| 1 | /* Target-dependent code for the Motorola 68000 series. |
| 2 | |
| 3 | Copyright (C) 1990-2013 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 "dwarf2-frame.h" |
| 22 | #include "frame.h" |
| 23 | #include "frame-base.h" |
| 24 | #include "frame-unwind.h" |
| 25 | #include "gdbtypes.h" |
| 26 | #include "symtab.h" |
| 27 | #include "gdbcore.h" |
| 28 | #include "value.h" |
| 29 | #include <string.h> |
| 30 | #include "gdb_assert.h" |
| 31 | #include "inferior.h" |
| 32 | #include "regcache.h" |
| 33 | #include "arch-utils.h" |
| 34 | #include "osabi.h" |
| 35 | #include "dis-asm.h" |
| 36 | #include "target-descriptions.h" |
| 37 | |
| 38 | #include "m68k-tdep.h" |
| 39 | \f |
| 40 | |
| 41 | #define P_LINKL_FP 0x480e |
| 42 | #define P_LINKW_FP 0x4e56 |
| 43 | #define P_PEA_FP 0x4856 |
| 44 | #define P_MOVEAL_SP_FP 0x2c4f |
| 45 | #define P_ADDAW_SP 0xdefc |
| 46 | #define P_ADDAL_SP 0xdffc |
| 47 | #define P_SUBQW_SP 0x514f |
| 48 | #define P_SUBQL_SP 0x518f |
| 49 | #define P_LEA_SP_SP 0x4fef |
| 50 | #define P_LEA_PC_A5 0x4bfb0170 |
| 51 | #define P_FMOVEMX_SP 0xf227 |
| 52 | #define P_MOVEL_SP 0x2f00 |
| 53 | #define P_MOVEML_SP 0x48e7 |
| 54 | |
| 55 | /* Offset from SP to first arg on stack at first instruction of a function. */ |
| 56 | #define SP_ARG0 (1 * 4) |
| 57 | |
| 58 | #if !defined (BPT_VECTOR) |
| 59 | #define BPT_VECTOR 0xf |
| 60 | #endif |
| 61 | |
| 62 | static const gdb_byte * |
| 63 | m68k_local_breakpoint_from_pc (struct gdbarch *gdbarch, |
| 64 | CORE_ADDR *pcptr, int *lenptr) |
| 65 | { |
| 66 | static gdb_byte break_insn[] = {0x4e, (0x40 | BPT_VECTOR)}; |
| 67 | *lenptr = sizeof (break_insn); |
| 68 | return break_insn; |
| 69 | } |
| 70 | \f |
| 71 | |
| 72 | /* Construct types for ISA-specific registers. */ |
| 73 | static struct type * |
| 74 | m68k_ps_type (struct gdbarch *gdbarch) |
| 75 | { |
| 76 | struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); |
| 77 | |
| 78 | if (!tdep->m68k_ps_type) |
| 79 | { |
| 80 | struct type *type; |
| 81 | |
| 82 | type = arch_flags_type (gdbarch, "builtin_type_m68k_ps", 4); |
| 83 | append_flags_type_flag (type, 0, "C"); |
| 84 | append_flags_type_flag (type, 1, "V"); |
| 85 | append_flags_type_flag (type, 2, "Z"); |
| 86 | append_flags_type_flag (type, 3, "N"); |
| 87 | append_flags_type_flag (type, 4, "X"); |
| 88 | append_flags_type_flag (type, 8, "I0"); |
| 89 | append_flags_type_flag (type, 9, "I1"); |
| 90 | append_flags_type_flag (type, 10, "I2"); |
| 91 | append_flags_type_flag (type, 12, "M"); |
| 92 | append_flags_type_flag (type, 13, "S"); |
| 93 | append_flags_type_flag (type, 14, "T0"); |
| 94 | append_flags_type_flag (type, 15, "T1"); |
| 95 | |
| 96 | tdep->m68k_ps_type = type; |
| 97 | } |
| 98 | |
| 99 | return tdep->m68k_ps_type; |
| 100 | } |
| 101 | |
| 102 | static struct type * |
| 103 | m68881_ext_type (struct gdbarch *gdbarch) |
| 104 | { |
| 105 | struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); |
| 106 | |
| 107 | if (!tdep->m68881_ext_type) |
| 108 | tdep->m68881_ext_type |
| 109 | = arch_float_type (gdbarch, -1, "builtin_type_m68881_ext", |
| 110 | floatformats_m68881_ext); |
| 111 | |
| 112 | return tdep->m68881_ext_type; |
| 113 | } |
| 114 | |
| 115 | /* Return the GDB type object for the "standard" data type of data in |
| 116 | register N. This should be int for D0-D7, SR, FPCONTROL and |
| 117 | FPSTATUS, long double for FP0-FP7, and void pointer for all others |
| 118 | (A0-A7, PC, FPIADDR). Note, for registers which contain |
| 119 | addresses return pointer to void, not pointer to char, because we |
| 120 | don't want to attempt to print the string after printing the |
| 121 | address. */ |
| 122 | |
| 123 | static struct type * |
| 124 | m68k_register_type (struct gdbarch *gdbarch, int regnum) |
| 125 | { |
| 126 | struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); |
| 127 | |
| 128 | if (tdep->fpregs_present) |
| 129 | { |
| 130 | if (regnum >= gdbarch_fp0_regnum (gdbarch) |
| 131 | && regnum <= gdbarch_fp0_regnum (gdbarch) + 7) |
| 132 | { |
| 133 | if (tdep->flavour == m68k_coldfire_flavour) |
| 134 | return builtin_type (gdbarch)->builtin_double; |
| 135 | else |
| 136 | return m68881_ext_type (gdbarch); |
| 137 | } |
| 138 | |
| 139 | if (regnum == M68K_FPI_REGNUM) |
| 140 | return builtin_type (gdbarch)->builtin_func_ptr; |
| 141 | |
| 142 | if (regnum == M68K_FPC_REGNUM || regnum == M68K_FPS_REGNUM) |
| 143 | return builtin_type (gdbarch)->builtin_int32; |
| 144 | } |
| 145 | else |
| 146 | { |
| 147 | if (regnum >= M68K_FP0_REGNUM && regnum <= M68K_FPI_REGNUM) |
| 148 | return builtin_type (gdbarch)->builtin_int0; |
| 149 | } |
| 150 | |
| 151 | if (regnum == gdbarch_pc_regnum (gdbarch)) |
| 152 | return builtin_type (gdbarch)->builtin_func_ptr; |
| 153 | |
| 154 | if (regnum >= M68K_A0_REGNUM && regnum <= M68K_A0_REGNUM + 7) |
| 155 | return builtin_type (gdbarch)->builtin_data_ptr; |
| 156 | |
| 157 | if (regnum == M68K_PS_REGNUM) |
| 158 | return m68k_ps_type (gdbarch); |
| 159 | |
| 160 | return builtin_type (gdbarch)->builtin_int32; |
| 161 | } |
| 162 | |
| 163 | static const char *m68k_register_names[] = { |
| 164 | "d0", "d1", "d2", "d3", "d4", "d5", "d6", "d7", |
| 165 | "a0", "a1", "a2", "a3", "a4", "a5", "fp", "sp", |
| 166 | "ps", "pc", |
| 167 | "fp0", "fp1", "fp2", "fp3", "fp4", "fp5", "fp6", "fp7", |
| 168 | "fpcontrol", "fpstatus", "fpiaddr" |
| 169 | }; |
| 170 | |
| 171 | /* Function: m68k_register_name |
| 172 | Returns the name of the standard m68k register regnum. */ |
| 173 | |
| 174 | static const char * |
| 175 | m68k_register_name (struct gdbarch *gdbarch, int regnum) |
| 176 | { |
| 177 | if (regnum < 0 || regnum >= ARRAY_SIZE (m68k_register_names)) |
| 178 | internal_error (__FILE__, __LINE__, |
| 179 | _("m68k_register_name: illegal register number %d"), |
| 180 | regnum); |
| 181 | else if (regnum >= M68K_FP0_REGNUM && regnum <= M68K_FPI_REGNUM |
| 182 | && gdbarch_tdep (gdbarch)->fpregs_present == 0) |
| 183 | return ""; |
| 184 | else |
| 185 | return m68k_register_names[regnum]; |
| 186 | } |
| 187 | \f |
| 188 | /* Return nonzero if a value of type TYPE stored in register REGNUM |
| 189 | needs any special handling. */ |
| 190 | |
| 191 | static int |
| 192 | m68k_convert_register_p (struct gdbarch *gdbarch, |
| 193 | int regnum, struct type *type) |
| 194 | { |
| 195 | if (!gdbarch_tdep (gdbarch)->fpregs_present) |
| 196 | return 0; |
| 197 | return (regnum >= M68K_FP0_REGNUM && regnum <= M68K_FP0_REGNUM + 7 |
| 198 | && type != register_type (gdbarch, M68K_FP0_REGNUM)); |
| 199 | } |
| 200 | |
| 201 | /* Read a value of type TYPE from register REGNUM in frame FRAME, and |
| 202 | return its contents in TO. */ |
| 203 | |
| 204 | static int |
| 205 | m68k_register_to_value (struct frame_info *frame, int regnum, |
| 206 | struct type *type, gdb_byte *to, |
| 207 | int *optimizedp, int *unavailablep) |
| 208 | { |
| 209 | gdb_byte from[M68K_MAX_REGISTER_SIZE]; |
| 210 | struct type *fpreg_type = register_type (get_frame_arch (frame), |
| 211 | M68K_FP0_REGNUM); |
| 212 | |
| 213 | /* We only support floating-point values. */ |
| 214 | if (TYPE_CODE (type) != TYPE_CODE_FLT) |
| 215 | { |
| 216 | warning (_("Cannot convert floating-point register value " |
| 217 | "to non-floating-point type.")); |
| 218 | *optimizedp = *unavailablep = 0; |
| 219 | return 0; |
| 220 | } |
| 221 | |
| 222 | /* Convert to TYPE. */ |
| 223 | |
| 224 | /* Convert to TYPE. */ |
| 225 | if (!get_frame_register_bytes (frame, regnum, 0, TYPE_LENGTH (type), |
| 226 | from, optimizedp, unavailablep)) |
| 227 | return 0; |
| 228 | |
| 229 | convert_typed_floating (from, fpreg_type, to, type); |
| 230 | *optimizedp = *unavailablep = 0; |
| 231 | return 1; |
| 232 | } |
| 233 | |
| 234 | /* Write the contents FROM of a value of type TYPE into register |
| 235 | REGNUM in frame FRAME. */ |
| 236 | |
| 237 | static void |
| 238 | m68k_value_to_register (struct frame_info *frame, int regnum, |
| 239 | struct type *type, const gdb_byte *from) |
| 240 | { |
| 241 | gdb_byte to[M68K_MAX_REGISTER_SIZE]; |
| 242 | struct type *fpreg_type = register_type (get_frame_arch (frame), |
| 243 | M68K_FP0_REGNUM); |
| 244 | |
| 245 | /* We only support floating-point values. */ |
| 246 | if (TYPE_CODE (type) != TYPE_CODE_FLT) |
| 247 | { |
| 248 | warning (_("Cannot convert non-floating-point type " |
| 249 | "to floating-point register value.")); |
| 250 | return; |
| 251 | } |
| 252 | |
| 253 | /* Convert from TYPE. */ |
| 254 | convert_typed_floating (from, type, to, fpreg_type); |
| 255 | put_frame_register (frame, regnum, to); |
| 256 | } |
| 257 | |
| 258 | \f |
| 259 | /* There is a fair number of calling conventions that are in somewhat |
| 260 | wide use. The 68000/08/10 don't support an FPU, not even as a |
| 261 | coprocessor. All function return values are stored in %d0/%d1. |
| 262 | Structures are returned in a static buffer, a pointer to which is |
| 263 | returned in %d0. This means that functions returning a structure |
| 264 | are not re-entrant. To avoid this problem some systems use a |
| 265 | convention where the caller passes a pointer to a buffer in %a1 |
| 266 | where the return values is to be stored. This convention is the |
| 267 | default, and is implemented in the function m68k_return_value. |
| 268 | |
| 269 | The 68020/030/040/060 do support an FPU, either as a coprocessor |
| 270 | (68881/2) or built-in (68040/68060). That's why System V release 4 |
| 271 | (SVR4) instroduces a new calling convention specified by the SVR4 |
| 272 | psABI. Integer values are returned in %d0/%d1, pointer return |
| 273 | values in %a0 and floating values in %fp0. When calling functions |
| 274 | returning a structure the caller should pass a pointer to a buffer |
| 275 | for the return value in %a0. This convention is implemented in the |
| 276 | function m68k_svr4_return_value, and by appropriately setting the |
| 277 | struct_value_regnum member of `struct gdbarch_tdep'. |
| 278 | |
| 279 | GNU/Linux returns values in the same way as SVR4 does, but uses %a1 |
| 280 | for passing the structure return value buffer. |
| 281 | |
| 282 | GCC can also generate code where small structures are returned in |
| 283 | %d0/%d1 instead of in memory by using -freg-struct-return. This is |
| 284 | the default on NetBSD a.out, OpenBSD and GNU/Linux and several |
| 285 | embedded systems. This convention is implemented by setting the |
| 286 | struct_return member of `struct gdbarch_tdep' to reg_struct_return. */ |
| 287 | |
| 288 | /* Read a function return value of TYPE from REGCACHE, and copy that |
| 289 | into VALBUF. */ |
| 290 | |
| 291 | static void |
| 292 | m68k_extract_return_value (struct type *type, struct regcache *regcache, |
| 293 | gdb_byte *valbuf) |
| 294 | { |
| 295 | int len = TYPE_LENGTH (type); |
| 296 | gdb_byte buf[M68K_MAX_REGISTER_SIZE]; |
| 297 | |
| 298 | if (len <= 4) |
| 299 | { |
| 300 | regcache_raw_read (regcache, M68K_D0_REGNUM, buf); |
| 301 | memcpy (valbuf, buf + (4 - len), len); |
| 302 | } |
| 303 | else if (len <= 8) |
| 304 | { |
| 305 | regcache_raw_read (regcache, M68K_D0_REGNUM, buf); |
| 306 | memcpy (valbuf, buf + (8 - len), len - 4); |
| 307 | regcache_raw_read (regcache, M68K_D1_REGNUM, valbuf + (len - 4)); |
| 308 | } |
| 309 | else |
| 310 | internal_error (__FILE__, __LINE__, |
| 311 | _("Cannot extract return value of %d bytes long."), len); |
| 312 | } |
| 313 | |
| 314 | static void |
| 315 | m68k_svr4_extract_return_value (struct type *type, struct regcache *regcache, |
| 316 | gdb_byte *valbuf) |
| 317 | { |
| 318 | gdb_byte buf[M68K_MAX_REGISTER_SIZE]; |
| 319 | struct gdbarch *gdbarch = get_regcache_arch (regcache); |
| 320 | struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); |
| 321 | |
| 322 | if (tdep->float_return && TYPE_CODE (type) == TYPE_CODE_FLT) |
| 323 | { |
| 324 | struct type *fpreg_type = register_type (gdbarch, M68K_FP0_REGNUM); |
| 325 | regcache_raw_read (regcache, M68K_FP0_REGNUM, buf); |
| 326 | convert_typed_floating (buf, fpreg_type, valbuf, type); |
| 327 | } |
| 328 | else if (TYPE_CODE (type) == TYPE_CODE_PTR && TYPE_LENGTH (type) == 4) |
| 329 | regcache_raw_read (regcache, M68K_A0_REGNUM, valbuf); |
| 330 | else |
| 331 | m68k_extract_return_value (type, regcache, valbuf); |
| 332 | } |
| 333 | |
| 334 | /* Write a function return value of TYPE from VALBUF into REGCACHE. */ |
| 335 | |
| 336 | static void |
| 337 | m68k_store_return_value (struct type *type, struct regcache *regcache, |
| 338 | const gdb_byte *valbuf) |
| 339 | { |
| 340 | int len = TYPE_LENGTH (type); |
| 341 | |
| 342 | if (len <= 4) |
| 343 | regcache_raw_write_part (regcache, M68K_D0_REGNUM, 4 - len, len, valbuf); |
| 344 | else if (len <= 8) |
| 345 | { |
| 346 | regcache_raw_write_part (regcache, M68K_D0_REGNUM, 8 - len, |
| 347 | len - 4, valbuf); |
| 348 | regcache_raw_write (regcache, M68K_D1_REGNUM, valbuf + (len - 4)); |
| 349 | } |
| 350 | else |
| 351 | internal_error (__FILE__, __LINE__, |
| 352 | _("Cannot store return value of %d bytes long."), len); |
| 353 | } |
| 354 | |
| 355 | static void |
| 356 | m68k_svr4_store_return_value (struct type *type, struct regcache *regcache, |
| 357 | const gdb_byte *valbuf) |
| 358 | { |
| 359 | struct gdbarch *gdbarch = get_regcache_arch (regcache); |
| 360 | struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); |
| 361 | |
| 362 | if (tdep->float_return && TYPE_CODE (type) == TYPE_CODE_FLT) |
| 363 | { |
| 364 | struct type *fpreg_type = register_type (gdbarch, M68K_FP0_REGNUM); |
| 365 | gdb_byte buf[M68K_MAX_REGISTER_SIZE]; |
| 366 | convert_typed_floating (valbuf, type, buf, fpreg_type); |
| 367 | regcache_raw_write (regcache, M68K_FP0_REGNUM, buf); |
| 368 | } |
| 369 | else if (TYPE_CODE (type) == TYPE_CODE_PTR && TYPE_LENGTH (type) == 4) |
| 370 | { |
| 371 | regcache_raw_write (regcache, M68K_A0_REGNUM, valbuf); |
| 372 | regcache_raw_write (regcache, M68K_D0_REGNUM, valbuf); |
| 373 | } |
| 374 | else |
| 375 | m68k_store_return_value (type, regcache, valbuf); |
| 376 | } |
| 377 | |
| 378 | /* Return non-zero if TYPE, which is assumed to be a structure, union or |
| 379 | complex type, should be returned in registers for architecture |
| 380 | GDBARCH. */ |
| 381 | |
| 382 | static int |
| 383 | m68k_reg_struct_return_p (struct gdbarch *gdbarch, struct type *type) |
| 384 | { |
| 385 | struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); |
| 386 | enum type_code code = TYPE_CODE (type); |
| 387 | int len = TYPE_LENGTH (type); |
| 388 | |
| 389 | gdb_assert (code == TYPE_CODE_STRUCT || code == TYPE_CODE_UNION |
| 390 | || code == TYPE_CODE_COMPLEX); |
| 391 | |
| 392 | if (tdep->struct_return == pcc_struct_return) |
| 393 | return 0; |
| 394 | |
| 395 | return (len == 1 || len == 2 || len == 4 || len == 8); |
| 396 | } |
| 397 | |
| 398 | /* Determine, for architecture GDBARCH, how a return value of TYPE |
| 399 | should be returned. If it is supposed to be returned in registers, |
| 400 | and READBUF is non-zero, read the appropriate value from REGCACHE, |
| 401 | and copy it into READBUF. If WRITEBUF is non-zero, write the value |
| 402 | from WRITEBUF into REGCACHE. */ |
| 403 | |
| 404 | static enum return_value_convention |
| 405 | m68k_return_value (struct gdbarch *gdbarch, struct value *function, |
| 406 | struct type *type, struct regcache *regcache, |
| 407 | gdb_byte *readbuf, const gdb_byte *writebuf) |
| 408 | { |
| 409 | enum type_code code = TYPE_CODE (type); |
| 410 | |
| 411 | /* GCC returns a `long double' in memory too. */ |
| 412 | if (((code == TYPE_CODE_STRUCT || code == TYPE_CODE_UNION |
| 413 | || code == TYPE_CODE_COMPLEX) |
| 414 | && !m68k_reg_struct_return_p (gdbarch, type)) |
| 415 | || (code == TYPE_CODE_FLT && TYPE_LENGTH (type) == 12)) |
| 416 | { |
| 417 | /* The default on m68k is to return structures in static memory. |
| 418 | Consequently a function must return the address where we can |
| 419 | find the return value. */ |
| 420 | |
| 421 | if (readbuf) |
| 422 | { |
| 423 | ULONGEST addr; |
| 424 | |
| 425 | regcache_raw_read_unsigned (regcache, M68K_D0_REGNUM, &addr); |
| 426 | read_memory (addr, readbuf, TYPE_LENGTH (type)); |
| 427 | } |
| 428 | |
| 429 | return RETURN_VALUE_ABI_RETURNS_ADDRESS; |
| 430 | } |
| 431 | |
| 432 | if (readbuf) |
| 433 | m68k_extract_return_value (type, regcache, readbuf); |
| 434 | if (writebuf) |
| 435 | m68k_store_return_value (type, regcache, writebuf); |
| 436 | |
| 437 | return RETURN_VALUE_REGISTER_CONVENTION; |
| 438 | } |
| 439 | |
| 440 | static enum return_value_convention |
| 441 | m68k_svr4_return_value (struct gdbarch *gdbarch, struct value *function, |
| 442 | struct type *type, struct regcache *regcache, |
| 443 | gdb_byte *readbuf, const gdb_byte *writebuf) |
| 444 | { |
| 445 | enum type_code code = TYPE_CODE (type); |
| 446 | |
| 447 | if ((code == TYPE_CODE_STRUCT || code == TYPE_CODE_UNION |
| 448 | || code == TYPE_CODE_COMPLEX) |
| 449 | && !m68k_reg_struct_return_p (gdbarch, type)) |
| 450 | { |
| 451 | /* The System V ABI says that: |
| 452 | |
| 453 | "A function returning a structure or union also sets %a0 to |
| 454 | the value it finds in %a0. Thus when the caller receives |
| 455 | control again, the address of the returned object resides in |
| 456 | register %a0." |
| 457 | |
| 458 | So the ABI guarantees that we can always find the return |
| 459 | value just after the function has returned. */ |
| 460 | |
| 461 | if (readbuf) |
| 462 | { |
| 463 | ULONGEST addr; |
| 464 | |
| 465 | regcache_raw_read_unsigned (regcache, M68K_A0_REGNUM, &addr); |
| 466 | read_memory (addr, readbuf, TYPE_LENGTH (type)); |
| 467 | } |
| 468 | |
| 469 | return RETURN_VALUE_ABI_RETURNS_ADDRESS; |
| 470 | } |
| 471 | |
| 472 | /* This special case is for structures consisting of a single |
| 473 | `float' or `double' member. These structures are returned in |
| 474 | %fp0. For these structures, we call ourselves recursively, |
| 475 | changing TYPE into the type of the first member of the structure. |
| 476 | Since that should work for all structures that have only one |
| 477 | member, we don't bother to check the member's type here. */ |
| 478 | if (code == TYPE_CODE_STRUCT && TYPE_NFIELDS (type) == 1) |
| 479 | { |
| 480 | type = check_typedef (TYPE_FIELD_TYPE (type, 0)); |
| 481 | return m68k_svr4_return_value (gdbarch, function, type, regcache, |
| 482 | readbuf, writebuf); |
| 483 | } |
| 484 | |
| 485 | if (readbuf) |
| 486 | m68k_svr4_extract_return_value (type, regcache, readbuf); |
| 487 | if (writebuf) |
| 488 | m68k_svr4_store_return_value (type, regcache, writebuf); |
| 489 | |
| 490 | return RETURN_VALUE_REGISTER_CONVENTION; |
| 491 | } |
| 492 | \f |
| 493 | |
| 494 | /* Always align the frame to a 4-byte boundary. This is required on |
| 495 | coldfire and harmless on the rest. */ |
| 496 | |
| 497 | static CORE_ADDR |
| 498 | m68k_frame_align (struct gdbarch *gdbarch, CORE_ADDR sp) |
| 499 | { |
| 500 | /* Align the stack to four bytes. */ |
| 501 | return sp & ~3; |
| 502 | } |
| 503 | |
| 504 | static CORE_ADDR |
| 505 | m68k_push_dummy_call (struct gdbarch *gdbarch, struct value *function, |
| 506 | struct regcache *regcache, CORE_ADDR bp_addr, int nargs, |
| 507 | struct value **args, CORE_ADDR sp, int struct_return, |
| 508 | CORE_ADDR struct_addr) |
| 509 | { |
| 510 | struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); |
| 511 | enum bfd_endian byte_order = gdbarch_byte_order (gdbarch); |
| 512 | gdb_byte buf[4]; |
| 513 | int i; |
| 514 | |
| 515 | /* Push arguments in reverse order. */ |
| 516 | for (i = nargs - 1; i >= 0; i--) |
| 517 | { |
| 518 | struct type *value_type = value_enclosing_type (args[i]); |
| 519 | int len = TYPE_LENGTH (value_type); |
| 520 | int container_len = (len + 3) & ~3; |
| 521 | int offset; |
| 522 | |
| 523 | /* Non-scalars bigger than 4 bytes are left aligned, others are |
| 524 | right aligned. */ |
| 525 | if ((TYPE_CODE (value_type) == TYPE_CODE_STRUCT |
| 526 | || TYPE_CODE (value_type) == TYPE_CODE_UNION |
| 527 | || TYPE_CODE (value_type) == TYPE_CODE_ARRAY) |
| 528 | && len > 4) |
| 529 | offset = 0; |
| 530 | else |
| 531 | offset = container_len - len; |
| 532 | sp -= container_len; |
| 533 | write_memory (sp + offset, value_contents_all (args[i]), len); |
| 534 | } |
| 535 | |
| 536 | /* Store struct value address. */ |
| 537 | if (struct_return) |
| 538 | { |
| 539 | store_unsigned_integer (buf, 4, byte_order, struct_addr); |
| 540 | regcache_cooked_write (regcache, tdep->struct_value_regnum, buf); |
| 541 | } |
| 542 | |
| 543 | /* Store return address. */ |
| 544 | sp -= 4; |
| 545 | store_unsigned_integer (buf, 4, byte_order, bp_addr); |
| 546 | write_memory (sp, buf, 4); |
| 547 | |
| 548 | /* Finally, update the stack pointer... */ |
| 549 | store_unsigned_integer (buf, 4, byte_order, sp); |
| 550 | regcache_cooked_write (regcache, M68K_SP_REGNUM, buf); |
| 551 | |
| 552 | /* ...and fake a frame pointer. */ |
| 553 | regcache_cooked_write (regcache, M68K_FP_REGNUM, buf); |
| 554 | |
| 555 | /* DWARF2/GCC uses the stack address *before* the function call as a |
| 556 | frame's CFA. */ |
| 557 | return sp + 8; |
| 558 | } |
| 559 | |
| 560 | /* Convert a dwarf or dwarf2 regnumber to a GDB regnum. */ |
| 561 | |
| 562 | static int |
| 563 | m68k_dwarf_reg_to_regnum (struct gdbarch *gdbarch, int num) |
| 564 | { |
| 565 | if (num < 8) |
| 566 | /* d0..7 */ |
| 567 | return (num - 0) + M68K_D0_REGNUM; |
| 568 | else if (num < 16) |
| 569 | /* a0..7 */ |
| 570 | return (num - 8) + M68K_A0_REGNUM; |
| 571 | else if (num < 24 && gdbarch_tdep (gdbarch)->fpregs_present) |
| 572 | /* fp0..7 */ |
| 573 | return (num - 16) + M68K_FP0_REGNUM; |
| 574 | else if (num == 25) |
| 575 | /* pc */ |
| 576 | return M68K_PC_REGNUM; |
| 577 | else |
| 578 | return gdbarch_num_regs (gdbarch) + gdbarch_num_pseudo_regs (gdbarch); |
| 579 | } |
| 580 | |
| 581 | \f |
| 582 | struct m68k_frame_cache |
| 583 | { |
| 584 | /* Base address. */ |
| 585 | CORE_ADDR base; |
| 586 | CORE_ADDR sp_offset; |
| 587 | CORE_ADDR pc; |
| 588 | |
| 589 | /* Saved registers. */ |
| 590 | CORE_ADDR saved_regs[M68K_NUM_REGS]; |
| 591 | CORE_ADDR saved_sp; |
| 592 | |
| 593 | /* Stack space reserved for local variables. */ |
| 594 | long locals; |
| 595 | }; |
| 596 | |
| 597 | /* Allocate and initialize a frame cache. */ |
| 598 | |
| 599 | static struct m68k_frame_cache * |
| 600 | m68k_alloc_frame_cache (void) |
| 601 | { |
| 602 | struct m68k_frame_cache *cache; |
| 603 | int i; |
| 604 | |
| 605 | cache = FRAME_OBSTACK_ZALLOC (struct m68k_frame_cache); |
| 606 | |
| 607 | /* Base address. */ |
| 608 | cache->base = 0; |
| 609 | cache->sp_offset = -4; |
| 610 | cache->pc = 0; |
| 611 | |
| 612 | /* Saved registers. We initialize these to -1 since zero is a valid |
| 613 | offset (that's where %fp is supposed to be stored). */ |
| 614 | for (i = 0; i < M68K_NUM_REGS; i++) |
| 615 | cache->saved_regs[i] = -1; |
| 616 | |
| 617 | /* Frameless until proven otherwise. */ |
| 618 | cache->locals = -1; |
| 619 | |
| 620 | return cache; |
| 621 | } |
| 622 | |
| 623 | /* Check whether PC points at a code that sets up a new stack frame. |
| 624 | If so, it updates CACHE and returns the address of the first |
| 625 | instruction after the sequence that sets removes the "hidden" |
| 626 | argument from the stack or CURRENT_PC, whichever is smaller. |
| 627 | Otherwise, return PC. */ |
| 628 | |
| 629 | static CORE_ADDR |
| 630 | m68k_analyze_frame_setup (struct gdbarch *gdbarch, |
| 631 | CORE_ADDR pc, CORE_ADDR current_pc, |
| 632 | struct m68k_frame_cache *cache) |
| 633 | { |
| 634 | enum bfd_endian byte_order = gdbarch_byte_order (gdbarch); |
| 635 | int op; |
| 636 | |
| 637 | if (pc >= current_pc) |
| 638 | return current_pc; |
| 639 | |
| 640 | op = read_memory_unsigned_integer (pc, 2, byte_order); |
| 641 | |
| 642 | if (op == P_LINKW_FP || op == P_LINKL_FP || op == P_PEA_FP) |
| 643 | { |
| 644 | cache->saved_regs[M68K_FP_REGNUM] = 0; |
| 645 | cache->sp_offset += 4; |
| 646 | if (op == P_LINKW_FP) |
| 647 | { |
| 648 | /* link.w %fp, #-N */ |
| 649 | /* link.w %fp, #0; adda.l #-N, %sp */ |
| 650 | cache->locals = -read_memory_integer (pc + 2, 2, byte_order); |
| 651 | |
| 652 | if (pc + 4 < current_pc && cache->locals == 0) |
| 653 | { |
| 654 | op = read_memory_unsigned_integer (pc + 4, 2, byte_order); |
| 655 | if (op == P_ADDAL_SP) |
| 656 | { |
| 657 | cache->locals = read_memory_integer (pc + 6, 4, byte_order); |
| 658 | return pc + 10; |
| 659 | } |
| 660 | } |
| 661 | |
| 662 | return pc + 4; |
| 663 | } |
| 664 | else if (op == P_LINKL_FP) |
| 665 | { |
| 666 | /* link.l %fp, #-N */ |
| 667 | cache->locals = -read_memory_integer (pc + 2, 4, byte_order); |
| 668 | return pc + 6; |
| 669 | } |
| 670 | else |
| 671 | { |
| 672 | /* pea (%fp); movea.l %sp, %fp */ |
| 673 | cache->locals = 0; |
| 674 | |
| 675 | if (pc + 2 < current_pc) |
| 676 | { |
| 677 | op = read_memory_unsigned_integer (pc + 2, 2, byte_order); |
| 678 | |
| 679 | if (op == P_MOVEAL_SP_FP) |
| 680 | { |
| 681 | /* move.l %sp, %fp */ |
| 682 | return pc + 4; |
| 683 | } |
| 684 | } |
| 685 | |
| 686 | return pc + 2; |
| 687 | } |
| 688 | } |
| 689 | else if ((op & 0170777) == P_SUBQW_SP || (op & 0170777) == P_SUBQL_SP) |
| 690 | { |
| 691 | /* subq.[wl] #N,%sp */ |
| 692 | /* subq.[wl] #8,%sp; subq.[wl] #N,%sp */ |
| 693 | cache->locals = (op & 07000) == 0 ? 8 : (op & 07000) >> 9; |
| 694 | if (pc + 2 < current_pc) |
| 695 | { |
| 696 | op = read_memory_unsigned_integer (pc + 2, 2, byte_order); |
| 697 | if ((op & 0170777) == P_SUBQW_SP || (op & 0170777) == P_SUBQL_SP) |
| 698 | { |
| 699 | cache->locals += (op & 07000) == 0 ? 8 : (op & 07000) >> 9; |
| 700 | return pc + 4; |
| 701 | } |
| 702 | } |
| 703 | return pc + 2; |
| 704 | } |
| 705 | else if (op == P_ADDAW_SP || op == P_LEA_SP_SP) |
| 706 | { |
| 707 | /* adda.w #-N,%sp */ |
| 708 | /* lea (-N,%sp),%sp */ |
| 709 | cache->locals = -read_memory_integer (pc + 2, 2, byte_order); |
| 710 | return pc + 4; |
| 711 | } |
| 712 | else if (op == P_ADDAL_SP) |
| 713 | { |
| 714 | /* adda.l #-N,%sp */ |
| 715 | cache->locals = -read_memory_integer (pc + 2, 4, byte_order); |
| 716 | return pc + 6; |
| 717 | } |
| 718 | |
| 719 | return pc; |
| 720 | } |
| 721 | |
| 722 | /* Check whether PC points at code that saves registers on the stack. |
| 723 | If so, it updates CACHE and returns the address of the first |
| 724 | instruction after the register saves or CURRENT_PC, whichever is |
| 725 | smaller. Otherwise, return PC. */ |
| 726 | |
| 727 | static CORE_ADDR |
| 728 | m68k_analyze_register_saves (struct gdbarch *gdbarch, CORE_ADDR pc, |
| 729 | CORE_ADDR current_pc, |
| 730 | struct m68k_frame_cache *cache) |
| 731 | { |
| 732 | enum bfd_endian byte_order = gdbarch_byte_order (gdbarch); |
| 733 | |
| 734 | if (cache->locals >= 0) |
| 735 | { |
| 736 | CORE_ADDR offset; |
| 737 | int op; |
| 738 | int i, mask, regno; |
| 739 | |
| 740 | offset = -4 - cache->locals; |
| 741 | while (pc < current_pc) |
| 742 | { |
| 743 | op = read_memory_unsigned_integer (pc, 2, byte_order); |
| 744 | if (op == P_FMOVEMX_SP |
| 745 | && gdbarch_tdep (gdbarch)->fpregs_present) |
| 746 | { |
| 747 | /* fmovem.x REGS,-(%sp) */ |
| 748 | op = read_memory_unsigned_integer (pc + 2, 2, byte_order); |
| 749 | if ((op & 0xff00) == 0xe000) |
| 750 | { |
| 751 | mask = op & 0xff; |
| 752 | for (i = 0; i < 16; i++, mask >>= 1) |
| 753 | { |
| 754 | if (mask & 1) |
| 755 | { |
| 756 | cache->saved_regs[i + M68K_FP0_REGNUM] = offset; |
| 757 | offset -= 12; |
| 758 | } |
| 759 | } |
| 760 | pc += 4; |
| 761 | } |
| 762 | else |
| 763 | break; |
| 764 | } |
| 765 | else if ((op & 0177760) == P_MOVEL_SP) |
| 766 | { |
| 767 | /* move.l %R,-(%sp) */ |
| 768 | regno = op & 017; |
| 769 | cache->saved_regs[regno] = offset; |
| 770 | offset -= 4; |
| 771 | pc += 2; |
| 772 | } |
| 773 | else if (op == P_MOVEML_SP) |
| 774 | { |
| 775 | /* movem.l REGS,-(%sp) */ |
| 776 | mask = read_memory_unsigned_integer (pc + 2, 2, byte_order); |
| 777 | for (i = 0; i < 16; i++, mask >>= 1) |
| 778 | { |
| 779 | if (mask & 1) |
| 780 | { |
| 781 | cache->saved_regs[15 - i] = offset; |
| 782 | offset -= 4; |
| 783 | } |
| 784 | } |
| 785 | pc += 4; |
| 786 | } |
| 787 | else |
| 788 | break; |
| 789 | } |
| 790 | } |
| 791 | |
| 792 | return pc; |
| 793 | } |
| 794 | |
| 795 | |
| 796 | /* Do a full analysis of the prologue at PC and update CACHE |
| 797 | accordingly. Bail out early if CURRENT_PC is reached. Return the |
| 798 | address where the analysis stopped. |
| 799 | |
| 800 | We handle all cases that can be generated by gcc. |
| 801 | |
| 802 | For allocating a stack frame: |
| 803 | |
| 804 | link.w %a6,#-N |
| 805 | link.l %a6,#-N |
| 806 | pea (%fp); move.l %sp,%fp |
| 807 | link.w %a6,#0; add.l #-N,%sp |
| 808 | subq.l #N,%sp |
| 809 | subq.w #N,%sp |
| 810 | subq.w #8,%sp; subq.w #N-8,%sp |
| 811 | add.w #-N,%sp |
| 812 | lea (-N,%sp),%sp |
| 813 | add.l #-N,%sp |
| 814 | |
| 815 | For saving registers: |
| 816 | |
| 817 | fmovem.x REGS,-(%sp) |
| 818 | move.l R1,-(%sp) |
| 819 | move.l R1,-(%sp); move.l R2,-(%sp) |
| 820 | movem.l REGS,-(%sp) |
| 821 | |
| 822 | For setting up the PIC register: |
| 823 | |
| 824 | lea (%pc,N),%a5 |
| 825 | |
| 826 | */ |
| 827 | |
| 828 | static CORE_ADDR |
| 829 | m68k_analyze_prologue (struct gdbarch *gdbarch, CORE_ADDR pc, |
| 830 | CORE_ADDR current_pc, struct m68k_frame_cache *cache) |
| 831 | { |
| 832 | enum bfd_endian byte_order = gdbarch_byte_order (gdbarch); |
| 833 | unsigned int op; |
| 834 | |
| 835 | pc = m68k_analyze_frame_setup (gdbarch, pc, current_pc, cache); |
| 836 | pc = m68k_analyze_register_saves (gdbarch, pc, current_pc, cache); |
| 837 | if (pc >= current_pc) |
| 838 | return current_pc; |
| 839 | |
| 840 | /* Check for GOT setup. */ |
| 841 | op = read_memory_unsigned_integer (pc, 4, byte_order); |
| 842 | if (op == P_LEA_PC_A5) |
| 843 | { |
| 844 | /* lea (%pc,N),%a5 */ |
| 845 | return pc + 8; |
| 846 | } |
| 847 | |
| 848 | return pc; |
| 849 | } |
| 850 | |
| 851 | /* Return PC of first real instruction. */ |
| 852 | |
| 853 | static CORE_ADDR |
| 854 | m68k_skip_prologue (struct gdbarch *gdbarch, CORE_ADDR start_pc) |
| 855 | { |
| 856 | struct m68k_frame_cache cache; |
| 857 | CORE_ADDR pc; |
| 858 | |
| 859 | cache.locals = -1; |
| 860 | pc = m68k_analyze_prologue (gdbarch, start_pc, (CORE_ADDR) -1, &cache); |
| 861 | if (cache.locals < 0) |
| 862 | return start_pc; |
| 863 | return pc; |
| 864 | } |
| 865 | |
| 866 | static CORE_ADDR |
| 867 | m68k_unwind_pc (struct gdbarch *gdbarch, struct frame_info *next_frame) |
| 868 | { |
| 869 | gdb_byte buf[8]; |
| 870 | |
| 871 | frame_unwind_register (next_frame, gdbarch_pc_regnum (gdbarch), buf); |
| 872 | return extract_typed_address (buf, builtin_type (gdbarch)->builtin_func_ptr); |
| 873 | } |
| 874 | \f |
| 875 | /* Normal frames. */ |
| 876 | |
| 877 | static struct m68k_frame_cache * |
| 878 | m68k_frame_cache (struct frame_info *this_frame, void **this_cache) |
| 879 | { |
| 880 | struct gdbarch *gdbarch = get_frame_arch (this_frame); |
| 881 | enum bfd_endian byte_order = gdbarch_byte_order (gdbarch); |
| 882 | struct m68k_frame_cache *cache; |
| 883 | gdb_byte buf[4]; |
| 884 | int i; |
| 885 | |
| 886 | if (*this_cache) |
| 887 | return *this_cache; |
| 888 | |
| 889 | cache = m68k_alloc_frame_cache (); |
| 890 | *this_cache = cache; |
| 891 | |
| 892 | /* In principle, for normal frames, %fp holds the frame pointer, |
| 893 | which holds the base address for the current stack frame. |
| 894 | However, for functions that don't need it, the frame pointer is |
| 895 | optional. For these "frameless" functions the frame pointer is |
| 896 | actually the frame pointer of the calling frame. Signal |
| 897 | trampolines are just a special case of a "frameless" function. |
| 898 | They (usually) share their frame pointer with the frame that was |
| 899 | in progress when the signal occurred. */ |
| 900 | |
| 901 | get_frame_register (this_frame, M68K_FP_REGNUM, buf); |
| 902 | cache->base = extract_unsigned_integer (buf, 4, byte_order); |
| 903 | if (cache->base == 0) |
| 904 | return cache; |
| 905 | |
| 906 | /* For normal frames, %pc is stored at 4(%fp). */ |
| 907 | cache->saved_regs[M68K_PC_REGNUM] = 4; |
| 908 | |
| 909 | cache->pc = get_frame_func (this_frame); |
| 910 | if (cache->pc != 0) |
| 911 | m68k_analyze_prologue (get_frame_arch (this_frame), cache->pc, |
| 912 | get_frame_pc (this_frame), cache); |
| 913 | |
| 914 | if (cache->locals < 0) |
| 915 | { |
| 916 | /* We didn't find a valid frame, which means that CACHE->base |
| 917 | currently holds the frame pointer for our calling frame. If |
| 918 | we're at the start of a function, or somewhere half-way its |
| 919 | prologue, the function's frame probably hasn't been fully |
| 920 | setup yet. Try to reconstruct the base address for the stack |
| 921 | frame by looking at the stack pointer. For truly "frameless" |
| 922 | functions this might work too. */ |
| 923 | |
| 924 | get_frame_register (this_frame, M68K_SP_REGNUM, buf); |
| 925 | cache->base = extract_unsigned_integer (buf, 4, byte_order) |
| 926 | + cache->sp_offset; |
| 927 | } |
| 928 | |
| 929 | /* Now that we have the base address for the stack frame we can |
| 930 | calculate the value of %sp in the calling frame. */ |
| 931 | cache->saved_sp = cache->base + 8; |
| 932 | |
| 933 | /* Adjust all the saved registers such that they contain addresses |
| 934 | instead of offsets. */ |
| 935 | for (i = 0; i < M68K_NUM_REGS; i++) |
| 936 | if (cache->saved_regs[i] != -1) |
| 937 | cache->saved_regs[i] += cache->base; |
| 938 | |
| 939 | return cache; |
| 940 | } |
| 941 | |
| 942 | static void |
| 943 | m68k_frame_this_id (struct frame_info *this_frame, void **this_cache, |
| 944 | struct frame_id *this_id) |
| 945 | { |
| 946 | struct m68k_frame_cache *cache = m68k_frame_cache (this_frame, this_cache); |
| 947 | |
| 948 | /* This marks the outermost frame. */ |
| 949 | if (cache->base == 0) |
| 950 | return; |
| 951 | |
| 952 | /* See the end of m68k_push_dummy_call. */ |
| 953 | *this_id = frame_id_build (cache->base + 8, cache->pc); |
| 954 | } |
| 955 | |
| 956 | static struct value * |
| 957 | m68k_frame_prev_register (struct frame_info *this_frame, void **this_cache, |
| 958 | int regnum) |
| 959 | { |
| 960 | struct m68k_frame_cache *cache = m68k_frame_cache (this_frame, this_cache); |
| 961 | |
| 962 | gdb_assert (regnum >= 0); |
| 963 | |
| 964 | if (regnum == M68K_SP_REGNUM && cache->saved_sp) |
| 965 | return frame_unwind_got_constant (this_frame, regnum, cache->saved_sp); |
| 966 | |
| 967 | if (regnum < M68K_NUM_REGS && cache->saved_regs[regnum] != -1) |
| 968 | return frame_unwind_got_memory (this_frame, regnum, |
| 969 | cache->saved_regs[regnum]); |
| 970 | |
| 971 | return frame_unwind_got_register (this_frame, regnum, regnum); |
| 972 | } |
| 973 | |
| 974 | static const struct frame_unwind m68k_frame_unwind = |
| 975 | { |
| 976 | NORMAL_FRAME, |
| 977 | default_frame_unwind_stop_reason, |
| 978 | m68k_frame_this_id, |
| 979 | m68k_frame_prev_register, |
| 980 | NULL, |
| 981 | default_frame_sniffer |
| 982 | }; |
| 983 | \f |
| 984 | static CORE_ADDR |
| 985 | m68k_frame_base_address (struct frame_info *this_frame, void **this_cache) |
| 986 | { |
| 987 | struct m68k_frame_cache *cache = m68k_frame_cache (this_frame, this_cache); |
| 988 | |
| 989 | return cache->base; |
| 990 | } |
| 991 | |
| 992 | static const struct frame_base m68k_frame_base = |
| 993 | { |
| 994 | &m68k_frame_unwind, |
| 995 | m68k_frame_base_address, |
| 996 | m68k_frame_base_address, |
| 997 | m68k_frame_base_address |
| 998 | }; |
| 999 | |
| 1000 | static struct frame_id |
| 1001 | m68k_dummy_id (struct gdbarch *gdbarch, struct frame_info *this_frame) |
| 1002 | { |
| 1003 | CORE_ADDR fp; |
| 1004 | |
| 1005 | fp = get_frame_register_unsigned (this_frame, M68K_FP_REGNUM); |
| 1006 | |
| 1007 | /* See the end of m68k_push_dummy_call. */ |
| 1008 | return frame_id_build (fp + 8, get_frame_pc (this_frame)); |
| 1009 | } |
| 1010 | \f |
| 1011 | |
| 1012 | /* Figure out where the longjmp will land. Slurp the args out of the stack. |
| 1013 | We expect the first arg to be a pointer to the jmp_buf structure from which |
| 1014 | we extract the pc (JB_PC) that we will land at. The pc is copied into PC. |
| 1015 | This routine returns true on success. */ |
| 1016 | |
| 1017 | static int |
| 1018 | m68k_get_longjmp_target (struct frame_info *frame, CORE_ADDR *pc) |
| 1019 | { |
| 1020 | gdb_byte *buf; |
| 1021 | CORE_ADDR sp, jb_addr; |
| 1022 | struct gdbarch *gdbarch = get_frame_arch (frame); |
| 1023 | struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); |
| 1024 | enum bfd_endian byte_order = gdbarch_byte_order (gdbarch); |
| 1025 | |
| 1026 | if (tdep->jb_pc < 0) |
| 1027 | { |
| 1028 | internal_error (__FILE__, __LINE__, |
| 1029 | _("m68k_get_longjmp_target: not implemented")); |
| 1030 | return 0; |
| 1031 | } |
| 1032 | |
| 1033 | buf = alloca (gdbarch_ptr_bit (gdbarch) / TARGET_CHAR_BIT); |
| 1034 | sp = get_frame_register_unsigned (frame, gdbarch_sp_regnum (gdbarch)); |
| 1035 | |
| 1036 | if (target_read_memory (sp + SP_ARG0, /* Offset of first arg on stack. */ |
| 1037 | buf, gdbarch_ptr_bit (gdbarch) / TARGET_CHAR_BIT)) |
| 1038 | return 0; |
| 1039 | |
| 1040 | jb_addr = extract_unsigned_integer (buf, gdbarch_ptr_bit (gdbarch) |
| 1041 | / TARGET_CHAR_BIT, byte_order); |
| 1042 | |
| 1043 | if (target_read_memory (jb_addr + tdep->jb_pc * tdep->jb_elt_size, buf, |
| 1044 | gdbarch_ptr_bit (gdbarch) / TARGET_CHAR_BIT), |
| 1045 | byte_order) |
| 1046 | return 0; |
| 1047 | |
| 1048 | *pc = extract_unsigned_integer (buf, gdbarch_ptr_bit (gdbarch) |
| 1049 | / TARGET_CHAR_BIT, byte_order); |
| 1050 | return 1; |
| 1051 | } |
| 1052 | \f |
| 1053 | |
| 1054 | /* This is the implementation of gdbarch method |
| 1055 | return_in_first_hidden_param_p. */ |
| 1056 | |
| 1057 | static int |
| 1058 | m68k_return_in_first_hidden_param_p (struct gdbarch *gdbarch, |
| 1059 | struct type *type) |
| 1060 | { |
| 1061 | return 0; |
| 1062 | } |
| 1063 | |
| 1064 | /* System V Release 4 (SVR4). */ |
| 1065 | |
| 1066 | void |
| 1067 | m68k_svr4_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch) |
| 1068 | { |
| 1069 | struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); |
| 1070 | |
| 1071 | /* SVR4 uses a different calling convention. */ |
| 1072 | set_gdbarch_return_value (gdbarch, m68k_svr4_return_value); |
| 1073 | |
| 1074 | /* SVR4 uses %a0 instead of %a1. */ |
| 1075 | tdep->struct_value_regnum = M68K_A0_REGNUM; |
| 1076 | } |
| 1077 | \f |
| 1078 | |
| 1079 | /* Function: m68k_gdbarch_init |
| 1080 | Initializer function for the m68k gdbarch vector. |
| 1081 | Called by gdbarch. Sets up the gdbarch vector(s) for this target. */ |
| 1082 | |
| 1083 | static struct gdbarch * |
| 1084 | m68k_gdbarch_init (struct gdbarch_info info, struct gdbarch_list *arches) |
| 1085 | { |
| 1086 | struct gdbarch_tdep *tdep = NULL; |
| 1087 | struct gdbarch *gdbarch; |
| 1088 | struct gdbarch_list *best_arch; |
| 1089 | struct tdesc_arch_data *tdesc_data = NULL; |
| 1090 | int i; |
| 1091 | enum m68k_flavour flavour = m68k_no_flavour; |
| 1092 | int has_fp = 1; |
| 1093 | const struct floatformat **long_double_format = floatformats_m68881_ext; |
| 1094 | |
| 1095 | /* Check any target description for validity. */ |
| 1096 | if (tdesc_has_registers (info.target_desc)) |
| 1097 | { |
| 1098 | const struct tdesc_feature *feature; |
| 1099 | int valid_p; |
| 1100 | |
| 1101 | feature = tdesc_find_feature (info.target_desc, |
| 1102 | "org.gnu.gdb.m68k.core"); |
| 1103 | |
| 1104 | if (feature == NULL) |
| 1105 | { |
| 1106 | feature = tdesc_find_feature (info.target_desc, |
| 1107 | "org.gnu.gdb.coldfire.core"); |
| 1108 | if (feature != NULL) |
| 1109 | flavour = m68k_coldfire_flavour; |
| 1110 | } |
| 1111 | |
| 1112 | if (feature == NULL) |
| 1113 | { |
| 1114 | feature = tdesc_find_feature (info.target_desc, |
| 1115 | "org.gnu.gdb.fido.core"); |
| 1116 | if (feature != NULL) |
| 1117 | flavour = m68k_fido_flavour; |
| 1118 | } |
| 1119 | |
| 1120 | if (feature == NULL) |
| 1121 | return NULL; |
| 1122 | |
| 1123 | tdesc_data = tdesc_data_alloc (); |
| 1124 | |
| 1125 | valid_p = 1; |
| 1126 | for (i = 0; i <= M68K_PC_REGNUM; i++) |
| 1127 | valid_p &= tdesc_numbered_register (feature, tdesc_data, i, |
| 1128 | m68k_register_names[i]); |
| 1129 | |
| 1130 | if (!valid_p) |
| 1131 | { |
| 1132 | tdesc_data_cleanup (tdesc_data); |
| 1133 | return NULL; |
| 1134 | } |
| 1135 | |
| 1136 | feature = tdesc_find_feature (info.target_desc, |
| 1137 | "org.gnu.gdb.coldfire.fp"); |
| 1138 | if (feature != NULL) |
| 1139 | { |
| 1140 | valid_p = 1; |
| 1141 | for (i = M68K_FP0_REGNUM; i <= M68K_FPI_REGNUM; i++) |
| 1142 | valid_p &= tdesc_numbered_register (feature, tdesc_data, i, |
| 1143 | m68k_register_names[i]); |
| 1144 | if (!valid_p) |
| 1145 | { |
| 1146 | tdesc_data_cleanup (tdesc_data); |
| 1147 | return NULL; |
| 1148 | } |
| 1149 | } |
| 1150 | else |
| 1151 | has_fp = 0; |
| 1152 | } |
| 1153 | |
| 1154 | /* The mechanism for returning floating values from function |
| 1155 | and the type of long double depend on whether we're |
| 1156 | on ColdFire or standard m68k. */ |
| 1157 | |
| 1158 | if (info.bfd_arch_info && info.bfd_arch_info->mach != 0) |
| 1159 | { |
| 1160 | const bfd_arch_info_type *coldfire_arch = |
| 1161 | bfd_lookup_arch (bfd_arch_m68k, bfd_mach_mcf_isa_a_nodiv); |
| 1162 | |
| 1163 | if (coldfire_arch |
| 1164 | && ((*info.bfd_arch_info->compatible) |
| 1165 | (info.bfd_arch_info, coldfire_arch))) |
| 1166 | flavour = m68k_coldfire_flavour; |
| 1167 | } |
| 1168 | |
| 1169 | /* If there is already a candidate, use it. */ |
| 1170 | for (best_arch = gdbarch_list_lookup_by_info (arches, &info); |
| 1171 | best_arch != NULL; |
| 1172 | best_arch = gdbarch_list_lookup_by_info (best_arch->next, &info)) |
| 1173 | { |
| 1174 | if (flavour != gdbarch_tdep (best_arch->gdbarch)->flavour) |
| 1175 | continue; |
| 1176 | |
| 1177 | if (has_fp != gdbarch_tdep (best_arch->gdbarch)->fpregs_present) |
| 1178 | continue; |
| 1179 | |
| 1180 | break; |
| 1181 | } |
| 1182 | |
| 1183 | if (best_arch != NULL) |
| 1184 | { |
| 1185 | if (tdesc_data != NULL) |
| 1186 | tdesc_data_cleanup (tdesc_data); |
| 1187 | return best_arch->gdbarch; |
| 1188 | } |
| 1189 | |
| 1190 | tdep = xzalloc (sizeof (struct gdbarch_tdep)); |
| 1191 | gdbarch = gdbarch_alloc (&info, tdep); |
| 1192 | tdep->fpregs_present = has_fp; |
| 1193 | tdep->flavour = flavour; |
| 1194 | |
| 1195 | if (flavour == m68k_coldfire_flavour || flavour == m68k_fido_flavour) |
| 1196 | long_double_format = floatformats_ieee_double; |
| 1197 | set_gdbarch_long_double_format (gdbarch, long_double_format); |
| 1198 | set_gdbarch_long_double_bit (gdbarch, long_double_format[0]->totalsize); |
| 1199 | |
| 1200 | set_gdbarch_skip_prologue (gdbarch, m68k_skip_prologue); |
| 1201 | set_gdbarch_breakpoint_from_pc (gdbarch, m68k_local_breakpoint_from_pc); |
| 1202 | |
| 1203 | /* Stack grows down. */ |
| 1204 | set_gdbarch_inner_than (gdbarch, core_addr_lessthan); |
| 1205 | set_gdbarch_frame_align (gdbarch, m68k_frame_align); |
| 1206 | |
| 1207 | set_gdbarch_believe_pcc_promotion (gdbarch, 1); |
| 1208 | if (flavour == m68k_coldfire_flavour || flavour == m68k_fido_flavour) |
| 1209 | set_gdbarch_decr_pc_after_break (gdbarch, 2); |
| 1210 | |
| 1211 | set_gdbarch_frame_args_skip (gdbarch, 8); |
| 1212 | set_gdbarch_dwarf2_reg_to_regnum (gdbarch, m68k_dwarf_reg_to_regnum); |
| 1213 | |
| 1214 | set_gdbarch_register_type (gdbarch, m68k_register_type); |
| 1215 | set_gdbarch_register_name (gdbarch, m68k_register_name); |
| 1216 | set_gdbarch_num_regs (gdbarch, M68K_NUM_REGS); |
| 1217 | set_gdbarch_sp_regnum (gdbarch, M68K_SP_REGNUM); |
| 1218 | set_gdbarch_pc_regnum (gdbarch, M68K_PC_REGNUM); |
| 1219 | set_gdbarch_ps_regnum (gdbarch, M68K_PS_REGNUM); |
| 1220 | set_gdbarch_convert_register_p (gdbarch, m68k_convert_register_p); |
| 1221 | set_gdbarch_register_to_value (gdbarch, m68k_register_to_value); |
| 1222 | set_gdbarch_value_to_register (gdbarch, m68k_value_to_register); |
| 1223 | |
| 1224 | if (has_fp) |
| 1225 | set_gdbarch_fp0_regnum (gdbarch, M68K_FP0_REGNUM); |
| 1226 | |
| 1227 | /* Try to figure out if the arch uses floating registers to return |
| 1228 | floating point values from functions. */ |
| 1229 | if (has_fp) |
| 1230 | { |
| 1231 | /* On ColdFire, floating point values are returned in D0. */ |
| 1232 | if (flavour == m68k_coldfire_flavour) |
| 1233 | tdep->float_return = 0; |
| 1234 | else |
| 1235 | tdep->float_return = 1; |
| 1236 | } |
| 1237 | else |
| 1238 | { |
| 1239 | /* No floating registers, so can't use them for returning values. */ |
| 1240 | tdep->float_return = 0; |
| 1241 | } |
| 1242 | |
| 1243 | /* Function call & return. */ |
| 1244 | set_gdbarch_push_dummy_call (gdbarch, m68k_push_dummy_call); |
| 1245 | set_gdbarch_return_value (gdbarch, m68k_return_value); |
| 1246 | set_gdbarch_return_in_first_hidden_param_p (gdbarch, |
| 1247 | m68k_return_in_first_hidden_param_p); |
| 1248 | |
| 1249 | |
| 1250 | /* Disassembler. */ |
| 1251 | set_gdbarch_print_insn (gdbarch, print_insn_m68k); |
| 1252 | |
| 1253 | #if defined JB_PC && defined JB_ELEMENT_SIZE |
| 1254 | tdep->jb_pc = JB_PC; |
| 1255 | tdep->jb_elt_size = JB_ELEMENT_SIZE; |
| 1256 | #else |
| 1257 | tdep->jb_pc = -1; |
| 1258 | #endif |
| 1259 | tdep->struct_value_regnum = M68K_A1_REGNUM; |
| 1260 | tdep->struct_return = reg_struct_return; |
| 1261 | |
| 1262 | /* Frame unwinder. */ |
| 1263 | set_gdbarch_dummy_id (gdbarch, m68k_dummy_id); |
| 1264 | set_gdbarch_unwind_pc (gdbarch, m68k_unwind_pc); |
| 1265 | |
| 1266 | /* Hook in the DWARF CFI frame unwinder. */ |
| 1267 | dwarf2_append_unwinders (gdbarch); |
| 1268 | |
| 1269 | frame_base_set_default (gdbarch, &m68k_frame_base); |
| 1270 | |
| 1271 | /* Hook in ABI-specific overrides, if they have been registered. */ |
| 1272 | gdbarch_init_osabi (info, gdbarch); |
| 1273 | |
| 1274 | /* Now we have tuned the configuration, set a few final things, |
| 1275 | based on what the OS ABI has told us. */ |
| 1276 | |
| 1277 | if (tdep->jb_pc >= 0) |
| 1278 | set_gdbarch_get_longjmp_target (gdbarch, m68k_get_longjmp_target); |
| 1279 | |
| 1280 | frame_unwind_append_unwinder (gdbarch, &m68k_frame_unwind); |
| 1281 | |
| 1282 | if (tdesc_data) |
| 1283 | tdesc_use_registers (gdbarch, info.target_desc, tdesc_data); |
| 1284 | |
| 1285 | return gdbarch; |
| 1286 | } |
| 1287 | |
| 1288 | |
| 1289 | static void |
| 1290 | m68k_dump_tdep (struct gdbarch *gdbarch, struct ui_file *file) |
| 1291 | { |
| 1292 | struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); |
| 1293 | |
| 1294 | if (tdep == NULL) |
| 1295 | return; |
| 1296 | } |
| 1297 | |
| 1298 | extern initialize_file_ftype _initialize_m68k_tdep; /* -Wmissing-prototypes */ |
| 1299 | |
| 1300 | void |
| 1301 | _initialize_m68k_tdep (void) |
| 1302 | { |
| 1303 | gdbarch_register (bfd_arch_m68k, m68k_gdbarch_init, m68k_dump_tdep); |
| 1304 | } |