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 /* We are missing register descriptions in the system header files. Sigh! */
49 int gregs
[32]; /* general purpose registers */
50 int pc
; /* program conter */
51 int ps
; /* processor status, or machine state */
55 double fpregs
[32]; /* floating GP registers */
59 /* To be used by function_frame_info. */
61 struct aix_framedata
{
62 int offset
; /* # of bytes in gpr's and fpr's are saved */
63 int saved_gpr
; /* smallest # of saved gpr */
64 int saved_fpr
; /* smallest # of saved fpr */
65 int alloca_reg
; /* alloca register number (frame ptr) */
66 char frameless
; /* true if frameless functions. */
67 char nosavedpc
; /* true if pc not saved. */
71 function_frame_info
PARAMS ((CORE_ADDR
, struct aix_framedata
*));
73 /* Define the byte order of the machine. */
75 #define TARGET_BYTE_ORDER BIG_ENDIAN
77 /* AIX's assembler doesn't grok dollar signs in identifiers.
78 So we use dots instead. This item must be coordinated with G++. */
80 #define CPLUS_MARKER '.'
82 /* Offset from address of function to start of its code.
83 Zero on most machines. */
85 #define FUNCTION_START_OFFSET 0
87 /* Advance PC across any function entry prologue instructions
88 to reach some "real" code. */
90 #define SKIP_PROLOGUE(pc) pc = skip_prologue (pc)
92 /* If PC is in some function-call trampoline code, return the PC
93 where the function itself actually starts. If not, return NULL. */
95 #define SKIP_TRAMPOLINE_CODE(pc) skip_trampoline_code (pc)
97 /* Number of trap signals we need to skip over, once the inferior process
100 #define START_INFERIOR_TRAPS_EXPECTED 2
102 /* AIX has a couple of strange returns from wait(). */
104 #define CHILD_SPECIAL_WAITSTATUS(ourstatus, hoststatus) ( \
105 /* "stop after load" status. */ \
106 (hoststatus) == 0x57c ? (ourstatus)->kind = TARGET_WAITKIND_LOADED, 1 : \
108 /* signal 0. I have no idea why wait(2) returns with this status word. */ \
109 /* It looks harmless. */ \
110 (hoststatus) == 0x7f ? (ourstatus)->kind = TARGET_WAITKIND_SPURIOUS, 1 : \
112 /* A normal waitstatus. Let the usual macros deal with it. */ \
115 /* In xcoff, we cannot process line numbers when we see them. This is
116 mainly because we don't know the boundaries of the include files. So,
117 we postpone that, and then enter and sort(?) the whole line table at
118 once, when we are closing the current symbol table in end_symtab(). */
120 #define PROCESS_LINENUMBER_HOOK() aix_process_linenos ()
122 /* Immediately after a function call, return the saved pc.
123 Can't go through the frames for this because on some machines
124 the new frame is not set up until the new function executes
125 some instructions. */
127 #define SAVED_PC_AFTER_CALL(frame) read_register (LR_REGNUM)
129 /* Address of end of stack space. */
131 #define STACK_END_ADDR 0x2ff80000
133 /* Stack grows downward. */
138 /* No, we shouldn't use this. push_arguments() should leave stack in a
140 /* Stack has strict alignment. */
142 #define STACK_ALIGN(ADDR) (((ADDR)+7)&-8)
145 /* This is how argumets pushed onto stack or passed in registers. */
147 #define PUSH_ARGUMENTS(nargs, args, sp, struct_return, struct_addr) \
148 sp = push_arguments(nargs, args, sp, struct_return, struct_addr)
150 /* Sequence of bytes for breakpoint instruction. */
152 #define BIG_BREAKPOINT { 0x7d, 0x82, 0x10, 0x08 }
153 #define LITTLE_BREAKPOINT { 0x08, 0x10, 0x82, 0x7d }
155 /* Amount PC must be decremented by after a breakpoint.
156 This is often the number of bytes in BREAKPOINT
159 #define DECR_PC_AFTER_BREAK 0
161 /* Nonzero if instruction at PC is a return instruction. */
162 /* Allow any of the return instructions, including a trapv and a return
165 #define ABOUT_TO_RETURN(pc) \
166 ((read_memory_integer (pc, 4) & 0xfe8007ff) == 0x4e800020)
168 /* Say how long (ordinary) registers are. This is a piece of bogosity
169 used in push_word and a few other places; REGISTER_RAW_SIZE is the
170 real way to know how big a register is. */
172 #define REGISTER_SIZE 4
174 /* Number of machine registers */
178 /* Initializer for an array of names of registers.
179 There should be NUM_REGS strings in this initializer. */
181 #define REGISTER_NAMES \
182 {"r0", "r1", "r2", "r3", "r4", "r5", "r6", "r7", \
183 "r8", "r9", "r10","r11","r12","r13","r14","r15", \
184 "r16","r17","r18","r19","r20","r21","r22","r23", \
185 "r24","r25","r26","r27","r28","r29","r30","r31", \
186 "f0", "f1", "f2", "f3", "f4", "f5", "f6", "f7", \
187 "f8", "f9", "f10","f11","f12","f13","f14","f15", \
188 "f16","f17","f18","f19","f20","f21","f22","f23", \
189 "f24","f25","f26","f27","f28","f29","f30","f31", \
190 "pc", "ps", "cnd", "lr", "cnt", "xer", "mq" }
192 /* Register numbers of various important registers.
193 Note that some of these values are "real" register numbers,
194 and correspond to the general registers of the machine,
195 and some are "phony" register numbers which are too large
196 to be actual register numbers as far as the user is concerned
197 but do serve to get the desired values when passed to read_register. */
199 #define FP_REGNUM 1 /* Contains address of executing stack frame */
200 #define SP_REGNUM 1 /* Contains address of top of stack */
201 #define TOC_REGNUM 2 /* TOC register */
202 #define FP0_REGNUM 32 /* Floating point register 0 */
203 #define GP0_REGNUM 0 /* GPR register 0 */
204 #define FP0_REGNUM 32 /* FPR (Floating point) register 0 */
205 #define FPLAST_REGNUM 63 /* Last floating point register */
207 /* Special purpose registers... */
208 /* P.S. keep these in the same order as in /usr/mstsave.h `mstsave' structure, for
211 #define PC_REGNUM 64 /* Program counter (instruction address %iar) */
212 #define PS_REGNUM 65 /* Processor (or machine) status (%msr) */
213 #define CR_REGNUM 66 /* Condition register */
214 #define LR_REGNUM 67 /* Link register */
215 #define CTR_REGNUM 68 /* Count register */
216 #define XER_REGNUM 69 /* Fixed point exception registers */
217 #define MQ_REGNUM 70 /* Multiply/quotient register */
219 #define FIRST_SP_REGNUM 64 /* first special register number */
220 #define LAST_SP_REGNUM 70 /* last special register number */
222 /* Total amount of space needed to store our copies of the machine's
223 register state, the array `registers'.
227 7 4-byte special purpose registers,
229 total 416 bytes. Keep some extra space for now, in case to add more. */
231 #define REGISTER_BYTES 420
234 /* Index within `registers' of the first byte of the space for
237 #define REGISTER_BYTE(N) \
239 ((N) > FPLAST_REGNUM) ? ((((N) - FPLAST_REGNUM -1) * 4) + 384)\
240 :((N) >= FP0_REGNUM) ? ((((N) - FP0_REGNUM) * 8) + 128) \
243 /* Number of bytes of storage in the actual machine representation
245 /* Note that the unsigned cast here forces the result of the
246 subtractiion to very high positive values if N < FP0_REGNUM */
248 #define REGISTER_RAW_SIZE(N) (((unsigned)(N) - FP0_REGNUM) < 32 ? 8 : 4)
250 /* Number of bytes of storage in the program's representation
251 for register N. On the RS6000, all regs are 4 bytes
252 except the floating point regs which are 8-byte doubles. */
254 #define REGISTER_VIRTUAL_SIZE(N) (((unsigned)(N) - FP0_REGNUM) < 32 ? 8 : 4)
256 /* Largest value REGISTER_RAW_SIZE can have. */
258 #define MAX_REGISTER_RAW_SIZE 8
260 /* Largest value REGISTER_VIRTUAL_SIZE can have. */
262 #define MAX_REGISTER_VIRTUAL_SIZE 8
264 /* convert a dbx stab register number (from `r' declaration) to a gdb REGNUM */
266 #define STAB_REG_TO_REGNUM(value) (value)
268 /* Nonzero if register N requires conversion
269 from raw format to virtual format.
270 The register format for rs6000 floating point registers is always
271 double, we need a conversion if the memory format is float. */
273 #define REGISTER_CONVERTIBLE(N) ((N) >= FP0_REGNUM && (N) <= FPLAST_REGNUM)
275 /* Convert data from raw format for register REGNUM in buffer FROM
276 to virtual format with type TYPE in buffer TO. */
278 #define REGISTER_CONVERT_TO_VIRTUAL(REGNUM,TYPE,FROM,TO) \
280 if (TYPE_LENGTH (TYPE) != REGISTER_RAW_SIZE (REGNUM)) \
282 double val = extract_floating ((FROM), REGISTER_RAW_SIZE (REGNUM)); \
283 store_floating ((TO), TYPE_LENGTH (TYPE), val); \
286 memcpy ((TO), (FROM), REGISTER_RAW_SIZE (REGNUM)); \
289 /* Convert data from virtual format with type TYPE in buffer FROM
290 to raw format for register REGNUM in buffer TO. */
292 #define REGISTER_CONVERT_TO_RAW(TYPE,REGNUM,FROM,TO) \
294 if (TYPE_LENGTH (TYPE) != REGISTER_RAW_SIZE (REGNUM)) \
296 double val = extract_floating ((FROM), TYPE_LENGTH (TYPE)); \
297 store_floating ((TO), REGISTER_RAW_SIZE (REGNUM), val); \
300 memcpy ((TO), (FROM), REGISTER_RAW_SIZE (REGNUM)); \
303 /* Return the GDB type object for the "standard" data type
304 of data in register N. */
306 #define REGISTER_VIRTUAL_TYPE(N) \
307 (((unsigned)(N) - FP0_REGNUM) < 32 ? builtin_type_double : builtin_type_int)
309 /* Store the address of the place in which to copy the structure the
310 subroutine will return. This is called from call_function. */
311 /* in RS6000, struct return addresses are passed as an extra parameter in r3.
312 In function return, callee is not responsible of returning this address back.
313 Since gdb needs to find it, we will store in a designated variable
314 `rs6000_struct_return_address'. */
316 extern CORE_ADDR rs6000_struct_return_address
;
318 #define STORE_STRUCT_RETURN(ADDR, SP) \
319 { write_register (3, (ADDR)); \
320 rs6000_struct_return_address = (ADDR); }
322 /* Extract from an array REGBUF containing the (raw) register state
323 a function return value of type TYPE, and copy that, in virtual format,
326 /* #define EXTRACT_RETURN_VALUE(TYPE,REGBUF,VALBUF) \
327 memcpy (VALBUF, REGBUF, TYPE_LENGTH (TYPE)) */
329 #define EXTRACT_RETURN_VALUE(TYPE,REGBUF,VALBUF) \
330 extract_return_value(TYPE,REGBUF,VALBUF)
332 /* Write into appropriate registers a function return value
333 of type TYPE, given in virtual format. */
335 #define STORE_RETURN_VALUE(TYPE,VALBUF) \
337 if (TYPE_CODE (TYPE) == TYPE_CODE_FLT) \
339 /* Floating point values are returned starting from FPR1 and up. \
340 Say a double_double_double type could be returned in \
341 FPR1/FPR2/FPR3 triple. */ \
343 write_register_bytes (REGISTER_BYTE (FP0_REGNUM+1), (VALBUF), \
344 TYPE_LENGTH (TYPE)); \
346 /* Everything else is returned in GPR3 and up. */ \
347 write_register_bytes (REGISTER_BYTE (GP0_REGNUM+3), (VALBUF), \
348 TYPE_LENGTH (TYPE)); \
352 /* Extract from an array REGBUF containing the (raw) register state
353 the address in which a function should return its structure value,
354 as a CORE_ADDR (or an expression that can be used as one). */
356 #define EXTRACT_STRUCT_VALUE_ADDRESS(REGBUF) rs6000_struct_return_address
358 /* Describe the pointer in each stack frame to the previous stack frame
361 /* FRAME_CHAIN takes a frame's nominal address
362 and produces the frame's chain-pointer. */
364 /* In the case of the RS6000, the frame's nominal address
365 is the address of a 4-byte word containing the calling frame's address. */
367 #define FRAME_CHAIN(thisframe) rs6000_frame_chain (thisframe)
371 CORE_ADDR rs6000_frame_chain
PARAMS ((struct frame_info
*));
373 /* Define other aspects of the stack frame. */
375 /* A macro that tells us whether the function invocation represented
376 by FI does not have a frame on the stack associated with it. If it
377 does not, FRAMELESS is set to 1, else 0. */
379 #define FRAMELESS_FUNCTION_INVOCATION(FI, FRAMELESS) \
380 FRAMELESS = frameless_function_invocation (FI, 0)
382 /* Functions calling alloca() change the value of the stack pointer. We
383 need to use initial stack pointer (which is saved in r31 by gcc) in
384 such cases. If a compiler emits traceback table, then we should use the
385 alloca register specified in traceback table. FIXME. */
386 /* Also, it is a good idea to cache information about frame's saved registers
387 in the frame structure to speed things up. See tm-m88k.h. FIXME. */
389 #define EXTRA_FRAME_INFO \
390 CORE_ADDR initial_sp; /* initial stack pointer. */ \
391 struct frame_saved_regs *cache_fsr; /* saved registers */
393 #define INIT_FRAME_PC_FIRST(fromleaf, prev) \
394 prev->pc = (fromleaf ? SAVED_PC_AFTER_CALL (prev->next) : \
395 prev->next ? FRAME_SAVED_PC (prev->next) : read_pc ());
396 #define INIT_FRAME_PC(fromleaf, prev) /* nothing */
397 #define INIT_EXTRA_FRAME_INFO(fromleaf, fi) \
398 fi->initial_sp = 0; \
400 if (fi->next != (CORE_ADDR)0 \
401 && fi->pc < TEXT_SEGMENT_BASE) \
402 /* We're in get_prev_frame_info */ \
403 /* and this is a special signal frame. */ \
404 /* (fi->pc will be some low address in the kernel, */ \
405 /* to which the signal handler returns). */ \
406 fi->signal_handler_caller = 1;
408 /* If the kernel has to deliver a signal, it pushes a sigcontext
409 structure on the stack and then calls the signal handler, passing
410 the address of the sigcontext in an argument register. Usually
411 the signal handler doesn't save this register, so we have to
412 access the sigcontext structure via an offset from the signal handler
414 The following constants were determined by experimentation on AIX 3.2. */
415 #define SIG_FRAME_PC_OFFSET 96
416 #define SIG_FRAME_FP_OFFSET 284
418 /* Frameless function invocation in IBM RS/6000 is sometimes
419 half-done. It perfectly sets up a new frame, e.g. a new frame (in
420 fact stack) pointer, etc, but it doesn't save the %pc. We call
421 frameless_function_invocation to tell us how to get the %pc. */
423 #define FRAME_SAVED_PC(FRAME) \
424 (frameless_function_invocation (FRAME, 1) \
425 ? SAVED_PC_AFTER_CALL (FRAME) \
426 : (FRAME)->signal_handler_caller \
427 ? read_memory_integer ((FRAME)->frame + SIG_FRAME_PC_OFFSET, 4) \
428 : read_memory_integer (rs6000_frame_chain (FRAME) + 8, 4))
430 #define FRAME_ARGS_ADDRESS(FI) \
431 (((struct frame_info*)(FI))->initial_sp ? \
432 ((struct frame_info*)(FI))->initial_sp : \
433 frame_initial_stack_address (FI))
435 #define FRAME_LOCALS_ADDRESS(FI) FRAME_ARGS_ADDRESS(FI)
438 /* Set VAL to the number of args passed to frame described by FI.
439 Can set VAL to -1, meaning no way to tell. */
441 /* We can't tell how many args there are
442 now that the C compiler delays popping them. */
444 #define FRAME_NUM_ARGS(val,fi) (val = -1)
446 /* Return number of bytes at start of arglist that are not really args. */
448 #define FRAME_ARGS_SKIP 8 /* Not sure on this. FIXMEmgo */
450 /* Put here the code to store, into a struct frame_saved_regs,
451 the addresses of the saved registers of frame described by FRAME_INFO.
452 This includes special registers such as pc and fp saved in special
453 ways in the stack frame. sp is even more special:
454 the address we return for it IS the sp for the next frame. */
455 /* In the following implementation for RS6000, we did *not* save sp. I am
456 not sure if it will be needed. The following macro takes care of gpr's
459 #define FRAME_FIND_SAVED_REGS(FRAME_INFO, FRAME_SAVED_REGS) \
462 CORE_ADDR frame_addr, func_start; \
463 struct aix_framedata fdata; \
465 /* find the start of the function and collect info about its frame. */\
467 func_start = get_pc_function_start ((FRAME_INFO)->pc) + FUNCTION_START_OFFSET; \
468 function_frame_info (func_start, &fdata); \
469 memset (&(FRAME_SAVED_REGS), '\0', sizeof (FRAME_SAVED_REGS)); \
471 /* if there were any saved registers, figure out parent's stack pointer. */ \
473 /* the following is true only if the frame doesn't have a call to alloca(), \
475 if (fdata.saved_fpr >= 0 || fdata.saved_gpr >= 0) { \
476 if ((FRAME_INFO)->prev && (FRAME_INFO)->prev->frame) \
477 frame_addr = (FRAME_INFO)->prev->frame; \
479 frame_addr = read_memory_integer ((FRAME_INFO)->frame, 4); \
482 /* if != -1, fdata.saved_fpr is the smallest number of saved_fpr. All fpr's \
483 from saved_fpr to fp31 are saved right underneath caller stack pointer, \
484 starting from fp31 first. */ \
486 if (fdata.saved_fpr >= 0) { \
487 for (ii=31; ii >= fdata.saved_fpr; --ii) \
488 (FRAME_SAVED_REGS).regs [FP0_REGNUM + ii] = frame_addr - ((32 - ii) * 8); \
489 frame_addr -= (32 - fdata.saved_fpr) * 8; \
492 /* if != -1, fdata.saved_gpr is the smallest number of saved_gpr. All gpr's \
493 from saved_gpr to gpr31 are saved right under saved fprs, starting \
496 if (fdata.saved_gpr >= 0) \
497 for (ii=31; ii >= fdata.saved_gpr; --ii) \
498 (FRAME_SAVED_REGS).regs [ii] = frame_addr - ((32 - ii) * 4); \
502 /* Things needed for making the inferior call functions. */
504 /* Push an empty stack frame, to record the current PC, etc. */
505 /* Change these names into rs6k_{push, pop}_frame(). FIXMEmgo. */
507 #define PUSH_DUMMY_FRAME push_dummy_frame ()
509 /* Discard from the stack the innermost frame,
510 restoring all saved registers. */
512 #define POP_FRAME pop_frame ()
514 /* This sequence of words is the instructions:
516 mflr r0 // 0x7c0802a6
518 stfd r?, num(r1) // 0xd8010000 there should be 32 of this??
520 stm r0, num(r1) // 0xbc010000
521 stu r1, num(r1) // 0x94210000
523 // the function we want to branch might be in a different load
524 // segment. reset the toc register. Note that the actual toc address
525 // will be fix by fix_call_dummy () along with function address.
527 st r2, 0x14(r1) // 0x90410014 save toc register
528 liu r2, 0x1234 // 0x3c401234 reset a new toc value 0x12345678
529 oril r2, r2,0x5678 // 0x60425678
531 // load absolute address 0x12345678 to r0
532 liu r0, 0x1234 // 0x3c001234
533 oril r0, r0,0x5678 // 0x60005678
534 mtctr r0 // 0x7c0903a6 ctr <- r0
535 bctrl // 0x4e800421 jump subroutine 0x12345678 (%ctr)
536 cror 0xf, 0xf, 0xf // 0x4def7b82
537 brpt // 0x7d821008, breakpoint
538 cror 0xf, 0xf, 0xf // 0x4def7b82 (for 8 byte alignment)
541 We actually start executing by saving the toc register first, since the pushing
542 of the registers is done by PUSH_DUMMY_FRAME. If this were real code,
543 the arguments for the function called by the `bctrl' would be pushed
544 between the `stu' and the `bctrl', and we could allow it to execute through.
545 But the arguments have to be pushed by GDB after the PUSH_DUMMY_FRAME is done,
546 and we cannot allow to push the registers again.
549 #define CALL_DUMMY {0x7c0802a6, 0xd8010000, 0xbc010000, 0x94210000, \
550 0x90410014, 0x3c401234, 0x60425678, \
551 0x3c001234, 0x60005678, 0x7c0903a6, 0x4e800421, \
552 0x4def7b82, 0x7d821008, 0x4def7b82 }
555 /* keep this as multiple of 8 (%sp requires 8 byte alignment) */
556 #define CALL_DUMMY_LENGTH 56
558 #define CALL_DUMMY_START_OFFSET 16
560 /* Insert the specified number of args and function address
561 into a call sequence of the above form stored at DUMMYNAME. */
563 #define FIX_CALL_DUMMY(dummyname, pc, fun, nargs, args, type, using_gcc) \
564 fix_call_dummy(dummyname, pc, fun, nargs, type)
566 /* Usually a function pointer's representation is simply the address of
567 the function. On the RS/6000 however, a function pointer is represented
568 by a pointer to a TOC entry. This TOC entry contains three words,
569 the first word is the address of the function, the second word is the
570 TOC pointer (r2), and the third word is the static chain value.
571 Throughout GDB it is currently assumed that a function pointer contains
572 the address of the function, which is not easy to fix.
573 In addition, the conversion of a function address to a function
574 pointer would require allocation of a TOC entry in the inferior's
575 memory space, with all its drawbacks.
576 To be able to call C++ virtual methods in the inferior (which are called
577 via function pointers), find_function_addr uses this macro to
578 get the function address from a function pointer. */
579 #define CONVERT_FROM_FUNC_PTR_ADDR(ADDR) read_memory_integer (ADDR, 4)
581 /* Flag for machine-specific stuff in shared files. FIXME */
582 #define IBM6000_TARGET
584 /* RS6000/AIX does not support PT_STEP. Has to be simulated. */
586 #define NO_SINGLE_STEP