1 /* Parameters for execution on a 68000 series machine.
2 Copyright 1986, 1987, 1989, 1990, 1992 Free Software Foundation, Inc.
4 This file is part of GDB.
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.
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.
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. */
20 /* Generic 68000 stuff, to be included by other tm-*.h files.
21 Define HAVE_68881 if that is the case. */
23 #if defined (HAVE_68881)
27 /* Define the bit, byte, and word ordering of the machine. */
28 #define TARGET_BYTE_ORDER BIG_ENDIAN
30 /* Offset from address of function to start of its code.
31 Zero on most machines. */
33 #define FUNCTION_START_OFFSET 0
35 /* Advance PC across any function entry prologue instructions
36 to reach some "real" code. */
38 #if !defined(SKIP_PROLOGUE)
39 #define SKIP_PROLOGUE(ip) {(ip) = m68k_skip_prologue(ip);}
40 extern CORE_ADDR m68k_skip_prologue
PARAMS ((CORE_ADDR ip
));
43 /* Immediately after a function call, return the saved pc.
44 Can't always go through the frames for this because on some machines
45 the new frame is not set up until the new function executes
48 #define SAVED_PC_AFTER_CALL(frame) \
49 read_memory_integer (read_register (SP_REGNUM), 4)
51 /* Stack grows downward. */
55 /* Sequence of bytes for breakpoint instruction.
56 This is a TRAP instruction. The last 4 bits (0xf below) is the
57 vector. Systems which don't use 0xf should define BPT_VECTOR
58 themselves before including this file. */
60 #if !defined (BPT_VECTOR)
61 #define BPT_VECTOR 0xf
64 #if !defined (BREAKPOINT)
65 #define BREAKPOINT {0x4e, (0x40 | BPT_VECTOR)}
68 /* If your kernel resets the pc after the trap happens you may need to
69 define this before including this file. */
71 #if !defined (DECR_PC_AFTER_BREAK)
72 #define DECR_PC_AFTER_BREAK 2
75 /* Nonzero if instruction at PC is a return instruction. */
76 /* Allow any of the return instructions, including a trapv and a return
79 #define ABOUT_TO_RETURN(pc) ((read_memory_integer (pc, 2) & ~0x3) == 0x4e74)
81 /* Return 1 if P points to an invalid floating point value. */
83 #define INVALID_FLOAT(p, len) 0 /* Just a first guess; not checked */
85 /* Say how long registers are. */
87 #define REGISTER_TYPE long
89 #if defined (HAVE_68881)
90 # if defined (GDB_TARGET_IS_SUN3)
91 /* Sun3 status includes fpflags, which shows whether the FPU has been used
92 by the process, and whether the FPU was done with an instruction or
93 was interrupted in the middle of a long instruction. See
95 /* a&d, pc,sr, fp, fpstat, fpflags */
97 # define REGISTER_BYTES (16*4 + 8 + 8*12 + 3*4 + 4)
98 # else /* Not sun3. */
100 # define REGISTER_BYTES (16*4 + 8 + 8*12 + 3*4)
101 # endif /* Not sun3. */
102 #else /* No 68881. */
104 # define REGISTER_BYTES (16*4 + 8)
105 #endif /* No 68881. */
107 /* Index within `registers' of the first byte of the space for
110 #if defined (HAVE_68881)
111 #define REGISTER_BYTE(N) \
112 ((N) >= FPC_REGNUM ? (((N) - FPC_REGNUM) * 4) + 168 \
113 : (N) >= FP0_REGNUM ? (((N) - FP0_REGNUM) * 12) + 72 \
116 /* Number of bytes of storage in the actual machine representation
117 for register N. On the 68000, all regs are 4 bytes
118 except the floating point regs which are 12 bytes. */
119 /* Note that the unsigned cast here forces the result of the
120 subtraction to very high positive values if N < FP0_REGNUM */
122 #define REGISTER_RAW_SIZE(N) (((unsigned)(N) - FP0_REGNUM) < 8 ? 12 : 4)
124 /* Number of bytes of storage in the program's representation
125 for register N. On the 68000, all regs are 4 bytes
126 except the floating point regs which are 8-byte doubles. */
128 #define REGISTER_VIRTUAL_SIZE(N) (((unsigned)(N) - FP0_REGNUM) < 8 ? 8 : 4)
130 /* Largest value REGISTER_RAW_SIZE can have. */
132 #define MAX_REGISTER_RAW_SIZE 12
134 /* Largest value REGISTER_VIRTUAL_SIZE can have. */
136 #define MAX_REGISTER_VIRTUAL_SIZE 8
138 /* Nonzero if register N requires conversion
139 from raw format to virtual format. */
141 #define REGISTER_CONVERTIBLE(N) (((unsigned)(N) - FP0_REGNUM) < 8)
143 /* Put the declaration out here because if it's in the macros, PCC
145 extern const struct ext_format ext_format_68881
;
147 /* Convert data from raw format for register REGNUM
148 to virtual format for register REGNUM. */
150 #define REGISTER_CONVERT_TO_VIRTUAL(REGNUM,FROM,TO) \
152 if ((REGNUM) >= FP0_REGNUM && (REGNUM) < FPC_REGNUM) \
153 ieee_extended_to_double (&ext_format_68881, (FROM), (double *)(TO)); \
155 memcpy ((TO), (FROM), 4); \
158 /* Convert data from virtual format for register REGNUM
159 to raw format for register REGNUM. */
161 #define REGISTER_CONVERT_TO_RAW(REGNUM,FROM,TO) \
163 if ((REGNUM) >= FP0_REGNUM && (REGNUM) < FPC_REGNUM) \
164 double_to_ieee_extended (&ext_format_68881, (double *)(FROM), (TO)); \
166 memcpy ((TO), (FROM), 4); \
169 /* Return the GDB type object for the "standard" data type
170 of data in register N. */
171 /* Note, for registers which contain addresses return
172 pointer to void, not pointer to char, because we don't
173 want to attempt to print the string after printing the address. */
174 #define REGISTER_VIRTUAL_TYPE(N) \
175 (((unsigned)(N) - FP0_REGNUM) < 8 ? builtin_type_double : \
176 (N) == PC_REGNUM || (N) == FP_REGNUM || (N) == SP_REGNUM ? \
177 lookup_pointer_type (builtin_type_void) : builtin_type_int)
179 #else /* no 68881. */
180 /* Index within `registers' of the first byte of the space for
183 #define REGISTER_BYTE(N) ((N) * 4)
185 /* Number of bytes of storage in the actual machine representation
186 for register N. On the 68000, all regs are 4 bytes. */
188 #define REGISTER_RAW_SIZE(N) 4
190 /* Number of bytes of storage in the program's representation
191 for register N. On the 68000, all regs are 4 bytes. */
193 #define REGISTER_VIRTUAL_SIZE(N) 4
195 /* Largest value REGISTER_RAW_SIZE can have. */
197 #define MAX_REGISTER_RAW_SIZE 4
199 /* Largest value REGISTER_VIRTUAL_SIZE can have. */
201 #define MAX_REGISTER_VIRTUAL_SIZE 4
203 /* Nonzero if register N requires conversion
204 from raw format to virtual format. */
206 #define REGISTER_CONVERTIBLE(N) 0
208 /* Convert data from raw format for register REGNUM
209 to virtual format for register REGNUM. */
211 #define REGISTER_CONVERT_TO_VIRTUAL(REGNUM,FROM,TO) memcpy ((TO), (FROM), 4);
213 /* Convert data from virtual format for register REGNUM
214 to raw format for register REGNUM. */
216 #define REGISTER_CONVERT_TO_RAW(REGNUM,FROM,TO) memcpy ((TO), (FROM), 4);
218 /* Return the GDB type object for the "standard" data type
219 of data in register N. */
221 #define REGISTER_VIRTUAL_TYPE(N) builtin_type_int
223 #endif /* No 68881. */
225 /* Initializer for an array of names of registers.
226 Entries beyond the first NUM_REGS are ignored. */
228 #define REGISTER_NAMES \
229 {"d0", "d1", "d2", "d3", "d4", "d5", "d6", "d7", \
230 "a0", "a1", "a2", "a3", "a4", "a5", "fp", "sp", \
232 "fp0", "fp1", "fp2", "fp3", "fp4", "fp5", "fp6", "fp7", \
233 "fpcontrol", "fpstatus", "fpiaddr", "fpcode", "fpflags" }
235 /* Register numbers of various important registers.
236 Note that some of these values are "real" register numbers,
237 and correspond to the general registers of the machine,
238 and some are "phony" register numbers which are too large
239 to be actual register numbers as far as the user is concerned
240 but do serve to get the desired values when passed to read_register. */
243 #define FP_REGNUM 14 /* Contains address of executing stack frame */
244 #define SP_REGNUM 15 /* Contains address of top of stack */
245 #define PS_REGNUM 16 /* Contains processor status */
246 #define PC_REGNUM 17 /* Contains program counter */
247 #if defined (HAVE_68881)
248 #define FP0_REGNUM 18 /* Floating point register 0 */
249 #define FPC_REGNUM 26 /* 68881 control register */
250 #define FPS_REGNUM 27 /* 68881 status register */
251 #define FPI_REGNUM 28 /* 68881 iaddr register */
254 /* Store the address of the place in which to copy the structure the
255 subroutine will return. This is called from call_function. */
257 #define STORE_STRUCT_RETURN(ADDR, SP) \
258 { write_register (A1_REGNUM, (ADDR)); }
260 /* Extract from an array REGBUF containing the (raw) register state
261 a function return value of type TYPE, and copy that, in virtual format,
262 into VALBUF. This is assuming that floating point values are returned
263 as doubles in d0/d1. */
265 #if !defined (EXTRACT_RETURN_VALUE)
266 #define EXTRACT_RETURN_VALUE(TYPE,REGBUF,VALBUF) \
269 (TYPE_LENGTH(TYPE) >= 4 ? 0 : 4 - TYPE_LENGTH(TYPE)), \
273 /* Write into appropriate registers a function return value
274 of type TYPE, given in virtual format. Assumes floats are passed
277 #if !defined (STORE_RETURN_VALUE)
278 #define STORE_RETURN_VALUE(TYPE,VALBUF) \
279 write_register_bytes (0, VALBUF, TYPE_LENGTH (TYPE))
282 /* Extract from an array REGBUF containing the (raw) register state
283 the address in which a function should return its structure value,
284 as a CORE_ADDR (or an expression that can be used as one). */
286 #define EXTRACT_STRUCT_VALUE_ADDRESS(REGBUF) (*(CORE_ADDR *)(REGBUF))
288 /* Describe the pointer in each stack frame to the previous stack frame
291 /* FRAME_CHAIN takes a frame's nominal address
292 and produces the frame's chain-pointer.
294 However, if FRAME_CHAIN_VALID returns zero,
295 it means the given frame is the outermost one and has no caller. */
297 /* In the case of the 68000, the frame's nominal address
298 is the address of a 4-byte word containing the calling frame's address. */
300 #define FRAME_CHAIN(thisframe) \
301 (outside_startup_file ((thisframe)->pc) ? \
302 read_memory_integer ((thisframe)->frame, 4) :\
305 #if defined (FRAME_CHAIN_VALID_ALTERNATE)
307 /* Use the alternate method of avoiding running up off the end of
308 the frame chain or following frames back into the startup code.
309 See the comments in blockframe.c */
311 #define FRAME_CHAIN_VALID(chain, thisframe) \
313 && !(inside_main_scope ((thisframe)->pc)) \
314 && !(inside_entry_scope ((thisframe)->pc)))
318 #define FRAME_CHAIN_VALID(chain, thisframe) \
319 (chain != 0 && outside_startup_file (FRAME_SAVED_PC (thisframe)))
321 #endif /* FRAME_CHAIN_VALID_ALTERNATE */
323 /* Define other aspects of the stack frame. */
325 /* A macro that tells us whether the function invocation represented
326 by FI does not have a frame on the stack associated with it. If it
327 does not, FRAMELESS is set to 1, else 0. */
328 #define FRAMELESS_FUNCTION_INVOCATION(FI, FRAMELESS) \
329 (FRAMELESS) = frameless_look_for_prologue(FI)
331 #define FRAME_SAVED_PC(FRAME) (read_memory_integer ((FRAME)->frame + 4, 4))
333 #define FRAME_ARGS_ADDRESS(fi) ((fi)->frame)
335 #define FRAME_LOCALS_ADDRESS(fi) ((fi)->frame)
337 /* Set VAL to the number of args passed to frame described by FI.
338 Can set VAL to -1, meaning no way to tell. */
340 /* We can't tell how many args there are
341 now that the C compiler delays popping them. */
342 #if !defined (FRAME_NUM_ARGS)
343 #define FRAME_NUM_ARGS(val,fi) (val = -1)
346 /* Return number of bytes at start of arglist that are not really args. */
348 #define FRAME_ARGS_SKIP 8
350 /* Put here the code to store, into a struct frame_saved_regs,
351 the addresses of the saved registers of frame described by FRAME_INFO.
352 This includes special registers such as pc and fp saved in special
353 ways in the stack frame. sp is even more special:
354 the address we return for it IS the sp for the next frame. */
356 #if !defined (FRAME_FIND_SAVED_REGS)
357 #if defined (HAVE_68881)
358 #define FRAME_FIND_SAVED_REGS(frame_info, frame_saved_regs) \
359 { register int regnum; \
360 register int regmask; \
361 register CORE_ADDR next_addr; \
362 register CORE_ADDR pc; \
364 bzero (&frame_saved_regs, sizeof frame_saved_regs); \
365 if ((frame_info)->pc >= (frame_info)->frame - CALL_DUMMY_LENGTH - FP_REGNUM*4 - 8*12 - 4 \
366 && (frame_info)->pc <= (frame_info)->frame) \
367 { next_addr = (frame_info)->frame; \
368 pc = (frame_info)->frame - CALL_DUMMY_LENGTH - FP_REGNUM * 4 - 8*12 - 4; }\
370 { pc = get_pc_function_start ((frame_info)->pc); \
371 /* Verify we have a link a6 instruction next; \
372 if not we lose. If we win, find the address above the saved \
373 regs using the amount of storage from the link instruction. */\
374 if (044016 == read_memory_integer (pc, 2)) \
375 next_addr = (frame_info)->frame + read_memory_integer (pc += 2, 4), pc+=4; \
376 else if (047126 == read_memory_integer (pc, 2)) \
377 next_addr = (frame_info)->frame + read_memory_integer (pc += 2, 2), pc+=2; \
379 /* If have an addal #-n, sp next, adjust next_addr. */ \
380 if ((0177777 & read_memory_integer (pc, 2)) == 0157774) \
381 next_addr += read_memory_integer (pc += 2, 4), pc += 4; \
383 /* next should be a moveml to (sp) or -(sp) or a movl r,-(sp) */ \
384 regmask = read_memory_integer (pc + 2, 2); \
385 /* But before that can come an fmovem. Check for it. */ \
386 nextinsn = 0xffff & read_memory_integer (pc, 2); \
387 if (0xf227 == nextinsn \
388 && (regmask & 0xff00) == 0xe000) \
389 { pc += 4; /* Regmask's low bit is for register fp7, the first pushed */ \
390 for (regnum = FP0_REGNUM + 7; regnum >= FP0_REGNUM; regnum--, regmask >>= 1) \
392 (frame_saved_regs).regs[regnum] = (next_addr -= 12); \
393 regmask = read_memory_integer (pc + 2, 2); } \
394 if (0044327 == read_memory_integer (pc, 2)) \
395 { pc += 4; /* Regmask's low bit is for register 0, the first written */ \
396 for (regnum = 0; regnum < 16; regnum++, regmask >>= 1) \
398 (frame_saved_regs).regs[regnum] = (next_addr += 4) - 4; } \
399 else if (0044347 == read_memory_integer (pc, 2)) \
400 { pc += 4; /* Regmask's low bit is for register 15, the first pushed */ \
401 for (regnum = 15; regnum >= 0; regnum--, regmask >>= 1) \
403 (frame_saved_regs).regs[regnum] = (next_addr -= 4); } \
404 else if (0x2f00 == (0xfff0 & read_memory_integer (pc, 2))) \
405 { regnum = 0xf & read_memory_integer (pc, 2); pc += 2; \
406 (frame_saved_regs).regs[regnum] = (next_addr -= 4); } \
407 /* fmovemx to index of sp may follow. */ \
408 regmask = read_memory_integer (pc + 2, 2); \
409 nextinsn = 0xffff & read_memory_integer (pc, 2); \
410 if (0xf236 == nextinsn \
411 && (regmask & 0xff00) == 0xf000) \
412 { pc += 10; /* Regmask's low bit is for register fp0, the first written */ \
413 for (regnum = FP0_REGNUM + 7; regnum >= FP0_REGNUM; regnum--, regmask >>= 1) \
415 (frame_saved_regs).regs[regnum] = (next_addr += 12) - 12; \
416 regmask = read_memory_integer (pc + 2, 2); } \
417 /* clrw -(sp); movw ccr,-(sp) may follow. */ \
418 if (0x426742e7 == read_memory_integer (pc, 4)) \
419 (frame_saved_regs).regs[PS_REGNUM] = (next_addr -= 4); \
421 (frame_saved_regs).regs[SP_REGNUM] = (frame_info)->frame + 8; \
422 (frame_saved_regs).regs[FP_REGNUM] = (frame_info)->frame; \
423 (frame_saved_regs).regs[PC_REGNUM] = (frame_info)->frame + 4; \
425 #else /* no 68881. */
426 #define FRAME_FIND_SAVED_REGS(frame_info, frame_saved_regs) \
427 { register int regnum; \
428 register int regmask; \
429 register CORE_ADDR next_addr; \
430 register CORE_ADDR pc; \
431 bzero (&frame_saved_regs, sizeof frame_saved_regs); \
432 if ((frame_info)->pc >= (frame_info)->frame - CALL_DUMMY_LENGTH - FP_REGNUM*4 - 4 \
433 && (frame_info)->pc <= (frame_info)->frame) \
434 { next_addr = (frame_info)->frame; \
435 pc = (frame_info)->frame - CALL_DUMMY_LENGTH - FP_REGNUM * 4 - 4; }\
437 { pc = get_pc_function_start ((frame_info)->pc); \
438 /* Verify we have a link a6 instruction next; \
439 if not we lose. If we win, find the address above the saved \
440 regs using the amount of storage from the link instruction. */\
441 if (044016 == read_memory_integer (pc, 2)) \
442 next_addr = (frame_info)->frame + read_memory_integer (pc += 2, 4), pc+=4; \
443 else if (047126 == read_memory_integer (pc, 2)) \
444 next_addr = (frame_info)->frame + read_memory_integer (pc += 2, 2), pc+=2; \
446 /* If have an addal #-n, sp next, adjust next_addr. */ \
447 if ((0177777 & read_memory_integer (pc, 2)) == 0157774) \
448 next_addr += read_memory_integer (pc += 2, 4), pc += 4; \
450 /* next should be a moveml to (sp) or -(sp) or a movl r,-(sp) */ \
451 regmask = read_memory_integer (pc + 2, 2); \
452 if (0044327 == read_memory_integer (pc, 2)) \
453 { pc += 4; /* Regmask's low bit is for register 0, the first written */ \
454 for (regnum = 0; regnum < 16; regnum++, regmask >>= 1) \
456 (frame_saved_regs).regs[regnum] = (next_addr += 4) - 4; } \
457 else if (0044347 == read_memory_integer (pc, 2)) \
458 { pc += 4; /* Regmask's low bit is for register 15, the first pushed */ \
459 for (regnum = 15; regnum >= 0; regnum--, regmask >>= 1) \
461 (frame_saved_regs).regs[regnum] = (next_addr -= 4); } \
462 else if (0x2f00 == 0xfff0 & read_memory_integer (pc, 2)) \
463 { regnum = 0xf & read_memory_integer (pc, 2); pc += 2; \
464 (frame_saved_regs).regs[regnum] = (next_addr -= 4); } \
465 /* clrw -(sp); movw ccr,-(sp) may follow. */ \
466 if (0x426742e7 == read_memory_integer (pc, 4)) \
467 (frame_saved_regs).regs[PS_REGNUM] = (next_addr -= 4); \
469 (frame_saved_regs).regs[SP_REGNUM] = (frame_info)->frame + 8; \
470 (frame_saved_regs).regs[FP_REGNUM] = (frame_info)->frame; \
471 (frame_saved_regs).regs[PC_REGNUM] = (frame_info)->frame + 4; \
473 #endif /* no 68881. */
474 #endif /* no FIND_FRAME_SAVED_REGS. */
477 /* Things needed for making the inferior call functions.
478 It seems like every m68k based machine has almost identical definitions
479 in the individual machine's configuration files. Most other cpu types
480 (mips, i386, etc) have routines in their *-tdep.c files to handle this
481 for most configurations. The m68k family should be able to do this as
482 well. These macros can still be overridden when necessary. */
484 /* The CALL_DUMMY macro is the sequence of instructions, as disassembled
487 fmovemx fp0-fp7,sp@- 0xf227 0xe0ff
488 moveml d0-a5,sp@- 0x48e7 0xfffc
490 movew ccr,sp@- 0x42e7
492 /..* The arguments are pushed at this point by GDB;
493 no code is needed in the dummy for this.
494 The CALL_DUMMY_START_OFFSET gives the position of
495 the following jsr instruction. *../
497 jsr @#0x32323232 0x4eb9 0x3232 0x3232
498 addal #0x69696969,sp 0xdffc 0x6969 0x6969
499 trap #<your BPT_VECTOR number here> 0x4e4?
502 Note this is CALL_DUMMY_LENGTH bytes (28 for the above example).
503 We actually start executing at the jsr, since the pushing of the
504 registers is done by PUSH_DUMMY_FRAME. If this were real code,
505 the arguments for the function called by the jsr would be pushed
506 between the moveml and the jsr, and we could allow it to execute through.
507 But the arguments have to be pushed by GDB after the PUSH_DUMMY_FRAME is
508 done, and we cannot allow the moveml to push the registers again lest
509 they be taken for the arguments. */
511 #if defined (HAVE_68881)
513 #define CALL_DUMMY {0xf227e0ff, 0x48e7fffc, 0x426742e7, 0x4eb93232, 0x3232dffc, 0x69696969, (0x4e404e71 | (BPT_VECTOR << 16))}
514 #define CALL_DUMMY_LENGTH 28 /* Size of CALL_DUMMY */
515 #define CALL_DUMMY_START_OFFSET 12 /* Offset to jsr instruction*/
519 #define CALL_DUMMY {0x48e7fffc, 0x426742e7, 0x4eb93232, 0x3232dffc, 0x69696969, (0x4e404e71 | (BPT_VECTOR << 16))}
520 #define CALL_DUMMY_LENGTH 24 /* Size of CALL_DUMMY */
521 #define CALL_DUMMY_START_OFFSET 8 /* Offset to jsr instruction*/
523 #endif /* HAVE_68881 */
525 /* Insert the specified number of args and function address
526 into a call sequence of the above form stored at DUMMYNAME. */
528 #define FIX_CALL_DUMMY(dummyname, pc, fun, nargs, args, type, gcc_p) \
529 { *(int *)((char *) dummyname + CALL_DUMMY_START_OFFSET + 2) = fun; \
530 *(int *)((char *) dummyname + CALL_DUMMY_START_OFFSET + 8) = nargs * 4; }
532 /* Push an empty stack frame, to record the current PC, etc. */
534 #define PUSH_DUMMY_FRAME { m68k_push_dummy_frame (); }
536 extern void m68k_push_dummy_frame
PARAMS ((void));
538 extern void m68k_pop_frame
PARAMS ((void));
540 /* Discard from the stack the innermost frame, restoring all registers. */
542 #define POP_FRAME { m68k_pop_frame (); }
544 /* Offset from SP to first arg on stack at first instruction of a function */
546 #define SP_ARG0 (1 * 4)