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 /* We always use vector 1 for the "remote" target. This is hardcoded in
70 #define REMOTE_BPT_VECTOR 1
71 #define REMOTE_BREAKPOINT {0x4e, (0x40 | REMOTE_BPT_VECTOR)}
73 /* If your kernel resets the pc after the trap happens you may need to
74 define this before including this file. */
76 #if !defined (DECR_PC_AFTER_BREAK)
77 #define DECR_PC_AFTER_BREAK 2
80 /* Nonzero if instruction at PC is a return instruction. */
81 /* Allow any of the return instructions, including a trapv and a return
84 #define ABOUT_TO_RETURN(pc) ((read_memory_integer (pc, 2) & ~0x3) == 0x4e74)
86 /* Return 1 if P points to an invalid floating point value. */
88 #define INVALID_FLOAT(p, len) 0 /* Just a first guess; not checked */
90 /* Say how long registers are. */
92 #define REGISTER_TYPE long
94 #if defined (HAVE_68881)
95 # if defined (GDB_TARGET_IS_SUN3)
96 /* Sun3 status includes fpflags, which shows whether the FPU has been used
97 by the process, and whether the FPU was done with an instruction or
98 was interrupted in the middle of a long instruction. See
100 /* a&d, pc,sr, fp, fpstat, fpflags */
102 # define REGISTER_BYTES (16*4 + 8 + 8*12 + 3*4 + 4)
103 # else /* Not sun3. */
105 # define REGISTER_BYTES (16*4 + 8 + 8*12 + 3*4)
106 # endif /* Not sun3. */
107 #else /* No 68881. */
109 # define REGISTER_BYTES (16*4 + 8)
110 #endif /* No 68881. */
112 /* Index within `registers' of the first byte of the space for
115 #if defined (HAVE_68881)
116 #define REGISTER_BYTE(N) \
117 ((N) >= FPC_REGNUM ? (((N) - FPC_REGNUM) * 4) + 168 \
118 : (N) >= FP0_REGNUM ? (((N) - FP0_REGNUM) * 12) + 72 \
121 /* Number of bytes of storage in the actual machine representation
122 for register N. On the 68000, all regs are 4 bytes
123 except the floating point regs which are 12 bytes. */
124 /* Note that the unsigned cast here forces the result of the
125 subtraction to very high positive values if N < FP0_REGNUM */
127 #define REGISTER_RAW_SIZE(N) (((unsigned)(N) - FP0_REGNUM) < 8 ? 12 : 4)
129 /* Number of bytes of storage in the program's representation
130 for register N. On the 68000, all regs are 4 bytes
131 except the floating point regs which are 8-byte doubles. */
133 #define REGISTER_VIRTUAL_SIZE(N) (((unsigned)(N) - FP0_REGNUM) < 8 ? 8 : 4)
135 /* Largest value REGISTER_RAW_SIZE can have. */
137 #define MAX_REGISTER_RAW_SIZE 12
139 /* Largest value REGISTER_VIRTUAL_SIZE can have. */
141 #define MAX_REGISTER_VIRTUAL_SIZE 8
143 /* Nonzero if register N requires conversion
144 from raw format to virtual format. */
146 #define REGISTER_CONVERTIBLE(N) (((unsigned)(N) - FP0_REGNUM) < 8)
148 /* Put the declaration out here because if it's in the macros, PCC
150 extern const struct ext_format ext_format_68881
;
152 /* Convert data from raw format for register REGNUM
153 to virtual format for register REGNUM. */
155 #define REGISTER_CONVERT_TO_VIRTUAL(REGNUM,FROM,TO) \
157 if ((REGNUM) >= FP0_REGNUM && (REGNUM) < FPC_REGNUM) \
158 ieee_extended_to_double (&ext_format_68881, (FROM), (double *)(TO)); \
160 memcpy ((TO), (FROM), 4); \
163 /* Convert data from virtual format for register REGNUM
164 to raw format for register REGNUM. */
166 #define REGISTER_CONVERT_TO_RAW(REGNUM,FROM,TO) \
168 if ((REGNUM) >= FP0_REGNUM && (REGNUM) < FPC_REGNUM) \
169 double_to_ieee_extended (&ext_format_68881, (double *)(FROM), (TO)); \
171 memcpy ((TO), (FROM), 4); \
174 /* Return the GDB type object for the "standard" data type
175 of data in register N. */
176 /* Note, for registers which contain addresses return
177 pointer to void, not pointer to char, because we don't
178 want to attempt to print the string after printing the address. */
179 #define REGISTER_VIRTUAL_TYPE(N) \
180 (((unsigned)(N) - FP0_REGNUM) < 8 ? builtin_type_double : \
181 (N) == PC_REGNUM || (N) == FP_REGNUM || (N) == SP_REGNUM ? \
182 lookup_pointer_type (builtin_type_void) : builtin_type_int)
184 #else /* no 68881. */
185 /* Index within `registers' of the first byte of the space for
188 #define REGISTER_BYTE(N) ((N) * 4)
190 /* Number of bytes of storage in the actual machine representation
191 for register N. On the 68000, all regs are 4 bytes. */
193 #define REGISTER_RAW_SIZE(N) 4
195 /* Number of bytes of storage in the program's representation
196 for register N. On the 68000, all regs are 4 bytes. */
198 #define REGISTER_VIRTUAL_SIZE(N) 4
200 /* Largest value REGISTER_RAW_SIZE can have. */
202 #define MAX_REGISTER_RAW_SIZE 4
204 /* Largest value REGISTER_VIRTUAL_SIZE can have. */
206 #define MAX_REGISTER_VIRTUAL_SIZE 4
208 /* Nonzero if register N requires conversion
209 from raw format to virtual format. */
211 #define REGISTER_CONVERTIBLE(N) 0
213 /* Convert data from raw format for register REGNUM
214 to virtual format for register REGNUM. */
216 #define REGISTER_CONVERT_TO_VIRTUAL(REGNUM,FROM,TO) memcpy ((TO), (FROM), 4);
218 /* Convert data from virtual format for register REGNUM
219 to raw format for register REGNUM. */
221 #define REGISTER_CONVERT_TO_RAW(REGNUM,FROM,TO) memcpy ((TO), (FROM), 4);
223 /* Return the GDB type object for the "standard" data type
224 of data in register N. */
226 #define REGISTER_VIRTUAL_TYPE(N) builtin_type_int
228 #endif /* No 68881. */
230 /* Initializer for an array of names of registers.
231 Entries beyond the first NUM_REGS are ignored. */
233 #define REGISTER_NAMES \
234 {"d0", "d1", "d2", "d3", "d4", "d5", "d6", "d7", \
235 "a0", "a1", "a2", "a3", "a4", "a5", "fp", "sp", \
237 "fp0", "fp1", "fp2", "fp3", "fp4", "fp5", "fp6", "fp7", \
238 "fpcontrol", "fpstatus", "fpiaddr", "fpcode", "fpflags" }
240 /* Register numbers of various important registers.
241 Note that some of these values are "real" register numbers,
242 and correspond to the general registers of the machine,
243 and some are "phony" register numbers which are too large
244 to be actual register numbers as far as the user is concerned
245 but do serve to get the desired values when passed to read_register. */
248 #define FP_REGNUM 14 /* Contains address of executing stack frame */
249 #define SP_REGNUM 15 /* Contains address of top of stack */
250 #define PS_REGNUM 16 /* Contains processor status */
251 #define PC_REGNUM 17 /* Contains program counter */
252 #if defined (HAVE_68881)
253 #define FP0_REGNUM 18 /* Floating point register 0 */
254 #define FPC_REGNUM 26 /* 68881 control register */
255 #define FPS_REGNUM 27 /* 68881 status register */
256 #define FPI_REGNUM 28 /* 68881 iaddr register */
259 /* Store the address of the place in which to copy the structure the
260 subroutine will return. This is called from call_function. */
262 #define STORE_STRUCT_RETURN(ADDR, SP) \
263 { write_register (A1_REGNUM, (ADDR)); }
265 /* Extract from an array REGBUF containing the (raw) register state
266 a function return value of type TYPE, and copy that, in virtual format,
267 into VALBUF. This is assuming that floating point values are returned
268 as doubles in d0/d1. */
270 #if !defined (EXTRACT_RETURN_VALUE)
271 #define EXTRACT_RETURN_VALUE(TYPE,REGBUF,VALBUF) \
274 (TYPE_LENGTH(TYPE) >= 4 ? 0 : 4 - TYPE_LENGTH(TYPE)), \
278 /* Write into appropriate registers a function return value
279 of type TYPE, given in virtual format. Assumes floats are passed
282 #if !defined (STORE_RETURN_VALUE)
283 #define STORE_RETURN_VALUE(TYPE,VALBUF) \
284 write_register_bytes (0, VALBUF, TYPE_LENGTH (TYPE))
287 /* Extract from an array REGBUF containing the (raw) register state
288 the address in which a function should return its structure value,
289 as a CORE_ADDR (or an expression that can be used as one). */
291 #define EXTRACT_STRUCT_VALUE_ADDRESS(REGBUF) (*(CORE_ADDR *)(REGBUF))
293 /* Describe the pointer in each stack frame to the previous stack frame
296 /* FRAME_CHAIN takes a frame's nominal address and produces the frame's
298 In the case of the 68000, the frame's nominal address
299 is the address of a 4-byte word containing the calling frame's address. */
301 /* If we are chaining from sigtramp, then manufacture a sigtramp frame
302 (which isn't really on the stack. I'm not sure this is right for anything
303 but BSD4.3 on an hp300. */
304 #define FRAME_CHAIN(thisframe) \
305 (thisframe->signal_handler_caller \
307 : (!inside_entry_file ((thisframe)->pc) \
308 ? read_memory_integer ((thisframe)->frame, 4) \
311 /* Define other aspects of the stack frame. */
313 /* A macro that tells us whether the function invocation represented
314 by FI does not have a frame on the stack associated with it. If it
315 does not, FRAMELESS is set to 1, else 0. */
316 #define FRAMELESS_FUNCTION_INVOCATION(FI, FRAMELESS) \
318 if ((FI)->signal_handler_caller) \
321 (FRAMELESS) = frameless_look_for_prologue(FI); \
324 /* This was determined by experimentation on hp300 BSD 4.3. Perhaps
325 it corresponds to some offset in /usr/include/sys/user.h or
326 something like that. Using some system include file would
327 have the advantage of probably being more robust in the face
328 of OS upgrades, but the disadvantage of being wrong for
331 #define SIG_PC_FP_OFFSET 530
333 #define FRAME_SAVED_PC(FRAME) \
334 (((FRAME)->signal_handler_caller \
336 ? read_memory_integer ((FRAME)->next->frame + SIG_PC_FP_OFFSET, 4) \
337 : read_memory_integer (read_register (SP_REGNUM) \
338 + SIG_PC_FP_OFFSET - 8, 4) \
340 : read_memory_integer ((FRAME)->frame + 4, 4)) \
343 #define FRAME_ARGS_ADDRESS(fi) ((fi)->frame)
345 #define FRAME_LOCALS_ADDRESS(fi) ((fi)->frame)
347 /* Set VAL to the number of args passed to frame described by FI.
348 Can set VAL to -1, meaning no way to tell. */
350 /* We can't tell how many args there are
351 now that the C compiler delays popping them. */
352 #if !defined (FRAME_NUM_ARGS)
353 #define FRAME_NUM_ARGS(val,fi) (val = -1)
356 /* Return number of bytes at start of arglist that are not really args. */
358 #define FRAME_ARGS_SKIP 8
360 /* Put here the code to store, into a struct frame_saved_regs,
361 the addresses of the saved registers of frame described by FRAME_INFO.
362 This includes special registers such as pc and fp saved in special
363 ways in the stack frame. sp is even more special:
364 the address we return for it IS the sp for the next frame. */
366 #if !defined (FRAME_FIND_SAVED_REGS)
367 #define FRAME_FIND_SAVED_REGS(fi,fsr) m68k_find_saved_regs ((fi), &(fsr))
368 #endif /* no FIND_FRAME_SAVED_REGS. */
371 /* Things needed for making the inferior call functions. */
373 /* The CALL_DUMMY macro is the sequence of instructions, as disassembled
376 fmovemx fp0-fp7,sp@- 0xf227 0xe0ff
377 moveml d0-a5,sp@- 0x48e7 0xfffc
379 movew ccr,sp@- 0x42e7
381 /..* The arguments are pushed at this point by GDB;
382 no code is needed in the dummy for this.
383 The CALL_DUMMY_START_OFFSET gives the position of
384 the following jsr instruction. *../
386 jsr @#0x32323232 0x4eb9 0x3232 0x3232
387 addal #0x69696969,sp 0xdffc 0x6969 0x6969
388 trap #<your BPT_VECTOR number here> 0x4e4?
391 Note this is CALL_DUMMY_LENGTH bytes (28 for the above example).
392 We actually start executing at the jsr, since the pushing of the
393 registers is done by PUSH_DUMMY_FRAME. If this were real code,
394 the arguments for the function called by the jsr would be pushed
395 between the moveml and the jsr, and we could allow it to execute through.
396 But the arguments have to be pushed by GDB after the PUSH_DUMMY_FRAME is
397 done, and we cannot allow the moveml to push the registers again lest
398 they be taken for the arguments. */
400 #if defined (HAVE_68881)
402 #define CALL_DUMMY {0xf227e0ff, 0x48e7fffc, 0x426742e7, 0x4eb93232, 0x3232dffc, 0x69696969, (0x4e404e71 | (BPT_VECTOR << 16))}
403 #define CALL_DUMMY_LENGTH 28 /* Size of CALL_DUMMY */
404 #define CALL_DUMMY_START_OFFSET 12 /* Offset to jsr instruction*/
408 #define CALL_DUMMY {0x48e7fffc, 0x426742e7, 0x4eb93232, 0x3232dffc, 0x69696969, (0x4e404e71 | (BPT_VECTOR << 16))}
409 #define CALL_DUMMY_LENGTH 24 /* Size of CALL_DUMMY */
410 #define CALL_DUMMY_START_OFFSET 8 /* Offset to jsr instruction*/
412 #endif /* HAVE_68881 */
414 /* Insert the specified number of args and function address
415 into a call sequence of the above form stored at DUMMYNAME.
416 We use the BFD routines to store a big-endian value of known size. */
418 #define FIX_CALL_DUMMY(dummyname, pc, fun, nargs, args, type, gcc_p) \
419 { bfd_putb32 (fun, (char *) dummyname + CALL_DUMMY_START_OFFSET + 2); \
420 bfd_putb32 (nargs*4, (char *) dummyname + CALL_DUMMY_START_OFFSET + 8); }
422 /* Push an empty stack frame, to record the current PC, etc. */
424 #define PUSH_DUMMY_FRAME { m68k_push_dummy_frame (); }
426 extern void m68k_push_dummy_frame
PARAMS ((void));
428 extern void m68k_pop_frame
PARAMS ((void));
430 /* Discard from the stack the innermost frame, restoring all registers. */
432 #define POP_FRAME { m68k_pop_frame (); }
434 /* Offset from SP to first arg on stack at first instruction of a function */
436 #define SP_ARG0 (1 * 4)