| 1 | /* Target-machine dependent code for Hitachi H8/300, for GDB. |
| 2 | Copyright (C) 1988, 1990, 1991 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 "dis-asm.h" |
| 30 | #include "gdbcmd.h" |
| 31 | #include "gdbtypes.h" |
| 32 | |
| 33 | #undef NUM_REGS |
| 34 | #define NUM_REGS 11 |
| 35 | |
| 36 | #define UNSIGNED_SHORT(X) ((X) & 0xffff) |
| 37 | |
| 38 | /* an easy to debug H8 stack frame looks like: |
| 39 | 0x6df6 push r6 |
| 40 | 0x0d76 mov.w r7,r6 |
| 41 | 0x6dfn push reg |
| 42 | 0x7905 nnnn mov.w #n,r5 or 0x1b87 subs #2,sp |
| 43 | 0x1957 sub.w r5,sp |
| 44 | |
| 45 | */ |
| 46 | |
| 47 | #define IS_PUSH(x) ((x & 0xff00)==0x6d00) |
| 48 | #define IS_PUSH_FP(x) (x == 0x6df6) |
| 49 | #define IS_MOVE_FP(x) (x == 0x0d76) |
| 50 | #define IS_MOV_SP_FP(x) (x == 0x0d76) |
| 51 | #define IS_SUB2_SP(x) (x==0x1b87) |
| 52 | #define IS_MOVK_R5(x) (x==0x7905) |
| 53 | #define IS_SUB_R5SP(x) (x==0x1957) |
| 54 | |
| 55 | static CORE_ADDR examine_prologue (); |
| 56 | |
| 57 | void frame_find_saved_regs (); |
| 58 | CORE_ADDR |
| 59 | h8300_skip_prologue (start_pc) |
| 60 | CORE_ADDR start_pc; |
| 61 | { |
| 62 | short int w; |
| 63 | |
| 64 | w = read_memory_unsigned_integer (start_pc, 2); |
| 65 | /* Skip past all push insns */ |
| 66 | while (IS_PUSH_FP (w)) |
| 67 | { |
| 68 | start_pc += 2; |
| 69 | w = read_memory_unsigned_integer (start_pc, 2); |
| 70 | } |
| 71 | |
| 72 | /* Skip past a move to FP */ |
| 73 | if (IS_MOVE_FP (w)) |
| 74 | { |
| 75 | start_pc += 2; |
| 76 | w = read_memory_unsigned_integer (start_pc, 2); |
| 77 | } |
| 78 | |
| 79 | /* Skip the stack adjust */ |
| 80 | |
| 81 | if (IS_MOVK_R5 (w)) |
| 82 | { |
| 83 | start_pc += 2; |
| 84 | w = read_memory_unsigned_integer (start_pc, 2); |
| 85 | } |
| 86 | if (IS_SUB_R5SP (w)) |
| 87 | { |
| 88 | start_pc += 2; |
| 89 | w = read_memory_unsigned_integer (start_pc, 2); |
| 90 | } |
| 91 | while (IS_SUB2_SP (w)) |
| 92 | { |
| 93 | start_pc += 2; |
| 94 | w = read_memory_unsigned_integer (start_pc, 2); |
| 95 | } |
| 96 | |
| 97 | return start_pc; |
| 98 | } |
| 99 | |
| 100 | int |
| 101 | gdb_print_insn_h8300 (memaddr, info) |
| 102 | bfd_vma memaddr; |
| 103 | disassemble_info *info; |
| 104 | { |
| 105 | if (h8300hmode) |
| 106 | return print_insn_h8300h (memaddr, info); |
| 107 | else |
| 108 | return print_insn_h8300 (memaddr, info); |
| 109 | } |
| 110 | |
| 111 | /* Given a GDB frame, determine the address of the calling function's frame. |
| 112 | This will be used to create a new GDB frame struct, and then |
| 113 | INIT_EXTRA_FRAME_INFO and INIT_FRAME_PC will be called for the new frame. |
| 114 | |
| 115 | For us, the frame address is its stack pointer value, so we look up |
| 116 | the function prologue to determine the caller's sp value, and return it. */ |
| 117 | |
| 118 | CORE_ADDR |
| 119 | h8300_frame_chain (thisframe) |
| 120 | struct frame_info *thisframe; |
| 121 | { |
| 122 | frame_find_saved_regs (thisframe, (struct frame_saved_regs *) 0); |
| 123 | return thisframe->fsr->regs[SP_REGNUM]; |
| 124 | } |
| 125 | |
| 126 | /* Put here the code to store, into a struct frame_saved_regs, |
| 127 | the addresses of the saved registers of frame described by FRAME_INFO. |
| 128 | This includes special registers such as pc and fp saved in special |
| 129 | ways in the stack frame. sp is even more special: |
| 130 | the address we return for it IS the sp for the next frame. |
| 131 | |
| 132 | We cache the result of doing this in the frame_cache_obstack, since |
| 133 | it is fairly expensive. */ |
| 134 | |
| 135 | void |
| 136 | frame_find_saved_regs (fi, fsr) |
| 137 | struct frame_info *fi; |
| 138 | struct frame_saved_regs *fsr; |
| 139 | { |
| 140 | register CORE_ADDR next_addr; |
| 141 | register CORE_ADDR *saved_regs; |
| 142 | register int regnum; |
| 143 | register struct frame_saved_regs *cache_fsr; |
| 144 | extern struct obstack frame_cache_obstack; |
| 145 | CORE_ADDR ip; |
| 146 | struct symtab_and_line sal; |
| 147 | CORE_ADDR limit; |
| 148 | |
| 149 | if (!fi->fsr) |
| 150 | { |
| 151 | cache_fsr = (struct frame_saved_regs *) |
| 152 | obstack_alloc (&frame_cache_obstack, |
| 153 | sizeof (struct frame_saved_regs)); |
| 154 | memset (cache_fsr, '\0', sizeof (struct frame_saved_regs)); |
| 155 | |
| 156 | fi->fsr = cache_fsr; |
| 157 | |
| 158 | /* Find the start and end of the function prologue. If the PC |
| 159 | is in the function prologue, we only consider the part that |
| 160 | has executed already. */ |
| 161 | |
| 162 | ip = get_pc_function_start (fi->pc); |
| 163 | sal = find_pc_line (ip, 0); |
| 164 | limit = (sal.end && sal.end < fi->pc) ? sal.end : fi->pc; |
| 165 | |
| 166 | /* This will fill in fields in *fi as well as in cache_fsr. */ |
| 167 | examine_prologue (ip, limit, fi->frame, cache_fsr, fi); |
| 168 | } |
| 169 | |
| 170 | if (fsr) |
| 171 | *fsr = *fi->fsr; |
| 172 | } |
| 173 | |
| 174 | /* Fetch the instruction at ADDR, returning 0 if ADDR is beyond LIM or |
| 175 | is not the address of a valid instruction, the address of the next |
| 176 | instruction beyond ADDR otherwise. *PWORD1 receives the first word |
| 177 | of the instruction.*/ |
| 178 | |
| 179 | CORE_ADDR |
| 180 | NEXT_PROLOGUE_INSN (addr, lim, pword1) |
| 181 | CORE_ADDR addr; |
| 182 | CORE_ADDR lim; |
| 183 | INSN_WORD *pword1; |
| 184 | { |
| 185 | char buf[2]; |
| 186 | if (addr < lim + 8) |
| 187 | { |
| 188 | read_memory (addr, buf, 2); |
| 189 | *pword1 = extract_signed_integer (buf, 2); |
| 190 | |
| 191 | return addr + 2; |
| 192 | } |
| 193 | return 0; |
| 194 | } |
| 195 | |
| 196 | /* Examine the prologue of a function. `ip' points to the first instruction. |
| 197 | `limit' is the limit of the prologue (e.g. the addr of the first |
| 198 | linenumber, or perhaps the program counter if we're stepping through). |
| 199 | `frame_sp' is the stack pointer value in use in this frame. |
| 200 | `fsr' is a pointer to a frame_saved_regs structure into which we put |
| 201 | info about the registers saved by this frame. |
| 202 | `fi' is a struct frame_info pointer; we fill in various fields in it |
| 203 | to reflect the offsets of the arg pointer and the locals pointer. */ |
| 204 | |
| 205 | static CORE_ADDR |
| 206 | examine_prologue (ip, limit, after_prolog_fp, fsr, fi) |
| 207 | register CORE_ADDR ip; |
| 208 | register CORE_ADDR limit; |
| 209 | CORE_ADDR after_prolog_fp; |
| 210 | struct frame_saved_regs *fsr; |
| 211 | struct frame_info *fi; |
| 212 | { |
| 213 | register CORE_ADDR next_ip; |
| 214 | int r; |
| 215 | int i; |
| 216 | int have_fp = 0; |
| 217 | register int src; |
| 218 | register struct pic_prologue_code *pcode; |
| 219 | INSN_WORD insn_word; |
| 220 | int size, offset; |
| 221 | /* Number of things pushed onto stack, starts at 2/4, 'cause the |
| 222 | PC is already there */ |
| 223 | unsigned int reg_save_depth = h8300hmode ? 4 : 2; |
| 224 | |
| 225 | unsigned int auto_depth = 0; /* Number of bytes of autos */ |
| 226 | |
| 227 | char in_frame[11]; /* One for each reg */ |
| 228 | |
| 229 | memset (in_frame, 1, 11); |
| 230 | for (r = 0; r < 8; r++) |
| 231 | { |
| 232 | fsr->regs[r] = 0; |
| 233 | } |
| 234 | if (after_prolog_fp == 0) |
| 235 | { |
| 236 | after_prolog_fp = read_register (SP_REGNUM); |
| 237 | } |
| 238 | if (ip == 0 || ip & (h8300hmode ? ~0xffff : ~0xffff)) |
| 239 | return 0; |
| 240 | |
| 241 | next_ip = NEXT_PROLOGUE_INSN (ip, limit, &insn_word); |
| 242 | |
| 243 | /* Skip over any fp push instructions */ |
| 244 | fsr->regs[6] = after_prolog_fp; |
| 245 | while (next_ip && IS_PUSH_FP (insn_word)) |
| 246 | { |
| 247 | ip = next_ip; |
| 248 | |
| 249 | in_frame[insn_word & 0x7] = reg_save_depth; |
| 250 | next_ip = NEXT_PROLOGUE_INSN (ip, limit, &insn_word); |
| 251 | reg_save_depth += 2; |
| 252 | } |
| 253 | |
| 254 | /* Is this a move into the fp */ |
| 255 | if (next_ip && IS_MOV_SP_FP (insn_word)) |
| 256 | { |
| 257 | ip = next_ip; |
| 258 | next_ip = NEXT_PROLOGUE_INSN (ip, limit, &insn_word); |
| 259 | have_fp = 1; |
| 260 | } |
| 261 | |
| 262 | /* Skip over any stack adjustment, happens either with a number of |
| 263 | sub#2,sp or a mov #x,r5 sub r5,sp */ |
| 264 | |
| 265 | if (next_ip && IS_SUB2_SP (insn_word)) |
| 266 | { |
| 267 | while (next_ip && IS_SUB2_SP (insn_word)) |
| 268 | { |
| 269 | auto_depth += 2; |
| 270 | ip = next_ip; |
| 271 | next_ip = NEXT_PROLOGUE_INSN (ip, limit, &insn_word); |
| 272 | } |
| 273 | } |
| 274 | else |
| 275 | { |
| 276 | if (next_ip && IS_MOVK_R5 (insn_word)) |
| 277 | { |
| 278 | ip = next_ip; |
| 279 | next_ip = NEXT_PROLOGUE_INSN (ip, limit, &insn_word); |
| 280 | auto_depth += insn_word; |
| 281 | |
| 282 | next_ip = NEXT_PROLOGUE_INSN (next_ip, limit, &insn_word); |
| 283 | auto_depth += insn_word; |
| 284 | } |
| 285 | } |
| 286 | /* Work out which regs are stored where */ |
| 287 | while (next_ip && IS_PUSH (insn_word)) |
| 288 | { |
| 289 | ip = next_ip; |
| 290 | next_ip = NEXT_PROLOGUE_INSN (ip, limit, &insn_word); |
| 291 | fsr->regs[r] = after_prolog_fp + auto_depth; |
| 292 | auto_depth += 2; |
| 293 | } |
| 294 | |
| 295 | /* The args are always reffed based from the stack pointer */ |
| 296 | fi->args_pointer = after_prolog_fp; |
| 297 | /* Locals are always reffed based from the fp */ |
| 298 | fi->locals_pointer = after_prolog_fp; |
| 299 | /* The PC is at a known place */ |
| 300 | fi->from_pc = read_memory_unsigned_integer (after_prolog_fp + 2, BINWORD); |
| 301 | |
| 302 | /* Rememeber any others too */ |
| 303 | in_frame[PC_REGNUM] = 0; |
| 304 | |
| 305 | if (have_fp) |
| 306 | /* We keep the old FP in the SP spot */ |
| 307 | fsr->regs[SP_REGNUM] = read_memory_unsigned_integer (fsr->regs[6], BINWORD); |
| 308 | else |
| 309 | fsr->regs[SP_REGNUM] = after_prolog_fp + auto_depth; |
| 310 | |
| 311 | return (ip); |
| 312 | } |
| 313 | |
| 314 | void |
| 315 | init_extra_frame_info (fromleaf, fi) |
| 316 | int fromleaf; |
| 317 | struct frame_info *fi; |
| 318 | { |
| 319 | fi->fsr = 0; /* Not yet allocated */ |
| 320 | fi->args_pointer = 0; /* Unknown */ |
| 321 | fi->locals_pointer = 0; /* Unknown */ |
| 322 | fi->from_pc = 0; |
| 323 | } |
| 324 | |
| 325 | /* Return the saved PC from this frame. |
| 326 | |
| 327 | If the frame has a memory copy of SRP_REGNUM, use that. If not, |
| 328 | just use the register SRP_REGNUM itself. */ |
| 329 | |
| 330 | CORE_ADDR |
| 331 | frame_saved_pc (frame) |
| 332 | struct frame_info *frame; |
| 333 | { |
| 334 | return frame->from_pc; |
| 335 | } |
| 336 | |
| 337 | CORE_ADDR |
| 338 | frame_locals_address (fi) |
| 339 | struct frame_info *fi; |
| 340 | { |
| 341 | if (!fi->locals_pointer) |
| 342 | { |
| 343 | struct frame_saved_regs ignore; |
| 344 | |
| 345 | get_frame_saved_regs (fi, &ignore); |
| 346 | |
| 347 | } |
| 348 | return fi->locals_pointer; |
| 349 | } |
| 350 | |
| 351 | /* Return the address of the argument block for the frame |
| 352 | described by FI. Returns 0 if the address is unknown. */ |
| 353 | |
| 354 | CORE_ADDR |
| 355 | frame_args_address (fi) |
| 356 | struct frame_info *fi; |
| 357 | { |
| 358 | if (!fi->args_pointer) |
| 359 | { |
| 360 | struct frame_saved_regs ignore; |
| 361 | |
| 362 | get_frame_saved_regs (fi, &ignore); |
| 363 | |
| 364 | } |
| 365 | |
| 366 | return fi->args_pointer; |
| 367 | } |
| 368 | |
| 369 | void |
| 370 | h8300_pop_frame () |
| 371 | { |
| 372 | unsigned regnum; |
| 373 | struct frame_saved_regs fsr; |
| 374 | struct frame_info *frame = get_current_frame (); |
| 375 | |
| 376 | get_frame_saved_regs (frame, &fsr); |
| 377 | |
| 378 | for (regnum = 0; regnum < 8; regnum++) |
| 379 | { |
| 380 | if (fsr.regs[regnum]) |
| 381 | write_register (regnum, read_memory_integer(fsr.regs[regnum]), BINWORD); |
| 382 | |
| 383 | flush_cached_frames (); |
| 384 | } |
| 385 | } |
| 386 | |
| 387 | |
| 388 | struct cmd_list_element *setmemorylist; |
| 389 | |
| 390 | static void |
| 391 | h8300_command(args, from_tty) |
| 392 | { |
| 393 | extern int h8300hmode; |
| 394 | h8300hmode = 0; |
| 395 | } |
| 396 | |
| 397 | static void |
| 398 | h8300h_command(args, from_tty) |
| 399 | { |
| 400 | extern int h8300hmode; |
| 401 | h8300hmode = 1; |
| 402 | } |
| 403 | |
| 404 | static void |
| 405 | set_machine (args, from_tty) |
| 406 | char *args; |
| 407 | int from_tty; |
| 408 | { |
| 409 | printf_unfiltered ("\"set machine\" must be followed by h8300 or h8300h.\n"); |
| 410 | help_list (setmemorylist, "set memory ", -1, gdb_stdout); |
| 411 | } |
| 412 | |
| 413 | void |
| 414 | _initialize_h8300m () |
| 415 | { |
| 416 | add_prefix_cmd ("machine", no_class, set_machine, |
| 417 | "set the machine type", &setmemorylist, "set machine ", 0, |
| 418 | &setlist); |
| 419 | |
| 420 | add_cmd ("h8300", class_support, h8300_command, |
| 421 | "Set machine to be H8/300.", &setmemorylist); |
| 422 | |
| 423 | add_cmd ("h8300h", class_support, h8300h_command, |
| 424 | "Set machine to be H8/300H.", &setmemorylist); |
| 425 | } |
| 426 | |
| 427 | |
| 428 | |
| 429 | void |
| 430 | print_register_hook (regno) |
| 431 | { |
| 432 | if (regno == 8) |
| 433 | { |
| 434 | /* CCR register */ |
| 435 | int C, Z, N, V; |
| 436 | unsigned char b[4]; |
| 437 | unsigned char l; |
| 438 | read_relative_register_raw_bytes (regno, b); |
| 439 | l = b[REGISTER_VIRTUAL_SIZE(8) -1]; |
| 440 | printf_unfiltered ("\t"); |
| 441 | printf_unfiltered ("I-%d - ", (l & 0x80) != 0); |
| 442 | printf_unfiltered ("H-%d - ", (l & 0x20) != 0); |
| 443 | N = (l & 0x8) != 0; |
| 444 | Z = (l & 0x4) != 0; |
| 445 | V = (l & 0x2) != 0; |
| 446 | C = (l & 0x1) != 0; |
| 447 | printf_unfiltered ("N-%d ", N); |
| 448 | printf_unfiltered ("Z-%d ", Z); |
| 449 | printf_unfiltered ("V-%d ", V); |
| 450 | printf_unfiltered ("C-%d ", C); |
| 451 | if ((C | Z) == 0) |
| 452 | printf_unfiltered ("u> "); |
| 453 | if ((C | Z) == 1) |
| 454 | printf_unfiltered ("u<= "); |
| 455 | if ((C == 0)) |
| 456 | printf_unfiltered ("u>= "); |
| 457 | if (C == 1) |
| 458 | printf_unfiltered ("u< "); |
| 459 | if (Z == 0) |
| 460 | printf_unfiltered ("!= "); |
| 461 | if (Z == 1) |
| 462 | printf_unfiltered ("== "); |
| 463 | if ((N ^ V) == 0) |
| 464 | printf_unfiltered (">= "); |
| 465 | if ((N ^ V) == 1) |
| 466 | printf_unfiltered ("< "); |
| 467 | if ((Z | (N ^ V)) == 0) |
| 468 | printf_unfiltered ("> "); |
| 469 | if ((Z | (N ^ V)) == 1) |
| 470 | printf_unfiltered ("<= "); |
| 471 | } |
| 472 | } |
| 473 | |
| 474 | void |
| 475 | _initialize_h8300_tdep () |
| 476 | { |
| 477 | tm_print_insn = gdb_print_insn_h8300; |
| 478 | } |