1 /* Definitions to make GDB run on a vax under 4.2bsd.
2 Copyright 1986, 1987, 1989, 1991, 1993 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 /* There is one known bug with VAX support that I don't know how to
21 fix: if you do a backtrace from a signal handler, you get something
23 #0 0xbc in kill (592, 3)
24 #1 0x7f in hand (...) (...)
25 #2 0x7fffec7e in ?? (2, 0, 2147478112, 94)
26 ^^ GDB doesn't know about sigtramp
27 #3 0x7fffec70 in ?? (592, 2)
28 ^^^^^^^^^^ wrong address
29 #4 0xae in main (...) (...)
31 when the correct backtrace (as given by adb) is:
32 _kill(250,3) from _hand+21
33 _hand(2,0,7fffea60,5e) from 7fffec7e
34 sigtramp(2,0,7fffea60,5e) from _kill+4
35 _kill(250,2) from _main+2e
36 _main(1,7fffeac4,7fffeacc) from start+3d
38 If anyone knows enough about VAX BSD to fix this, please send the
39 fix to bug-gdb@prep.ai.mit.edu. */
41 #define TARGET_BYTE_ORDER LITTLE_ENDIAN
43 /* Offset from address of function to start of its code.
44 Zero on most machines. */
46 #define FUNCTION_START_OFFSET 2
48 /* Advance PC across any function entry prologue instructions
49 to reach some "real" code. */
51 #define SKIP_PROLOGUE(pc) \
52 { register int op = (unsigned char) read_memory_integer (pc, 1); \
53 if (op == 0x11) pc += 2; /* skip brb */ \
54 if (op == 0x31) pc += 3; /* skip brw */ \
56 ((unsigned char) read_memory_integer (pc+2, 1)) == 0x5E) \
57 pc += 3; /* skip subl2 */ \
59 ((unsigned char) read_memory_integer (pc+1, 1)) == 0xAE && \
60 ((unsigned char) read_memory_integer(pc+3, 1)) == 0x5E) \
61 pc += 4; /* skip movab */ \
63 ((unsigned char) read_memory_integer (pc+1, 1)) == 0xCE && \
64 ((unsigned char) read_memory_integer(pc+4, 1)) == 0x5E) \
65 pc += 5; /* skip movab */ \
67 ((unsigned char) read_memory_integer (pc+1, 1)) == 0xEE && \
68 ((unsigned char) read_memory_integer(pc+6, 1)) == 0x5E) \
69 pc += 7; /* skip movab */ \
72 /* Immediately after a function call, return the saved pc.
73 Can't always go through the frames for this because on some machines
74 the new frame is not set up until the new function executes
77 #define SAVED_PC_AFTER_CALL(frame) FRAME_SAVED_PC(frame)
79 #define TARGET_UPAGES 10
80 #define TARGET_NBPG 512
81 #define STACK_END_ADDR (0x80000000 - (TARGET_UPAGES * TARGET_NBPG))
83 /* On the VAX, sigtramp is in the u area. Can't check the exact
84 addresses because for cross-debugging we don't have VAX include
85 files around. This should be close enough. */
86 #define IN_SIGTRAMP(pc, name) ((pc) >= STACK_END_ADDR && (pc < 0x80000000))
88 /* Stack grows downward. */
92 /* Sequence of bytes for breakpoint instruction. */
94 #define BREAKPOINT {3}
96 /* Amount PC must be decremented by after a breakpoint.
97 This is often the number of bytes in BREAKPOINT
100 #define DECR_PC_AFTER_BREAK 0
102 /* Nonzero if instruction at PC is a return instruction. */
104 #define ABOUT_TO_RETURN(pc) (read_memory_integer (pc, 1) == 04)
106 /* Return 1 if P points to an invalid floating point value.
107 LEN is the length in bytes -- not relevant on the Vax. */
109 #define INVALID_FLOAT(p, len) ((*(short *) p & 0xff80) == 0x8000)
111 /* Say how long (ordinary) registers are. */
113 #define REGISTER_TYPE long
115 /* Number of machine registers */
119 /* Initializer for an array of names of registers.
120 There should be NUM_REGS strings in this initializer. */
122 #define REGISTER_NAMES {"r0", "r1", "r2", "r3", "r4", "r5", "r6", "r7", "r8", "r9", "r10", "r11", "ap", "fp", "sp", "pc", "ps"}
124 /* Register numbers of various important registers.
125 Note that some of these values are "real" register numbers,
126 and correspond to the general registers of the machine,
127 and some are "phony" register numbers which are too large
128 to be actual register numbers as far as the user is concerned
129 but do serve to get the desired values when passed to read_register. */
132 #define FP_REGNUM 13 /* Contains address of executing stack frame */
133 #define SP_REGNUM 14 /* Contains address of top of stack */
134 #define PC_REGNUM 15 /* Contains program counter */
135 #define PS_REGNUM 16 /* Contains processor status */
137 /* Total amount of space needed to store our copies of the machine's
138 register state, the array `registers'. */
139 #define REGISTER_BYTES (17*4)
141 /* Index within `registers' of the first byte of the space for
144 #define REGISTER_BYTE(N) ((N) * 4)
146 /* Number of bytes of storage in the actual machine representation
147 for register N. On the vax, all regs are 4 bytes. */
149 #define REGISTER_RAW_SIZE(N) 4
151 /* Number of bytes of storage in the program's representation
152 for register N. On the vax, all regs are 4 bytes. */
154 #define REGISTER_VIRTUAL_SIZE(N) 4
156 /* Largest value REGISTER_RAW_SIZE can have. */
158 #define MAX_REGISTER_RAW_SIZE 4
160 /* Largest value REGISTER_VIRTUAL_SIZE can have. */
162 #define MAX_REGISTER_VIRTUAL_SIZE 4
164 /* Nonzero if register N requires conversion
165 from raw format to virtual format. */
167 #define REGISTER_CONVERTIBLE(N) 0
169 /* Convert data from raw format for register REGNUM
170 to virtual format for register REGNUM. */
172 #define REGISTER_CONVERT_TO_VIRTUAL(REGNUM,FROM,TO) \
173 bcopy ((FROM), (TO), 4);
175 /* Convert data from virtual format for register REGNUM
176 to raw format for register REGNUM. */
178 #define REGISTER_CONVERT_TO_RAW(REGNUM,FROM,TO) \
179 bcopy ((FROM), (TO), 4);
181 /* Return the GDB type object for the "standard" data type
182 of data in register N. */
184 #define REGISTER_VIRTUAL_TYPE(N) builtin_type_int
186 /* Store the address of the place in which to copy the structure the
187 subroutine will return. This is called from call_function. */
189 #define STORE_STRUCT_RETURN(ADDR, SP) \
190 { write_register (1, (ADDR)); }
192 /* Extract from an array REGBUF containing the (raw) register state
193 a function return value of type TYPE, and copy that, in virtual format,
196 #define EXTRACT_RETURN_VALUE(TYPE,REGBUF,VALBUF) \
197 bcopy (REGBUF, VALBUF, TYPE_LENGTH (TYPE))
199 /* Write into appropriate registers a function return value
200 of type TYPE, given in virtual format. */
202 #define STORE_RETURN_VALUE(TYPE,VALBUF) \
203 write_register_bytes (0, VALBUF, TYPE_LENGTH (TYPE))
205 /* Extract from an array REGBUF containing the (raw) register state
206 the address in which a function should return its structure value,
207 as a CORE_ADDR (or an expression that can be used as one). */
209 #define EXTRACT_STRUCT_VALUE_ADDRESS(REGBUF) (*(int *)(REGBUF))
212 /* Describe the pointer in each stack frame to the previous stack frame
215 /* FRAME_CHAIN takes a frame's nominal address
216 and produces the frame's chain-pointer. */
218 /* In the case of the Vax, the frame's nominal address is the FP value,
219 and 12 bytes later comes the saved previous FP value as a 4-byte word. */
221 #define FRAME_CHAIN(thisframe) \
222 (!inside_entry_file ((thisframe)->pc) ? \
223 read_memory_integer ((thisframe)->frame + 12, 4) :\
226 /* Define other aspects of the stack frame. */
228 /* A macro that tells us whether the function invocation represented
229 by FI does not have a frame on the stack associated with it. If it
230 does not, FRAMELESS is set to 1, else 0. */
231 /* On the vax, all functions have frames. */
232 #define FRAMELESS_FUNCTION_INVOCATION(FI, FRAMELESS) {(FRAMELESS) = 0;}
236 #define FRAME_SAVED_PC(FRAME) (read_memory_integer ((FRAME)->frame + 16, 4))
238 /* Cannot find the AP register value directly from the FP value. Must
239 find it saved in the frame called by this one, or in the AP
240 register for the innermost frame. However, there is no way to tell
241 the difference between the innermost frame and a frame for which we
242 just don't know the frame that it called (e.g. "info frame
243 0x7ffec789"). For the sake of argument suppose that the stack is
244 somewhat trashed (which is one reason that "info frame" exists).
245 So return 0 (indicating we don't know the address of
246 the arglist) if we don't know what frame this frame calls. */
247 #define FRAME_ARGS_ADDRESS_CORRECT(fi) \
249 ? read_memory_integer ((fi)->next->frame + 8, 4) \
250 : /* read_register (AP_REGNUM) */ 0))
252 /* In most of GDB, getting the args address is too important to
253 just say "I don't know". This is sometimes wrong for functions
254 that aren't on top of the stack, but c'est la vie. */
255 #define FRAME_ARGS_ADDRESS(fi) \
257 ? read_memory_integer ((fi)->next->frame + 8, 4) \
258 : read_register (AP_REGNUM) /* 0 */))
260 #define FRAME_LOCALS_ADDRESS(fi) ((fi)->frame)
262 /* Return number of args passed to a frame.
263 Can return -1, meaning no way to tell. */
265 #define FRAME_NUM_ARGS(numargs, fi) \
266 { numargs = (0xff & read_memory_integer (FRAME_ARGS_ADDRESS (fi), 1)); }
268 /* Return number of bytes at start of arglist that are not really args. */
270 #define FRAME_ARGS_SKIP 4
272 /* Put here the code to store, into a struct frame_saved_regs,
273 the addresses of the saved registers of frame described by FRAME_INFO.
274 This includes special registers such as pc and fp saved in special
275 ways in the stack frame. sp is even more special:
276 the address we return for it IS the sp for the next frame. */
278 #define FRAME_FIND_SAVED_REGS(frame_info, frame_saved_regs) \
279 { register int regnum; \
280 register int regmask = read_memory_integer ((frame_info)->frame+4, 4) >> 16; \
281 register CORE_ADDR next_addr; \
282 bzero (&frame_saved_regs, sizeof frame_saved_regs); \
283 next_addr = (frame_info)->frame + 16; \
284 /* Regmask's low bit is for register 0, \
285 which is the first one that would be pushed. */ \
286 for (regnum = 0; regnum < 12; regnum++, regmask >>= 1) \
287 (frame_saved_regs).regs[regnum] = (regmask & 1) ? (next_addr += 4) : 0; \
288 (frame_saved_regs).regs[SP_REGNUM] = next_addr + 4; \
289 if (read_memory_integer ((frame_info)->frame + 4, 4) & 0x20000000) \
290 (frame_saved_regs).regs[SP_REGNUM] += 4 + 4 * read_memory_integer (next_addr + 4, 4); \
291 (frame_saved_regs).regs[PC_REGNUM] = (frame_info)->frame + 16; \
292 (frame_saved_regs).regs[FP_REGNUM] = (frame_info)->frame + 12; \
293 (frame_saved_regs).regs[AP_REGNUM] = (frame_info)->frame + 8; \
294 (frame_saved_regs).regs[PS_REGNUM] = (frame_info)->frame + 4; \
297 /* Things needed for making the inferior call functions. */
299 /* Push an empty stack frame, to record the current PC, etc. */
301 #define PUSH_DUMMY_FRAME \
302 { register CORE_ADDR sp = read_register (SP_REGNUM);\
303 register int regnum; \
304 sp = push_word (sp, 0); /* arglist */ \
305 for (regnum = 11; regnum >= 0; regnum--) \
306 sp = push_word (sp, read_register (regnum)); \
307 sp = push_word (sp, read_register (PC_REGNUM)); \
308 sp = push_word (sp, read_register (FP_REGNUM)); \
309 sp = push_word (sp, read_register (AP_REGNUM)); \
310 sp = push_word (sp, (read_register (PS_REGNUM) & 0xffef) \
312 sp = push_word (sp, 0); \
313 write_register (SP_REGNUM, sp); \
314 write_register (FP_REGNUM, sp); \
315 write_register (AP_REGNUM, sp + 17 * sizeof (int)); }
317 /* Discard from the stack the innermost frame, restoring all registers. */
320 { register CORE_ADDR fp = read_register (FP_REGNUM); \
321 register int regnum; \
322 register int regmask = read_memory_integer (fp + 4, 4); \
323 write_register (PS_REGNUM, \
325 | (read_register (PS_REGNUM) & 0xffff0000)); \
326 write_register (PC_REGNUM, read_memory_integer (fp + 16, 4)); \
327 write_register (FP_REGNUM, read_memory_integer (fp + 12, 4)); \
328 write_register (AP_REGNUM, read_memory_integer (fp + 8, 4)); \
330 for (regnum = 0; regnum < 12; regnum++) \
331 if (regmask & (0x10000 << regnum)) \
332 write_register (regnum, read_memory_integer (fp += 4, 4)); \
333 fp = fp + 4 + ((regmask >> 30) & 3); \
334 if (regmask & 0x20000000) \
335 { regnum = read_memory_integer (fp, 4); \
336 fp += (regnum + 1) * 4; } \
337 write_register (SP_REGNUM, fp); \
338 flush_cached_frames (); \
339 set_current_frame (create_new_frame (read_register (FP_REGNUM),\
342 /* This sequence of words is the instructions
343 calls #69, @#32323232
345 Note this is 8 bytes. */
347 #define CALL_DUMMY {0x329f69fb, 0x03323232}
349 #define CALL_DUMMY_START_OFFSET 0 /* Start execution at beginning of dummy */
351 /* Insert the specified number of args and function address
352 into a call sequence of the above form stored at DUMMYNAME. */
354 #define FIX_CALL_DUMMY(dummyname, pc, fun, nargs, args, type, gcc_p) \
355 { *((char *) dummyname + 1) = nargs; \
356 *(int *)((char *) dummyname + 3) = fun; }
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