1 /* Parameters for target execution on an RS6000, for GDB, the GNU debugger.
2 Copyright 1986, 1987, 1989, 1991, 1992, 1993, 1994
3 Free Software Foundation, Inc.
4 Contributed by IBM Corporation.
6 This file is part of GDB.
8 This program is free software; you can redistribute it and/or modify
9 it under the terms of the GNU General Public License as published by
10 the Free Software Foundation; either version 2 of the License, or
11 (at your option) any later version.
13 This program is distributed in the hope that it will be useful,
14 but WITHOUT ANY WARRANTY; without even the implied warranty of
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 GNU General Public License for more details.
18 You should have received a copy of the GNU General Public License
19 along with this program; if not, write to the Free Software
20 Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */
22 /* Minimum possible text address in AIX */
24 #define TEXT_SEGMENT_BASE 0x10000000
26 /* Load segment of a given pc value. */
28 #define PC_LOAD_SEGMENT(PC) pc_load_segment_name(PC)
30 /* AIX cc seems to get this right. */
32 #define BELIEVE_PCC_PROMOTION 1
34 /* return true if a given `pc' value is in `call dummy' function. */
35 /* FIXME: This just checks for the end of the stack, which is broken
36 for things like stepping through gcc nested function stubs. */
37 #define PC_IN_CALL_DUMMY(STOP_PC, STOP_SP, STOP_FRAME_ADDR) \
38 (STOP_SP < STOP_PC && STOP_PC < STACK_END_ADDR)
41 extern unsigned int text_start
, data_start
;
42 extern char *corefile
;
44 extern int inferior_pid
;
46 /* setpgrp() messes up controling terminal. The other version of it
48 #define setpgrp(XX,YY) setpgid (XX, YY)
50 /* We are missing register descriptions in the system header files. Sigh! */
53 int gregs
[32]; /* general purpose registers */
54 int pc
; /* program conter */
55 int ps
; /* processor status, or machine state */
59 double fpregs
[32]; /* floating GP registers */
63 /* To be used by function_frame_info. */
65 struct aix_framedata
{
66 int offset
; /* # of bytes in gpr's and fpr's are saved */
67 int saved_gpr
; /* smallest # of saved gpr */
68 int saved_fpr
; /* smallest # of saved fpr */
69 int alloca_reg
; /* alloca register number (frame ptr) */
70 char frameless
; /* true if frameless functions. */
71 char nosavedpc
; /* true if pc not saved. */
75 function_frame_info
PARAMS ((CORE_ADDR
, struct aix_framedata
*));
77 /* Define the byte order of the machine. */
79 #define TARGET_BYTE_ORDER BIG_ENDIAN
81 /* AIX's assembler doesn't grok dollar signs in identifiers.
82 So we use dots instead. This item must be coordinated with G++. */
84 #define CPLUS_MARKER '.'
86 /* Offset from address of function to start of its code.
87 Zero on most machines. */
89 #define FUNCTION_START_OFFSET 0
91 /* Advance PC across any function entry prologue instructions
92 to reach some "real" code. */
94 #define SKIP_PROLOGUE(pc) pc = skip_prologue (pc)
96 /* If PC is in some function-call trampoline code, return the PC
97 where the function itself actually starts. If not, return NULL. */
99 #define SKIP_TRAMPOLINE_CODE(pc) skip_trampoline_code (pc)
101 /* Number of trap signals we need to skip over, once the inferior process
104 #define START_INFERIOR_TRAPS_EXPECTED 2
106 /* AIX has a couple of strange returns from wait(). */
108 #define CHILD_SPECIAL_WAITSTATUS(ourstatus, hoststatus) ( \
109 /* "stop after load" status. */ \
110 (hoststatus) == 0x57c ? (ourstatus)->kind = TARGET_WAITKIND_LOADED, 1 : \
112 /* signal 0. I have no idea why wait(2) returns with this status word. */ \
113 /* It looks harmless. */ \
114 (hoststatus) == 0x7f ? (ourstatus)->kind = TARGET_WAITKIND_SPURIOUS, 1 : \
116 /* A normal waitstatus. Let the usual macros deal with it. */ \
119 /* In xcoff, we cannot process line numbers when we see them. This is
120 mainly because we don't know the boundaries of the include files. So,
121 we postpone that, and then enter and sort(?) the whole line table at
122 once, when we are closing the current symbol table in end_symtab(). */
124 #define PROCESS_LINENUMBER_HOOK() aix_process_linenos ()
126 /* Immediately after a function call, return the saved pc.
127 Can't go through the frames for this because on some machines
128 the new frame is not set up until the new function executes
129 some instructions. */
131 #define SAVED_PC_AFTER_CALL(frame) read_register (LR_REGNUM)
133 /* Address of end of stack space. */
135 #define STACK_END_ADDR 0x2ff80000
137 /* Stack grows downward. */
142 /* No, we shouldn't use this. push_arguments() should leave stack in a
144 /* Stack has strict alignment. */
146 #define STACK_ALIGN(ADDR) (((ADDR)+7)&-8)
149 /* This is how argumets pushed onto stack or passed in registers. */
151 #define PUSH_ARGUMENTS(nargs, args, sp, struct_return, struct_addr) \
152 sp = push_arguments(nargs, args, sp, struct_return, struct_addr)
154 /* Sequence of bytes for breakpoint instruction. */
156 #define BREAKPOINT {0x7d, 0x82, 0x10, 0x08}
158 /* Amount PC must be decremented by after a breakpoint.
159 This is often the number of bytes in BREAKPOINT
162 #define DECR_PC_AFTER_BREAK 0
164 /* Nonzero if instruction at PC is a return instruction. */
165 /* Allow any of the return instructions, including a trapv and a return
168 #define ABOUT_TO_RETURN(pc) \
169 ((read_memory_integer (pc, 4) & 0xfe8007ff) == 0x4e800020)
171 /* Say how long (ordinary) registers are. This is a piece of bogosity
172 used in push_word and a few other places; REGISTER_RAW_SIZE is the
173 real way to know how big a register is. */
175 #define REGISTER_SIZE 4
177 /* Number of machine registers */
181 /* Initializer for an array of names of registers.
182 There should be NUM_REGS strings in this initializer. */
184 #define REGISTER_NAMES \
185 {"r0", "r1", "r2", "r3", "r4", "r5", "r6", "r7", \
186 "r8", "r9", "r10","r11","r12","r13","r14","r15", \
187 "r16","r17","r18","r19","r20","r21","r22","r23", \
188 "r24","r25","r26","r27","r28","r29","r30","r31", \
189 "f0", "f1", "f2", "f3", "f4", "f5", "f6", "f7", \
190 "f8", "f9", "f10","f11","f12","f13","f14","f15", \
191 "f16","f17","f18","f19","f20","f21","f22","f23", \
192 "f24","f25","f26","f27","f28","f29","f30","f31", \
193 "pc", "ps", "cnd", "lr", "cnt", "xer", "mq" }
195 /* Register numbers of various important registers.
196 Note that some of these values are "real" register numbers,
197 and correspond to the general registers of the machine,
198 and some are "phony" register numbers which are too large
199 to be actual register numbers as far as the user is concerned
200 but do serve to get the desired values when passed to read_register. */
202 #define FP_REGNUM 1 /* Contains address of executing stack frame */
203 #define SP_REGNUM 1 /* Contains address of top of stack */
204 #define TOC_REGNUM 2 /* TOC register */
205 #define FP0_REGNUM 32 /* Floating point register 0 */
206 #define GP0_REGNUM 0 /* GPR register 0 */
207 #define FP0_REGNUM 32 /* FPR (Floating point) register 0 */
208 #define FPLAST_REGNUM 63 /* Last floating point register */
210 /* Special purpose registers... */
211 /* P.S. keep these in the same order as in /usr/mstsave.h `mstsave' structure, for
214 #define PC_REGNUM 64 /* Program counter (instruction address %iar) */
215 #define PS_REGNUM 65 /* Processor (or machine) status (%msr) */
216 #define CR_REGNUM 66 /* Condition register */
217 #define LR_REGNUM 67 /* Link register */
218 #define CTR_REGNUM 68 /* Count register */
219 #define XER_REGNUM 69 /* Fixed point exception registers */
220 #define MQ_REGNUM 70 /* Multiply/quotient register */
222 #define FIRST_SP_REGNUM 64 /* first special register number */
223 #define LAST_SP_REGNUM 70 /* last special register number */
225 /* Total amount of space needed to store our copies of the machine's
226 register state, the array `registers'.
230 7 4-byte special purpose registers,
232 total 416 bytes. Keep some extra space for now, in case to add more. */
234 #define REGISTER_BYTES 420
237 /* Index within `registers' of the first byte of the space for
240 #define REGISTER_BYTE(N) \
242 ((N) > FPLAST_REGNUM) ? ((((N) - FPLAST_REGNUM -1) * 4) + 384)\
243 :((N) >= FP0_REGNUM) ? ((((N) - FP0_REGNUM) * 8) + 128) \
246 /* Number of bytes of storage in the actual machine representation
248 /* Note that the unsigned cast here forces the result of the
249 subtractiion to very high positive values if N < FP0_REGNUM */
251 #define REGISTER_RAW_SIZE(N) (((unsigned)(N) - FP0_REGNUM) < 32 ? 8 : 4)
253 /* Number of bytes of storage in the program's representation
254 for register N. On the RS6000, all regs are 4 bytes
255 except the floating point regs which are 8-byte doubles. */
257 #define REGISTER_VIRTUAL_SIZE(N) (((unsigned)(N) - FP0_REGNUM) < 32 ? 8 : 4)
259 /* Largest value REGISTER_RAW_SIZE can have. */
261 #define MAX_REGISTER_RAW_SIZE 8
263 /* Largest value REGISTER_VIRTUAL_SIZE can have. */
265 #define MAX_REGISTER_VIRTUAL_SIZE 8
267 /* convert a dbx stab register number (from `r' declaration) to a gdb REGNUM */
269 #define STAB_REG_TO_REGNUM(value) (value)
271 /* Nonzero if register N requires conversion
272 from raw format to virtual format.
273 The register format for rs6000 floating point registers is always
274 double, we need a conversion if the memory format is float. */
276 #define REGISTER_CONVERTIBLE(N) ((N) >= FP0_REGNUM && (N) <= FPLAST_REGNUM)
278 /* Convert data from raw format for register REGNUM in buffer FROM
279 to virtual format with type TYPE in buffer TO. */
281 #define REGISTER_CONVERT_TO_VIRTUAL(REGNUM,TYPE,FROM,TO) \
283 if (TYPE_LENGTH (TYPE) != REGISTER_RAW_SIZE (REGNUM)) \
285 double val = extract_floating ((FROM), REGISTER_RAW_SIZE (REGNUM)); \
286 store_floating ((TO), TYPE_LENGTH (TYPE), val); \
289 memcpy ((TO), (FROM), REGISTER_RAW_SIZE (REGNUM)); \
292 /* Convert data from virtual format with type TYPE in buffer FROM
293 to raw format for register REGNUM in buffer TO. */
295 #define REGISTER_CONVERT_TO_RAW(TYPE,REGNUM,FROM,TO) \
297 if (TYPE_LENGTH (TYPE) != REGISTER_RAW_SIZE (REGNUM)) \
299 double val = extract_floating ((FROM), TYPE_LENGTH (TYPE)); \
300 store_floating ((TO), REGISTER_RAW_SIZE (REGNUM), val); \
303 memcpy ((TO), (FROM), REGISTER_RAW_SIZE (REGNUM)); \
306 /* Return the GDB type object for the "standard" data type
307 of data in register N. */
309 #define REGISTER_VIRTUAL_TYPE(N) \
310 (((unsigned)(N) - FP0_REGNUM) < 32 ? builtin_type_double : builtin_type_int)
312 /* Store the address of the place in which to copy the structure the
313 subroutine will return. This is called from call_function. */
314 /* in RS6000, struct return addresses are passed as an extra parameter in r3.
315 In function return, callee is not responsible of returning this address back.
316 Since gdb needs to find it, we will store in a designated variable
317 `rs6000_struct_return_address'. */
319 extern CORE_ADDR rs6000_struct_return_address
;
321 #define STORE_STRUCT_RETURN(ADDR, SP) \
322 { write_register (3, (ADDR)); \
323 rs6000_struct_return_address = (ADDR); }
325 /* Extract from an array REGBUF containing the (raw) register state
326 a function return value of type TYPE, and copy that, in virtual format,
329 /* #define EXTRACT_RETURN_VALUE(TYPE,REGBUF,VALBUF) \
330 memcpy (VALBUF, REGBUF, TYPE_LENGTH (TYPE)) */
332 #define EXTRACT_RETURN_VALUE(TYPE,REGBUF,VALBUF) \
333 extract_return_value(TYPE,REGBUF,VALBUF)
335 /* Write into appropriate registers a function return value
336 of type TYPE, given in virtual format. */
338 #define STORE_RETURN_VALUE(TYPE,VALBUF) \
340 if (TYPE_CODE (TYPE) == TYPE_CODE_FLT) \
342 /* Floating point values are returned starting from FPR1 and up. \
343 Say a double_double_double type could be returned in \
344 FPR1/FPR2/FPR3 triple. */ \
346 write_register_bytes (REGISTER_BYTE (FP0_REGNUM+1), (VALBUF), \
347 TYPE_LENGTH (TYPE)); \
349 /* Everything else is returned in GPR3 and up. */ \
350 write_register_bytes (REGISTER_BYTE (GP0_REGNUM+3), (VALBUF), \
351 TYPE_LENGTH (TYPE)); \
355 /* Extract from an array REGBUF containing the (raw) register state
356 the address in which a function should return its structure value,
357 as a CORE_ADDR (or an expression that can be used as one). */
359 #define EXTRACT_STRUCT_VALUE_ADDRESS(REGBUF) rs6000_struct_return_address
361 /* Describe the pointer in each stack frame to the previous stack frame
364 /* FRAME_CHAIN takes a frame's nominal address
365 and produces the frame's chain-pointer. */
367 /* In the case of the RS6000, the frame's nominal address
368 is the address of a 4-byte word containing the calling frame's address. */
370 #define FRAME_CHAIN(thisframe) rs6000_frame_chain (thisframe)
374 CORE_ADDR rs6000_frame_chain
PARAMS ((struct frame_info
*));
376 /* Define other aspects of the stack frame. */
378 /* A macro that tells us whether the function invocation represented
379 by FI does not have a frame on the stack associated with it. If it
380 does not, FRAMELESS is set to 1, else 0. */
382 #define FRAMELESS_FUNCTION_INVOCATION(FI, FRAMELESS) \
383 FRAMELESS = frameless_function_invocation (FI, 0)
385 /* Functions calling alloca() change the value of the stack pointer. We
386 need to use initial stack pointer (which is saved in r31 by gcc) in
387 such cases. If a compiler emits traceback table, then we should use the
388 alloca register specified in traceback table. FIXME. */
389 /* Also, it is a good idea to cache information about frame's saved registers
390 in the frame structure to speed things up. See tm-m88k.h. FIXME. */
392 #define EXTRA_FRAME_INFO \
393 CORE_ADDR initial_sp; /* initial stack pointer. */ \
394 struct frame_saved_regs *cache_fsr; /* saved registers */
396 #define INIT_FRAME_PC_FIRST(fromleaf, prev) \
397 prev->pc = (fromleaf ? SAVED_PC_AFTER_CALL (prev->next) : \
398 prev->next ? FRAME_SAVED_PC (prev->next) : read_pc ());
399 #define INIT_FRAME_PC(fromleaf, prev) /* nothing */
400 #define INIT_EXTRA_FRAME_INFO(fromleaf, fi) \
401 fi->initial_sp = 0; \
403 if (fi->next != (CORE_ADDR)0 \
404 && fi->pc < TEXT_SEGMENT_BASE) \
405 /* We're in get_prev_frame_info */ \
406 /* and this is a special signal frame. */ \
407 /* (fi->pc will be some low address in the kernel, */ \
408 /* to which the signal handler returns). */
409 fi
->signal_handler_caller
= 1;
411 /* If the kernel has to deliver a signal, it pushes a sigcontext
412 structure on the stack and then calls the signal handler, passing
413 the address of the sigcontext in an argument register. Usually
414 the signal handler doesn't save this register, so we have to
415 access the sigcontext structure via an offset from the signal handler
417 The following constants were determined by experimentation on AIX 3.2. */
418 #define SIG_FRAME_PC_OFFSET 96
419 #define SIG_FRAME_FP_OFFSET 284
421 /* Frameless function invocation in IBM RS/6000 is sometimes
422 half-done. It perfectly sets up a new frame, e.g. a new frame (in
423 fact stack) pointer, etc, but it doesn't save the %pc. We call
424 frameless_function_invocation to tell us how to get the %pc. */
426 #define FRAME_SAVED_PC(FRAME) \
427 (frameless_function_invocation (FRAME, 1) \
428 ? SAVED_PC_AFTER_CALL (FRAME) \
429 : (FRAME)->signal_handler_caller \
430 ? read_memory_integer ((FRAME)->frame + SIG_FRAME_PC_OFFSET, 4) \
431 : read_memory_integer (rs6000_frame_chain (FRAME) + 8, 4))
433 #define FRAME_ARGS_ADDRESS(FI) \
434 (((struct frame_info*)(FI))->initial_sp ? \
435 ((struct frame_info*)(FI))->initial_sp : \
436 frame_initial_stack_address (FI))
438 #define FRAME_LOCALS_ADDRESS(FI) FRAME_ARGS_ADDRESS(FI)
441 /* Set VAL to the number of args passed to frame described by FI.
442 Can set VAL to -1, meaning no way to tell. */
444 /* We can't tell how many args there are
445 now that the C compiler delays popping them. */
447 #define FRAME_NUM_ARGS(val,fi) (val = -1)
449 /* Return number of bytes at start of arglist that are not really args. */
451 #define FRAME_ARGS_SKIP 8 /* Not sure on this. FIXMEmgo */
453 /* Put here the code to store, into a struct frame_saved_regs,
454 the addresses of the saved registers of frame described by FRAME_INFO.
455 This includes special registers such as pc and fp saved in special
456 ways in the stack frame. sp is even more special:
457 the address we return for it IS the sp for the next frame. */
458 /* In the following implementation for RS6000, we did *not* save sp. I am
459 not sure if it will be needed. The following macro takes care of gpr's
462 #define FRAME_FIND_SAVED_REGS(FRAME_INFO, FRAME_SAVED_REGS) \
465 CORE_ADDR frame_addr, func_start; \
466 struct aix_framedata fdata; \
468 /* find the start of the function and collect info about its frame. */\
470 func_start = get_pc_function_start ((FRAME_INFO)->pc) + FUNCTION_START_OFFSET; \
471 function_frame_info (func_start, &fdata); \
472 memset (&(FRAME_SAVED_REGS), '\0', sizeof (FRAME_SAVED_REGS)); \
474 /* if there were any saved registers, figure out parent's stack pointer. */ \
476 /* the following is true only if the frame doesn't have a call to alloca(), \
478 if (fdata.saved_fpr >= 0 || fdata.saved_gpr >= 0) { \
479 if ((FRAME_INFO)->prev && (FRAME_INFO)->prev->frame) \
480 frame_addr = (FRAME_INFO)->prev->frame; \
482 frame_addr = read_memory_integer ((FRAME_INFO)->frame, 4); \
485 /* if != -1, fdata.saved_fpr is the smallest number of saved_fpr. All fpr's \
486 from saved_fpr to fp31 are saved right underneath caller stack pointer, \
487 starting from fp31 first. */ \
489 if (fdata.saved_fpr >= 0) { \
490 for (ii=31; ii >= fdata.saved_fpr; --ii) \
491 (FRAME_SAVED_REGS).regs [FP0_REGNUM + ii] = frame_addr - ((32 - ii) * 8); \
492 frame_addr -= (32 - fdata.saved_fpr) * 8; \
495 /* if != -1, fdata.saved_gpr is the smallest number of saved_gpr. All gpr's \
496 from saved_gpr to gpr31 are saved right under saved fprs, starting \
499 if (fdata.saved_gpr >= 0) \
500 for (ii=31; ii >= fdata.saved_gpr; --ii) \
501 (FRAME_SAVED_REGS).regs [ii] = frame_addr - ((32 - ii) * 4); \
505 /* Things needed for making the inferior call functions. */
507 /* Push an empty stack frame, to record the current PC, etc. */
508 /* Change these names into rs6k_{push, pop}_frame(). FIXMEmgo. */
510 #define PUSH_DUMMY_FRAME push_dummy_frame ()
512 /* Discard from the stack the innermost frame,
513 restoring all saved registers. */
515 #define POP_FRAME pop_frame ()
517 /* This sequence of words is the instructions:
519 mflr r0 // 0x7c0802a6
521 stfd r?, num(r1) // 0xd8010000 there should be 32 of this??
523 stm r0, num(r1) // 0xbc010000
524 stu r1, num(r1) // 0x94210000
526 // the function we want to branch might be in a different load
527 // segment. reset the toc register. Note that the actual toc address
528 // will be fix by fix_call_dummy () along with function address.
530 st r2, 0x14(r1) // 0x90410014 save toc register
531 liu r2, 0x1234 // 0x3c401234 reset a new toc value 0x12345678
532 oril r2, r2,0x5678 // 0x60425678
534 // load absolute address 0x12345678 to r0
535 liu r0, 0x1234 // 0x3c001234
536 oril r0, r0,0x5678 // 0x60005678
537 mtctr r0 // 0x7c0903a6 ctr <- r0
538 bctrl // 0x4e800421 jump subroutine 0x12345678 (%ctr)
539 cror 0xf, 0xf, 0xf // 0x4def7b82
540 brpt // 0x7d821008, breakpoint
541 cror 0xf, 0xf, 0xf // 0x4def7b82 (for 8 byte alignment)
544 We actually start executing by saving the toc register first, since the pushing
545 of the registers is done by PUSH_DUMMY_FRAME. If this were real code,
546 the arguments for the function called by the `bctrl' would be pushed
547 between the `stu' and the `bctrl', and we could allow it to execute through.
548 But the arguments have to be pushed by GDB after the PUSH_DUMMY_FRAME is done,
549 and we cannot allow to push the registers again.
552 #define CALL_DUMMY {0x7c0802a6, 0xd8010000, 0xbc010000, 0x94210000, \
553 0x90410014, 0x3c401234, 0x60425678, \
554 0x3c001234, 0x60005678, 0x7c0903a6, 0x4e800421, \
555 0x4def7b82, 0x7d821008, 0x4def7b82 }
558 /* keep this as multiple of 8 (%sp requires 8 byte alignment) */
559 #define CALL_DUMMY_LENGTH 56
561 #define CALL_DUMMY_START_OFFSET 16
563 /* Insert the specified number of args and function address
564 into a call sequence of the above form stored at DUMMYNAME. */
566 #define FIX_CALL_DUMMY(dummyname, pc, fun, nargs, args, type, using_gcc) \
567 fix_call_dummy(dummyname, pc, fun, nargs, type)
569 /* Usually a function pointer's representation is simply the address of
570 the function. On the RS/6000 however, a function pointer is represented
571 by a pointer to a TOC entry. This TOC entry contains three words,
572 the first word is the address of the function, the second word is the
573 TOC pointer (r2), and the third word is the static chain value.
574 Throughout GDB it is currently assumed that a function pointer contains
575 the address of the function, which is not easy to fix.
576 In addition, the conversion of a function address to a function
577 pointer would require allocation of a TOC entry in the inferior's
578 memory space, with all its drawbacks.
579 To be able to call C++ virtual methods in the inferior (which are called
580 via function pointers), find_function_addr uses this macro to
581 get the function address from a function pointer. */
582 #define CONVERT_FROM_FUNC_PTR_ADDR(ADDR) read_memory_integer (ADDR, 4)
584 /* Flag for machine-specific stuff in shared files. FIXME */
585 #define IBM6000_TARGET
587 /* RS6000/AIX does not support PT_STEP. Has to be simulated. */
589 #define NO_SINGLE_STEP