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. */
24 /* Define the bit, byte, and word ordering of the machine. */
25 #define TARGET_BYTE_ORDER BIG_ENDIAN
27 /* Offset from address of function to start of its code.
28 Zero on most machines. */
30 #define FUNCTION_START_OFFSET 0
32 /* Advance PC across any function entry prologue instructions
33 to reach some "real" code. */
35 #if !defined(SKIP_PROLOGUE)
36 #define SKIP_PROLOGUE(ip) {(ip) = m68k_skip_prologue(ip);}
37 extern CORE_ADDR m68k_skip_prologue
PARAMS ((CORE_ADDR ip
));
40 /* Immediately after a function call, return the saved pc.
41 Can't always go through the frames for this because on some machines
42 the new frame is not set up until the new function executes
45 #define SAVED_PC_AFTER_CALL(frame) \
46 read_memory_integer (read_register (SP_REGNUM), 4)
48 /* Stack grows downward. */
52 /* Sequence of bytes for breakpoint instruction.
53 This is a TRAP instruction. The last 4 bits (0xf below) is the
54 vector. Systems which don't use 0xf should define BPT_VECTOR
55 themselves before including this file. */
57 #if !defined (BPT_VECTOR)
58 #define BPT_VECTOR 0xf
61 #if !defined (BREAKPOINT)
62 #define BREAKPOINT {0x4e, (0x40 | BPT_VECTOR)}
65 /* We always use vector 1 for the "remote" target. This is hardcoded in
67 #define REMOTE_BPT_VECTOR 1
68 #define REMOTE_BREAKPOINT {0x4e, (0x40 | REMOTE_BPT_VECTOR)}
70 /* If your kernel resets the pc after the trap happens you may need to
71 define this before including this file. */
73 #if !defined (DECR_PC_AFTER_BREAK)
74 #define DECR_PC_AFTER_BREAK 2
77 /* Nonzero if instruction at PC is a return instruction. */
78 /* Allow any of the return instructions, including a trapv and a return
81 #define ABOUT_TO_RETURN(pc) ((read_memory_integer (pc, 2) & ~0x3) == 0x4e74)
83 /* Return 1 if P points to an invalid floating point value. */
85 #define INVALID_FLOAT(p, len) 0 /* Just a first guess; not checked */
87 /* Say how long registers are. */
89 #define REGISTER_TYPE long
91 #define REGISTER_BYTES_SUN3 (16*4 + 8 + 8*12 + 3*4 + 4)
92 #define REGISTER_BYTES_FP (16*4 + 8 + 8*12 + 3*4)
93 #define REGISTER_BYTES_NOFP (16*4 + 8)
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 # define REGISTER_BYTES_OK(b) \
104 ((b) == REGISTER_BYTES_SUN3 \
105 || (b) == REGISTER_BYTES_FP \
106 || (b) == REGISTER_BYTES_NOFP)
107 #else /* Not sun3. */
109 # define REGISTER_BYTES_OK(b) \
110 ((b) == REGISTER_BYTES_FP \
111 || (b) == REGISTER_BYTES_NOFP)
112 # define REGISTER_BYTES (16*4 + 8 + 8*12 + 3*4)
113 #endif /* Not sun3. */
115 /* Index within `registers' of the first byte of the space for
118 #define REGISTER_BYTE(N) \
119 ((N) >= FPC_REGNUM ? (((N) - FPC_REGNUM) * 4) + 168 \
120 : (N) >= FP0_REGNUM ? (((N) - FP0_REGNUM) * 12) + 72 \
123 /* Number of bytes of storage in the actual machine representation
124 for register N. On the 68000, all regs are 4 bytes
125 except the floating point regs which are 12 bytes. */
126 /* Note that the unsigned cast here forces the result of the
127 subtraction to very high positive values if N < FP0_REGNUM */
129 #define REGISTER_RAW_SIZE(N) (((unsigned)(N) - FP0_REGNUM) < 8 ? 12 : 4)
131 /* Number of bytes of storage in the program's representation
132 for register N. On the 68000, all regs are 4 bytes
133 except the floating point regs which are 8-byte doubles. */
135 #define REGISTER_VIRTUAL_SIZE(N) (((unsigned)(N) - FP0_REGNUM) < 8 ? 8 : 4)
137 /* Largest value REGISTER_RAW_SIZE can have. */
139 #define MAX_REGISTER_RAW_SIZE 12
141 /* Largest value REGISTER_VIRTUAL_SIZE can have. */
143 #define MAX_REGISTER_VIRTUAL_SIZE 8
145 /* Nonzero if register N requires conversion
146 from raw format to virtual format. */
148 #define REGISTER_CONVERTIBLE(N) (((unsigned)(N) - FP0_REGNUM) < 8)
150 /* Put the declaration out here because if it's in the macros, PCC
152 extern const struct ext_format ext_format_68881
;
154 /* Convert data from raw format for register REGNUM
155 to virtual format for register REGNUM. */
157 #define REGISTER_CONVERT_TO_VIRTUAL(REGNUM,FROM,TO) \
159 if ((REGNUM) >= FP0_REGNUM && (REGNUM) < FPC_REGNUM) \
160 ieee_extended_to_double (&ext_format_68881, (FROM), (double *)(TO)); \
162 memcpy ((TO), (FROM), 4); \
165 /* Convert data from virtual format for register REGNUM
166 to raw format for register REGNUM. */
168 #define REGISTER_CONVERT_TO_RAW(REGNUM,FROM,TO) \
170 if ((REGNUM) >= FP0_REGNUM && (REGNUM) < FPC_REGNUM) \
171 double_to_ieee_extended (&ext_format_68881, (double *)(FROM), (TO)); \
173 memcpy ((TO), (FROM), 4); \
176 /* Return the GDB type object for the "standard" data type
177 of data in register N. */
178 /* Note, for registers which contain addresses return
179 pointer to void, not pointer to char, because we don't
180 want to attempt to print the string after printing the address. */
181 #define REGISTER_VIRTUAL_TYPE(N) \
182 (((unsigned)(N) - FP0_REGNUM) < 8 ? builtin_type_double : \
183 (N) == PC_REGNUM || (N) == FP_REGNUM || (N) == SP_REGNUM ? \
184 lookup_pointer_type (builtin_type_void) : builtin_type_int)
186 /* Initializer for an array of names of registers.
187 Entries beyond the first NUM_REGS are ignored. */
189 #define REGISTER_NAMES \
190 {"d0", "d1", "d2", "d3", "d4", "d5", "d6", "d7", \
191 "a0", "a1", "a2", "a3", "a4", "a5", "fp", "sp", \
193 "fp0", "fp1", "fp2", "fp3", "fp4", "fp5", "fp6", "fp7", \
194 "fpcontrol", "fpstatus", "fpiaddr", "fpcode", "fpflags" }
196 /* Register numbers of various important registers.
197 Note that some of these values are "real" register numbers,
198 and correspond to the general registers of the machine,
199 and some are "phony" register numbers which are too large
200 to be actual register numbers as far as the user is concerned
201 but do serve to get the desired values when passed to read_register. */
204 #define FP_REGNUM 14 /* Contains address of executing stack frame */
205 #define SP_REGNUM 15 /* Contains address of top of stack */
206 #define PS_REGNUM 16 /* Contains processor status */
207 #define PC_REGNUM 17 /* Contains program counter */
208 #define FP0_REGNUM 18 /* Floating point register 0 */
209 #define FPC_REGNUM 26 /* 68881 control register */
210 #define FPS_REGNUM 27 /* 68881 status register */
211 #define FPI_REGNUM 28 /* 68881 iaddr register */
213 /* Store the address of the place in which to copy the structure the
214 subroutine will return. This is called from call_function. */
216 #define STORE_STRUCT_RETURN(ADDR, SP) \
217 { write_register (A1_REGNUM, (ADDR)); }
219 /* Extract from an array REGBUF containing the (raw) register state
220 a function return value of type TYPE, and copy that, in virtual format,
221 into VALBUF. This is assuming that floating point values are returned
222 as doubles in d0/d1. */
224 #if !defined (EXTRACT_RETURN_VALUE)
225 #define EXTRACT_RETURN_VALUE(TYPE,REGBUF,VALBUF) \
228 (TYPE_LENGTH(TYPE) >= 4 ? 0 : 4 - TYPE_LENGTH(TYPE)), \
232 /* Write into appropriate registers a function return value
233 of type TYPE, given in virtual format. Assumes floats are passed
236 #if !defined (STORE_RETURN_VALUE)
237 #define STORE_RETURN_VALUE(TYPE,VALBUF) \
238 write_register_bytes (0, VALBUF, TYPE_LENGTH (TYPE))
241 /* Extract from an array REGBUF containing the (raw) register state
242 the address in which a function should return its structure value,
243 as a CORE_ADDR (or an expression that can be used as one). */
245 #define EXTRACT_STRUCT_VALUE_ADDRESS(REGBUF) (*(CORE_ADDR *)(REGBUF))
247 /* Describe the pointer in each stack frame to the previous stack frame
250 /* FRAME_CHAIN takes a frame's nominal address and produces the frame's
252 In the case of the 68000, the frame's nominal address
253 is the address of a 4-byte word containing the calling frame's address. */
255 /* If we are chaining from sigtramp, then manufacture a sigtramp frame
256 (which isn't really on the stack. I'm not sure this is right for anything
257 but BSD4.3 on an hp300. */
258 #define FRAME_CHAIN(thisframe) \
259 (thisframe->signal_handler_caller \
261 : (!inside_entry_file ((thisframe)->pc) \
262 ? read_memory_integer ((thisframe)->frame, 4) \
265 /* Define other aspects of the stack frame. */
267 /* A macro that tells us whether the function invocation represented
268 by FI does not have a frame on the stack associated with it. If it
269 does not, FRAMELESS is set to 1, else 0. */
270 #define FRAMELESS_FUNCTION_INVOCATION(FI, FRAMELESS) \
272 if ((FI)->signal_handler_caller) \
275 (FRAMELESS) = frameless_look_for_prologue(FI); \
278 /* This was determined by experimentation on hp300 BSD 4.3. Perhaps
279 it corresponds to some offset in /usr/include/sys/user.h or
280 something like that. Using some system include file would
281 have the advantage of probably being more robust in the face
282 of OS upgrades, but the disadvantage of being wrong for
285 #define SIG_PC_FP_OFFSET 530
287 #define FRAME_SAVED_PC(FRAME) \
288 (((FRAME)->signal_handler_caller \
290 ? read_memory_integer ((FRAME)->next->frame + SIG_PC_FP_OFFSET, 4) \
291 : read_memory_integer (read_register (SP_REGNUM) \
292 + SIG_PC_FP_OFFSET - 8, 4) \
294 : read_memory_integer ((FRAME)->frame + 4, 4)) \
297 #define FRAME_ARGS_ADDRESS(fi) ((fi)->frame)
299 #define FRAME_LOCALS_ADDRESS(fi) ((fi)->frame)
301 /* Set VAL to the number of args passed to frame described by FI.
302 Can set VAL to -1, meaning no way to tell. */
304 /* We can't tell how many args there are
305 now that the C compiler delays popping them. */
306 #if !defined (FRAME_NUM_ARGS)
307 #define FRAME_NUM_ARGS(val,fi) (val = -1)
310 /* Return number of bytes at start of arglist that are not really args. */
312 #define FRAME_ARGS_SKIP 8
314 /* Put here the code to store, into a struct frame_saved_regs,
315 the addresses of the saved registers of frame described by FRAME_INFO.
316 This includes special registers such as pc and fp saved in special
317 ways in the stack frame. sp is even more special:
318 the address we return for it IS the sp for the next frame. */
320 #if !defined (FRAME_FIND_SAVED_REGS)
321 #define FRAME_FIND_SAVED_REGS(fi,fsr) m68k_find_saved_regs ((fi), &(fsr))
322 #endif /* no FIND_FRAME_SAVED_REGS. */
325 /* Things needed for making the inferior call functions. */
327 /* The CALL_DUMMY macro is the sequence of instructions, as disassembled
330 These instructions exist only so that m68k_find_saved_regs can parse
331 them as a "prologue"; they are never executed.
333 fmovemx fp0-fp7,sp@- 0xf227 0xe0ff
334 moveml d0-a5,sp@- 0x48e7 0xfffc
336 movew ccr,sp@- 0x42e7
338 The arguments are pushed at this point by GDB; no code is needed in
339 the dummy for this. The CALL_DUMMY_START_OFFSET gives the position
340 of the following jsr instruction. That is where we start
343 jsr @#0x32323232 0x4eb9 0x3232 0x3232
344 addal #0x69696969,sp 0xdffc 0x6969 0x6969
345 trap #<your BPT_VECTOR number here> 0x4e4?
348 Note this is CALL_DUMMY_LENGTH bytes (28 for the above example).
350 The dummy frame always saves the floating-point registers, whether they
351 actually exist on this target or not. */
353 /* FIXME: Wrong to hardwire this as BPT_VECTOR when sometimes it
354 should be REMOTE_BPT_VECTOR. We should be using
355 target_insert_breakpoint (but then I think we need
356 target_remove_breakpoint somewhere--easiest way to make this happen
357 is to make this breakpoint a real breakpoint.c type breakpoint). */
359 #define CALL_DUMMY {0xf227e0ff, 0x48e7fffc, 0x426742e7, 0x4eb93232, 0x3232dffc, 0x69696969, (0x4e404e71 | (BPT_VECTOR << 16))}
360 #define CALL_DUMMY_LENGTH 28 /* Size of CALL_DUMMY */
361 #define CALL_DUMMY_START_OFFSET 12 /* Offset to jsr instruction*/
363 /* Insert the specified number of args and function address
364 into a call sequence of the above form stored at DUMMYNAME.
365 We use the BFD routines to store a big-endian value of known size. */
367 #define FIX_CALL_DUMMY(dummyname, pc, fun, nargs, args, type, gcc_p) \
368 { bfd_putb32 (fun, (char *) dummyname + CALL_DUMMY_START_OFFSET + 2); \
369 bfd_putb32 (nargs*4, (char *) dummyname + CALL_DUMMY_START_OFFSET + 8); }
371 /* Push an empty stack frame, to record the current PC, etc. */
373 #define PUSH_DUMMY_FRAME { m68k_push_dummy_frame (); }
375 extern void m68k_push_dummy_frame
PARAMS ((void));
377 extern void m68k_pop_frame
PARAMS ((void));
379 /* Discard from the stack the innermost frame, restoring all registers. */
381 #define POP_FRAME { m68k_pop_frame (); }
383 /* Offset from SP to first arg on stack at first instruction of a function */
385 #define SP_ARG0 (1 * 4)