| 1 | /* Target-dependent code for the Matsushita MN10200 for GDB, the GNU debugger. |
| 2 | Copyright 1997 Free Software Foundation, Inc. |
| 3 | |
| 4 | This file is part of GDB. |
| 5 | |
| 6 | This program is free software; you can redistribute it and/or modify |
| 7 | it under the terms of the GNU General Public License as published by |
| 8 | the Free Software Foundation; either version 2 of the License, or |
| 9 | (at your option) any later version. |
| 10 | |
| 11 | This program is distributed in the hope that it will be useful, |
| 12 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 13 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 14 | GNU General Public License for more details. |
| 15 | |
| 16 | You should have received a copy of the GNU General Public License |
| 17 | along with this program; if not, write to the Free Software |
| 18 | Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */ |
| 19 | |
| 20 | #include "defs.h" |
| 21 | #include "frame.h" |
| 22 | #include "inferior.h" |
| 23 | #include "obstack.h" |
| 24 | #include "target.h" |
| 25 | #include "value.h" |
| 26 | #include "bfd.h" |
| 27 | #include "gdb_string.h" |
| 28 | #include "gdbcore.h" |
| 29 | #include "symfile.h" |
| 30 | |
| 31 | |
| 32 | /* Should call_function allocate stack space for a struct return? */ |
| 33 | int |
| 34 | mn10200_use_struct_convention (gcc_p, type) |
| 35 | int gcc_p; |
| 36 | struct type *type; |
| 37 | { |
| 38 | return (TYPE_NFIELDS (type) > 1 || TYPE_LENGTH (type) > 8); |
| 39 | } |
| 40 | |
| 41 | |
| 42 | |
| 43 | /* The main purpose of this file is dealing with prologues to extract |
| 44 | information about stack frames and saved registers. |
| 45 | |
| 46 | For reference here's how prologues look on the mn10200: |
| 47 | |
| 48 | With frame pointer: |
| 49 | mov fp,a0 |
| 50 | mov sp,fp |
| 51 | add <size>,sp |
| 52 | Register saves for d2, d3, a1, a2 as needed. Saves start |
| 53 | at fp - <size> + <outgoing_args_size> and work towards higher |
| 54 | addresses. Note that the saves are actually done off the stack |
| 55 | pointer in the prologue! This makes for smaller code and easier |
| 56 | prologue scanning as the displacement fields will unlikely |
| 57 | be more than 8 bits! |
| 58 | |
| 59 | Without frame pointer: |
| 60 | add <size>,sp |
| 61 | Register saves for d2, d3, a1, a2 as needed. Saves start |
| 62 | at sp + <outgoing_args_size> and work towards higher addresses. |
| 63 | |
| 64 | Out of line prologue: |
| 65 | add <local size>,sp -- optional |
| 66 | jsr __prologue |
| 67 | add <outgoing_size>,sp -- optional |
| 68 | |
| 69 | The stack pointer remains constant throughout the life of most |
| 70 | functions. As a result the compiler will usually omit the |
| 71 | frame pointer, so we must handle frame pointerless functions. */ |
| 72 | |
| 73 | /* Analyze the prologue to determine where registers are saved, |
| 74 | the end of the prologue, etc etc. Return the end of the prologue |
| 75 | scanned. |
| 76 | |
| 77 | We store into FI (if non-null) several tidbits of information: |
| 78 | |
| 79 | * stack_size -- size of this stack frame. Note that if we stop in |
| 80 | certain parts of the prologue/epilogue we may claim the size of the |
| 81 | current frame is zero. This happens when the current frame has |
| 82 | not been allocated yet or has already been deallocated. |
| 83 | |
| 84 | * fsr -- Addresses of registers saved in the stack by this frame. |
| 85 | |
| 86 | * status -- A (relatively) generic status indicator. It's a bitmask |
| 87 | with the following bits: |
| 88 | |
| 89 | MY_FRAME_IN_SP: The base of the current frame is actually in |
| 90 | the stack pointer. This can happen for frame pointerless |
| 91 | functions, or cases where we're stopped in the prologue/epilogue |
| 92 | itself. For these cases mn10200_analyze_prologue will need up |
| 93 | update fi->frame before returning or analyzing the register |
| 94 | save instructions. |
| 95 | |
| 96 | MY_FRAME_IN_FP: The base of the current frame is in the |
| 97 | frame pointer register ($a2). |
| 98 | |
| 99 | CALLER_A2_IN_A0: $a2 from the caller's frame is temporarily |
| 100 | in $a0. This can happen if we're stopped in the prologue. |
| 101 | |
| 102 | NO_MORE_FRAMES: Set this if the current frame is "start" or |
| 103 | if the first instruction looks like mov <imm>,sp. This tells |
| 104 | frame chain to not bother trying to unwind past this frame. */ |
| 105 | |
| 106 | #define MY_FRAME_IN_SP 0x1 |
| 107 | #define MY_FRAME_IN_FP 0x2 |
| 108 | #define CALLER_A2_IN_A0 0x4 |
| 109 | #define NO_MORE_FRAMES 0x8 |
| 110 | |
| 111 | static CORE_ADDR |
| 112 | mn10200_analyze_prologue (fi, pc) |
| 113 | struct frame_info *fi; |
| 114 | CORE_ADDR pc; |
| 115 | { |
| 116 | CORE_ADDR func_addr, func_end, addr, stop; |
| 117 | CORE_ADDR stack_size; |
| 118 | unsigned char buf[4]; |
| 119 | int status; |
| 120 | char *name; |
| 121 | int out_of_line_prologue = 0; |
| 122 | |
| 123 | /* Use the PC in the frame if it's provided to look up the |
| 124 | start of this function. */ |
| 125 | pc = (fi ? fi->pc : pc); |
| 126 | |
| 127 | /* Find the start of this function. */ |
| 128 | status = find_pc_partial_function (pc, &name, &func_addr, &func_end); |
| 129 | |
| 130 | /* Do nothing if we couldn't find the start of this function or if we're |
| 131 | stopped at the first instruction in the prologue. */ |
| 132 | if (status == 0) |
| 133 | return pc; |
| 134 | |
| 135 | /* If we're in start, then give up. */ |
| 136 | if (strcmp (name, "start") == 0) |
| 137 | { |
| 138 | if (fi) |
| 139 | fi->status = NO_MORE_FRAMES; |
| 140 | return pc; |
| 141 | } |
| 142 | |
| 143 | /* At the start of a function our frame is in the stack pointer. */ |
| 144 | if (fi) |
| 145 | fi->status = MY_FRAME_IN_SP; |
| 146 | |
| 147 | /* If we're physically on an RTS instruction, then our frame has already |
| 148 | been deallocated. |
| 149 | |
| 150 | fi->frame is bogus, we need to fix it. */ |
| 151 | if (fi && fi->pc + 1 == func_end) |
| 152 | { |
| 153 | status = target_read_memory (fi->pc, buf, 1); |
| 154 | if (status != 0) |
| 155 | { |
| 156 | if (fi->next == NULL) |
| 157 | fi->frame = read_sp (); |
| 158 | return fi->pc; |
| 159 | } |
| 160 | |
| 161 | if (buf[0] == 0xfe) |
| 162 | { |
| 163 | if (fi->next == NULL) |
| 164 | fi->frame = read_sp (); |
| 165 | return fi->pc; |
| 166 | } |
| 167 | } |
| 168 | |
| 169 | /* Similarly if we're stopped on the first insn of a prologue as our |
| 170 | frame hasn't been allocated yet. */ |
| 171 | if (fi && fi->pc == func_addr) |
| 172 | { |
| 173 | if (fi->next == NULL) |
| 174 | fi->frame = read_sp (); |
| 175 | return fi->pc; |
| 176 | } |
| 177 | |
| 178 | /* Figure out where to stop scanning. */ |
| 179 | stop = fi ? fi->pc : func_end; |
| 180 | |
| 181 | /* Don't walk off the end of the function. */ |
| 182 | stop = stop > func_end ? func_end : stop; |
| 183 | |
| 184 | /* Start scanning on the first instruction of this function. */ |
| 185 | addr = func_addr; |
| 186 | |
| 187 | status = target_read_memory (addr, buf, 2); |
| 188 | if (status != 0) |
| 189 | { |
| 190 | if (fi && fi->next == NULL && fi->status & MY_FRAME_IN_SP) |
| 191 | fi->frame = read_sp (); |
| 192 | return addr; |
| 193 | } |
| 194 | |
| 195 | /* First see if this insn sets the stack pointer; if so, it's something |
| 196 | we won't understand, so quit now. */ |
| 197 | if (buf[0] == 0xdf |
| 198 | || (buf[0] == 0xf4 && buf[1] == 0x77)) |
| 199 | { |
| 200 | if (fi) |
| 201 | fi->status = NO_MORE_FRAMES; |
| 202 | return addr; |
| 203 | } |
| 204 | |
| 205 | /* Now see if we have a frame pointer. |
| 206 | |
| 207 | Search for mov a2,a0 (0xf278) |
| 208 | then mov a3,a2 (0xf27e). */ |
| 209 | |
| 210 | if (buf[0] == 0xf2 && buf[1] == 0x78) |
| 211 | { |
| 212 | /* Our caller's $a2 will be found in $a0 now. Note it for |
| 213 | our callers. */ |
| 214 | if (fi) |
| 215 | fi->status |= CALLER_A2_IN_A0; |
| 216 | addr += 2; |
| 217 | if (addr >= stop) |
| 218 | { |
| 219 | /* We still haven't allocated our local stack. Handle this |
| 220 | as if we stopped on the first or last insn of a function. */ |
| 221 | if (fi && fi->next == NULL) |
| 222 | fi->frame = read_sp (); |
| 223 | return addr; |
| 224 | } |
| 225 | |
| 226 | status = target_read_memory (addr, buf, 2); |
| 227 | if (status != 0) |
| 228 | { |
| 229 | if (fi && fi->next == NULL) |
| 230 | fi->frame = read_sp (); |
| 231 | return addr; |
| 232 | } |
| 233 | if (buf[0] == 0xf2 && buf[1] == 0x7e) |
| 234 | { |
| 235 | addr += 2; |
| 236 | |
| 237 | /* Our frame pointer is valid now. */ |
| 238 | if (fi) |
| 239 | { |
| 240 | fi->status |= MY_FRAME_IN_FP; |
| 241 | fi->status &= ~MY_FRAME_IN_SP; |
| 242 | } |
| 243 | if (addr >= stop) |
| 244 | return addr; |
| 245 | } |
| 246 | else |
| 247 | { |
| 248 | if (fi && fi->next == NULL) |
| 249 | fi->frame = read_sp (); |
| 250 | return addr; |
| 251 | } |
| 252 | } |
| 253 | |
| 254 | /* Next we should allocate the local frame. |
| 255 | |
| 256 | Search for add imm8,a3 (0xd3XX) |
| 257 | or add imm16,a3 (0xf70bXXXX) |
| 258 | or add imm24,a3 (0xf467XXXXXX). |
| 259 | |
| 260 | If none of the above was found, then this prologue has |
| 261 | no stack, and therefore can't have any register saves, |
| 262 | so quit now. */ |
| 263 | status = target_read_memory (addr, buf, 2); |
| 264 | if (status != 0) |
| 265 | { |
| 266 | if (fi && fi->next == NULL && (fi->status & MY_FRAME_IN_SP)) |
| 267 | fi->frame = read_sp (); |
| 268 | return addr; |
| 269 | } |
| 270 | if (buf[0] == 0xd3) |
| 271 | { |
| 272 | stack_size = extract_signed_integer (&buf[1], 1); |
| 273 | if (fi) |
| 274 | fi->stack_size = stack_size; |
| 275 | addr += 2; |
| 276 | if (addr >= stop) |
| 277 | { |
| 278 | if (fi && fi->next == NULL && (fi->status & MY_FRAME_IN_SP)) |
| 279 | fi->frame = read_sp () - stack_size; |
| 280 | return addr; |
| 281 | } |
| 282 | } |
| 283 | else if (buf[0] == 0xf7 && buf[1] == 0x0b) |
| 284 | { |
| 285 | status = target_read_memory (addr + 2, buf, 2); |
| 286 | if (status != 0) |
| 287 | { |
| 288 | if (fi && fi->next == NULL && (fi->status & MY_FRAME_IN_SP)) |
| 289 | fi->frame = read_sp (); |
| 290 | return addr; |
| 291 | } |
| 292 | stack_size = extract_signed_integer (buf, 2); |
| 293 | if (fi) |
| 294 | fi->stack_size = stack_size; |
| 295 | addr += 4; |
| 296 | if (addr >= stop) |
| 297 | { |
| 298 | if (fi && fi->next == NULL && (fi->status & MY_FRAME_IN_SP)) |
| 299 | fi->frame = read_sp () - stack_size; |
| 300 | return addr; |
| 301 | } |
| 302 | } |
| 303 | else if (buf[0] == 0xf4 && buf[1] == 0x67) |
| 304 | { |
| 305 | status = target_read_memory (addr + 2, buf, 3); |
| 306 | if (status != 0) |
| 307 | { |
| 308 | if (fi && fi->next == NULL && (fi->status & MY_FRAME_IN_SP)) |
| 309 | fi->frame = read_sp (); |
| 310 | return addr; |
| 311 | } |
| 312 | stack_size = extract_signed_integer (buf, 3); |
| 313 | if (fi) |
| 314 | fi->stack_size = stack_size; |
| 315 | addr += 5; |
| 316 | if (addr >= stop) |
| 317 | { |
| 318 | if (fi && fi->next == NULL && (fi->status & MY_FRAME_IN_SP)) |
| 319 | fi->frame = read_sp () - stack_size; |
| 320 | return addr; |
| 321 | } |
| 322 | } |
| 323 | |
| 324 | /* Now see if we have a call to __prologue for an out of line |
| 325 | prologue. */ |
| 326 | status = target_read_memory (addr, buf, 2); |
| 327 | if (status != 0) |
| 328 | return addr; |
| 329 | |
| 330 | /* First check for 16bit pc-relative call to __prologue. */ |
| 331 | if (buf[0] == 0xfd) |
| 332 | { |
| 333 | CORE_ADDR temp; |
| 334 | status = target_read_memory (addr + 1, buf, 2); |
| 335 | if (status != 0) |
| 336 | { |
| 337 | if (fi && fi->next == NULL && (fi->status & MY_FRAME_IN_SP)) |
| 338 | fi->frame = read_sp (); |
| 339 | return addr; |
| 340 | } |
| 341 | |
| 342 | /* Get the PC this instruction will branch to. */ |
| 343 | temp = (extract_signed_integer (buf, 2) + addr + 3) & 0xffffff; |
| 344 | |
| 345 | /* Get the name of the function at the target address. */ |
| 346 | status = find_pc_partial_function (temp, &name, NULL, NULL); |
| 347 | if (status == 0) |
| 348 | { |
| 349 | if (fi && fi->next == NULL && (fi->status & MY_FRAME_IN_SP)) |
| 350 | fi->frame = read_sp (); |
| 351 | return addr; |
| 352 | } |
| 353 | |
| 354 | /* Note if it is an out of line prologue. */ |
| 355 | out_of_line_prologue = (strcmp (name, "__prologue") == 0); |
| 356 | |
| 357 | /* This sucks up 3 bytes of instruction space. */ |
| 358 | if (out_of_line_prologue) |
| 359 | addr += 3; |
| 360 | |
| 361 | if (addr >= stop) |
| 362 | { |
| 363 | if (fi && fi->next == NULL) |
| 364 | { |
| 365 | fi->stack_size -= 16; |
| 366 | fi->frame = read_sp () - fi->stack_size; |
| 367 | } |
| 368 | return addr; |
| 369 | } |
| 370 | } |
| 371 | /* Now check for the 24bit pc-relative call to __prologue. */ |
| 372 | else if (buf[0] == 0xf4 && buf[1] == 0xe1) |
| 373 | { |
| 374 | CORE_ADDR temp; |
| 375 | status = target_read_memory (addr + 2, buf, 3); |
| 376 | if (status != 0) |
| 377 | { |
| 378 | if (fi && fi->next == NULL && (fi->status & MY_FRAME_IN_SP)) |
| 379 | fi->frame = read_sp (); |
| 380 | return addr; |
| 381 | } |
| 382 | |
| 383 | /* Get the PC this instruction will branch to. */ |
| 384 | temp = (extract_signed_integer (buf, 3) + addr + 5) & 0xffffff; |
| 385 | |
| 386 | /* Get the name of the function at the target address. */ |
| 387 | status = find_pc_partial_function (temp, &name, NULL, NULL); |
| 388 | if (status == 0) |
| 389 | { |
| 390 | if (fi && fi->next == NULL && (fi->status & MY_FRAME_IN_SP)) |
| 391 | fi->frame = read_sp (); |
| 392 | return addr; |
| 393 | } |
| 394 | |
| 395 | /* Note if it is an out of line prologue. */ |
| 396 | out_of_line_prologue = (strcmp (name, "__prologue") == 0); |
| 397 | |
| 398 | /* This sucks up 5 bytes of instruction space. */ |
| 399 | if (out_of_line_prologue) |
| 400 | addr += 5; |
| 401 | |
| 402 | if (addr >= stop) |
| 403 | { |
| 404 | if (fi && fi->next == NULL && (fi->status & MY_FRAME_IN_SP)) |
| 405 | { |
| 406 | fi->stack_size -= 16; |
| 407 | fi->frame = read_sp () - fi->stack_size; |
| 408 | } |
| 409 | return addr; |
| 410 | } |
| 411 | } |
| 412 | |
| 413 | /* Now actually handle the out of line prologue. */ |
| 414 | if (out_of_line_prologue) |
| 415 | { |
| 416 | int outgoing_args_size = 0; |
| 417 | |
| 418 | /* First adjust the stack size for this function. The out of |
| 419 | line prologue saves 4 registers (16bytes of data). */ |
| 420 | if (fi) |
| 421 | fi->stack_size -= 16; |
| 422 | |
| 423 | /* Update fi->frame if necessary. */ |
| 424 | if (fi && fi->next == NULL) |
| 425 | fi->frame = read_sp () - fi->stack_size; |
| 426 | |
| 427 | /* After the out of line prologue, there may be another |
| 428 | stack adjustment for the outgoing arguments. |
| 429 | |
| 430 | Search for add imm8,a3 (0xd3XX) |
| 431 | or add imm16,a3 (0xf70bXXXX) |
| 432 | or add imm24,a3 (0xf467XXXXXX). */ |
| 433 | |
| 434 | status = target_read_memory (addr, buf, 2); |
| 435 | if (status != 0) |
| 436 | { |
| 437 | if (fi) |
| 438 | { |
| 439 | fi->fsr.regs[2] = fi->frame + fi->stack_size + 4; |
| 440 | fi->fsr.regs[3] = fi->frame + fi->stack_size + 8; |
| 441 | fi->fsr.regs[5] = fi->frame + fi->stack_size + 12; |
| 442 | fi->fsr.regs[6] = fi->frame + fi->stack_size + 16; |
| 443 | } |
| 444 | return addr; |
| 445 | } |
| 446 | |
| 447 | if (buf[0] == 0xd3) |
| 448 | { |
| 449 | outgoing_args_size = extract_signed_integer (&buf[1], 1); |
| 450 | addr += 2; |
| 451 | } |
| 452 | else if (buf[0] == 0xf7 && buf[1] == 0x0b) |
| 453 | { |
| 454 | status = target_read_memory (addr + 2, buf, 2); |
| 455 | if (status != 0) |
| 456 | { |
| 457 | if (fi) |
| 458 | { |
| 459 | fi->fsr.regs[2] = fi->frame + fi->stack_size + 4; |
| 460 | fi->fsr.regs[3] = fi->frame + fi->stack_size + 8; |
| 461 | fi->fsr.regs[5] = fi->frame + fi->stack_size + 12; |
| 462 | fi->fsr.regs[6] = fi->frame + fi->stack_size + 16; |
| 463 | } |
| 464 | return addr; |
| 465 | } |
| 466 | outgoing_args_size = extract_signed_integer (buf, 2); |
| 467 | addr += 4; |
| 468 | } |
| 469 | else if (buf[0] == 0xf4 && buf[1] == 0x67) |
| 470 | { |
| 471 | status = target_read_memory (addr + 2, buf, 3); |
| 472 | if (status != 0) |
| 473 | { |
| 474 | if (fi && fi->next == NULL) |
| 475 | { |
| 476 | fi->fsr.regs[2] = fi->frame + fi->stack_size + 4; |
| 477 | fi->fsr.regs[3] = fi->frame + fi->stack_size + 8; |
| 478 | fi->fsr.regs[5] = fi->frame + fi->stack_size + 12; |
| 479 | fi->fsr.regs[6] = fi->frame + fi->stack_size + 16; |
| 480 | } |
| 481 | return addr; |
| 482 | } |
| 483 | outgoing_args_size = extract_signed_integer (buf, 3); |
| 484 | addr += 5; |
| 485 | } |
| 486 | else |
| 487 | outgoing_args_size = 0; |
| 488 | |
| 489 | /* Now that we know the size of the outgoing arguments, fix |
| 490 | fi->frame again if this is the innermost frame. */ |
| 491 | if (fi && fi->next == NULL) |
| 492 | fi->frame -= outgoing_args_size; |
| 493 | |
| 494 | /* Note the register save information and update the stack |
| 495 | size for this frame too. */ |
| 496 | if (fi) |
| 497 | { |
| 498 | fi->fsr.regs[2] = fi->frame + fi->stack_size + 4; |
| 499 | fi->fsr.regs[3] = fi->frame + fi->stack_size + 8; |
| 500 | fi->fsr.regs[5] = fi->frame + fi->stack_size + 12; |
| 501 | fi->fsr.regs[6] = fi->frame + fi->stack_size + 16; |
| 502 | fi->stack_size += outgoing_args_size; |
| 503 | } |
| 504 | /* There can be no more prologue insns, so return now. */ |
| 505 | return addr; |
| 506 | } |
| 507 | |
| 508 | /* At this point fi->frame needs to be correct. |
| 509 | |
| 510 | If MY_FRAME_IN_SP is set and we're the innermost frame, then we |
| 511 | need to fix fi->frame so that backtracing, find_frame_saved_regs, |
| 512 | etc work correctly. */ |
| 513 | if (fi && fi->next == NULL && (fi->status & MY_FRAME_IN_SP) != 0) |
| 514 | fi->frame = read_sp () - fi->stack_size; |
| 515 | |
| 516 | /* And last we have the register saves. These are relatively |
| 517 | simple because they're physically done off the stack pointer, |
| 518 | and thus the number of different instructions we need to |
| 519 | check is greatly reduced because we know the displacements |
| 520 | will be small. |
| 521 | |
| 522 | Search for movx d2,(X,a3) (0xf55eXX) |
| 523 | then movx d3,(X,a3) (0xf55fXX) |
| 524 | then mov a1,(X,a3) (0x5dXX) No frame pointer case |
| 525 | then mov a2,(X,a3) (0x5eXX) No frame pointer case |
| 526 | or mov a0,(X,a3) (0x5cXX) Frame pointer case. */ |
| 527 | |
| 528 | status = target_read_memory (addr, buf, 2); |
| 529 | if (status != 0) |
| 530 | return addr; |
| 531 | if (buf[0] == 0xf5 && buf[1] == 0x5e) |
| 532 | { |
| 533 | if (fi) |
| 534 | { |
| 535 | status = target_read_memory (addr + 2, buf, 1); |
| 536 | if (status != 0) |
| 537 | return addr; |
| 538 | fi->fsr.regs[2] = (fi->frame + stack_size |
| 539 | + extract_signed_integer (buf, 1)); |
| 540 | } |
| 541 | addr += 3; |
| 542 | if (addr >= stop) |
| 543 | return addr; |
| 544 | status = target_read_memory (addr, buf, 2); |
| 545 | if (status != 0) |
| 546 | return addr; |
| 547 | } |
| 548 | if (buf[0] == 0xf5 && buf[1] == 0x5f) |
| 549 | { |
| 550 | if (fi) |
| 551 | { |
| 552 | status = target_read_memory (addr + 2, buf, 1); |
| 553 | if (status != 0) |
| 554 | return addr; |
| 555 | fi->fsr.regs[3] = (fi->frame + stack_size |
| 556 | + extract_signed_integer (buf, 1)); |
| 557 | } |
| 558 | addr += 3; |
| 559 | if (addr >= stop) |
| 560 | return addr; |
| 561 | status = target_read_memory (addr, buf, 2); |
| 562 | if (status != 0) |
| 563 | return addr; |
| 564 | } |
| 565 | if (buf[0] == 0x5d) |
| 566 | { |
| 567 | if (fi) |
| 568 | { |
| 569 | status = target_read_memory (addr + 1, buf, 1); |
| 570 | if (status != 0) |
| 571 | return addr; |
| 572 | fi->fsr.regs[5] = (fi->frame + stack_size |
| 573 | + extract_signed_integer (buf, 1)); |
| 574 | } |
| 575 | addr += 2; |
| 576 | if (addr >= stop) |
| 577 | return addr; |
| 578 | status = target_read_memory (addr, buf, 2); |
| 579 | if (status != 0) |
| 580 | return addr; |
| 581 | } |
| 582 | if (buf[0] == 0x5e || buf[0] == 0x5c) |
| 583 | { |
| 584 | if (fi) |
| 585 | { |
| 586 | status = target_read_memory (addr + 1, buf, 1); |
| 587 | if (status != 0) |
| 588 | return addr; |
| 589 | fi->fsr.regs[6] = (fi->frame + stack_size |
| 590 | + extract_signed_integer (buf, 1)); |
| 591 | fi->status &= ~CALLER_A2_IN_A0; |
| 592 | } |
| 593 | addr += 2; |
| 594 | if (addr >= stop) |
| 595 | return addr; |
| 596 | return addr; |
| 597 | } |
| 598 | return addr; |
| 599 | } |
| 600 | |
| 601 | /* Function: frame_chain |
| 602 | Figure out and return the caller's frame pointer given current |
| 603 | frame_info struct. |
| 604 | |
| 605 | We don't handle dummy frames yet but we would probably just return the |
| 606 | stack pointer that was in use at the time the function call was made? */ |
| 607 | |
| 608 | CORE_ADDR |
| 609 | mn10200_frame_chain (fi) |
| 610 | struct frame_info *fi; |
| 611 | { |
| 612 | struct frame_info dummy_frame; |
| 613 | |
| 614 | /* Walk through the prologue to determine the stack size, |
| 615 | location of saved registers, end of the prologue, etc. */ |
| 616 | if (fi->status == 0) |
| 617 | mn10200_analyze_prologue (fi, (CORE_ADDR)0); |
| 618 | |
| 619 | /* Quit now if mn10200_analyze_prologue set NO_MORE_FRAMES. */ |
| 620 | if (fi->status & NO_MORE_FRAMES) |
| 621 | return 0; |
| 622 | |
| 623 | /* Now that we've analyzed our prologue, determine the frame |
| 624 | pointer for our caller. |
| 625 | |
| 626 | If our caller has a frame pointer, then we need to |
| 627 | find the entry value of $a2 to our function. |
| 628 | |
| 629 | If CALLER_A2_IN_A0, then the chain is in $a0. |
| 630 | |
| 631 | If fsr.regs[6] is nonzero, then it's at the memory |
| 632 | location pointed to by fsr.regs[6]. |
| 633 | |
| 634 | Else it's still in $a2. |
| 635 | |
| 636 | If our caller does not have a frame pointer, then his |
| 637 | frame base is fi->frame + -caller's stack size + 4. */ |
| 638 | |
| 639 | /* The easiest way to get that info is to analyze our caller's frame. |
| 640 | |
| 641 | So we set up a dummy frame and call mn10200_analyze_prologue to |
| 642 | find stuff for us. */ |
| 643 | dummy_frame.pc = FRAME_SAVED_PC (fi); |
| 644 | dummy_frame.frame = fi->frame; |
| 645 | memset (dummy_frame.fsr.regs, '\000', sizeof dummy_frame.fsr.regs); |
| 646 | dummy_frame.status = 0; |
| 647 | dummy_frame.stack_size = 0; |
| 648 | mn10200_analyze_prologue (&dummy_frame); |
| 649 | |
| 650 | if (dummy_frame.status & MY_FRAME_IN_FP) |
| 651 | { |
| 652 | /* Our caller has a frame pointer. So find the frame in $a2, $a0, |
| 653 | or in the stack. */ |
| 654 | if (fi->fsr.regs[6]) |
| 655 | return (read_memory_integer (fi->fsr.regs[FP_REGNUM], REGISTER_SIZE) |
| 656 | & 0xffffff); |
| 657 | else if (fi->status & CALLER_A2_IN_A0) |
| 658 | return read_register (4); |
| 659 | else |
| 660 | return read_register (FP_REGNUM); |
| 661 | } |
| 662 | else |
| 663 | { |
| 664 | /* Our caller does not have a frame pointer. So his frame starts |
| 665 | at the base of our frame (fi->frame) + <his size> + 4 (saved pc). */ |
| 666 | return fi->frame + -dummy_frame.stack_size + 4; |
| 667 | } |
| 668 | } |
| 669 | |
| 670 | /* Function: skip_prologue |
| 671 | Return the address of the first inst past the prologue of the function. */ |
| 672 | |
| 673 | CORE_ADDR |
| 674 | mn10200_skip_prologue (pc) |
| 675 | CORE_ADDR pc; |
| 676 | { |
| 677 | /* We used to check the debug symbols, but that can lose if |
| 678 | we have a null prologue. */ |
| 679 | return mn10200_analyze_prologue (NULL, pc); |
| 680 | } |
| 681 | |
| 682 | /* Function: pop_frame |
| 683 | This routine gets called when either the user uses the `return' |
| 684 | command, or the call dummy breakpoint gets hit. */ |
| 685 | |
| 686 | void |
| 687 | mn10200_pop_frame (frame) |
| 688 | struct frame_info *frame; |
| 689 | { |
| 690 | int regnum; |
| 691 | |
| 692 | if (PC_IN_CALL_DUMMY(frame->pc, frame->frame, frame->frame)) |
| 693 | generic_pop_dummy_frame (); |
| 694 | else |
| 695 | { |
| 696 | write_register (PC_REGNUM, FRAME_SAVED_PC (frame)); |
| 697 | |
| 698 | /* Restore any saved registers. */ |
| 699 | for (regnum = 0; regnum < NUM_REGS; regnum++) |
| 700 | if (frame->fsr.regs[regnum] != 0) |
| 701 | { |
| 702 | ULONGEST value; |
| 703 | |
| 704 | value = read_memory_unsigned_integer (frame->fsr.regs[regnum], |
| 705 | REGISTER_RAW_SIZE (regnum)); |
| 706 | write_register (regnum, value); |
| 707 | } |
| 708 | |
| 709 | /* Actually cut back the stack. */ |
| 710 | write_register (SP_REGNUM, FRAME_FP (frame)); |
| 711 | |
| 712 | /* Don't we need to set the PC?!? XXX FIXME. */ |
| 713 | } |
| 714 | |
| 715 | /* Throw away any cached frame information. */ |
| 716 | flush_cached_frames (); |
| 717 | } |
| 718 | |
| 719 | /* Function: push_arguments |
| 720 | Setup arguments for a call to the target. Arguments go in |
| 721 | order on the stack. */ |
| 722 | |
| 723 | CORE_ADDR |
| 724 | mn10200_push_arguments (nargs, args, sp, struct_return, struct_addr) |
| 725 | int nargs; |
| 726 | value_ptr *args; |
| 727 | CORE_ADDR sp; |
| 728 | unsigned char struct_return; |
| 729 | CORE_ADDR struct_addr; |
| 730 | { |
| 731 | int argnum = 0; |
| 732 | int len = 0; |
| 733 | int stack_offset = 0; |
| 734 | int regsused = struct_return ? 1 : 0; |
| 735 | |
| 736 | /* This should be a nop, but align the stack just in case something |
| 737 | went wrong. Stacks are two byte aligned on the mn10200. */ |
| 738 | sp &= ~1; |
| 739 | |
| 740 | /* Now make space on the stack for the args. |
| 741 | |
| 742 | XXX This doesn't appear to handle pass-by-invisible reference |
| 743 | arguments. */ |
| 744 | for (argnum = 0; argnum < nargs; argnum++) |
| 745 | { |
| 746 | int arg_length = (TYPE_LENGTH (VALUE_TYPE (args[argnum])) + 1) & ~1; |
| 747 | |
| 748 | /* If we've used all argument registers, then this argument is |
| 749 | pushed. */ |
| 750 | if (regsused >= 2 || arg_length > 4) |
| 751 | { |
| 752 | regsused = 2; |
| 753 | len += arg_length; |
| 754 | } |
| 755 | /* We know we've got some arg register space left. If this argument |
| 756 | will fit entirely in regs, then put it there. */ |
| 757 | else if (arg_length <= 2 |
| 758 | || TYPE_CODE (VALUE_TYPE (args[argnum])) == TYPE_CODE_PTR) |
| 759 | { |
| 760 | regsused++; |
| 761 | } |
| 762 | else if (regsused == 0) |
| 763 | { |
| 764 | regsused = 2; |
| 765 | } |
| 766 | else |
| 767 | { |
| 768 | regsused = 2; |
| 769 | len += arg_length; |
| 770 | } |
| 771 | } |
| 772 | |
| 773 | /* Allocate stack space. */ |
| 774 | sp -= len; |
| 775 | |
| 776 | regsused = struct_return ? 1 : 0; |
| 777 | /* Push all arguments onto the stack. */ |
| 778 | for (argnum = 0; argnum < nargs; argnum++) |
| 779 | { |
| 780 | int len; |
| 781 | char *val; |
| 782 | |
| 783 | /* XXX Check this. What about UNIONS? */ |
| 784 | if (TYPE_CODE (VALUE_TYPE (*args)) == TYPE_CODE_STRUCT |
| 785 | && TYPE_LENGTH (VALUE_TYPE (*args)) > 8) |
| 786 | { |
| 787 | /* XXX Wrong, we want a pointer to this argument. */ |
| 788 | len = TYPE_LENGTH (VALUE_TYPE (*args)); |
| 789 | val = (char *)VALUE_CONTENTS (*args); |
| 790 | } |
| 791 | else |
| 792 | { |
| 793 | len = TYPE_LENGTH (VALUE_TYPE (*args)); |
| 794 | val = (char *)VALUE_CONTENTS (*args); |
| 795 | } |
| 796 | |
| 797 | if (regsused < 2 |
| 798 | && (len <= 2 |
| 799 | || TYPE_CODE (VALUE_TYPE (*args)) == TYPE_CODE_PTR)) |
| 800 | { |
| 801 | write_register (regsused, extract_unsigned_integer (val, 4)); |
| 802 | regsused++; |
| 803 | } |
| 804 | else if (regsused == 0 && len == 4) |
| 805 | { |
| 806 | write_register (regsused, extract_unsigned_integer (val, 2)); |
| 807 | write_register (regsused + 1, extract_unsigned_integer (val + 2, 2)); |
| 808 | regsused = 2; |
| 809 | } |
| 810 | else |
| 811 | { |
| 812 | regsused = 2; |
| 813 | while (len > 0) |
| 814 | { |
| 815 | write_memory (sp + stack_offset, val, 2); |
| 816 | |
| 817 | len -= 2; |
| 818 | val += 2; |
| 819 | stack_offset += 2; |
| 820 | } |
| 821 | } |
| 822 | args++; |
| 823 | } |
| 824 | |
| 825 | return sp; |
| 826 | } |
| 827 | |
| 828 | /* Function: push_return_address (pc) |
| 829 | Set up the return address for the inferior function call. |
| 830 | Needed for targets where we don't actually execute a JSR/BSR instruction */ |
| 831 | |
| 832 | CORE_ADDR |
| 833 | mn10200_push_return_address (pc, sp) |
| 834 | CORE_ADDR pc; |
| 835 | CORE_ADDR sp; |
| 836 | { |
| 837 | unsigned char buf[4]; |
| 838 | |
| 839 | store_unsigned_integer (buf, 4, CALL_DUMMY_ADDRESS ()); |
| 840 | write_memory (sp - 4, buf, 4); |
| 841 | return sp - 4; |
| 842 | } |
| 843 | |
| 844 | /* Function: store_struct_return (addr,sp) |
| 845 | Store the structure value return address for an inferior function |
| 846 | call. */ |
| 847 | |
| 848 | CORE_ADDR |
| 849 | mn10200_store_struct_return (addr, sp) |
| 850 | CORE_ADDR addr; |
| 851 | CORE_ADDR sp; |
| 852 | { |
| 853 | /* The structure return address is passed as the first argument. */ |
| 854 | write_register (0, addr); |
| 855 | return sp; |
| 856 | } |
| 857 | |
| 858 | /* Function: frame_saved_pc |
| 859 | Find the caller of this frame. We do this by seeing if RP_REGNUM |
| 860 | is saved in the stack anywhere, otherwise we get it from the |
| 861 | registers. If the inner frame is a dummy frame, return its PC |
| 862 | instead of RP, because that's where "caller" of the dummy-frame |
| 863 | will be found. */ |
| 864 | |
| 865 | CORE_ADDR |
| 866 | mn10200_frame_saved_pc (fi) |
| 867 | struct frame_info *fi; |
| 868 | { |
| 869 | /* The saved PC will always be at the base of the current frame. */ |
| 870 | return (read_memory_integer (fi->frame, REGISTER_SIZE) & 0xffffff); |
| 871 | } |
| 872 | |
| 873 | void |
| 874 | get_saved_register (raw_buffer, optimized, addrp, frame, regnum, lval) |
| 875 | char *raw_buffer; |
| 876 | int *optimized; |
| 877 | CORE_ADDR *addrp; |
| 878 | struct frame_info *frame; |
| 879 | int regnum; |
| 880 | enum lval_type *lval; |
| 881 | { |
| 882 | generic_get_saved_register (raw_buffer, optimized, addrp, |
| 883 | frame, regnum, lval); |
| 884 | } |
| 885 | |
| 886 | /* Function: init_extra_frame_info |
| 887 | Setup the frame's frame pointer, pc, and frame addresses for saved |
| 888 | registers. Most of the work is done in mn10200_analyze_prologue(). |
| 889 | |
| 890 | Note that when we are called for the last frame (currently active frame), |
| 891 | that fi->pc and fi->frame will already be setup. However, fi->frame will |
| 892 | be valid only if this routine uses FP. For previous frames, fi-frame will |
| 893 | always be correct. mn10200_analyze_prologue will fix fi->frame if |
| 894 | it's not valid. |
| 895 | |
| 896 | We can be called with the PC in the call dummy under two circumstances. |
| 897 | First, during normal backtracing, second, while figuring out the frame |
| 898 | pointer just prior to calling the target function (see run_stack_dummy). */ |
| 899 | |
| 900 | void |
| 901 | mn10200_init_extra_frame_info (fi) |
| 902 | struct frame_info *fi; |
| 903 | { |
| 904 | if (fi->next) |
| 905 | fi->pc = FRAME_SAVED_PC (fi->next); |
| 906 | |
| 907 | memset (fi->fsr.regs, '\000', sizeof fi->fsr.regs); |
| 908 | fi->status = 0; |
| 909 | fi->stack_size = 0; |
| 910 | |
| 911 | mn10200_analyze_prologue (fi, 0); |
| 912 | } |
| 913 | |
| 914 | void |
| 915 | _initialize_mn10200_tdep () |
| 916 | { |
| 917 | tm_print_insn = print_insn_mn10200; |
| 918 | } |
| 919 | |