1 /* Parameters for target machine Intel 960, for GDB, the GNU debugger.
2 Copyright (C) 1990-1991 Free Software Foundation, Inc.
3 Contributed by Intel Corporation.
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 /* Definitions to target GDB to any i960. */
26 /* Hook for the SYMBOL_CLASS of a parameter when decoding DBX symbol
27 information. In the i960, parameters can be stored as locals or as
28 args, depending on the type of the debug record.
30 From empirical observation, gcc960 uses N_LSYM to indicate
31 arguments passed in registers and then copied immediately
32 to the frame, and N_PSYM to indicate arguments passed in a
33 g14-relative argument block. */
35 #define DBX_PARM_SYMBOL_CLASS(type) ((type == N_LSYM)? LOC_LOCAL_ARG: LOC_ARG)
37 /* Byte order is configurable, but this machine runs little-endian. */
38 #define TARGET_BYTE_ORDER LITTLE_ENDIAN
40 /* We have IEEE floating point, if we have any float at all. */
44 /* Define this if the C compiler puts an underscore at the front
45 of external names before giving them to the linker. */
47 #define NAMES_HAVE_UNDERSCORE
50 /* Offset from address of function to start of its code.
51 Zero on most machines. */
53 #define FUNCTION_START_OFFSET 0
55 /* Advance ip across any function entry prologue instructions
56 to reach some "real" code. */
58 #define SKIP_PROLOGUE(ip) { ip = skip_prologue (ip); }
59 extern CORE_ADDR skip_prologue ();
61 /* Immediately after a function call, return the saved ip.
62 Can't always go through the frames for this because on some machines
63 the new frame is not set up until the new function
64 executes some instructions. */
66 #define SAVED_PC_AFTER_CALL(frame) (saved_pc_after_call (frame))
67 extern CORE_ADDR saved_pc_after_call ();
69 /* Stack grows upward */
73 /* Nonzero if instruction at ip is a return instruction. */
75 #define ABOUT_TO_RETURN(ip) (read_memory_integer(ip,4) == 0x0a000000)
77 /* Return 1 if P points to an invalid floating point value.
78 LEN is the length in bytes. */
80 #define INVALID_FLOAT(p, len) (0)
82 /* How long (ordinary) registers are */
84 #define REGISTER_TYPE long
86 /* Number of machine registers */
89 /* Initializer for an array of names of registers.
90 There should be NUM_REGS strings in this initializer. */
92 #define REGISTER_NAMES { \
93 /* 0 */ "pfp", "sp", "rip", "r3", "r4", "r5", "r6", "r7", \
94 /* 8 */ "r8", "r9", "r10", "r11", "r12", "r13", "r14", "r15",\
95 /* 16 */ "g0", "g1", "g2", "g3", "g4", "g5", "g6", "g7", \
96 /* 24 */ "g8", "g9", "g10", "g11", "g12", "g13", "g14", "fp", \
97 /* 32 */ "pc", "ac", "ip", "tc", "fp0", "fp1", "fp2", "fp3", \
100 /* Register numbers of various important registers (used to index
101 into arrays of register names and register values). */
103 #define R0_REGNUM 0 /* First local register */
104 #define SP_REGNUM 1 /* Contains address of top of stack */
105 #define RIP_REGNUM 2 /* Return instruction pointer (local r2) */
106 #define R15_REGNUM 15 /* Last local register */
107 #define G0_REGNUM 16 /* First global register */
108 #define G13_REGNUM 29 /* g13 - holds struct return address */
109 #define G14_REGNUM 30 /* g14 - ptr to arg block / leafproc return address */
110 #define FP_REGNUM 31 /* Contains address of executing stack frame */
111 #define PCW_REGNUM 32 /* process control word */
112 #define ACW_REGNUM 33 /* arithmetic control word */
113 #define IP_REGNUM 34 /* instruction pointer */
114 #define TCW_REGNUM 35 /* trace control word */
115 #define FP0_REGNUM 36 /* First floating point register */
117 /* Some registers have more than one name */
119 #define PC_REGNUM IP_REGNUM /* GDB refers to ip as the Program Counter */
120 #define PFP_REGNUM R0_REGNUM /* Previous frame pointer */
122 /* Total amount of space needed to store our copies of the machine's
123 register state, the array `registers'. */
124 #define REGISTER_BYTES ((36*4) + (4*10))
126 /* Index within `registers' of the first byte of the space for register N. */
128 #define REGISTER_BYTE(N) ( (N) < FP0_REGNUM ? \
129 (4*(N)) : ((10*(N)) - (6*FP0_REGNUM)) )
131 /* The i960 has register windows, sort of. */
133 #define HAVE_REGISTER_WINDOWS
135 /* Is this register part of the register window system? A yes answer
136 implies that 1) The name of this register will not be the same in
137 other frames, and 2) This register is automatically "saved" upon
138 subroutine calls and thus there is no need to search more than one
141 On the i960, in fact, the name of this register in another frame is
142 "mud" -- there is no overlap between the windows. Each window is
143 simply saved into the stack (true for our purposes, after having been
144 flushed; normally they reside on-chip and are restored from on-chip
145 without ever going to memory). */
147 #define REGISTER_IN_WINDOW_P(regnum) ((regnum) <= R15_REGNUM)
149 /* Number of bytes of storage in the actual machine representation
150 for register N. On the i960, all regs are 4 bytes except for floating
151 point, which are 10. NINDY only sends us 8 byte values for these,
152 which is a pain, but VxWorks handles this correctly, so we must. */
154 #define REGISTER_RAW_SIZE(N) ( (N) < FP0_REGNUM ? 4 : 10 )
156 /* Number of bytes of storage in the program's representation for register N. */
158 #define REGISTER_VIRTUAL_SIZE(N) ( (N) < FP0_REGNUM ? 4 : 8 )
160 /* Largest value REGISTER_RAW_SIZE can have. */
162 #define MAX_REGISTER_RAW_SIZE 10
164 /* Largest value REGISTER_VIRTUAL_SIZE can have. */
166 #define MAX_REGISTER_VIRTUAL_SIZE 8
168 /* Nonzero if register N requires conversion from raw format to virtual
171 #define REGISTER_CONVERTIBLE(N) ((N) >= FP0_REGNUM)
173 /* Convert data from raw format for register REGNUM
174 to virtual format for register REGNUM. */
176 #define REGISTER_CONVERT_TO_VIRTUAL(REGNUM,FROM,TO) \
178 extern struct ext_format ext_format_i960; \
180 if ((REGNUM) >= FP0_REGNUM) \
181 ieee_extended_to_double (&ext_format_i960, (FROM), (double *)(TO)); \
183 bcopy ((FROM), (TO), 4); \
186 /* Convert data from virtual format for register REGNUM
187 to raw format for register REGNUM. */
189 #define REGISTER_CONVERT_TO_RAW(REGNUM,FROM,TO) \
191 extern struct ext_format ext_format_i960; \
193 if ((REGNUM) >= FP0_REGNUM) \
194 double_to_ieee_extended (&ext_format_i960, (double *)(FROM), (TO)); \
196 bcopy ((FROM), (TO), 4); \
200 /* Return the GDB type object for the "standard" data type
201 of data in register N. */
203 #define REGISTER_VIRTUAL_TYPE(N) ((N) < FP0_REGNUM ? \
204 builtin_type_int : builtin_type_double)
206 /* Macros for understanding function return values... */
208 /* Does the specified function use the "struct returning" convention
209 or the "value returning" convention? The "value returning" convention
210 almost invariably returns the entire value in registers. The
211 "struct returning" convention often returns the entire value in
212 memory, and passes a pointer (out of or into the function) saying
213 where the value (is or should go).
215 Since this sometimes depends on whether it was compiled with GCC,
216 this is also an argument. This is used in call_function to build a
217 stack, and in value_being_returned to print return values.
219 On i960, a structure is returned in registers g0-g3, if it will fit.
220 If it's more than 16 bytes long, g13 pointed to it on entry. */
222 #define USE_STRUCT_CONVENTION(gcc_p, type) (TYPE_LENGTH (type) > 16)
224 /* Extract from an array REGBUF containing the (raw) register state
225 a function return value of type TYPE, and copy that, in virtual format,
226 into VALBUF. This is only called if USE_STRUCT_CONVENTION for this
229 On the i960 we just take as many bytes as we need from G0 through G3. */
231 #define EXTRACT_RETURN_VALUE(TYPE,REGBUF,VALBUF) \
232 bcopy(REGBUF+REGISTER_BYTE(G0_REGNUM), VALBUF, TYPE_LENGTH (TYPE))
234 /* If USE_STRUCT_CONVENTION produces a 1,
235 extract from an array REGBUF containing the (raw) register state
236 the address in which a function should return its structure value,
237 as a CORE_ADDR (or an expression that can be used as one).
239 Address of where to put structure was passed in in global
240 register g13 on entry. God knows what's in g13 now. The
241 (..., 0) below is to make it appear to return a value, though
242 actually all it does is call error(). */
244 #define EXTRACT_STRUCT_VALUE_ADDRESS(REGBUF) \
245 (error("Don't know where large structure is returned on i960"), 0)
247 /* Write into appropriate registers a function return value
248 of type TYPE, given in virtual format, for "value returning" functions.
250 For 'return' command: not (yet) implemented for i960. */
252 #define STORE_RETURN_VALUE(TYPE,VALBUF) \
253 error ("Returning values from functions is not implemented in i960 gdb")
255 /* Store the address of the place in which to copy the structure the
256 subroutine will return. This is called from call_function. */
258 #define STORE_STRUCT_RETURN(ADDR, SP) \
259 error ("Returning values from functions is not implemented in i960 gdb")
261 /* Describe the pointer in each stack frame to the previous stack frame
264 /* FRAME_CHAIN takes a frame's nominal address
265 and produces the frame's chain-pointer.
267 FRAME_CHAIN_COMBINE takes the chain pointer and the frame's nominal address
268 and produces the nominal address of the caller frame.
270 However, if FRAME_CHAIN_VALID returns zero,
271 it means the given frame is the outermost one and has no caller.
272 In that case, FRAME_CHAIN_COMBINE is not used. */
274 /* We cache information about saved registers in the frame structure,
275 to save us from having to re-scan function prologues every time
276 a register in a non-current frame is accessed. */
278 #define EXTRA_FRAME_INFO \
279 struct frame_saved_regs *fsr; \
280 CORE_ADDR arg_pointer;
282 /* Zero the frame_saved_regs pointer when the frame is initialized,
283 so that FRAME_FIND_SAVED_REGS () will know to allocate and
284 initialize a frame_saved_regs struct the first time it is called.
285 Set the arg_pointer to -1, which is not valid; 0 and other values
286 indicate real, cached values. */
288 #define INIT_EXTRA_FRAME_INFO(fromleaf, fi) \
289 ((fi)->fsr = 0, (fi)->arg_pointer = -1)
291 /* On the i960, we get the chain pointer by reading the PFP saved
292 on the stack and clearing the status bits. */
294 #define FRAME_CHAIN(thisframe) \
295 (read_memory_integer (FRAME_FP(thisframe), 4) & ~0xf)
297 #define FRAME_CHAIN_COMBINE(chain, thisframe) (chain)
299 /* FRAME_CHAIN_VALID returns zero if the given frame is the outermost one
300 and has no caller. In that case, FRAME_CHAIN_COMBINE is not used.
302 On the i960, each various target system type must define FRAME_CHAIN_VALID,
303 since it differs between NINDY and VxWorks, the two currently supported
304 targets types. We leave it undefined here. */
307 /* A macro that tells us whether the function invocation represented
308 by FI does not have a frame on the stack associated with it. If it
309 does not, FRAMELESS is set to 1, else 0. */
311 #define FRAMELESS_FUNCTION_INVOCATION(FI, FRAMELESS) \
312 { (FRAMELESS) = (leafproc_return ((FI)->pc) != 0); }
314 /* Note that in the i960 architecture the return pointer is saved in the
315 *caller's* stack frame.
317 Make sure to zero low-order bits because of bug in 960CA A-step part
318 (instruction addresses should always be word-aligned anyway). */
320 #define FRAME_SAVED_PC(frame) \
321 ((read_memory_integer(FRAME_CHAIN(frame)+8,4)) & ~3)
323 /* On the i960, FRAME_ARGS_ADDRESS should return the value of
324 g14 as passed into the frame, if known. We need a function for this.
325 We cache this value in the frame info if we've already looked it up. */
327 #define FRAME_ARGS_ADDRESS(fi) \
328 (((fi)->arg_pointer != -1)? (fi)->arg_pointer: frame_args_address (fi, 0))
329 extern CORE_ADDR frame_args_address (); /* i960-tdep.c */
331 /* This is the same except it should return 0 when
332 it does not really know where the args are, rather than guessing.
333 This value is not cached since it is only used infrequently. */
335 #define FRAME_ARGS_ADDRESS_CORRECT(fi) (frame_args_address (fi, 1))
337 #define FRAME_LOCALS_ADDRESS(fi) (fi)->frame
339 /* Set NUMARGS to the number of args passed to a frame.
340 Can return -1, meaning no way to tell. */
342 #define FRAME_NUM_ARGS(numargs, fi) (numargs = -1)
344 /* Return number of bytes at start of arglist that are not really args. */
346 #define FRAME_ARGS_SKIP 0
348 /* Produce the positions of the saved registers in a stack frame. */
350 #define FRAME_FIND_SAVED_REGS(frame_info_addr, sr) \
351 frame_find_saved_regs (frame_info_addr, &sr)
352 extern void frame_find_saved_regs(); /* See i960-tdep.c */
355 /* Print status when we get a random unexpected signal. We have more
356 kinds of signals than Unix does... */
358 #define PRINT_RANDOM_SIGNAL(stop_signal) print_fault (stop_signal)
360 /* Things needed for making calls to functions in the inferior process */
362 /* Push an empty stack frame, to record the current ip, etc.
364 Not (yet?) implemented for i960. */
366 #define PUSH_DUMMY_FRAME \
367 error("Function calls into the inferior process are not supported on the i960")
369 /* Discard from the stack the innermost frame, restoring all registers. */
375 /* This sequence of words is the instructions
381 /* #define CALL_DUMMY { 0x86003000, 0x00000000, 0x66003e00 } */
383 /* #define CALL_DUMMY_START_OFFSET 0 *//* Start execution at beginning of dummy */
385 /* Indicate that we don't support calling inferior child functions. */
389 /* Insert the specified number of args and function address
390 into a call sequence of the above form stored at 'dummyname'.
392 Ignore arg count on i960. */
394 /* #define FIX_CALL_DUMMY(dummyname, fun, nargs) *(((int *)dummyname)+1) = fun */
396 #undef FIX_CALL_DUMMY
399 /* Interface definitions for kernel debugger KDB */
400 /* (Not relevant to i960.) */