| 1 | /* Target-dependent code for the Motorola 68000 series. |
| 2 | |
| 3 | Copyright 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1999, 2000, |
| 4 | 2001, 2002, 2003, 2004, 2005 Free Software Foundation, Inc. |
| 5 | |
| 6 | This file is part of GDB. |
| 7 | |
| 8 | This program is free software; you can redistribute it and/or modify |
| 9 | it under the terms of the GNU General Public License as published by |
| 10 | the Free Software Foundation; either version 2 of the License, or |
| 11 | (at your option) any later version. |
| 12 | |
| 13 | This program is distributed in the hope that it will be useful, |
| 14 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 15 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 16 | GNU General Public License for more details. |
| 17 | |
| 18 | You should have received a copy of the GNU General Public License |
| 19 | along with this program; if not, write to the Free Software |
| 20 | Foundation, Inc., 59 Temple Place - Suite 330, |
| 21 | Boston, MA 02111-1307, USA. */ |
| 22 | |
| 23 | #include "defs.h" |
| 24 | #include "dwarf2-frame.h" |
| 25 | #include "frame.h" |
| 26 | #include "frame-base.h" |
| 27 | #include "frame-unwind.h" |
| 28 | #include "floatformat.h" |
| 29 | #include "symtab.h" |
| 30 | #include "gdbcore.h" |
| 31 | #include "value.h" |
| 32 | #include "gdb_string.h" |
| 33 | #include "gdb_assert.h" |
| 34 | #include "inferior.h" |
| 35 | #include "regcache.h" |
| 36 | #include "arch-utils.h" |
| 37 | #include "osabi.h" |
| 38 | #include "dis-asm.h" |
| 39 | |
| 40 | #include "m68k-tdep.h" |
| 41 | \f |
| 42 | |
| 43 | #define P_LINKL_FP 0x480e |
| 44 | #define P_LINKW_FP 0x4e56 |
| 45 | #define P_PEA_FP 0x4856 |
| 46 | #define P_MOVEAL_SP_FP 0x2c4f |
| 47 | #define P_ADDAW_SP 0xdefc |
| 48 | #define P_ADDAL_SP 0xdffc |
| 49 | #define P_SUBQW_SP 0x514f |
| 50 | #define P_SUBQL_SP 0x518f |
| 51 | #define P_LEA_SP_SP 0x4fef |
| 52 | #define P_LEA_PC_A5 0x4bfb0170 |
| 53 | #define P_FMOVEMX_SP 0xf227 |
| 54 | #define P_MOVEL_SP 0x2f00 |
| 55 | #define P_MOVEML_SP 0x48e7 |
| 56 | |
| 57 | |
| 58 | #define REGISTER_BYTES_FP (16*4 + 8 + 8*12 + 3*4) |
| 59 | #define REGISTER_BYTES_NOFP (16*4 + 8) |
| 60 | |
| 61 | /* Offset from SP to first arg on stack at first instruction of a function */ |
| 62 | #define SP_ARG0 (1 * 4) |
| 63 | |
| 64 | #if !defined (BPT_VECTOR) |
| 65 | #define BPT_VECTOR 0xf |
| 66 | #endif |
| 67 | |
| 68 | static const gdb_byte * |
| 69 | m68k_local_breakpoint_from_pc (CORE_ADDR *pcptr, int *lenptr) |
| 70 | { |
| 71 | static gdb_byte break_insn[] = {0x4e, (0x40 | BPT_VECTOR)}; |
| 72 | *lenptr = sizeof (break_insn); |
| 73 | return break_insn; |
| 74 | } |
| 75 | |
| 76 | |
| 77 | static int |
| 78 | m68k_register_bytes_ok (long numbytes) |
| 79 | { |
| 80 | return ((numbytes == REGISTER_BYTES_FP) |
| 81 | || (numbytes == REGISTER_BYTES_NOFP)); |
| 82 | } |
| 83 | |
| 84 | /* Return the GDB type object for the "standard" data type of data in |
| 85 | register N. This should be int for D0-D7, SR, FPCONTROL and |
| 86 | FPSTATUS, long double for FP0-FP7, and void pointer for all others |
| 87 | (A0-A7, PC, FPIADDR). Note, for registers which contain |
| 88 | addresses return pointer to void, not pointer to char, because we |
| 89 | don't want to attempt to print the string after printing the |
| 90 | address. */ |
| 91 | |
| 92 | static struct type * |
| 93 | m68k_register_type (struct gdbarch *gdbarch, int regnum) |
| 94 | { |
| 95 | if (regnum >= FP0_REGNUM && regnum <= FP0_REGNUM + 7) |
| 96 | return builtin_type_m68881_ext; |
| 97 | |
| 98 | if (regnum == M68K_FPI_REGNUM || regnum == PC_REGNUM) |
| 99 | return builtin_type_void_func_ptr; |
| 100 | |
| 101 | if (regnum == M68K_FPC_REGNUM || regnum == M68K_FPS_REGNUM |
| 102 | || regnum == PS_REGNUM) |
| 103 | return builtin_type_int32; |
| 104 | |
| 105 | if (regnum >= M68K_A0_REGNUM && regnum <= M68K_A0_REGNUM + 7) |
| 106 | return builtin_type_void_data_ptr; |
| 107 | |
| 108 | return builtin_type_int32; |
| 109 | } |
| 110 | |
| 111 | /* Function: m68k_register_name |
| 112 | Returns the name of the standard m68k register regnum. */ |
| 113 | |
| 114 | static const char * |
| 115 | m68k_register_name (int regnum) |
| 116 | { |
| 117 | static char *register_names[] = { |
| 118 | "d0", "d1", "d2", "d3", "d4", "d5", "d6", "d7", |
| 119 | "a0", "a1", "a2", "a3", "a4", "a5", "fp", "sp", |
| 120 | "ps", "pc", |
| 121 | "fp0", "fp1", "fp2", "fp3", "fp4", "fp5", "fp6", "fp7", |
| 122 | "fpcontrol", "fpstatus", "fpiaddr", "fpcode", "fpflags" |
| 123 | }; |
| 124 | |
| 125 | if (regnum < 0 || |
| 126 | regnum >= sizeof (register_names) / sizeof (register_names[0])) |
| 127 | internal_error (__FILE__, __LINE__, |
| 128 | _("m68k_register_name: illegal register number %d"), regnum); |
| 129 | else |
| 130 | return register_names[regnum]; |
| 131 | } |
| 132 | \f |
| 133 | /* Return nonzero if a value of type TYPE stored in register REGNUM |
| 134 | needs any special handling. */ |
| 135 | |
| 136 | static int |
| 137 | m68k_convert_register_p (int regnum, struct type *type) |
| 138 | { |
| 139 | return (regnum >= M68K_FP0_REGNUM && regnum <= M68K_FP0_REGNUM + 7); |
| 140 | } |
| 141 | |
| 142 | /* Read a value of type TYPE from register REGNUM in frame FRAME, and |
| 143 | return its contents in TO. */ |
| 144 | |
| 145 | static void |
| 146 | m68k_register_to_value (struct frame_info *frame, int regnum, |
| 147 | struct type *type, gdb_byte *to) |
| 148 | { |
| 149 | gdb_byte from[M68K_MAX_REGISTER_SIZE]; |
| 150 | |
| 151 | /* We only support floating-point values. */ |
| 152 | if (TYPE_CODE (type) != TYPE_CODE_FLT) |
| 153 | { |
| 154 | warning (_("Cannot convert floating-point register value " |
| 155 | "to non-floating-point type.")); |
| 156 | return; |
| 157 | } |
| 158 | |
| 159 | /* Convert to TYPE. This should be a no-op if TYPE is equivalent to |
| 160 | the extended floating-point format used by the FPU. */ |
| 161 | get_frame_register (frame, regnum, from); |
| 162 | convert_typed_floating (from, builtin_type_m68881_ext, to, type); |
| 163 | } |
| 164 | |
| 165 | /* Write the contents FROM of a value of type TYPE into register |
| 166 | REGNUM in frame FRAME. */ |
| 167 | |
| 168 | static void |
| 169 | m68k_value_to_register (struct frame_info *frame, int regnum, |
| 170 | struct type *type, const gdb_byte *from) |
| 171 | { |
| 172 | gdb_byte to[M68K_MAX_REGISTER_SIZE]; |
| 173 | |
| 174 | /* We only support floating-point values. */ |
| 175 | if (TYPE_CODE (type) != TYPE_CODE_FLT) |
| 176 | { |
| 177 | warning (_("Cannot convert non-floating-point type " |
| 178 | "to floating-point register value.")); |
| 179 | return; |
| 180 | } |
| 181 | |
| 182 | /* Convert from TYPE. This should be a no-op if TYPE is equivalent |
| 183 | to the extended floating-point format used by the FPU. */ |
| 184 | convert_typed_floating (from, type, to, builtin_type_m68881_ext); |
| 185 | put_frame_register (frame, regnum, to); |
| 186 | } |
| 187 | |
| 188 | \f |
| 189 | /* There is a fair number of calling conventions that are in somewhat |
| 190 | wide use. The 68000/08/10 don't support an FPU, not even as a |
| 191 | coprocessor. All function return values are stored in %d0/%d1. |
| 192 | Structures are returned in a static buffer, a pointer to which is |
| 193 | returned in %d0. This means that functions returning a structure |
| 194 | are not re-entrant. To avoid this problem some systems use a |
| 195 | convention where the caller passes a pointer to a buffer in %a1 |
| 196 | where the return values is to be stored. This convention is the |
| 197 | default, and is implemented in the function m68k_return_value. |
| 198 | |
| 199 | The 68020/030/040/060 do support an FPU, either as a coprocessor |
| 200 | (68881/2) or built-in (68040/68060). That's why System V release 4 |
| 201 | (SVR4) instroduces a new calling convention specified by the SVR4 |
| 202 | psABI. Integer values are returned in %d0/%d1, pointer return |
| 203 | values in %a0 and floating values in %fp0. When calling functions |
| 204 | returning a structure the caller should pass a pointer to a buffer |
| 205 | for the return value in %a0. This convention is implemented in the |
| 206 | function m68k_svr4_return_value, and by appropriately setting the |
| 207 | struct_value_regnum member of `struct gdbarch_tdep'. |
| 208 | |
| 209 | GNU/Linux returns values in the same way as SVR4 does, but uses %a1 |
| 210 | for passing the structure return value buffer. |
| 211 | |
| 212 | GCC can also generate code where small structures are returned in |
| 213 | %d0/%d1 instead of in memory by using -freg-struct-return. This is |
| 214 | the default on NetBSD a.out, OpenBSD and GNU/Linux and several |
| 215 | embedded systems. This convention is implemented by setting the |
| 216 | struct_return member of `struct gdbarch_tdep' to reg_struct_return. */ |
| 217 | |
| 218 | /* Read a function return value of TYPE from REGCACHE, and copy that |
| 219 | into VALBUF. */ |
| 220 | |
| 221 | static void |
| 222 | m68k_extract_return_value (struct type *type, struct regcache *regcache, |
| 223 | gdb_byte *valbuf) |
| 224 | { |
| 225 | int len = TYPE_LENGTH (type); |
| 226 | gdb_byte buf[M68K_MAX_REGISTER_SIZE]; |
| 227 | |
| 228 | if (len <= 4) |
| 229 | { |
| 230 | regcache_raw_read (regcache, M68K_D0_REGNUM, buf); |
| 231 | memcpy (valbuf, buf + (4 - len), len); |
| 232 | } |
| 233 | else if (len <= 8) |
| 234 | { |
| 235 | regcache_raw_read (regcache, M68K_D0_REGNUM, buf); |
| 236 | memcpy (valbuf, buf + (8 - len), len - 4); |
| 237 | regcache_raw_read (regcache, M68K_D1_REGNUM, valbuf + (len - 4)); |
| 238 | } |
| 239 | else |
| 240 | internal_error (__FILE__, __LINE__, |
| 241 | _("Cannot extract return value of %d bytes long."), len); |
| 242 | } |
| 243 | |
| 244 | static void |
| 245 | m68k_svr4_extract_return_value (struct type *type, struct regcache *regcache, |
| 246 | gdb_byte *valbuf) |
| 247 | { |
| 248 | int len = TYPE_LENGTH (type); |
| 249 | gdb_byte buf[M68K_MAX_REGISTER_SIZE]; |
| 250 | |
| 251 | if (TYPE_CODE (type) == TYPE_CODE_FLT) |
| 252 | { |
| 253 | regcache_raw_read (regcache, M68K_FP0_REGNUM, buf); |
| 254 | convert_typed_floating (buf, builtin_type_m68881_ext, valbuf, type); |
| 255 | } |
| 256 | else if (TYPE_CODE (type) == TYPE_CODE_PTR && len == 4) |
| 257 | regcache_raw_read (regcache, M68K_A0_REGNUM, valbuf); |
| 258 | else |
| 259 | m68k_extract_return_value (type, regcache, valbuf); |
| 260 | } |
| 261 | |
| 262 | /* Write a function return value of TYPE from VALBUF into REGCACHE. */ |
| 263 | |
| 264 | static void |
| 265 | m68k_store_return_value (struct type *type, struct regcache *regcache, |
| 266 | const gdb_byte *valbuf) |
| 267 | { |
| 268 | int len = TYPE_LENGTH (type); |
| 269 | |
| 270 | if (len <= 4) |
| 271 | regcache_raw_write_part (regcache, M68K_D0_REGNUM, 4 - len, len, valbuf); |
| 272 | else if (len <= 8) |
| 273 | { |
| 274 | regcache_raw_write_part (regcache, M68K_D0_REGNUM, 8 - len, |
| 275 | len - 4, valbuf); |
| 276 | regcache_raw_write (regcache, M68K_D1_REGNUM, valbuf + (len - 4)); |
| 277 | } |
| 278 | else |
| 279 | internal_error (__FILE__, __LINE__, |
| 280 | _("Cannot store return value of %d bytes long."), len); |
| 281 | } |
| 282 | |
| 283 | static void |
| 284 | m68k_svr4_store_return_value (struct type *type, struct regcache *regcache, |
| 285 | const gdb_byte *valbuf) |
| 286 | { |
| 287 | int len = TYPE_LENGTH (type); |
| 288 | |
| 289 | if (TYPE_CODE (type) == TYPE_CODE_FLT) |
| 290 | { |
| 291 | gdb_byte buf[M68K_MAX_REGISTER_SIZE]; |
| 292 | convert_typed_floating (valbuf, type, buf, builtin_type_m68881_ext); |
| 293 | regcache_raw_write (regcache, M68K_FP0_REGNUM, buf); |
| 294 | } |
| 295 | else if (TYPE_CODE (type) == TYPE_CODE_PTR && len == 4) |
| 296 | { |
| 297 | regcache_raw_write (regcache, M68K_A0_REGNUM, valbuf); |
| 298 | regcache_raw_write (regcache, M68K_D0_REGNUM, valbuf); |
| 299 | } |
| 300 | else |
| 301 | m68k_store_return_value (type, regcache, valbuf); |
| 302 | } |
| 303 | |
| 304 | /* Return non-zero if TYPE, which is assumed to be a structure or |
| 305 | union type, should be returned in registers for architecture |
| 306 | GDBARCH. */ |
| 307 | |
| 308 | static int |
| 309 | m68k_reg_struct_return_p (struct gdbarch *gdbarch, struct type *type) |
| 310 | { |
| 311 | struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); |
| 312 | enum type_code code = TYPE_CODE (type); |
| 313 | int len = TYPE_LENGTH (type); |
| 314 | |
| 315 | gdb_assert (code == TYPE_CODE_STRUCT || code == TYPE_CODE_UNION); |
| 316 | |
| 317 | if (tdep->struct_return == pcc_struct_return) |
| 318 | return 0; |
| 319 | |
| 320 | return (len == 1 || len == 2 || len == 4 || len == 8); |
| 321 | } |
| 322 | |
| 323 | /* Determine, for architecture GDBARCH, how a return value of TYPE |
| 324 | should be returned. If it is supposed to be returned in registers, |
| 325 | and READBUF is non-zero, read the appropriate value from REGCACHE, |
| 326 | and copy it into READBUF. If WRITEBUF is non-zero, write the value |
| 327 | from WRITEBUF into REGCACHE. */ |
| 328 | |
| 329 | static enum return_value_convention |
| 330 | m68k_return_value (struct gdbarch *gdbarch, struct type *type, |
| 331 | struct regcache *regcache, gdb_byte *readbuf, |
| 332 | const gdb_byte *writebuf) |
| 333 | { |
| 334 | enum type_code code = TYPE_CODE (type); |
| 335 | |
| 336 | if ((code == TYPE_CODE_STRUCT || code == TYPE_CODE_UNION) |
| 337 | && !m68k_reg_struct_return_p (gdbarch, type)) |
| 338 | return RETURN_VALUE_STRUCT_CONVENTION; |
| 339 | |
| 340 | /* GCC returns a `long double' in memory. */ |
| 341 | if (code == TYPE_CODE_FLT && TYPE_LENGTH (type) == 12) |
| 342 | return RETURN_VALUE_STRUCT_CONVENTION; |
| 343 | |
| 344 | if (readbuf) |
| 345 | m68k_extract_return_value (type, regcache, readbuf); |
| 346 | if (writebuf) |
| 347 | m68k_store_return_value (type, regcache, writebuf); |
| 348 | |
| 349 | return RETURN_VALUE_REGISTER_CONVENTION; |
| 350 | } |
| 351 | |
| 352 | static enum return_value_convention |
| 353 | m68k_svr4_return_value (struct gdbarch *gdbarch, struct type *type, |
| 354 | struct regcache *regcache, gdb_byte *readbuf, |
| 355 | const gdb_byte *writebuf) |
| 356 | { |
| 357 | enum type_code code = TYPE_CODE (type); |
| 358 | |
| 359 | if ((code == TYPE_CODE_STRUCT || code == TYPE_CODE_UNION) |
| 360 | && !m68k_reg_struct_return_p (gdbarch, type)) |
| 361 | { |
| 362 | /* The System V ABI says that: |
| 363 | |
| 364 | "A function returning a structure or union also sets %a0 to |
| 365 | the value it finds in %a0. Thus when the caller receives |
| 366 | control again, the address of the returned object resides in |
| 367 | register %a0." |
| 368 | |
| 369 | So the ABI guarantees that we can always find the return |
| 370 | value just after the function has returned. */ |
| 371 | |
| 372 | if (readbuf) |
| 373 | { |
| 374 | ULONGEST addr; |
| 375 | |
| 376 | regcache_raw_read_unsigned (regcache, M68K_A0_REGNUM, &addr); |
| 377 | read_memory (addr, readbuf, TYPE_LENGTH (type)); |
| 378 | } |
| 379 | |
| 380 | return RETURN_VALUE_ABI_RETURNS_ADDRESS; |
| 381 | } |
| 382 | |
| 383 | /* This special case is for structures consisting of a single |
| 384 | `float' or `double' member. These structures are returned in |
| 385 | %fp0. For these structures, we call ourselves recursively, |
| 386 | changing TYPE into the type of the first member of the structure. |
| 387 | Since that should work for all structures that have only one |
| 388 | member, we don't bother to check the member's type here. */ |
| 389 | if (code == TYPE_CODE_STRUCT && TYPE_NFIELDS (type) == 1) |
| 390 | { |
| 391 | type = check_typedef (TYPE_FIELD_TYPE (type, 0)); |
| 392 | return m68k_svr4_return_value (gdbarch, type, regcache, |
| 393 | readbuf, writebuf); |
| 394 | } |
| 395 | |
| 396 | if (readbuf) |
| 397 | m68k_svr4_extract_return_value (type, regcache, readbuf); |
| 398 | if (writebuf) |
| 399 | m68k_svr4_store_return_value (type, regcache, writebuf); |
| 400 | |
| 401 | return RETURN_VALUE_REGISTER_CONVENTION; |
| 402 | } |
| 403 | \f |
| 404 | |
| 405 | static CORE_ADDR |
| 406 | m68k_push_dummy_call (struct gdbarch *gdbarch, struct value *function, |
| 407 | struct regcache *regcache, CORE_ADDR bp_addr, int nargs, |
| 408 | struct value **args, CORE_ADDR sp, int struct_return, |
| 409 | CORE_ADDR struct_addr) |
| 410 | { |
| 411 | struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); |
| 412 | gdb_byte buf[4]; |
| 413 | int i; |
| 414 | |
| 415 | /* Push arguments in reverse order. */ |
| 416 | for (i = nargs - 1; i >= 0; i--) |
| 417 | { |
| 418 | struct type *value_type = value_enclosing_type (args[i]); |
| 419 | int len = TYPE_LENGTH (value_type); |
| 420 | int container_len = (len + 3) & ~3; |
| 421 | int offset; |
| 422 | |
| 423 | /* Non-scalars bigger than 4 bytes are left aligned, others are |
| 424 | right aligned. */ |
| 425 | if ((TYPE_CODE (value_type) == TYPE_CODE_STRUCT |
| 426 | || TYPE_CODE (value_type) == TYPE_CODE_UNION |
| 427 | || TYPE_CODE (value_type) == TYPE_CODE_ARRAY) |
| 428 | && len > 4) |
| 429 | offset = 0; |
| 430 | else |
| 431 | offset = container_len - len; |
| 432 | sp -= container_len; |
| 433 | write_memory (sp + offset, value_contents_all (args[i]), len); |
| 434 | } |
| 435 | |
| 436 | /* Store struct value address. */ |
| 437 | if (struct_return) |
| 438 | { |
| 439 | store_unsigned_integer (buf, 4, struct_addr); |
| 440 | regcache_cooked_write (regcache, tdep->struct_value_regnum, buf); |
| 441 | } |
| 442 | |
| 443 | /* Store return address. */ |
| 444 | sp -= 4; |
| 445 | store_unsigned_integer (buf, 4, bp_addr); |
| 446 | write_memory (sp, buf, 4); |
| 447 | |
| 448 | /* Finally, update the stack pointer... */ |
| 449 | store_unsigned_integer (buf, 4, sp); |
| 450 | regcache_cooked_write (regcache, M68K_SP_REGNUM, buf); |
| 451 | |
| 452 | /* ...and fake a frame pointer. */ |
| 453 | regcache_cooked_write (regcache, M68K_FP_REGNUM, buf); |
| 454 | |
| 455 | /* DWARF2/GCC uses the stack address *before* the function call as a |
| 456 | frame's CFA. */ |
| 457 | return sp + 8; |
| 458 | } |
| 459 | \f |
| 460 | struct m68k_frame_cache |
| 461 | { |
| 462 | /* Base address. */ |
| 463 | CORE_ADDR base; |
| 464 | CORE_ADDR sp_offset; |
| 465 | CORE_ADDR pc; |
| 466 | |
| 467 | /* Saved registers. */ |
| 468 | CORE_ADDR saved_regs[M68K_NUM_REGS]; |
| 469 | CORE_ADDR saved_sp; |
| 470 | |
| 471 | /* Stack space reserved for local variables. */ |
| 472 | long locals; |
| 473 | }; |
| 474 | |
| 475 | /* Allocate and initialize a frame cache. */ |
| 476 | |
| 477 | static struct m68k_frame_cache * |
| 478 | m68k_alloc_frame_cache (void) |
| 479 | { |
| 480 | struct m68k_frame_cache *cache; |
| 481 | int i; |
| 482 | |
| 483 | cache = FRAME_OBSTACK_ZALLOC (struct m68k_frame_cache); |
| 484 | |
| 485 | /* Base address. */ |
| 486 | cache->base = 0; |
| 487 | cache->sp_offset = -4; |
| 488 | cache->pc = 0; |
| 489 | |
| 490 | /* Saved registers. We initialize these to -1 since zero is a valid |
| 491 | offset (that's where %fp is supposed to be stored). */ |
| 492 | for (i = 0; i < M68K_NUM_REGS; i++) |
| 493 | cache->saved_regs[i] = -1; |
| 494 | |
| 495 | /* Frameless until proven otherwise. */ |
| 496 | cache->locals = -1; |
| 497 | |
| 498 | return cache; |
| 499 | } |
| 500 | |
| 501 | /* Check whether PC points at a code that sets up a new stack frame. |
| 502 | If so, it updates CACHE and returns the address of the first |
| 503 | instruction after the sequence that sets removes the "hidden" |
| 504 | argument from the stack or CURRENT_PC, whichever is smaller. |
| 505 | Otherwise, return PC. */ |
| 506 | |
| 507 | static CORE_ADDR |
| 508 | m68k_analyze_frame_setup (CORE_ADDR pc, CORE_ADDR current_pc, |
| 509 | struct m68k_frame_cache *cache) |
| 510 | { |
| 511 | int op; |
| 512 | |
| 513 | if (pc >= current_pc) |
| 514 | return current_pc; |
| 515 | |
| 516 | op = read_memory_unsigned_integer (pc, 2); |
| 517 | |
| 518 | if (op == P_LINKW_FP || op == P_LINKL_FP || op == P_PEA_FP) |
| 519 | { |
| 520 | cache->saved_regs[M68K_FP_REGNUM] = 0; |
| 521 | cache->sp_offset += 4; |
| 522 | if (op == P_LINKW_FP) |
| 523 | { |
| 524 | /* link.w %fp, #-N */ |
| 525 | /* link.w %fp, #0; adda.l #-N, %sp */ |
| 526 | cache->locals = -read_memory_integer (pc + 2, 2); |
| 527 | |
| 528 | if (pc + 4 < current_pc && cache->locals == 0) |
| 529 | { |
| 530 | op = read_memory_unsigned_integer (pc + 4, 2); |
| 531 | if (op == P_ADDAL_SP) |
| 532 | { |
| 533 | cache->locals = read_memory_integer (pc + 6, 4); |
| 534 | return pc + 10; |
| 535 | } |
| 536 | } |
| 537 | |
| 538 | return pc + 4; |
| 539 | } |
| 540 | else if (op == P_LINKL_FP) |
| 541 | { |
| 542 | /* link.l %fp, #-N */ |
| 543 | cache->locals = -read_memory_integer (pc + 2, 4); |
| 544 | return pc + 6; |
| 545 | } |
| 546 | else |
| 547 | { |
| 548 | /* pea (%fp); movea.l %sp, %fp */ |
| 549 | cache->locals = 0; |
| 550 | |
| 551 | if (pc + 2 < current_pc) |
| 552 | { |
| 553 | op = read_memory_unsigned_integer (pc + 2, 2); |
| 554 | |
| 555 | if (op == P_MOVEAL_SP_FP) |
| 556 | { |
| 557 | /* move.l %sp, %fp */ |
| 558 | return pc + 4; |
| 559 | } |
| 560 | } |
| 561 | |
| 562 | return pc + 2; |
| 563 | } |
| 564 | } |
| 565 | else if ((op & 0170777) == P_SUBQW_SP || (op & 0170777) == P_SUBQL_SP) |
| 566 | { |
| 567 | /* subq.[wl] #N,%sp */ |
| 568 | /* subq.[wl] #8,%sp; subq.[wl] #N,%sp */ |
| 569 | cache->locals = (op & 07000) == 0 ? 8 : (op & 07000) >> 9; |
| 570 | if (pc + 2 < current_pc) |
| 571 | { |
| 572 | op = read_memory_unsigned_integer (pc + 2, 2); |
| 573 | if ((op & 0170777) == P_SUBQW_SP || (op & 0170777) == P_SUBQL_SP) |
| 574 | { |
| 575 | cache->locals += (op & 07000) == 0 ? 8 : (op & 07000) >> 9; |
| 576 | return pc + 4; |
| 577 | } |
| 578 | } |
| 579 | return pc + 2; |
| 580 | } |
| 581 | else if (op == P_ADDAW_SP || op == P_LEA_SP_SP) |
| 582 | { |
| 583 | /* adda.w #-N,%sp */ |
| 584 | /* lea (-N,%sp),%sp */ |
| 585 | cache->locals = -read_memory_integer (pc + 2, 2); |
| 586 | return pc + 4; |
| 587 | } |
| 588 | else if (op == P_ADDAL_SP) |
| 589 | { |
| 590 | /* adda.l #-N,%sp */ |
| 591 | cache->locals = -read_memory_integer (pc + 2, 4); |
| 592 | return pc + 6; |
| 593 | } |
| 594 | |
| 595 | return pc; |
| 596 | } |
| 597 | |
| 598 | /* Check whether PC points at code that saves registers on the stack. |
| 599 | If so, it updates CACHE and returns the address of the first |
| 600 | instruction after the register saves or CURRENT_PC, whichever is |
| 601 | smaller. Otherwise, return PC. */ |
| 602 | |
| 603 | static CORE_ADDR |
| 604 | m68k_analyze_register_saves (CORE_ADDR pc, CORE_ADDR current_pc, |
| 605 | struct m68k_frame_cache *cache) |
| 606 | { |
| 607 | if (cache->locals >= 0) |
| 608 | { |
| 609 | CORE_ADDR offset; |
| 610 | int op; |
| 611 | int i, mask, regno; |
| 612 | |
| 613 | offset = -4 - cache->locals; |
| 614 | while (pc < current_pc) |
| 615 | { |
| 616 | op = read_memory_unsigned_integer (pc, 2); |
| 617 | if (op == P_FMOVEMX_SP) |
| 618 | { |
| 619 | /* fmovem.x REGS,-(%sp) */ |
| 620 | op = read_memory_unsigned_integer (pc + 2, 2); |
| 621 | if ((op & 0xff00) == 0xe000) |
| 622 | { |
| 623 | mask = op & 0xff; |
| 624 | for (i = 0; i < 16; i++, mask >>= 1) |
| 625 | { |
| 626 | if (mask & 1) |
| 627 | { |
| 628 | cache->saved_regs[i + M68K_FP0_REGNUM] = offset; |
| 629 | offset -= 12; |
| 630 | } |
| 631 | } |
| 632 | pc += 4; |
| 633 | } |
| 634 | else |
| 635 | break; |
| 636 | } |
| 637 | else if ((op & 0170677) == P_MOVEL_SP) |
| 638 | { |
| 639 | /* move.l %R,-(%sp) */ |
| 640 | regno = ((op & 07000) >> 9) | ((op & 0100) >> 3); |
| 641 | cache->saved_regs[regno] = offset; |
| 642 | offset -= 4; |
| 643 | pc += 2; |
| 644 | } |
| 645 | else if (op == P_MOVEML_SP) |
| 646 | { |
| 647 | /* movem.l REGS,-(%sp) */ |
| 648 | mask = read_memory_unsigned_integer (pc + 2, 2); |
| 649 | for (i = 0; i < 16; i++, mask >>= 1) |
| 650 | { |
| 651 | if (mask & 1) |
| 652 | { |
| 653 | cache->saved_regs[15 - i] = offset; |
| 654 | offset -= 4; |
| 655 | } |
| 656 | } |
| 657 | pc += 4; |
| 658 | } |
| 659 | else |
| 660 | break; |
| 661 | } |
| 662 | } |
| 663 | |
| 664 | return pc; |
| 665 | } |
| 666 | |
| 667 | |
| 668 | /* Do a full analysis of the prologue at PC and update CACHE |
| 669 | accordingly. Bail out early if CURRENT_PC is reached. Return the |
| 670 | address where the analysis stopped. |
| 671 | |
| 672 | We handle all cases that can be generated by gcc. |
| 673 | |
| 674 | For allocating a stack frame: |
| 675 | |
| 676 | link.w %a6,#-N |
| 677 | link.l %a6,#-N |
| 678 | pea (%fp); move.l %sp,%fp |
| 679 | link.w %a6,#0; add.l #-N,%sp |
| 680 | subq.l #N,%sp |
| 681 | subq.w #N,%sp |
| 682 | subq.w #8,%sp; subq.w #N-8,%sp |
| 683 | add.w #-N,%sp |
| 684 | lea (-N,%sp),%sp |
| 685 | add.l #-N,%sp |
| 686 | |
| 687 | For saving registers: |
| 688 | |
| 689 | fmovem.x REGS,-(%sp) |
| 690 | move.l R1,-(%sp) |
| 691 | move.l R1,-(%sp); move.l R2,-(%sp) |
| 692 | movem.l REGS,-(%sp) |
| 693 | |
| 694 | For setting up the PIC register: |
| 695 | |
| 696 | lea (%pc,N),%a5 |
| 697 | |
| 698 | */ |
| 699 | |
| 700 | static CORE_ADDR |
| 701 | m68k_analyze_prologue (CORE_ADDR pc, CORE_ADDR current_pc, |
| 702 | struct m68k_frame_cache *cache) |
| 703 | { |
| 704 | unsigned int op; |
| 705 | |
| 706 | pc = m68k_analyze_frame_setup (pc, current_pc, cache); |
| 707 | pc = m68k_analyze_register_saves (pc, current_pc, cache); |
| 708 | if (pc >= current_pc) |
| 709 | return current_pc; |
| 710 | |
| 711 | /* Check for GOT setup. */ |
| 712 | op = read_memory_unsigned_integer (pc, 4); |
| 713 | if (op == P_LEA_PC_A5) |
| 714 | { |
| 715 | /* lea (%pc,N),%a5 */ |
| 716 | return pc + 6; |
| 717 | } |
| 718 | |
| 719 | return pc; |
| 720 | } |
| 721 | |
| 722 | /* Return PC of first real instruction. */ |
| 723 | |
| 724 | static CORE_ADDR |
| 725 | m68k_skip_prologue (CORE_ADDR start_pc) |
| 726 | { |
| 727 | struct m68k_frame_cache cache; |
| 728 | CORE_ADDR pc; |
| 729 | int op; |
| 730 | |
| 731 | cache.locals = -1; |
| 732 | pc = m68k_analyze_prologue (start_pc, (CORE_ADDR) -1, &cache); |
| 733 | if (cache.locals < 0) |
| 734 | return start_pc; |
| 735 | return pc; |
| 736 | } |
| 737 | |
| 738 | static CORE_ADDR |
| 739 | m68k_unwind_pc (struct gdbarch *gdbarch, struct frame_info *next_frame) |
| 740 | { |
| 741 | gdb_byte buf[8]; |
| 742 | |
| 743 | frame_unwind_register (next_frame, PC_REGNUM, buf); |
| 744 | return extract_typed_address (buf, builtin_type_void_func_ptr); |
| 745 | } |
| 746 | \f |
| 747 | /* Normal frames. */ |
| 748 | |
| 749 | static struct m68k_frame_cache * |
| 750 | m68k_frame_cache (struct frame_info *next_frame, void **this_cache) |
| 751 | { |
| 752 | struct m68k_frame_cache *cache; |
| 753 | gdb_byte buf[4]; |
| 754 | int i; |
| 755 | |
| 756 | if (*this_cache) |
| 757 | return *this_cache; |
| 758 | |
| 759 | cache = m68k_alloc_frame_cache (); |
| 760 | *this_cache = cache; |
| 761 | |
| 762 | /* In principle, for normal frames, %fp holds the frame pointer, |
| 763 | which holds the base address for the current stack frame. |
| 764 | However, for functions that don't need it, the frame pointer is |
| 765 | optional. For these "frameless" functions the frame pointer is |
| 766 | actually the frame pointer of the calling frame. Signal |
| 767 | trampolines are just a special case of a "frameless" function. |
| 768 | They (usually) share their frame pointer with the frame that was |
| 769 | in progress when the signal occurred. */ |
| 770 | |
| 771 | frame_unwind_register (next_frame, M68K_FP_REGNUM, buf); |
| 772 | cache->base = extract_unsigned_integer (buf, 4); |
| 773 | if (cache->base == 0) |
| 774 | return cache; |
| 775 | |
| 776 | /* For normal frames, %pc is stored at 4(%fp). */ |
| 777 | cache->saved_regs[M68K_PC_REGNUM] = 4; |
| 778 | |
| 779 | cache->pc = frame_func_unwind (next_frame); |
| 780 | if (cache->pc != 0) |
| 781 | m68k_analyze_prologue (cache->pc, frame_pc_unwind (next_frame), cache); |
| 782 | |
| 783 | if (cache->locals < 0) |
| 784 | { |
| 785 | /* We didn't find a valid frame, which means that CACHE->base |
| 786 | currently holds the frame pointer for our calling frame. If |
| 787 | we're at the start of a function, or somewhere half-way its |
| 788 | prologue, the function's frame probably hasn't been fully |
| 789 | setup yet. Try to reconstruct the base address for the stack |
| 790 | frame by looking at the stack pointer. For truly "frameless" |
| 791 | functions this might work too. */ |
| 792 | |
| 793 | frame_unwind_register (next_frame, M68K_SP_REGNUM, buf); |
| 794 | cache->base = extract_unsigned_integer (buf, 4) + cache->sp_offset; |
| 795 | } |
| 796 | |
| 797 | /* Now that we have the base address for the stack frame we can |
| 798 | calculate the value of %sp in the calling frame. */ |
| 799 | cache->saved_sp = cache->base + 8; |
| 800 | |
| 801 | /* Adjust all the saved registers such that they contain addresses |
| 802 | instead of offsets. */ |
| 803 | for (i = 0; i < M68K_NUM_REGS; i++) |
| 804 | if (cache->saved_regs[i] != -1) |
| 805 | cache->saved_regs[i] += cache->base; |
| 806 | |
| 807 | return cache; |
| 808 | } |
| 809 | |
| 810 | static void |
| 811 | m68k_frame_this_id (struct frame_info *next_frame, void **this_cache, |
| 812 | struct frame_id *this_id) |
| 813 | { |
| 814 | struct m68k_frame_cache *cache = m68k_frame_cache (next_frame, this_cache); |
| 815 | |
| 816 | /* This marks the outermost frame. */ |
| 817 | if (cache->base == 0) |
| 818 | return; |
| 819 | |
| 820 | /* See the end of m68k_push_dummy_call. */ |
| 821 | *this_id = frame_id_build (cache->base + 8, cache->pc); |
| 822 | } |
| 823 | |
| 824 | static void |
| 825 | m68k_frame_prev_register (struct frame_info *next_frame, void **this_cache, |
| 826 | int regnum, int *optimizedp, |
| 827 | enum lval_type *lvalp, CORE_ADDR *addrp, |
| 828 | int *realnump, gdb_byte *valuep) |
| 829 | { |
| 830 | struct m68k_frame_cache *cache = m68k_frame_cache (next_frame, this_cache); |
| 831 | |
| 832 | gdb_assert (regnum >= 0); |
| 833 | |
| 834 | if (regnum == M68K_SP_REGNUM && cache->saved_sp) |
| 835 | { |
| 836 | *optimizedp = 0; |
| 837 | *lvalp = not_lval; |
| 838 | *addrp = 0; |
| 839 | *realnump = -1; |
| 840 | if (valuep) |
| 841 | { |
| 842 | /* Store the value. */ |
| 843 | store_unsigned_integer (valuep, 4, cache->saved_sp); |
| 844 | } |
| 845 | return; |
| 846 | } |
| 847 | |
| 848 | if (regnum < M68K_NUM_REGS && cache->saved_regs[regnum] != -1) |
| 849 | { |
| 850 | *optimizedp = 0; |
| 851 | *lvalp = lval_memory; |
| 852 | *addrp = cache->saved_regs[regnum]; |
| 853 | *realnump = -1; |
| 854 | if (valuep) |
| 855 | { |
| 856 | /* Read the value in from memory. */ |
| 857 | read_memory (*addrp, valuep, |
| 858 | register_size (current_gdbarch, regnum)); |
| 859 | } |
| 860 | return; |
| 861 | } |
| 862 | |
| 863 | *optimizedp = 0; |
| 864 | *lvalp = lval_register; |
| 865 | *addrp = 0; |
| 866 | *realnump = regnum; |
| 867 | if (valuep) |
| 868 | frame_unwind_register (next_frame, (*realnump), valuep); |
| 869 | } |
| 870 | |
| 871 | static const struct frame_unwind m68k_frame_unwind = |
| 872 | { |
| 873 | NORMAL_FRAME, |
| 874 | m68k_frame_this_id, |
| 875 | m68k_frame_prev_register |
| 876 | }; |
| 877 | |
| 878 | static const struct frame_unwind * |
| 879 | m68k_frame_sniffer (struct frame_info *next_frame) |
| 880 | { |
| 881 | return &m68k_frame_unwind; |
| 882 | } |
| 883 | \f |
| 884 | static CORE_ADDR |
| 885 | m68k_frame_base_address (struct frame_info *next_frame, void **this_cache) |
| 886 | { |
| 887 | struct m68k_frame_cache *cache = m68k_frame_cache (next_frame, this_cache); |
| 888 | |
| 889 | return cache->base; |
| 890 | } |
| 891 | |
| 892 | static const struct frame_base m68k_frame_base = |
| 893 | { |
| 894 | &m68k_frame_unwind, |
| 895 | m68k_frame_base_address, |
| 896 | m68k_frame_base_address, |
| 897 | m68k_frame_base_address |
| 898 | }; |
| 899 | |
| 900 | static struct frame_id |
| 901 | m68k_unwind_dummy_id (struct gdbarch *gdbarch, struct frame_info *next_frame) |
| 902 | { |
| 903 | gdb_byte buf[4]; |
| 904 | CORE_ADDR fp; |
| 905 | |
| 906 | frame_unwind_register (next_frame, M68K_FP_REGNUM, buf); |
| 907 | fp = extract_unsigned_integer (buf, 4); |
| 908 | |
| 909 | /* See the end of m68k_push_dummy_call. */ |
| 910 | return frame_id_build (fp + 8, frame_pc_unwind (next_frame)); |
| 911 | } |
| 912 | \f |
| 913 | #ifdef USE_PROC_FS /* Target dependent support for /proc */ |
| 914 | |
| 915 | #include <sys/procfs.h> |
| 916 | |
| 917 | /* Prototypes for supply_gregset etc. */ |
| 918 | #include "gregset.h" |
| 919 | |
| 920 | /* The /proc interface divides the target machine's register set up into |
| 921 | two different sets, the general register set (gregset) and the floating |
| 922 | point register set (fpregset). For each set, there is an ioctl to get |
| 923 | the current register set and another ioctl to set the current values. |
| 924 | |
| 925 | The actual structure passed through the ioctl interface is, of course, |
| 926 | naturally machine dependent, and is different for each set of registers. |
| 927 | For the m68k for example, the general register set is typically defined |
| 928 | by: |
| 929 | |
| 930 | typedef int gregset_t[18]; |
| 931 | |
| 932 | #define R_D0 0 |
| 933 | ... |
| 934 | #define R_PS 17 |
| 935 | |
| 936 | and the floating point set by: |
| 937 | |
| 938 | typedef struct fpregset { |
| 939 | int f_pcr; |
| 940 | int f_psr; |
| 941 | int f_fpiaddr; |
| 942 | int f_fpregs[8][3]; (8 regs, 96 bits each) |
| 943 | } fpregset_t; |
| 944 | |
| 945 | These routines provide the packing and unpacking of gregset_t and |
| 946 | fpregset_t formatted data. |
| 947 | |
| 948 | */ |
| 949 | |
| 950 | /* Atari SVR4 has R_SR but not R_PS */ |
| 951 | |
| 952 | #if !defined (R_PS) && defined (R_SR) |
| 953 | #define R_PS R_SR |
| 954 | #endif |
| 955 | |
| 956 | /* Given a pointer to a general register set in /proc format (gregset_t *), |
| 957 | unpack the register contents and supply them as gdb's idea of the current |
| 958 | register values. */ |
| 959 | |
| 960 | void |
| 961 | supply_gregset (gregset_t *gregsetp) |
| 962 | { |
| 963 | int regi; |
| 964 | greg_t *regp = (greg_t *) gregsetp; |
| 965 | |
| 966 | for (regi = 0; regi < R_PC; regi++) |
| 967 | { |
| 968 | regcache_raw_supply (current_regcache, regi, (char *) (regp + regi)); |
| 969 | } |
| 970 | regcache_raw_supply (current_regcache, PS_REGNUM, (char *) (regp + R_PS)); |
| 971 | regcache_raw_supply (current_regcache, PC_REGNUM, (char *) (regp + R_PC)); |
| 972 | } |
| 973 | |
| 974 | void |
| 975 | fill_gregset (gregset_t *gregsetp, int regno) |
| 976 | { |
| 977 | int regi; |
| 978 | greg_t *regp = (greg_t *) gregsetp; |
| 979 | |
| 980 | for (regi = 0; regi < R_PC; regi++) |
| 981 | { |
| 982 | if (regno == -1 || regno == regi) |
| 983 | regcache_raw_collect (current_regcache, regi, regp + regi); |
| 984 | } |
| 985 | if (regno == -1 || regno == PS_REGNUM) |
| 986 | regcache_raw_collect (current_regcache, PS_REGNUM, regp + R_PS); |
| 987 | if (regno == -1 || regno == PC_REGNUM) |
| 988 | regcache_raw_collect (current_regcache, PC_REGNUM, regp + R_PC); |
| 989 | } |
| 990 | |
| 991 | #if defined (FP0_REGNUM) |
| 992 | |
| 993 | /* Given a pointer to a floating point register set in /proc format |
| 994 | (fpregset_t *), unpack the register contents and supply them as gdb's |
| 995 | idea of the current floating point register values. */ |
| 996 | |
| 997 | void |
| 998 | supply_fpregset (fpregset_t *fpregsetp) |
| 999 | { |
| 1000 | int regi; |
| 1001 | char *from; |
| 1002 | |
| 1003 | for (regi = FP0_REGNUM; regi < M68K_FPC_REGNUM; regi++) |
| 1004 | { |
| 1005 | from = (char *) &(fpregsetp->f_fpregs[regi - FP0_REGNUM][0]); |
| 1006 | regcache_raw_supply (current_regcache, regi, from); |
| 1007 | } |
| 1008 | regcache_raw_supply (current_regcache, M68K_FPC_REGNUM, |
| 1009 | (char *) &(fpregsetp->f_pcr)); |
| 1010 | regcache_raw_supply (current_regcache, M68K_FPS_REGNUM, |
| 1011 | (char *) &(fpregsetp->f_psr)); |
| 1012 | regcache_raw_supply (current_regcache, M68K_FPI_REGNUM, |
| 1013 | (char *) &(fpregsetp->f_fpiaddr)); |
| 1014 | } |
| 1015 | |
| 1016 | /* Given a pointer to a floating point register set in /proc format |
| 1017 | (fpregset_t *), update the register specified by REGNO from gdb's idea |
| 1018 | of the current floating point register set. If REGNO is -1, update |
| 1019 | them all. */ |
| 1020 | |
| 1021 | void |
| 1022 | fill_fpregset (fpregset_t *fpregsetp, int regno) |
| 1023 | { |
| 1024 | int regi; |
| 1025 | |
| 1026 | for (regi = FP0_REGNUM; regi < M68K_FPC_REGNUM; regi++) |
| 1027 | { |
| 1028 | if (regno == -1 || regno == regi) |
| 1029 | regcache_raw_collect (current_regcache, regi, |
| 1030 | &fpregsetp->f_fpregs[regi - FP0_REGNUM][0]); |
| 1031 | } |
| 1032 | if (regno == -1 || regno == M68K_FPC_REGNUM) |
| 1033 | regcache_raw_collect (current_regcache, M68K_FPC_REGNUM, |
| 1034 | &fpregsetp->f_pcr); |
| 1035 | if (regno == -1 || regno == M68K_FPS_REGNUM) |
| 1036 | regcache_raw_collect (current_regcache, M68K_FPS_REGNUM, |
| 1037 | &fpregsetp->f_psr); |
| 1038 | if (regno == -1 || regno == M68K_FPI_REGNUM) |
| 1039 | regcache_raw_collect (current_regcache, M68K_FPI_REGNUM, |
| 1040 | &fpregsetp->f_fpiaddr); |
| 1041 | } |
| 1042 | |
| 1043 | #endif /* defined (FP0_REGNUM) */ |
| 1044 | |
| 1045 | #endif /* USE_PROC_FS */ |
| 1046 | |
| 1047 | /* Figure out where the longjmp will land. Slurp the args out of the stack. |
| 1048 | We expect the first arg to be a pointer to the jmp_buf structure from which |
| 1049 | we extract the pc (JB_PC) that we will land at. The pc is copied into PC. |
| 1050 | This routine returns true on success. */ |
| 1051 | |
| 1052 | static int |
| 1053 | m68k_get_longjmp_target (CORE_ADDR *pc) |
| 1054 | { |
| 1055 | gdb_byte *buf; |
| 1056 | CORE_ADDR sp, jb_addr; |
| 1057 | struct gdbarch_tdep *tdep = gdbarch_tdep (current_gdbarch); |
| 1058 | |
| 1059 | if (tdep->jb_pc < 0) |
| 1060 | { |
| 1061 | internal_error (__FILE__, __LINE__, |
| 1062 | _("m68k_get_longjmp_target: not implemented")); |
| 1063 | return 0; |
| 1064 | } |
| 1065 | |
| 1066 | buf = alloca (TARGET_PTR_BIT / TARGET_CHAR_BIT); |
| 1067 | sp = read_register (SP_REGNUM); |
| 1068 | |
| 1069 | if (target_read_memory (sp + SP_ARG0, /* Offset of first arg on stack */ |
| 1070 | buf, TARGET_PTR_BIT / TARGET_CHAR_BIT)) |
| 1071 | return 0; |
| 1072 | |
| 1073 | jb_addr = extract_unsigned_integer (buf, TARGET_PTR_BIT / TARGET_CHAR_BIT); |
| 1074 | |
| 1075 | if (target_read_memory (jb_addr + tdep->jb_pc * tdep->jb_elt_size, buf, |
| 1076 | TARGET_PTR_BIT / TARGET_CHAR_BIT)) |
| 1077 | return 0; |
| 1078 | |
| 1079 | *pc = extract_unsigned_integer (buf, TARGET_PTR_BIT / TARGET_CHAR_BIT); |
| 1080 | return 1; |
| 1081 | } |
| 1082 | \f |
| 1083 | |
| 1084 | /* System V Release 4 (SVR4). */ |
| 1085 | |
| 1086 | void |
| 1087 | m68k_svr4_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch) |
| 1088 | { |
| 1089 | struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); |
| 1090 | |
| 1091 | /* SVR4 uses a different calling convention. */ |
| 1092 | set_gdbarch_return_value (gdbarch, m68k_svr4_return_value); |
| 1093 | |
| 1094 | /* SVR4 uses %a0 instead of %a1. */ |
| 1095 | tdep->struct_value_regnum = M68K_A0_REGNUM; |
| 1096 | } |
| 1097 | \f |
| 1098 | |
| 1099 | /* Function: m68k_gdbarch_init |
| 1100 | Initializer function for the m68k gdbarch vector. |
| 1101 | Called by gdbarch. Sets up the gdbarch vector(s) for this target. */ |
| 1102 | |
| 1103 | static struct gdbarch * |
| 1104 | m68k_gdbarch_init (struct gdbarch_info info, struct gdbarch_list *arches) |
| 1105 | { |
| 1106 | struct gdbarch_tdep *tdep = NULL; |
| 1107 | struct gdbarch *gdbarch; |
| 1108 | |
| 1109 | /* find a candidate among the list of pre-declared architectures. */ |
| 1110 | arches = gdbarch_list_lookup_by_info (arches, &info); |
| 1111 | if (arches != NULL) |
| 1112 | return (arches->gdbarch); |
| 1113 | |
| 1114 | tdep = xmalloc (sizeof (struct gdbarch_tdep)); |
| 1115 | gdbarch = gdbarch_alloc (&info, tdep); |
| 1116 | |
| 1117 | set_gdbarch_long_double_format (gdbarch, &floatformat_m68881_ext); |
| 1118 | set_gdbarch_long_double_bit (gdbarch, 96); |
| 1119 | |
| 1120 | set_gdbarch_skip_prologue (gdbarch, m68k_skip_prologue); |
| 1121 | set_gdbarch_breakpoint_from_pc (gdbarch, m68k_local_breakpoint_from_pc); |
| 1122 | |
| 1123 | /* Stack grows down. */ |
| 1124 | set_gdbarch_inner_than (gdbarch, core_addr_lessthan); |
| 1125 | |
| 1126 | set_gdbarch_believe_pcc_promotion (gdbarch, 1); |
| 1127 | set_gdbarch_decr_pc_after_break (gdbarch, 2); |
| 1128 | |
| 1129 | set_gdbarch_frame_args_skip (gdbarch, 8); |
| 1130 | |
| 1131 | set_gdbarch_register_type (gdbarch, m68k_register_type); |
| 1132 | set_gdbarch_register_name (gdbarch, m68k_register_name); |
| 1133 | set_gdbarch_num_regs (gdbarch, 29); |
| 1134 | set_gdbarch_register_bytes_ok (gdbarch, m68k_register_bytes_ok); |
| 1135 | set_gdbarch_sp_regnum (gdbarch, M68K_SP_REGNUM); |
| 1136 | set_gdbarch_pc_regnum (gdbarch, M68K_PC_REGNUM); |
| 1137 | set_gdbarch_ps_regnum (gdbarch, M68K_PS_REGNUM); |
| 1138 | set_gdbarch_fp0_regnum (gdbarch, M68K_FP0_REGNUM); |
| 1139 | set_gdbarch_convert_register_p (gdbarch, m68k_convert_register_p); |
| 1140 | set_gdbarch_register_to_value (gdbarch, m68k_register_to_value); |
| 1141 | set_gdbarch_value_to_register (gdbarch, m68k_value_to_register); |
| 1142 | |
| 1143 | set_gdbarch_push_dummy_call (gdbarch, m68k_push_dummy_call); |
| 1144 | set_gdbarch_return_value (gdbarch, m68k_return_value); |
| 1145 | |
| 1146 | /* Disassembler. */ |
| 1147 | set_gdbarch_print_insn (gdbarch, print_insn_m68k); |
| 1148 | |
| 1149 | #if defined JB_PC && defined JB_ELEMENT_SIZE |
| 1150 | tdep->jb_pc = JB_PC; |
| 1151 | tdep->jb_elt_size = JB_ELEMENT_SIZE; |
| 1152 | #else |
| 1153 | tdep->jb_pc = -1; |
| 1154 | #endif |
| 1155 | tdep->struct_value_regnum = M68K_A1_REGNUM; |
| 1156 | tdep->struct_return = reg_struct_return; |
| 1157 | |
| 1158 | /* Frame unwinder. */ |
| 1159 | set_gdbarch_unwind_dummy_id (gdbarch, m68k_unwind_dummy_id); |
| 1160 | set_gdbarch_unwind_pc (gdbarch, m68k_unwind_pc); |
| 1161 | |
| 1162 | /* Hook in the DWARF CFI frame unwinder. */ |
| 1163 | frame_unwind_append_sniffer (gdbarch, dwarf2_frame_sniffer); |
| 1164 | |
| 1165 | frame_base_set_default (gdbarch, &m68k_frame_base); |
| 1166 | |
| 1167 | /* Hook in ABI-specific overrides, if they have been registered. */ |
| 1168 | gdbarch_init_osabi (info, gdbarch); |
| 1169 | |
| 1170 | /* Now we have tuned the configuration, set a few final things, |
| 1171 | based on what the OS ABI has told us. */ |
| 1172 | |
| 1173 | if (tdep->jb_pc >= 0) |
| 1174 | set_gdbarch_get_longjmp_target (gdbarch, m68k_get_longjmp_target); |
| 1175 | |
| 1176 | frame_unwind_append_sniffer (gdbarch, m68k_frame_sniffer); |
| 1177 | |
| 1178 | return gdbarch; |
| 1179 | } |
| 1180 | |
| 1181 | |
| 1182 | static void |
| 1183 | m68k_dump_tdep (struct gdbarch *current_gdbarch, struct ui_file *file) |
| 1184 | { |
| 1185 | struct gdbarch_tdep *tdep = gdbarch_tdep (current_gdbarch); |
| 1186 | |
| 1187 | if (tdep == NULL) |
| 1188 | return; |
| 1189 | } |
| 1190 | |
| 1191 | extern initialize_file_ftype _initialize_m68k_tdep; /* -Wmissing-prototypes */ |
| 1192 | |
| 1193 | void |
| 1194 | _initialize_m68k_tdep (void) |
| 1195 | { |
| 1196 | gdbarch_register (bfd_arch_m68k, m68k_gdbarch_init, m68k_dump_tdep); |
| 1197 | } |