| 1 | /* ARC target-dependent stuff. |
| 2 | Copyright (C) 1995 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 "gdbcore.h" |
| 24 | #include "target.h" |
| 25 | #include "floatformat.h" |
| 26 | #include "symtab.h" |
| 27 | #include "gdbcmd.h" |
| 28 | |
| 29 | /* Current CPU, set with the "set cpu" command. */ |
| 30 | static int arc_bfd_mach_type; |
| 31 | char *arc_cpu_type; |
| 32 | char *tmp_arc_cpu_type; |
| 33 | |
| 34 | /* Table of cpu names. */ |
| 35 | struct { |
| 36 | char *name; |
| 37 | int value; |
| 38 | } arc_cpu_type_table[] = { |
| 39 | { "base", bfd_mach_arc_base }, |
| 40 | { "host", bfd_mach_arc_host }, |
| 41 | { "graphics", bfd_mach_arc_graphics }, |
| 42 | { "audio", bfd_mach_arc_audio }, |
| 43 | { NULL, 0 } |
| 44 | }; |
| 45 | |
| 46 | /* Used by simulator. */ |
| 47 | int display_pipeline_p; |
| 48 | int cpu_timer; |
| 49 | /* This one must have the same type as used in the emulator. |
| 50 | It's currently an enum so this should be ok for now. */ |
| 51 | int debug_pipeline_p; |
| 52 | |
| 53 | #define ARC_CALL_SAVED_REG(r) ((r) >= 16 && (r) < 24) |
| 54 | |
| 55 | #define OPMASK 0xf8000000 |
| 56 | |
| 57 | /* Instruction field accessor macros. |
| 58 | See the Programmer's Reference Manual. */ |
| 59 | #define X_OP(i) (((i) >> 27) & 0x1f) |
| 60 | #define X_A(i) (((i) >> 21) & 0x3f) |
| 61 | #define X_B(i) (((i) >> 15) & 0x3f) |
| 62 | #define X_C(i) (((i) >> 9) & 0x3f) |
| 63 | #define X_D(i) ((((i) & 0x1ff) ^ 0x100) - 0x100) |
| 64 | #define X_L(i) (((((i) >> 5) & 0x3ffffc) ^ 0x200000) - 0x200000) |
| 65 | #define X_N(i) (((i) >> 5) & 3) |
| 66 | #define X_Q(i) ((i) & 0x1f) |
| 67 | |
| 68 | /* Return non-zero if X is a short immediate data indicator. */ |
| 69 | #define SHIMM_P(x) ((x) == 61 || (x) == 63) |
| 70 | |
| 71 | /* Return non-zero if X is a "long" (32 bit) immediate data indicator. */ |
| 72 | #define LIMM_P(x) ((x) == 62) |
| 73 | |
| 74 | /* Build a simple instruction. */ |
| 75 | #define BUILD_INSN(op, a, b, c, d) \ |
| 76 | ((((op) & 31) << 27) \ |
| 77 | | (((a) & 63) << 21) \ |
| 78 | | (((b) & 63) << 15) \ |
| 79 | | (((c) & 63) << 9) \ |
| 80 | | ((d) & 511)) |
| 81 | \f |
| 82 | /* Codestream stuff. */ |
| 83 | static void codestream_read PARAMS ((unsigned int *, int)); |
| 84 | static void codestream_seek PARAMS ((CORE_ADDR)); |
| 85 | static unsigned int codestream_fill PARAMS ((int)); |
| 86 | |
| 87 | #define CODESTREAM_BUFSIZ 16 |
| 88 | static CORE_ADDR codestream_next_addr; |
| 89 | static CORE_ADDR codestream_addr; |
| 90 | static unsigned int codestream_buf[CODESTREAM_BUFSIZ]; |
| 91 | static int codestream_off; |
| 92 | static int codestream_cnt; |
| 93 | |
| 94 | #define codestream_tell() \ |
| 95 | (codestream_addr + codestream_off * sizeof (codestream_buf[0])) |
| 96 | #define codestream_peek() \ |
| 97 | (codestream_cnt == 0 \ |
| 98 | ? codestream_fill (1) \ |
| 99 | : codestream_buf[codestream_off]) |
| 100 | #define codestream_get() \ |
| 101 | (codestream_cnt-- == 0 \ |
| 102 | ? codestream_fill (0) \ |
| 103 | : codestream_buf[codestream_off++]) |
| 104 | |
| 105 | static unsigned int |
| 106 | codestream_fill (peek_flag) |
| 107 | int peek_flag; |
| 108 | { |
| 109 | codestream_addr = codestream_next_addr; |
| 110 | codestream_next_addr += CODESTREAM_BUFSIZ * sizeof (codestream_buf[0]); |
| 111 | codestream_off = 0; |
| 112 | codestream_cnt = CODESTREAM_BUFSIZ; |
| 113 | read_memory (codestream_addr, (char *) codestream_buf, |
| 114 | CODESTREAM_BUFSIZ * sizeof (codestream_buf[0])); |
| 115 | /* FIXME: check return code? */ |
| 116 | |
| 117 | /* Handle byte order differences. */ |
| 118 | if (HOST_BYTE_ORDER != TARGET_BYTE_ORDER) |
| 119 | { |
| 120 | register unsigned int i, j, n = sizeof (codestream_buf[0]); |
| 121 | register char tmp, *p; |
| 122 | for (i = 0, p = (char *) codestream_buf; i < CODESTREAM_BUFSIZ; |
| 123 | ++i, p += n) |
| 124 | for (j = 0; j < n / 2; ++j) |
| 125 | tmp = p[j], p[j] = p[n - 1 - j], p[n - 1 - j] = tmp; |
| 126 | } |
| 127 | |
| 128 | if (peek_flag) |
| 129 | return codestream_peek (); |
| 130 | else |
| 131 | return codestream_get (); |
| 132 | } |
| 133 | |
| 134 | static void |
| 135 | codestream_seek (place) |
| 136 | CORE_ADDR place; |
| 137 | { |
| 138 | codestream_next_addr = place / CODESTREAM_BUFSIZ; |
| 139 | codestream_next_addr *= CODESTREAM_BUFSIZ; |
| 140 | codestream_cnt = 0; |
| 141 | codestream_fill (1); |
| 142 | while (codestream_tell () != place) |
| 143 | codestream_get (); |
| 144 | } |
| 145 | |
| 146 | /* This function is currently unused but leave in for now. */ |
| 147 | |
| 148 | static void |
| 149 | codestream_read (buf, count) |
| 150 | unsigned int *buf; |
| 151 | int count; |
| 152 | { |
| 153 | unsigned int *p; |
| 154 | int i; |
| 155 | p = buf; |
| 156 | for (i = 0; i < count; i++) |
| 157 | *p++ = codestream_get (); |
| 158 | } |
| 159 | \f |
| 160 | /* Set up prologue scanning and return the first insn. */ |
| 161 | |
| 162 | static unsigned int |
| 163 | setup_prologue_scan (pc) |
| 164 | CORE_ADDR pc; |
| 165 | { |
| 166 | unsigned int insn; |
| 167 | |
| 168 | codestream_seek (pc); |
| 169 | insn = codestream_get (); |
| 170 | |
| 171 | return insn; |
| 172 | } |
| 173 | |
| 174 | /* |
| 175 | * Find & return amount a local space allocated, and advance codestream to |
| 176 | * first register push (if any). |
| 177 | * If entry sequence doesn't make sense, return -1, and leave |
| 178 | * codestream pointer random. |
| 179 | */ |
| 180 | |
| 181 | static long |
| 182 | arc_get_frame_setup (pc) |
| 183 | CORE_ADDR pc; |
| 184 | { |
| 185 | unsigned int insn; |
| 186 | /* Size of frame or -1 if unrecognizable prologue. */ |
| 187 | int frame_size = -1; |
| 188 | /* An initial "sub sp,sp,N" may or may not be for a stdarg fn. */ |
| 189 | int maybe_stdarg_decr = -1; |
| 190 | |
| 191 | insn = setup_prologue_scan (pc); |
| 192 | |
| 193 | /* The authority for what appears here is the home-grown ABI. |
| 194 | The most recent version is 1.2. */ |
| 195 | |
| 196 | /* First insn may be "sub sp,sp,N" if stdarg fn. */ |
| 197 | if ((insn & BUILD_INSN (-1, -1, -1, -1, 0)) |
| 198 | == BUILD_INSN (10, SP_REGNUM, SP_REGNUM, SHIMM_REGNUM, 0)) |
| 199 | { |
| 200 | maybe_stdarg_decr = X_D (insn); |
| 201 | insn = codestream_get (); |
| 202 | } |
| 203 | |
| 204 | if ((insn & BUILD_INSN (-1, 0, -1, -1, -1)) /* st blink,[sp,4] */ |
| 205 | == BUILD_INSN (2, 0, SP_REGNUM, BLINK_REGNUM, 4)) |
| 206 | { |
| 207 | insn = codestream_get (); |
| 208 | /* Frame may not be necessary, even though blink is saved. |
| 209 | At least this is something we recognize. */ |
| 210 | frame_size = 0; |
| 211 | } |
| 212 | |
| 213 | if ((insn & BUILD_INSN (-1, 0, -1, -1, -1)) /* st fp,[sp] */ |
| 214 | == BUILD_INSN (2, 0, SP_REGNUM, FP_REGNUM, 0)) |
| 215 | { |
| 216 | insn = codestream_get (); |
| 217 | if ((insn & BUILD_INSN (-1, -1, -1, -1, 0)) |
| 218 | != BUILD_INSN (12, FP_REGNUM, SP_REGNUM, SP_REGNUM, 0)) |
| 219 | return -1; |
| 220 | |
| 221 | /* Check for stack adjustment sub sp,sp,N. */ |
| 222 | insn = codestream_peek (); |
| 223 | if ((insn & BUILD_INSN (-1, -1, -1, 0, 0)) |
| 224 | == BUILD_INSN (10, SP_REGNUM, SP_REGNUM, 0, 0)) |
| 225 | { |
| 226 | if (LIMM_P (X_C (insn))) |
| 227 | frame_size = codestream_get (); |
| 228 | else if (SHIMM_P (X_C (insn))) |
| 229 | frame_size = X_D (insn); |
| 230 | else |
| 231 | return -1; |
| 232 | if (frame_size < 0) |
| 233 | return -1; |
| 234 | |
| 235 | codestream_get (); |
| 236 | |
| 237 | /* This sequence is used to get the address of the return |
| 238 | buffer for a function that returns a structure. */ |
| 239 | insn = codestream_peek (); |
| 240 | if (insn & OPMASK == 0x60000000) |
| 241 | codestream_get (); |
| 242 | } |
| 243 | /* Frameless fn. */ |
| 244 | else |
| 245 | { |
| 246 | frame_size = 0; |
| 247 | } |
| 248 | } |
| 249 | |
| 250 | /* If we found a "sub sp,sp,N" and nothing else, it may or may not be a |
| 251 | stdarg fn. The stdarg decrement is not treated as part of the frame size, |
| 252 | so we have a dilemma: what do we return? For now, if we get a |
| 253 | "sub sp,sp,N" and nothing else assume this isn't a stdarg fn. One way |
| 254 | to fix this completely would be to add a bit to the function descriptor |
| 255 | that says the function is a stdarg function. */ |
| 256 | |
| 257 | if (frame_size < 0 && maybe_stdarg_decr > 0) |
| 258 | return maybe_stdarg_decr; |
| 259 | return frame_size; |
| 260 | } |
| 261 | |
| 262 | /* Given a pc value, skip it forward past the function prologue by |
| 263 | disassembling instructions that appear to be a prologue. |
| 264 | |
| 265 | If FRAMELESS_P is set, we are only testing to see if the function |
| 266 | is frameless. If it is a frameless function, return PC unchanged. |
| 267 | This allows a quicker answer. */ |
| 268 | |
| 269 | CORE_ADDR |
| 270 | skip_prologue (pc, frameless_p) |
| 271 | CORE_ADDR pc; |
| 272 | int frameless_p; |
| 273 | { |
| 274 | unsigned int insn; |
| 275 | int i, frame_size; |
| 276 | |
| 277 | if ((frame_size = arc_get_frame_setup (pc)) < 0) |
| 278 | return (pc); |
| 279 | |
| 280 | if (frameless_p) |
| 281 | return frame_size == 0 ? pc : codestream_tell (); |
| 282 | |
| 283 | /* Skip over register saves. */ |
| 284 | for (i = 0; i < 8; i++) |
| 285 | { |
| 286 | insn = codestream_peek (); |
| 287 | if ((insn & BUILD_INSN (-1, 0, -1, 0, 0)) |
| 288 | != BUILD_INSN (2, 0, SP_REGNUM, 0, 0)) |
| 289 | break; /* not st insn */ |
| 290 | if (! ARC_CALL_SAVED_REG (X_C (insn))) |
| 291 | break; |
| 292 | codestream_get (); |
| 293 | } |
| 294 | |
| 295 | return codestream_tell (); |
| 296 | } |
| 297 | |
| 298 | /* Return the return address for a frame. |
| 299 | This is used to implement FRAME_SAVED_PC. |
| 300 | This is taken from frameless_look_for_prologue. */ |
| 301 | |
| 302 | CORE_ADDR |
| 303 | arc_frame_saved_pc (frame) |
| 304 | struct frame_info *frame; |
| 305 | { |
| 306 | CORE_ADDR func_start; |
| 307 | unsigned int insn; |
| 308 | |
| 309 | func_start = get_pc_function_start (frame->pc) + FUNCTION_START_OFFSET; |
| 310 | if (func_start == 0) |
| 311 | { |
| 312 | /* Best guess. */ |
| 313 | return ARC_PC_TO_REAL_ADDRESS (read_memory_integer (FRAME_FP (frame) + 4, 4)); |
| 314 | } |
| 315 | |
| 316 | /* The authority for what appears here is the home-grown ABI. |
| 317 | The most recent version is 1.2. */ |
| 318 | |
| 319 | insn = setup_prologue_scan (func_start); |
| 320 | |
| 321 | /* First insn may be "sub sp,sp,N" if stdarg fn. */ |
| 322 | if ((insn & BUILD_INSN (-1, -1, -1, -1, 0)) |
| 323 | == BUILD_INSN (10, SP_REGNUM, SP_REGNUM, SHIMM_REGNUM, 0)) |
| 324 | insn = codestream_get (); |
| 325 | |
| 326 | /* If the next insn is "st blink,[sp,4]" we can get blink from there. |
| 327 | Otherwise this is a leaf function and we can use blink. Note that |
| 328 | this still allows for the case where a leaf function saves/clobbers/ |
| 329 | restores blink. */ |
| 330 | |
| 331 | if ((insn & BUILD_INSN (-1, 0, -1, -1, -1)) /* st blink,[sp,4] */ |
| 332 | != BUILD_INSN (2, 0, SP_REGNUM, BLINK_REGNUM, 4)) |
| 333 | return ARC_PC_TO_REAL_ADDRESS (read_register (BLINK_REGNUM)); |
| 334 | else |
| 335 | return ARC_PC_TO_REAL_ADDRESS (read_memory_integer (FRAME_FP (frame) + 4, 4)); |
| 336 | } |
| 337 | |
| 338 | /* |
| 339 | * Parse the first few instructions of the function to see |
| 340 | * what registers were stored. |
| 341 | * |
| 342 | * The startup sequence can be at the start of the function. |
| 343 | * 'st blink,[sp+4], st fp,[sp], mov fp,sp' |
| 344 | * |
| 345 | * Local space is allocated just below by sub sp,sp,nnn. |
| 346 | * Next, the registers used by this function are stored (as offsets from sp). |
| 347 | */ |
| 348 | |
| 349 | void |
| 350 | frame_find_saved_regs (fip, fsrp) |
| 351 | struct frame_info *fip; |
| 352 | struct frame_saved_regs *fsrp; |
| 353 | { |
| 354 | long locals; |
| 355 | unsigned int insn; |
| 356 | CORE_ADDR dummy_bottom; |
| 357 | CORE_ADDR adr; |
| 358 | int i, regnum, offset; |
| 359 | |
| 360 | memset (fsrp, 0, sizeof *fsrp); |
| 361 | |
| 362 | /* If frame is the end of a dummy, compute where the beginning would be. */ |
| 363 | dummy_bottom = fip->frame - 4 - REGISTER_BYTES - CALL_DUMMY_LENGTH; |
| 364 | |
| 365 | /* Check if the PC is in the stack, in a dummy frame. */ |
| 366 | if (dummy_bottom <= fip->pc && fip->pc <= fip->frame) |
| 367 | { |
| 368 | /* all regs were saved by push_call_dummy () */ |
| 369 | adr = fip->frame; |
| 370 | for (i = 0; i < NUM_REGS; i++) |
| 371 | { |
| 372 | adr -= REGISTER_RAW_SIZE (i); |
| 373 | fsrp->regs[i] = adr; |
| 374 | } |
| 375 | return; |
| 376 | } |
| 377 | |
| 378 | locals = arc_get_frame_setup (get_pc_function_start (fip->pc)); |
| 379 | |
| 380 | if (locals >= 0) |
| 381 | { |
| 382 | /* Set `adr' to the value of `sp'. */ |
| 383 | adr = fip->frame - locals; |
| 384 | for (i = 0; i < 8; i++) |
| 385 | { |
| 386 | insn = codestream_get (); |
| 387 | if ((insn & BUILD_INSN (-1, 0, -1, 0, 0)) |
| 388 | != BUILD_INSN (2, 0, SP_REGNUM, 0, 0)) |
| 389 | break; |
| 390 | regnum = X_C (insn); |
| 391 | offset = X_D (insn); |
| 392 | fsrp->regs[regnum] = adr + offset; |
| 393 | } |
| 394 | } |
| 395 | |
| 396 | fsrp->regs[PC_REGNUM] = fip->frame + 4; |
| 397 | fsrp->regs[FP_REGNUM] = fip->frame; |
| 398 | } |
| 399 | |
| 400 | void |
| 401 | push_dummy_frame () |
| 402 | { |
| 403 | CORE_ADDR sp = read_register (SP_REGNUM); |
| 404 | int regnum; |
| 405 | char regbuf[MAX_REGISTER_RAW_SIZE]; |
| 406 | |
| 407 | read_register_gen (PC_REGNUM, regbuf); |
| 408 | write_memory (sp+4, regbuf, REGISTER_SIZE); |
| 409 | read_register_gen (FP_REGNUM, regbuf); |
| 410 | write_memory (sp, regbuf, REGISTER_SIZE); |
| 411 | write_register (FP_REGNUM, sp); |
| 412 | for (regnum = 0; regnum < NUM_REGS; regnum++) |
| 413 | { |
| 414 | read_register_gen (regnum, regbuf); |
| 415 | sp = push_bytes (sp, regbuf, REGISTER_RAW_SIZE (regnum)); |
| 416 | } |
| 417 | sp += (2*REGISTER_SIZE); |
| 418 | write_register (SP_REGNUM, sp); |
| 419 | } |
| 420 | |
| 421 | void |
| 422 | pop_frame () |
| 423 | { |
| 424 | struct frame_info *frame = get_current_frame (); |
| 425 | CORE_ADDR fp; |
| 426 | int regnum; |
| 427 | struct frame_saved_regs fsr; |
| 428 | char regbuf[MAX_REGISTER_RAW_SIZE]; |
| 429 | |
| 430 | fp = FRAME_FP (frame); |
| 431 | get_frame_saved_regs (frame, &fsr); |
| 432 | for (regnum = 0; regnum < NUM_REGS; regnum++) |
| 433 | { |
| 434 | CORE_ADDR adr; |
| 435 | adr = fsr.regs[regnum]; |
| 436 | if (adr) |
| 437 | { |
| 438 | read_memory (adr, regbuf, REGISTER_RAW_SIZE (regnum)); |
| 439 | write_register_bytes (REGISTER_BYTE (regnum), regbuf, |
| 440 | REGISTER_RAW_SIZE (regnum)); |
| 441 | } |
| 442 | } |
| 443 | write_register (FP_REGNUM, read_memory_integer (fp, 4)); |
| 444 | write_register (PC_REGNUM, read_memory_integer (fp + 4, 4)); |
| 445 | write_register (SP_REGNUM, fp + 8); |
| 446 | flush_cached_frames (); |
| 447 | } |
| 448 | \f |
| 449 | /* Simulate single-step. */ |
| 450 | |
| 451 | typedef enum |
| 452 | { |
| 453 | NORMAL4, /* a normal 4 byte insn */ |
| 454 | NORMAL8, /* a normal 8 byte insn */ |
| 455 | BRANCH4, /* a 4 byte branch insn, including ones without delay slots */ |
| 456 | BRANCH8, /* an 8 byte branch insn, including ones with delay slots */ |
| 457 | } insn_type; |
| 458 | |
| 459 | /* Return the type of INSN and store in TARGET the destination address of a |
| 460 | branch if this is one. */ |
| 461 | /* ??? Need to verify all cases are properly handled. */ |
| 462 | |
| 463 | static insn_type |
| 464 | get_insn_type (insn, pc, target) |
| 465 | unsigned long insn; |
| 466 | CORE_ADDR pc, *target; |
| 467 | { |
| 468 | unsigned long limm; |
| 469 | |
| 470 | switch (insn >> 27) |
| 471 | { |
| 472 | case 0 : case 1 : case 2 : /* load/store insns */ |
| 473 | if (LIMM_P (X_A (insn)) |
| 474 | || LIMM_P (X_B (insn)) |
| 475 | || LIMM_P (X_C (insn))) |
| 476 | return NORMAL8; |
| 477 | return NORMAL4; |
| 478 | case 4 : case 5 : case 6 : /* branch insns */ |
| 479 | *target = pc + 4 + X_L (insn); |
| 480 | /* ??? It isn't clear that this is always the right answer. |
| 481 | The problem occurs when the next insn is an 8 byte insn. If the |
| 482 | branch is conditional there's no worry as there shouldn't be an 8 |
| 483 | byte insn following. The programmer may be cheating if s/he knows |
| 484 | the branch will never be taken, but we don't deal with that. |
| 485 | Note that the programmer is also allowed to play games by putting |
| 486 | an insn with long immediate data in the delay slot and then duplicate |
| 487 | the long immediate data at the branch target. Ugh! */ |
| 488 | if (X_N (insn) == 0) |
| 489 | return BRANCH4; |
| 490 | return BRANCH8; |
| 491 | case 7 : /* jump insns */ |
| 492 | if (LIMM_P (X_B (insn))) |
| 493 | { |
| 494 | limm = read_memory_integer (pc + 4, 4); |
| 495 | *target = ARC_PC_TO_REAL_ADDRESS (limm); |
| 496 | return BRANCH8; |
| 497 | } |
| 498 | if (SHIMM_P (X_B (insn))) |
| 499 | *target = ARC_PC_TO_REAL_ADDRESS (X_D (insn)); |
| 500 | else |
| 501 | *target = ARC_PC_TO_REAL_ADDRESS (read_register (X_B (insn))); |
| 502 | if (X_Q (insn) == 0 && X_N (insn) == 0) |
| 503 | return BRANCH4; |
| 504 | return BRANCH8; |
| 505 | default : /* arithmetic insns, etc. */ |
| 506 | if (LIMM_P (X_A (insn)) |
| 507 | || LIMM_P (X_B (insn)) |
| 508 | || LIMM_P (X_C (insn))) |
| 509 | return NORMAL8; |
| 510 | return NORMAL4; |
| 511 | } |
| 512 | } |
| 513 | |
| 514 | /* Non-zero if we just simulated a single-step. This is needed because we |
| 515 | cannot remove the breakpoints in the inferior process until after the |
| 516 | `wait' in `wait_for_inferior'. */ |
| 517 | |
| 518 | int one_stepped; |
| 519 | |
| 520 | /* single_step() is called just before we want to resume the inferior, if we |
| 521 | want to single-step it but there is no hardware or kernel single-step |
| 522 | support. We find all the possible targets of the coming instruction and |
| 523 | breakpoint them. |
| 524 | |
| 525 | single_step is also called just after the inferior stops. If we had |
| 526 | set up a simulated single-step, we undo our damage. */ |
| 527 | |
| 528 | void |
| 529 | single_step (ignore) |
| 530 | enum target_signal ignore; /* sig, but we don't need it */ |
| 531 | { |
| 532 | static CORE_ADDR next_pc, target; |
| 533 | static int brktrg_p; |
| 534 | typedef char binsn_quantum[BREAKPOINT_MAX]; |
| 535 | static binsn_quantum break_mem[2]; |
| 536 | |
| 537 | if (!one_stepped) |
| 538 | { |
| 539 | insn_type type; |
| 540 | CORE_ADDR pc; |
| 541 | unsigned long insn; |
| 542 | |
| 543 | pc = read_register (PC_REGNUM); |
| 544 | insn = read_memory_integer (pc, 4); |
| 545 | type = get_insn_type (insn, pc, &target); |
| 546 | |
| 547 | /* Always set a breakpoint for the insn after the branch. */ |
| 548 | next_pc = pc + ((type == NORMAL8 || type == BRANCH8) ? 8 : 4); |
| 549 | target_insert_breakpoint (next_pc, break_mem[0]); |
| 550 | |
| 551 | brktrg_p = 0; |
| 552 | |
| 553 | if ((type == BRANCH4 || type == BRANCH8) |
| 554 | /* Watch out for branches to the following location. |
| 555 | We just stored a breakpoint there and another call to |
| 556 | target_insert_breakpoint will think the real insn is the |
| 557 | breakpoint we just stored there. */ |
| 558 | && target != next_pc) |
| 559 | { |
| 560 | brktrg_p = 1; |
| 561 | target_insert_breakpoint (target, break_mem[1]); |
| 562 | } |
| 563 | |
| 564 | /* We are ready to let it go. */ |
| 565 | one_stepped = 1; |
| 566 | } |
| 567 | else |
| 568 | { |
| 569 | /* Remove breakpoints. */ |
| 570 | target_remove_breakpoint (next_pc, break_mem[0]); |
| 571 | |
| 572 | if (brktrg_p) |
| 573 | target_remove_breakpoint (target, break_mem[1]); |
| 574 | |
| 575 | /* Fix the pc. */ |
| 576 | stop_pc -= DECR_PC_AFTER_BREAK; |
| 577 | write_pc (stop_pc); |
| 578 | |
| 579 | one_stepped = 0; |
| 580 | } |
| 581 | } |
| 582 | \f |
| 583 | #ifdef GET_LONGJMP_TARGET |
| 584 | /* Figure out where the longjmp will land. Slurp the args out of the stack. |
| 585 | We expect the first arg to be a pointer to the jmp_buf structure from which |
| 586 | we extract the pc (JB_PC) that we will land at. The pc is copied into PC. |
| 587 | This routine returns true on success. */ |
| 588 | |
| 589 | int |
| 590 | get_longjmp_target(pc) |
| 591 | CORE_ADDR *pc; |
| 592 | { |
| 593 | char buf[TARGET_PTR_BIT / TARGET_CHAR_BIT]; |
| 594 | CORE_ADDR sp, jb_addr; |
| 595 | |
| 596 | sp = read_register (SP_REGNUM); |
| 597 | |
| 598 | if (target_read_memory (sp + SP_ARG0, /* Offset of first arg on stack */ |
| 599 | buf, |
| 600 | TARGET_PTR_BIT / TARGET_CHAR_BIT)) |
| 601 | return 0; |
| 602 | |
| 603 | jb_addr = extract_address (buf, TARGET_PTR_BIT / TARGET_CHAR_BIT); |
| 604 | |
| 605 | if (target_read_memory (jb_addr + JB_PC * JB_ELEMENT_SIZE, buf, |
| 606 | TARGET_PTR_BIT / TARGET_CHAR_BIT)) |
| 607 | return 0; |
| 608 | |
| 609 | *pc = extract_address (buf, TARGET_PTR_BIT / TARGET_CHAR_BIT); |
| 610 | |
| 611 | return 1; |
| 612 | } |
| 613 | #endif /* GET_LONGJMP_TARGET */ |
| 614 | \f |
| 615 | /* Disassemble one instruction. */ |
| 616 | |
| 617 | static int |
| 618 | arc_print_insn (vma, info) |
| 619 | bfd_vma vma; |
| 620 | disassemble_info *info; |
| 621 | { |
| 622 | static int current_mach; |
| 623 | static int current_endian; |
| 624 | static disassembler_ftype current_disasm; |
| 625 | |
| 626 | if (current_disasm == NULL |
| 627 | || arc_bfd_mach_type != current_mach |
| 628 | || TARGET_BYTE_ORDER != current_endian) |
| 629 | { |
| 630 | current_mach = arc_bfd_mach_type; |
| 631 | current_endian = TARGET_BYTE_ORDER; |
| 632 | current_disasm = arc_get_disassembler (current_mach, |
| 633 | current_endian == BIG_ENDIAN); |
| 634 | } |
| 635 | |
| 636 | return (*current_disasm) (vma, info); |
| 637 | } |
| 638 | \f |
| 639 | /* Command to set cpu type. */ |
| 640 | |
| 641 | void |
| 642 | arc_set_cpu_type_command (args, from_tty) |
| 643 | char *args; |
| 644 | int from_tty; |
| 645 | { |
| 646 | int i; |
| 647 | |
| 648 | if (tmp_arc_cpu_type == NULL || *tmp_arc_cpu_type == '\0') |
| 649 | { |
| 650 | printf_unfiltered ("The known ARC cpu types are as follows:\n"); |
| 651 | for (i = 0; arc_cpu_type_table[i].name != NULL; ++i) |
| 652 | printf_unfiltered ("%s\n", arc_cpu_type_table[i].name); |
| 653 | |
| 654 | /* Restore the value. */ |
| 655 | tmp_arc_cpu_type = strsave (arc_cpu_type); |
| 656 | |
| 657 | return; |
| 658 | } |
| 659 | |
| 660 | if (!arc_set_cpu_type (tmp_arc_cpu_type)) |
| 661 | { |
| 662 | error ("Unknown cpu type `%s'.", tmp_arc_cpu_type); |
| 663 | /* Restore its value. */ |
| 664 | tmp_arc_cpu_type = strsave (arc_cpu_type); |
| 665 | } |
| 666 | } |
| 667 | |
| 668 | static void |
| 669 | arc_show_cpu_type_command (args, from_tty) |
| 670 | char *args; |
| 671 | int from_tty; |
| 672 | { |
| 673 | } |
| 674 | |
| 675 | /* Modify the actual cpu type. |
| 676 | Result is a boolean indicating success. */ |
| 677 | |
| 678 | int |
| 679 | arc_set_cpu_type (str) |
| 680 | char *str; |
| 681 | { |
| 682 | int i, j; |
| 683 | |
| 684 | if (str == NULL) |
| 685 | return 0; |
| 686 | |
| 687 | for (i = 0; arc_cpu_type_table[i].name != NULL; ++i) |
| 688 | { |
| 689 | if (strcasecmp (str, arc_cpu_type_table[i].name) == 0) |
| 690 | { |
| 691 | arc_cpu_type = str; |
| 692 | arc_bfd_mach_type = arc_cpu_type_table[i].value; |
| 693 | return 1; |
| 694 | } |
| 695 | } |
| 696 | |
| 697 | return 0; |
| 698 | } |
| 699 | \f |
| 700 | void |
| 701 | _initialize_arc_tdep () |
| 702 | { |
| 703 | struct cmd_list_element *c; |
| 704 | |
| 705 | c = add_set_cmd ("cpu", class_support, var_string_noescape, |
| 706 | (char *) &tmp_arc_cpu_type, |
| 707 | "Set the type of ARC cpu in use.\n\ |
| 708 | This command has two purposes. In a multi-cpu system it lets one\n\ |
| 709 | change the cpu being debugged. It also gives one access to\n\ |
| 710 | cpu-type-specific registers and recognize cpu-type-specific instructions.\ |
| 711 | ", |
| 712 | &setlist); |
| 713 | c->function.cfunc = arc_set_cpu_type_command; |
| 714 | c = add_show_from_set (c, &showlist); |
| 715 | c->function.cfunc = arc_show_cpu_type_command; |
| 716 | |
| 717 | /* We have to use strsave here because the `set' command frees it before |
| 718 | setting a new value. */ |
| 719 | tmp_arc_cpu_type = strsave (DEFAULT_ARC_CPU_TYPE); |
| 720 | arc_set_cpu_type (tmp_arc_cpu_type); |
| 721 | |
| 722 | c = add_set_cmd ("displaypipeline", class_support, var_zinteger, |
| 723 | (char *) &display_pipeline_p, |
| 724 | "Set pipeline display (simulator only).\n\ |
| 725 | When enabled, the state of the pipeline after each cycle is displayed.", |
| 726 | &setlist); |
| 727 | c = add_show_from_set (c, &showlist); |
| 728 | |
| 729 | c = add_set_cmd ("debugpipeline", class_support, var_zinteger, |
| 730 | (char *) &debug_pipeline_p, |
| 731 | "Set pipeline debug display (simulator only).\n\ |
| 732 | When enabled, debugging information about the pipeline is displayed.", |
| 733 | &setlist); |
| 734 | c = add_show_from_set (c, &showlist); |
| 735 | |
| 736 | c = add_set_cmd ("cputimer", class_support, var_zinteger, |
| 737 | (char *) &cpu_timer, |
| 738 | "Set maximum cycle count (simulator only).\n\ |
| 739 | Control will return to gdb if the timer expires.\n\ |
| 740 | A negative value disables the timer.", |
| 741 | &setlist); |
| 742 | c = add_show_from_set (c, &showlist); |
| 743 | |
| 744 | tm_print_insn = arc_print_insn; |
| 745 | } |