| 1 | /* Target-machine dependent code for Zilog Z8000, for GDB. |
| 2 | Copyright (C) 1992, 1993, 1994 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., 675 Mass Ave, Cambridge, MA 02139, USA. */ |
| 19 | |
| 20 | /* |
| 21 | Contributed by Steve Chamberlain |
| 22 | sac@cygnus.com |
| 23 | */ |
| 24 | |
| 25 | #include "defs.h" |
| 26 | #include "frame.h" |
| 27 | #include "obstack.h" |
| 28 | #include "symtab.h" |
| 29 | #include "gdbcmd.h" |
| 30 | #include "gdbtypes.h" |
| 31 | #include "dis-asm.h" |
| 32 | |
| 33 | /* Return the saved PC from this frame. |
| 34 | |
| 35 | If the frame has a memory copy of SRP_REGNUM, use that. If not, |
| 36 | just use the register SRP_REGNUM itself. */ |
| 37 | |
| 38 | CORE_ADDR |
| 39 | frame_saved_pc (frame) |
| 40 | struct frame_info *frame; |
| 41 | { |
| 42 | return read_memory_pointer (frame->frame + (BIG ? 4 : 2)); |
| 43 | } |
| 44 | |
| 45 | #define IS_PUSHL(x) (BIG ? ((x & 0xfff0) == 0x91e0):((x & 0xfff0) == 0x91F0)) |
| 46 | #define IS_PUSHW(x) (BIG ? ((x & 0xfff0) == 0x93e0):((x & 0xfff0)==0x93f0)) |
| 47 | #define IS_MOVE_FP(x) (BIG ? x == 0xa1ea : x == 0xa1fa) |
| 48 | #define IS_MOV_SP_FP(x) (BIG ? x == 0x94ea : x == 0x0d76) |
| 49 | #define IS_SUB2_SP(x) (x==0x1b87) |
| 50 | #define IS_MOVK_R5(x) (x==0x7905) |
| 51 | #define IS_SUB_SP(x) ((x & 0xffff) == 0x020f) |
| 52 | #define IS_PUSH_FP(x) (BIG ? (x == 0x93ea) : (x == 0x93fa)) |
| 53 | |
| 54 | /* work out how much local space is on the stack and |
| 55 | return the pc pointing to the first push */ |
| 56 | |
| 57 | static CORE_ADDR |
| 58 | skip_adjust (pc, size) |
| 59 | CORE_ADDR pc; |
| 60 | int *size; |
| 61 | { |
| 62 | *size = 0; |
| 63 | |
| 64 | if (IS_PUSH_FP (read_memory_short (pc)) |
| 65 | && IS_MOV_SP_FP (read_memory_short (pc + 2))) |
| 66 | { |
| 67 | /* This is a function with an explict frame pointer */ |
| 68 | pc += 4; |
| 69 | *size += 2; /* remember the frame pointer */ |
| 70 | } |
| 71 | |
| 72 | /* remember any stack adjustment */ |
| 73 | if (IS_SUB_SP (read_memory_short (pc))) |
| 74 | { |
| 75 | *size += read_memory_short (pc + 2); |
| 76 | pc += 4; |
| 77 | } |
| 78 | return pc; |
| 79 | } |
| 80 | |
| 81 | int |
| 82 | examine_frame (pc, regs, sp) |
| 83 | CORE_ADDR pc; |
| 84 | struct frame_saved_regs *regs; |
| 85 | CORE_ADDR sp; |
| 86 | { |
| 87 | int w = read_memory_short (pc); |
| 88 | int offset = 0; |
| 89 | int regno; |
| 90 | |
| 91 | for (regno = 0; regno < NUM_REGS; regno++) |
| 92 | regs->regs[regno] = 0; |
| 93 | |
| 94 | while (IS_PUSHW (w) || IS_PUSHL (w)) |
| 95 | { |
| 96 | /* work out which register is being pushed to where */ |
| 97 | if (IS_PUSHL (w)) |
| 98 | { |
| 99 | regs->regs[w & 0xf] = offset; |
| 100 | regs->regs[(w & 0xf) + 1] = offset + 2; |
| 101 | offset += 4; |
| 102 | } |
| 103 | else |
| 104 | { |
| 105 | regs->regs[w & 0xf] = offset; |
| 106 | offset += 2; |
| 107 | } |
| 108 | pc += 2; |
| 109 | w = read_memory_short (pc); |
| 110 | } |
| 111 | |
| 112 | if (IS_MOVE_FP (w)) |
| 113 | { |
| 114 | /* We know the fp */ |
| 115 | |
| 116 | } |
| 117 | else if (IS_SUB_SP (w)) |
| 118 | { |
| 119 | /* Subtracting a value from the sp, so were in a function |
| 120 | which needs stack space for locals, but has no fp. We fake up |
| 121 | the values as if we had an fp */ |
| 122 | regs->regs[FP_REGNUM] = sp; |
| 123 | } |
| 124 | else |
| 125 | { |
| 126 | /* This one didn't have an fp, we'll fake it up */ |
| 127 | regs->regs[SP_REGNUM] = sp; |
| 128 | } |
| 129 | /* stack pointer contains address of next frame */ |
| 130 | /* regs->regs[fp_regnum()] = fp;*/ |
| 131 | regs->regs[SP_REGNUM] = sp; |
| 132 | return pc; |
| 133 | } |
| 134 | |
| 135 | CORE_ADDR |
| 136 | z8k_skip_prologue (start_pc) |
| 137 | CORE_ADDR start_pc; |
| 138 | { |
| 139 | struct frame_saved_regs dummy; |
| 140 | |
| 141 | return examine_frame (start_pc, &dummy, 0); |
| 142 | } |
| 143 | |
| 144 | CORE_ADDR |
| 145 | addr_bits_remove (x) |
| 146 | CORE_ADDR x; |
| 147 | { |
| 148 | return x & PTR_MASK; |
| 149 | } |
| 150 | |
| 151 | int |
| 152 | read_memory_pointer (x) |
| 153 | CORE_ADDR x; |
| 154 | { |
| 155 | return read_memory_integer (ADDR_BITS_REMOVE (x), BIG ? 4 : 2); |
| 156 | } |
| 157 | |
| 158 | CORE_ADDR |
| 159 | frame_chain (thisframe) |
| 160 | struct frame_info *thisframe; |
| 161 | { |
| 162 | if (thisframe->prev == 0) |
| 163 | { |
| 164 | /* This is the top of the stack, let's get the sp for real */ |
| 165 | } |
| 166 | if (!inside_entry_file (thisframe->pc)) |
| 167 | { |
| 168 | return read_memory_pointer (thisframe->frame); |
| 169 | } |
| 170 | return 0; |
| 171 | } |
| 172 | |
| 173 | init_frame_pc () |
| 174 | { |
| 175 | abort (); |
| 176 | } |
| 177 | |
| 178 | /* Put here the code to store, into a struct frame_saved_regs, |
| 179 | the addresses of the saved registers of frame described by FRAME_INFO. |
| 180 | This includes special registers such as pc and fp saved in special |
| 181 | ways in the stack frame. sp is even more special: |
| 182 | the address we return for it IS the sp for the next frame. */ |
| 183 | |
| 184 | void |
| 185 | get_frame_saved_regs (frame_info, frame_saved_regs) |
| 186 | struct frame_info *frame_info; |
| 187 | struct frame_saved_regs *frame_saved_regs; |
| 188 | |
| 189 | { |
| 190 | CORE_ADDR pc; |
| 191 | int w; |
| 192 | |
| 193 | memset (frame_saved_regs, '\0', sizeof (*frame_saved_regs)); |
| 194 | pc = get_pc_function_start (frame_info->pc); |
| 195 | |
| 196 | /* wander down the instruction stream */ |
| 197 | examine_frame (pc, frame_saved_regs, frame_info->frame); |
| 198 | |
| 199 | } |
| 200 | |
| 201 | void |
| 202 | z8k_push_dummy_frame () |
| 203 | { |
| 204 | abort (); |
| 205 | } |
| 206 | |
| 207 | int |
| 208 | gdb_print_insn_z8k (memaddr, info) |
| 209 | bfd_vma memaddr; |
| 210 | disassemble_info *info; |
| 211 | { |
| 212 | if (BIG) |
| 213 | return print_insn_z8001 (memaddr, info); |
| 214 | else |
| 215 | return print_insn_z8002 (memaddr, info); |
| 216 | } |
| 217 | |
| 218 | /* Fetch the instruction at ADDR, returning 0 if ADDR is beyond LIM or |
| 219 | is not the address of a valid instruction, the address of the next |
| 220 | instruction beyond ADDR otherwise. *PWORD1 receives the first word |
| 221 | of the instruction.*/ |
| 222 | |
| 223 | CORE_ADDR |
| 224 | NEXT_PROLOGUE_INSN (addr, lim, pword1) |
| 225 | CORE_ADDR addr; |
| 226 | CORE_ADDR lim; |
| 227 | short *pword1; |
| 228 | { |
| 229 | char buf[2]; |
| 230 | if (addr < lim + 8) |
| 231 | { |
| 232 | read_memory (addr, buf, 2); |
| 233 | *pword1 = extract_signed_integer (buf, 2); |
| 234 | |
| 235 | return addr + 2; |
| 236 | } |
| 237 | return 0; |
| 238 | } |
| 239 | |
| 240 | /* Put here the code to store, into a struct frame_saved_regs, |
| 241 | the addresses of the saved registers of frame described by FRAME_INFO. |
| 242 | This includes special registers such as pc and fp saved in special |
| 243 | ways in the stack frame. sp is even more special: |
| 244 | the address we return for it IS the sp for the next frame. |
| 245 | |
| 246 | We cache the result of doing this in the frame_cache_obstack, since |
| 247 | it is fairly expensive. */ |
| 248 | |
| 249 | void |
| 250 | frame_find_saved_regs (fip, fsrp) |
| 251 | struct frame_info *fip; |
| 252 | struct frame_saved_regs *fsrp; |
| 253 | { |
| 254 | int locals; |
| 255 | CORE_ADDR pc; |
| 256 | CORE_ADDR adr; |
| 257 | int i; |
| 258 | |
| 259 | memset (fsrp, 0, sizeof *fsrp); |
| 260 | |
| 261 | pc = skip_adjust (get_pc_function_start (fip->pc), &locals); |
| 262 | |
| 263 | { |
| 264 | adr = FRAME_FP (fip) - locals; |
| 265 | for (i = 0; i < 8; i++) |
| 266 | { |
| 267 | int word = read_memory_short (pc); |
| 268 | |
| 269 | pc += 2; |
| 270 | if (IS_PUSHL (word)) |
| 271 | { |
| 272 | fsrp->regs[word & 0xf] = adr; |
| 273 | fsrp->regs[(word & 0xf) + 1] = adr - 2; |
| 274 | adr -= 4; |
| 275 | } |
| 276 | else if (IS_PUSHW (word)) |
| 277 | { |
| 278 | fsrp->regs[word & 0xf] = adr; |
| 279 | adr -= 2; |
| 280 | } |
| 281 | else |
| 282 | break; |
| 283 | } |
| 284 | |
| 285 | } |
| 286 | |
| 287 | fsrp->regs[PC_REGNUM] = fip->frame + 4; |
| 288 | fsrp->regs[FP_REGNUM] = fip->frame; |
| 289 | |
| 290 | } |
| 291 | |
| 292 | int |
| 293 | saved_pc_after_call () |
| 294 | { |
| 295 | return addr_bits_remove |
| 296 | (read_memory_integer (read_register (SP_REGNUM), PTR_SIZE)); |
| 297 | } |
| 298 | |
| 299 | |
| 300 | extract_return_value (type, regbuf, valbuf) |
| 301 | struct type *type; |
| 302 | char *regbuf; |
| 303 | char *valbuf; |
| 304 | { |
| 305 | int b; |
| 306 | int len = TYPE_LENGTH (type); |
| 307 | |
| 308 | for (b = 0; b < len; b += 2) |
| 309 | { |
| 310 | int todo = len - b; |
| 311 | |
| 312 | if (todo > 2) |
| 313 | todo = 2; |
| 314 | memcpy (valbuf + b, regbuf + b, todo); |
| 315 | } |
| 316 | } |
| 317 | |
| 318 | void |
| 319 | write_return_value (type, valbuf) |
| 320 | struct type *type; |
| 321 | char *valbuf; |
| 322 | { |
| 323 | int reg; |
| 324 | int len; |
| 325 | |
| 326 | for (len = 0; len < TYPE_LENGTH (type); len += 2) |
| 327 | write_register_bytes (REGISTER_BYTE (len / 2 + 2), valbuf + len, 2); |
| 328 | } |
| 329 | |
| 330 | void |
| 331 | store_struct_return (addr, sp) |
| 332 | CORE_ADDR addr; |
| 333 | CORE_ADDR sp; |
| 334 | { |
| 335 | write_register (2, addr); |
| 336 | } |
| 337 | |
| 338 | |
| 339 | void |
| 340 | print_register_hook (regno) |
| 341 | int regno; |
| 342 | { |
| 343 | if ((regno & 1) == 0 && regno < 16) |
| 344 | { |
| 345 | unsigned short l[2]; |
| 346 | |
| 347 | read_relative_register_raw_bytes (regno, (char *) (l + 0)); |
| 348 | read_relative_register_raw_bytes (regno + 1, (char *) (l + 1)); |
| 349 | printf_unfiltered ("\t"); |
| 350 | printf_unfiltered ("%04x%04x", l[0], l[1]); |
| 351 | } |
| 352 | |
| 353 | if ((regno & 3) == 0 && regno < 16) |
| 354 | { |
| 355 | unsigned short l[4]; |
| 356 | |
| 357 | read_relative_register_raw_bytes (regno, (char *) (l + 0)); |
| 358 | read_relative_register_raw_bytes (regno + 1, (char *) (l + 1)); |
| 359 | read_relative_register_raw_bytes (regno + 2, (char *) (l + 2)); |
| 360 | read_relative_register_raw_bytes (regno + 3, (char *) (l + 3)); |
| 361 | |
| 362 | printf_unfiltered ("\t"); |
| 363 | printf_unfiltered ("%04x%04x%04x%04x", l[0], l[1], l[2], l[3]); |
| 364 | } |
| 365 | if (regno == 15) |
| 366 | { |
| 367 | unsigned short rval; |
| 368 | int i; |
| 369 | |
| 370 | read_relative_register_raw_bytes (regno, (char *) (&rval)); |
| 371 | |
| 372 | printf_unfiltered ("\n"); |
| 373 | for (i = 0; i < 10; i += 2) |
| 374 | { |
| 375 | printf_unfiltered ("(sp+%d=%04x)", i, read_memory_short (rval + i)); |
| 376 | } |
| 377 | } |
| 378 | |
| 379 | } |
| 380 | |
| 381 | void |
| 382 | z8k_pop_frame () |
| 383 | { |
| 384 | } |
| 385 | |
| 386 | struct cmd_list_element *setmemorylist; |
| 387 | |
| 388 | void |
| 389 | z8k_set_pointer_size (newsize) |
| 390 | int newsize; |
| 391 | { |
| 392 | static int oldsize = 0; |
| 393 | |
| 394 | if (oldsize != newsize) |
| 395 | { |
| 396 | printf_unfiltered ("pointer size set to %d bits\n", newsize); |
| 397 | oldsize = newsize; |
| 398 | if (newsize == 32) |
| 399 | { |
| 400 | BIG = 1; |
| 401 | } |
| 402 | else |
| 403 | { |
| 404 | BIG = 0; |
| 405 | } |
| 406 | _initialize_gdbtypes (); |
| 407 | } |
| 408 | } |
| 409 | |
| 410 | static void |
| 411 | segmented_command (args, from_tty) |
| 412 | char *args; |
| 413 | int from_tty; |
| 414 | { |
| 415 | z8k_set_pointer_size (32); |
| 416 | } |
| 417 | |
| 418 | static void |
| 419 | unsegmented_command (args, from_tty) |
| 420 | char *args; |
| 421 | int from_tty; |
| 422 | { |
| 423 | z8k_set_pointer_size (16); |
| 424 | } |
| 425 | |
| 426 | static void |
| 427 | set_memory (args, from_tty) |
| 428 | char *args; |
| 429 | int from_tty; |
| 430 | { |
| 431 | printf_unfiltered ("\"set memory\" must be followed by the name of a memory subcommand.\n"); |
| 432 | help_list (setmemorylist, "set memory ", -1, gdb_stdout); |
| 433 | } |
| 434 | |
| 435 | void |
| 436 | _initialize_z8ktdep () |
| 437 | { |
| 438 | tm_print_insn = gdb_print_insn_z8k; |
| 439 | |
| 440 | add_prefix_cmd ("memory", no_class, set_memory, |
| 441 | "set the memory model", &setmemorylist, "set memory ", 0, |
| 442 | &setlist); |
| 443 | add_cmd ("segmented", class_support, segmented_command, |
| 444 | "Set segmented memory model.", &setmemorylist); |
| 445 | add_cmd ("unsegmented", class_support, unsegmented_command, |
| 446 | "Set unsegmented memory model.", &setmemorylist); |
| 447 | |
| 448 | } |