522 | static struct m32r_unwind_cache * |
| 523 | m32r_frame_unwind_cache (struct frame_info *this_frame, |
| 524 | void **this_prologue_cache) |
| 525 | { |
| 526 | CORE_ADDR pc, scan_limit; |
| 527 | ULONGEST prev_sp; |
| 528 | ULONGEST this_base; |
| 529 | unsigned long op; |
| 530 | int i; |
| 531 | struct m32r_unwind_cache *info; |
| 532 | |
| 533 | |
| 534 | if ((*this_prologue_cache)) |
| 535 | return (struct m32r_unwind_cache *) (*this_prologue_cache); |
| 536 | |
| 537 | info = FRAME_OBSTACK_ZALLOC (struct m32r_unwind_cache); |
| 538 | (*this_prologue_cache) = info; |
| 539 | info->saved_regs = trad_frame_alloc_saved_regs (this_frame); |
| 540 | |
| 541 | info->size = 0; |
| 542 | info->sp_offset = 0; |
| 543 | info->uses_frame = 0; |
| 544 | |
| 545 | scan_limit = get_frame_pc (this_frame); |
| 546 | for (pc = get_frame_func (this_frame); |
| 547 | pc > 0 && pc < scan_limit; pc += 2) |
| 548 | { |
| 549 | if ((pc & 2) == 0) |
| 550 | { |
| 551 | op = get_frame_memory_unsigned (this_frame, pc, 4); |
| 552 | if ((op & 0x80000000) == 0x80000000) |
| 553 | { |
| 554 | /* 32-bit instruction */ |
| 555 | if ((op & 0xffff0000) == 0x8faf0000) |
| 556 | { |
| 557 | /* add3 sp,sp,xxxx */ |
| 558 | short n = op & 0xffff; |
| 559 | info->sp_offset += n; |
| 560 | } |
| 561 | else if (((op >> 8) == 0xe4) |
| 562 | && get_frame_memory_unsigned (this_frame, pc + 2, |
| 563 | 2) == 0x0f24) |
| 564 | { |
| 565 | /* ld24 r4, xxxxxx; sub sp, r4 */ |
| 566 | unsigned long n = op & 0xffffff; |
| 567 | info->sp_offset += n; |
| 568 | pc += 2; /* skip sub instruction */ |
| 569 | } |
| 570 | |
| 571 | if (pc == scan_limit) |
| 572 | scan_limit += 2; /* extend the search */ |
| 573 | pc += 2; /* skip the immediate data */ |
| 574 | continue; |
| 575 | } |
| 576 | } |
| 577 | |
| 578 | /* 16-bit instructions */ |
| 579 | op = get_frame_memory_unsigned (this_frame, pc, 2) & 0x7fff; |
| 580 | if ((op & 0xf0ff) == 0x207f) |
| 581 | { |
| 582 | /* st rn, @-sp */ |
| 583 | int regno = ((op >> 8) & 0xf); |
| 584 | info->sp_offset -= 4; |
| 585 | info->saved_regs[regno].addr = info->sp_offset; |
| 586 | } |
| 587 | else if ((op & 0xff00) == 0x4f00) |
| 588 | { |
| 589 | /* addi sp, xx */ |
| 590 | int n = (signed char) (op & 0xff); |
| 591 | info->sp_offset += n; |
| 592 | } |
| 593 | else if (op == 0x1d8f) |
| 594 | { |
| 595 | /* mv fp, sp */ |
| 596 | info->uses_frame = 1; |
| 597 | info->r13_offset = info->sp_offset; |
| 598 | break; /* end of stack adjustments */ |
| 599 | } |
| 600 | else if ((op & 0xfff0) == 0x10f0) |
| 601 | { |
| 602 | /* End of prologue if this is a trap instruction. */ |
| 603 | break; /* End of stack adjustments. */ |
| 604 | } |
| 605 | } |
| 606 | |
| 607 | info->size = -info->sp_offset; |
| 608 | |
| 609 | /* Compute the previous frame's stack pointer (which is also the |
| 610 | frame's ID's stack address), and this frame's base pointer. */ |
| 611 | if (info->uses_frame) |
| 612 | { |
| 613 | /* The SP was moved to the FP. This indicates that a new frame |
| 614 | was created. Get THIS frame's FP value by unwinding it from |
| 615 | the next frame. */ |
| 616 | this_base = get_frame_register_unsigned (this_frame, M32R_FP_REGNUM); |
| 617 | /* The FP points at the last saved register. Adjust the FP back |
| 618 | to before the first saved register giving the SP. */ |
| 619 | prev_sp = this_base + info->size; |
| 620 | } |
| 621 | else |
| 622 | { |
| 623 | /* Assume that the FP is this frame's SP but with that pushed |
| 624 | stack space added back. */ |
| 625 | this_base = get_frame_register_unsigned (this_frame, M32R_SP_REGNUM); |
| 626 | prev_sp = this_base + info->size; |
| 627 | } |
| 628 | |
| 629 | /* Convert that SP/BASE into real addresses. */ |
| 630 | info->prev_sp = prev_sp; |
| 631 | info->base = this_base; |
| 632 | |
| 633 | /* Adjust all the saved registers so that they contain addresses and |
| 634 | not offsets. */ |
| 635 | for (i = 0; i < gdbarch_num_regs (get_frame_arch (this_frame)) - 1; i++) |
| 636 | if (trad_frame_addr_p (info->saved_regs, i)) |
| 637 | info->saved_regs[i].addr = (info->prev_sp + info->saved_regs[i].addr); |
| 638 | |
| 639 | /* The call instruction moves the caller's PC in the callee's LR. |
| 640 | Since this is an unwind, do the reverse. Copy the location of LR |
| 641 | into PC (the address / regnum) so that a request for PC will be |
| 642 | converted into a request for the LR. */ |
| 643 | info->saved_regs[M32R_PC_REGNUM] = info->saved_regs[LR_REGNUM]; |
| 644 | |
| 645 | /* The previous frame's SP needed to be computed. Save the computed |
| 646 | value. */ |
| 647 | trad_frame_set_value (info->saved_regs, M32R_SP_REGNUM, prev_sp); |
| 648 | |
| 649 | return info; |
| 650 | } |
| 651 | |
| 652 | static CORE_ADDR |
| 653 | m32r_unwind_sp (struct gdbarch *gdbarch, struct frame_info *next_frame) |
| 654 | { |
| 655 | return frame_unwind_register_unsigned (next_frame, M32R_SP_REGNUM); |
| 656 | } |
| 657 | |
| 658 | |
| 659 | static CORE_ADDR |
| 660 | m32r_push_dummy_call (struct gdbarch *gdbarch, struct value *function, |
| 661 | struct regcache *regcache, CORE_ADDR bp_addr, int nargs, |
| 662 | struct value **args, CORE_ADDR sp, int struct_return, |
| 663 | CORE_ADDR struct_addr) |
| 664 | { |
| 665 | enum bfd_endian byte_order = gdbarch_byte_order (gdbarch); |
| 666 | int stack_offset, stack_alloc; |
| 667 | int argreg = ARG1_REGNUM; |
| 668 | int argnum; |
| 669 | struct type *type; |
| 670 | enum type_code typecode; |
| 671 | CORE_ADDR regval; |
| 672 | gdb_byte *val; |
| 673 | gdb_byte valbuf[M32R_ARG_REGISTER_SIZE]; |
| 674 | int len; |
| 675 | |
| 676 | /* First force sp to a 4-byte alignment. */ |
| 677 | sp = sp & ~3; |
| 678 | |
| 679 | /* Set the return address. For the m32r, the return breakpoint is |
| 680 | always at BP_ADDR. */ |
| 681 | regcache_cooked_write_unsigned (regcache, LR_REGNUM, bp_addr); |
| 682 | |
| 683 | /* If STRUCT_RETURN is true, then the struct return address (in |
| 684 | STRUCT_ADDR) will consume the first argument-passing register. |
| 685 | Both adjust the register count and store that value. */ |
| 686 | if (struct_return) |
| 687 | { |
| 688 | regcache_cooked_write_unsigned (regcache, argreg, struct_addr); |
| 689 | argreg++; |
| 690 | } |
| 691 | |
| 692 | /* Now make sure there's space on the stack. */ |
| 693 | for (argnum = 0, stack_alloc = 0; argnum < nargs; argnum++) |
| 694 | stack_alloc += ((TYPE_LENGTH (value_type (args[argnum])) + 3) & ~3); |
| 695 | sp -= stack_alloc; /* Make room on stack for args. */ |
| 696 | |
| 697 | for (argnum = 0, stack_offset = 0; argnum < nargs; argnum++) |
| 698 | { |
| 699 | type = value_type (args[argnum]); |
| 700 | typecode = TYPE_CODE (type); |
| 701 | len = TYPE_LENGTH (type); |
| 702 | |
| 703 | memset (valbuf, 0, sizeof (valbuf)); |
| 704 | |
| 705 | /* Passes structures that do not fit in 2 registers by reference. */ |
| 706 | if (len > 8 |
| 707 | && (typecode == TYPE_CODE_STRUCT || typecode == TYPE_CODE_UNION)) |
| 708 | { |
| 709 | store_unsigned_integer (valbuf, 4, byte_order, |
| 710 | value_address (args[argnum])); |
| 711 | typecode = TYPE_CODE_PTR; |
| 712 | len = 4; |
| 713 | val = valbuf; |
| 714 | } |
| 715 | else if (len < 4) |
| 716 | { |
| 717 | /* Value gets right-justified in the register or stack word. */ |
| 718 | memcpy (valbuf + (register_size (gdbarch, argreg) - len), |
| 719 | (gdb_byte *) value_contents (args[argnum]), len); |
| 720 | val = valbuf; |
| 721 | } |
| 722 | else |
| 723 | val = (gdb_byte *) value_contents (args[argnum]); |
| 724 | |
| 725 | while (len > 0) |
| 726 | { |
| 727 | if (argreg > ARGN_REGNUM) |
| 728 | { |
| 729 | /* Must go on the stack. */ |
| 730 | write_memory (sp + stack_offset, val, 4); |
| 731 | stack_offset += 4; |
| 732 | } |
| 733 | else if (argreg <= ARGN_REGNUM) |
| 734 | { |
| 735 | /* There's room in a register. */ |
| 736 | regval = |
| 737 | extract_unsigned_integer (val, |
| 738 | register_size (gdbarch, argreg), |
| 739 | byte_order); |
| 740 | regcache_cooked_write_unsigned (regcache, argreg++, regval); |
| 741 | } |
| 742 | |
| 743 | /* Store the value 4 bytes at a time. This means that things |
| 744 | larger than 4 bytes may go partly in registers and partly |
| 745 | on the stack. */ |
| 746 | len -= register_size (gdbarch, argreg); |
| 747 | val += register_size (gdbarch, argreg); |
| 748 | } |
| 749 | } |
| 750 | |
| 751 | /* Finally, update the SP register. */ |
| 752 | regcache_cooked_write_unsigned (regcache, M32R_SP_REGNUM, sp); |
| 753 | |
| 754 | return sp; |
| 755 | } |
| 756 | |
| 757 | |
| 758 | /* Given a return value in `regbuf' with a type `valtype', |
| 759 | extract and copy its value into `valbuf'. */ |
| 760 | |
| 761 | static void |
| 762 | m32r_extract_return_value (struct type *type, struct regcache *regcache, |
| 763 | gdb_byte *dst) |
| 764 | { |
| 765 | struct gdbarch *gdbarch = regcache->arch (); |
| 766 | enum bfd_endian byte_order = gdbarch_byte_order (gdbarch); |
| 767 | int len = TYPE_LENGTH (type); |
| 768 | ULONGEST tmp; |
| 769 | |
| 770 | /* By using store_unsigned_integer we avoid having to do |
| 771 | anything special for small big-endian values. */ |
| 772 | regcache_cooked_read_unsigned (regcache, RET1_REGNUM, &tmp); |
| 773 | store_unsigned_integer (dst, (len > 4 ? len - 4 : len), byte_order, tmp); |
| 774 | |
| 775 | /* Ignore return values more than 8 bytes in size because the m32r |
| 776 | returns anything more than 8 bytes in the stack. */ |
| 777 | if (len > 4) |
| 778 | { |
| 779 | regcache_cooked_read_unsigned (regcache, RET1_REGNUM + 1, &tmp); |
| 780 | store_unsigned_integer (dst + len - 4, 4, byte_order, tmp); |
| 781 | } |
| 782 | } |
| 783 | |
| 784 | static enum return_value_convention |
| 785 | m32r_return_value (struct gdbarch *gdbarch, struct value *function, |
| 786 | struct type *valtype, struct regcache *regcache, |
| 787 | gdb_byte *readbuf, const gdb_byte *writebuf) |
| 788 | { |
| 789 | if (TYPE_LENGTH (valtype) > 8) |
| 790 | return RETURN_VALUE_STRUCT_CONVENTION; |
| 791 | else |
| 792 | { |
| 793 | if (readbuf != NULL) |
| 794 | m32r_extract_return_value (valtype, regcache, readbuf); |
| 795 | if (writebuf != NULL) |
| 796 | m32r_store_return_value (valtype, regcache, writebuf); |
| 797 | return RETURN_VALUE_REGISTER_CONVENTION; |
| 798 | } |
| 799 | } |
| 800 | |
| 801 | |
| 802 | |
| 803 | static CORE_ADDR |
| 804 | m32r_unwind_pc (struct gdbarch *gdbarch, struct frame_info *next_frame) |
| 805 | { |
| 806 | return frame_unwind_register_unsigned (next_frame, M32R_PC_REGNUM); |
| 807 | } |
| 808 | |
| 809 | /* Given a GDB frame, determine the address of the calling function's |
| 810 | frame. This will be used to create a new GDB frame struct. */ |
| 811 | |
| 812 | static void |
| 813 | m32r_frame_this_id (struct frame_info *this_frame, |
| 814 | void **this_prologue_cache, struct frame_id *this_id) |
| 815 | { |
| 816 | struct m32r_unwind_cache *info |
| 817 | = m32r_frame_unwind_cache (this_frame, this_prologue_cache); |
| 818 | CORE_ADDR base; |
| 819 | CORE_ADDR func; |
| 820 | struct bound_minimal_symbol msym_stack; |
| 821 | struct frame_id id; |
| 822 | |
| 823 | /* The FUNC is easy. */ |
| 824 | func = get_frame_func (this_frame); |
| 825 | |
| 826 | /* Check if the stack is empty. */ |
| 827 | msym_stack = lookup_minimal_symbol ("_stack", NULL, NULL); |
| 828 | if (msym_stack.minsym && info->base == BMSYMBOL_VALUE_ADDRESS (msym_stack)) |
| 829 | return; |
| 830 | |
| 831 | /* Hopefully the prologue analysis either correctly determined the |
| 832 | frame's base (which is the SP from the previous frame), or set |
| 833 | that base to "NULL". */ |
| 834 | base = info->prev_sp; |
| 835 | if (base == 0) |
| 836 | return; |
| 837 | |
| 838 | id = frame_id_build (base, func); |
| 839 | (*this_id) = id; |
| 840 | } |
| 841 | |
| 842 | static struct value * |
| 843 | m32r_frame_prev_register (struct frame_info *this_frame, |
| 844 | void **this_prologue_cache, int regnum) |
| 845 | { |
| 846 | struct m32r_unwind_cache *info |
| 847 | = m32r_frame_unwind_cache (this_frame, this_prologue_cache); |
| 848 | return trad_frame_get_prev_register (this_frame, info->saved_regs, regnum); |
| 849 | } |
| 850 | |
| 851 | static const struct frame_unwind m32r_frame_unwind = { |
| 852 | NORMAL_FRAME, |
| 853 | default_frame_unwind_stop_reason, |
| 854 | m32r_frame_this_id, |
| 855 | m32r_frame_prev_register, |
| 856 | NULL, |
| 857 | default_frame_sniffer |
| 858 | }; |
| 859 | |
| 860 | static CORE_ADDR |
| 861 | m32r_frame_base_address (struct frame_info *this_frame, void **this_cache) |
| 862 | { |
| 863 | struct m32r_unwind_cache *info |
| 864 | = m32r_frame_unwind_cache (this_frame, this_cache); |
| 865 | return info->base; |
| 866 | } |
| 867 | |
| 868 | static const struct frame_base m32r_frame_base = { |
| 869 | &m32r_frame_unwind, |
| 870 | m32r_frame_base_address, |
| 871 | m32r_frame_base_address, |
| 872 | m32r_frame_base_address |
| 873 | }; |
| 874 | |
| 875 | /* Assuming THIS_FRAME is a dummy, return the frame ID of that dummy |
| 876 | frame. The frame ID's base needs to match the TOS value saved by |
| 877 | save_dummy_frame_tos(), and the PC match the dummy frame's breakpoint. */ |
| 878 | |
| 879 | static struct frame_id |
| 880 | m32r_dummy_id (struct gdbarch *gdbarch, struct frame_info *this_frame) |
| 881 | { |
| 882 | CORE_ADDR sp = get_frame_register_unsigned (this_frame, M32R_SP_REGNUM); |
| 883 | return frame_id_build (sp, get_frame_pc (this_frame)); |
| 884 | } |
| 885 | |
| 886 | |
| 887 | static gdbarch_init_ftype m32r_gdbarch_init; |
| 888 | |
| 889 | static struct gdbarch * |
| 890 | m32r_gdbarch_init (struct gdbarch_info info, struct gdbarch_list *arches) |
| 891 | { |
| 892 | struct gdbarch *gdbarch; |
| 893 | struct gdbarch_tdep *tdep; |
| 894 | |
| 895 | /* If there is already a candidate, use it. */ |
| 896 | arches = gdbarch_list_lookup_by_info (arches, &info); |
| 897 | if (arches != NULL) |
| 898 | return arches->gdbarch; |
| 899 | |
| 900 | /* Allocate space for the new architecture. */ |
| 901 | tdep = XCNEW (struct gdbarch_tdep); |
| 902 | gdbarch = gdbarch_alloc (&info, tdep); |
| 903 | |
| 904 | set_gdbarch_wchar_bit (gdbarch, 16); |
| 905 | set_gdbarch_wchar_signed (gdbarch, 0); |
| 906 | |
| 907 | set_gdbarch_unwind_sp (gdbarch, m32r_unwind_sp); |
| 908 | |
| 909 | set_gdbarch_num_regs (gdbarch, M32R_NUM_REGS); |
| 910 | set_gdbarch_pc_regnum (gdbarch, M32R_PC_REGNUM); |
| 911 | set_gdbarch_sp_regnum (gdbarch, M32R_SP_REGNUM); |
| 912 | set_gdbarch_register_name (gdbarch, m32r_register_name); |
| 913 | set_gdbarch_register_type (gdbarch, m32r_register_type); |
| 914 | |
| 915 | set_gdbarch_push_dummy_call (gdbarch, m32r_push_dummy_call); |
| 916 | set_gdbarch_return_value (gdbarch, m32r_return_value); |
| 917 | |
| 918 | set_gdbarch_skip_prologue (gdbarch, m32r_skip_prologue); |
| 919 | set_gdbarch_inner_than (gdbarch, core_addr_lessthan); |
| 920 | set_gdbarch_breakpoint_kind_from_pc (gdbarch, m32r_breakpoint_kind_from_pc); |
| 921 | set_gdbarch_sw_breakpoint_from_kind (gdbarch, m32r_sw_breakpoint_from_kind); |
| 922 | set_gdbarch_memory_insert_breakpoint (gdbarch, |
| 923 | m32r_memory_insert_breakpoint); |
| 924 | set_gdbarch_memory_remove_breakpoint (gdbarch, |
| 925 | m32r_memory_remove_breakpoint); |
| 926 | |
| 927 | set_gdbarch_frame_align (gdbarch, m32r_frame_align); |
| 928 | |
| 929 | frame_base_set_default (gdbarch, &m32r_frame_base); |
| 930 | |
| 931 | /* Methods for saving / extracting a dummy frame's ID. The ID's |
| 932 | stack address must match the SP value returned by |
| 933 | PUSH_DUMMY_CALL, and saved by generic_save_dummy_frame_tos. */ |
| 934 | set_gdbarch_dummy_id (gdbarch, m32r_dummy_id); |
| 935 | |
| 936 | /* Return the unwound PC value. */ |
| 937 | set_gdbarch_unwind_pc (gdbarch, m32r_unwind_pc); |
| 938 | |
| 939 | /* Hook in ABI-specific overrides, if they have been registered. */ |
| 940 | gdbarch_init_osabi (info, gdbarch); |
| 941 | |
| 942 | /* Hook in the default unwinders. */ |
| 943 | frame_unwind_append_unwinder (gdbarch, &m32r_frame_unwind); |
| 944 | |
| 945 | /* Support simple overlay manager. */ |
| 946 | set_gdbarch_overlay_update (gdbarch, simple_overlay_update); |
| 947 | |
| 948 | return gdbarch; |
| 949 | } |
| 950 | |
| 951 | void |
| 952 | _initialize_m32r_tdep (void) |
| 953 | { |
| 954 | register_gdbarch_init (bfd_arch_m32r, m32r_gdbarch_init); |
| 955 | } |