xref: /openbsd-src/gnu/usr.bin/binutils/gdb/lynx-nat.c (revision b2ea75c1b17e1a9a339660e7ed45cd24946b230e)
1 /* Native-dependent code for LynxOS.
2    Copyright 1993, 1994 Free Software Foundation, Inc.
3 
4 This file is part of GDB.
5 
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.
10 
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.
15 
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., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.  */
19 
20 #include "defs.h"
21 #include "frame.h"
22 #include "inferior.h"
23 #include "target.h"
24 #include "gdbcore.h"
25 
26 #include <sys/ptrace.h>
27 #include <sys/wait.h>
28 #include <sys/fpp.h>
29 
30 static unsigned long registers_addr PARAMS ((int pid));
31 static void fetch_core_registers PARAMS ((char *, unsigned, int, CORE_ADDR);
32 
33 #define X(ENTRY)(offsetof(struct econtext, ENTRY))
34 
35 #ifdef I386
36 /* Mappings from tm-i386v.h */
37 
38 static int regmap[] =
39 {
40   X(eax),
41   X(ecx),
42   X(edx),
43   X(ebx),
44   X(esp),			/* sp */
45   X(ebp),			/* fp */
46   X(esi),
47   X(edi),
48   X(eip),			/* pc */
49   X(flags),			/* ps */
50   X(cs),
51   X(ss),
52   X(ds),
53   X(es),
54   X(ecode),			/* Lynx doesn't give us either fs or gs, so */
55   X(fault),			/* we just substitute these two in the hopes
56 				   that they are useful. */
57 };
58 #endif /* I386 */
59 
60 #ifdef M68K
61 /* Mappings from tm-m68k.h */
62 
63 static int regmap[] =
64 {
65   X(regs[0]),			/* d0 */
66   X(regs[1]),			/* d1 */
67   X(regs[2]),			/* d2 */
68   X(regs[3]),			/* d3 */
69   X(regs[4]),			/* d4 */
70   X(regs[5]),			/* d5 */
71   X(regs[6]),			/* d6 */
72   X(regs[7]),			/* d7 */
73   X(regs[8]),			/* a0 */
74   X(regs[9]),			/* a1 */
75   X(regs[10]),			/* a2 */
76   X(regs[11]),			/* a3 */
77   X(regs[12]),			/* a4 */
78   X(regs[13]),			/* a5 */
79   X(regs[14]),			/* fp */
80   offsetof (st_t, usp) - offsetof (st_t, ec), /* sp */
81   X(status),			/* ps */
82   X(pc),
83 
84   X(fregs[0*3]),		/* fp0 */
85   X(fregs[1*3]),		/* fp1 */
86   X(fregs[2*3]),		/* fp2 */
87   X(fregs[3*3]),		/* fp3 */
88   X(fregs[4*3]),		/* fp4 */
89   X(fregs[5*3]),		/* fp5 */
90   X(fregs[6*3]),		/* fp6 */
91   X(fregs[7*3]),		/* fp7 */
92 
93   X(fcregs[0]),			/* fpcontrol */
94   X(fcregs[1]),			/* fpstatus */
95   X(fcregs[2]),			/* fpiaddr */
96   X(ssw),			/* fpcode */
97   X(fault),			/* fpflags */
98 };
99 #endif /* M68K */
100 
101 #ifdef SPARC
102 /* Mappings from tm-sparc.h */
103 
104 #define FX(ENTRY)(offsetof(struct fcontext, ENTRY))
105 
106 static int regmap[] =
107 {
108   -1,				/* g0 */
109   X(g1),
110   X(g2),
111   X(g3),
112   X(g4),
113   -1,				/* g5->g7 aren't saved by Lynx */
114   -1,
115   -1,
116 
117   X(o[0]),
118   X(o[1]),
119   X(o[2]),
120   X(o[3]),
121   X(o[4]),
122   X(o[5]),
123   X(o[6]),			/* sp */
124   X(o[7]),			/* ra */
125 
126   -1,-1,-1,-1,-1,-1,-1,-1,	/* l0 -> l7 */
127 
128   -1,-1,-1,-1,-1,-1,-1,-1,	/* i0 -> i7 */
129 
130   FX(f.fregs[0]),		/* f0 */
131   FX(f.fregs[1]),
132   FX(f.fregs[2]),
133   FX(f.fregs[3]),
134   FX(f.fregs[4]),
135   FX(f.fregs[5]),
136   FX(f.fregs[6]),
137   FX(f.fregs[7]),
138   FX(f.fregs[8]),
139   FX(f.fregs[9]),
140   FX(f.fregs[10]),
141   FX(f.fregs[11]),
142   FX(f.fregs[12]),
143   FX(f.fregs[13]),
144   FX(f.fregs[14]),
145   FX(f.fregs[15]),
146   FX(f.fregs[16]),
147   FX(f.fregs[17]),
148   FX(f.fregs[18]),
149   FX(f.fregs[19]),
150   FX(f.fregs[20]),
151   FX(f.fregs[21]),
152   FX(f.fregs[22]),
153   FX(f.fregs[23]),
154   FX(f.fregs[24]),
155   FX(f.fregs[25]),
156   FX(f.fregs[26]),
157   FX(f.fregs[27]),
158   FX(f.fregs[28]),
159   FX(f.fregs[29]),
160   FX(f.fregs[30]),
161   FX(f.fregs[31]),
162 
163   X(y),
164   X(psr),
165   X(wim),
166   X(tbr),
167   X(pc),
168   X(npc),
169   FX(fsr),			/* fpsr */
170   -1,				/* cpsr */
171 };
172 #endif /* SPARC */
173 
174 #ifdef rs6000
175 
176 static int regmap[] =
177 {
178   X(iregs[0]),			/* r0 */
179   X(iregs[1]),
180   X(iregs[2]),
181   X(iregs[3]),
182   X(iregs[4]),
183   X(iregs[5]),
184   X(iregs[6]),
185   X(iregs[7]),
186   X(iregs[8]),
187   X(iregs[9]),
188   X(iregs[10]),
189   X(iregs[11]),
190   X(iregs[12]),
191   X(iregs[13]),
192   X(iregs[14]),
193   X(iregs[15]),
194   X(iregs[16]),
195   X(iregs[17]),
196   X(iregs[18]),
197   X(iregs[19]),
198   X(iregs[20]),
199   X(iregs[21]),
200   X(iregs[22]),
201   X(iregs[23]),
202   X(iregs[24]),
203   X(iregs[25]),
204   X(iregs[26]),
205   X(iregs[27]),
206   X(iregs[28]),
207   X(iregs[29]),
208   X(iregs[30]),
209   X(iregs[31]),
210 
211   X(fregs[0]),			/* f0 */
212   X(fregs[1]),
213   X(fregs[2]),
214   X(fregs[3]),
215   X(fregs[4]),
216   X(fregs[5]),
217   X(fregs[6]),
218   X(fregs[7]),
219   X(fregs[8]),
220   X(fregs[9]),
221   X(fregs[10]),
222   X(fregs[11]),
223   X(fregs[12]),
224   X(fregs[13]),
225   X(fregs[14]),
226   X(fregs[15]),
227   X(fregs[16]),
228   X(fregs[17]),
229   X(fregs[18]),
230   X(fregs[19]),
231   X(fregs[20]),
232   X(fregs[21]),
233   X(fregs[22]),
234   X(fregs[23]),
235   X(fregs[24]),
236   X(fregs[25]),
237   X(fregs[26]),
238   X(fregs[27]),
239   X(fregs[28]),
240   X(fregs[29]),
241   X(fregs[30]),
242   X(fregs[31]),
243 
244   X(srr0),			/* IAR (PC) */
245   X(srr1),			/* MSR (PS) */
246   X(cr),			/* CR */
247   X(lr),			/* LR */
248   X(ctr),			/* CTR */
249   X(xer),			/* XER */
250   X(mq)				/* MQ */
251 };
252 
253 #endif /* rs6000 */
254 
255 #ifdef SPARC
256 
257 /* This routine handles some oddball cases for Sparc registers and LynxOS.
258    In partucular, it causes refs to G0, g5->7, and all fp regs to return zero.
259    It also handles knows where to find the I & L regs on the stack.  */
260 
261 void
262 fetch_inferior_registers (regno)
263      int regno;
264 {
265   int whatregs = 0;
266 
267 #define WHATREGS_FLOAT 1
268 #define WHATREGS_GEN 2
269 #define WHATREGS_STACK 4
270 
271   if (regno == -1)
272     whatregs = WHATREGS_FLOAT | WHATREGS_GEN | WHATREGS_STACK;
273   else if (regno >= L0_REGNUM && regno <= I7_REGNUM)
274     whatregs = WHATREGS_STACK;
275   else if (regno >= FP0_REGNUM && regno < FP0_REGNUM + 32)
276     whatregs = WHATREGS_FLOAT;
277   else
278     whatregs = WHATREGS_GEN;
279 
280   if (whatregs & WHATREGS_GEN)
281     {
282       struct econtext ec;		/* general regs */
283       char buf[MAX_REGISTER_RAW_SIZE];
284       int retval;
285       int i;
286 
287       errno = 0;
288       retval = ptrace (PTRACE_GETREGS, inferior_pid, (PTRACE_ARG3_TYPE) &ec,
289 		       0);
290       if (errno)
291 	perror_with_name ("ptrace(PTRACE_GETREGS)");
292 
293       memset (buf, 0, REGISTER_RAW_SIZE (G0_REGNUM));
294       supply_register (G0_REGNUM, buf);
295       supply_register (TBR_REGNUM, (char *)&ec.tbr);
296 
297       memcpy (&registers[REGISTER_BYTE (G1_REGNUM)], &ec.g1,
298 	      4 * REGISTER_RAW_SIZE (G1_REGNUM));
299       for (i = G1_REGNUM; i <= G1_REGNUM + 3; i++)
300 	register_valid[i] = 1;
301 
302       supply_register (PS_REGNUM, (char *)&ec.psr);
303       supply_register (Y_REGNUM, (char *)&ec.y);
304       supply_register (PC_REGNUM, (char *)&ec.pc);
305       supply_register (NPC_REGNUM, (char *)&ec.npc);
306       supply_register (WIM_REGNUM, (char *)&ec.wim);
307 
308       memcpy (&registers[REGISTER_BYTE (O0_REGNUM)], ec.o,
309 	      8 * REGISTER_RAW_SIZE (O0_REGNUM));
310       for (i = O0_REGNUM; i <= O0_REGNUM + 7; i++)
311 	register_valid[i] = 1;
312     }
313 
314   if (whatregs & WHATREGS_STACK)
315     {
316       CORE_ADDR sp;
317       int i;
318 
319       sp = read_register (SP_REGNUM);
320 
321       target_xfer_memory (sp + FRAME_SAVED_I0,
322 			  &registers[REGISTER_BYTE(I0_REGNUM)],
323 			  8 * REGISTER_RAW_SIZE (I0_REGNUM), 0);
324       for (i = I0_REGNUM; i <= I7_REGNUM; i++)
325 	register_valid[i] = 1;
326 
327       target_xfer_memory (sp + FRAME_SAVED_L0,
328 			  &registers[REGISTER_BYTE(L0_REGNUM)],
329 			  8 * REGISTER_RAW_SIZE (L0_REGNUM), 0);
330       for (i = L0_REGNUM; i <= L0_REGNUM + 7; i++)
331 	register_valid[i] = 1;
332     }
333 
334   if (whatregs & WHATREGS_FLOAT)
335     {
336       struct fcontext fc;		/* fp regs */
337       int retval;
338       int i;
339 
340       errno = 0;
341       retval = ptrace (PTRACE_GETFPREGS, inferior_pid, (PTRACE_ARG3_TYPE) &fc,
342 		       0);
343       if (errno)
344 	perror_with_name ("ptrace(PTRACE_GETFPREGS)");
345 
346       memcpy (&registers[REGISTER_BYTE (FP0_REGNUM)], fc.f.fregs,
347 	      32 * REGISTER_RAW_SIZE (FP0_REGNUM));
348       for (i = FP0_REGNUM; i <= FP0_REGNUM + 31; i++)
349 	register_valid[i] = 1;
350 
351       supply_register (FPS_REGNUM, (char *)&fc.fsr);
352     }
353 }
354 
355 /* This routine handles storing of the I & L regs for the Sparc.  The trick
356    here is that they actually live on the stack.  The really tricky part is
357    that when changing the stack pointer, the I & L regs must be written to
358    where the new SP points, otherwise the regs will be incorrect when the
359    process is started up again.   We assume that the I & L regs are valid at
360    this point.  */
361 
362 void
363 store_inferior_registers (regno)
364      int regno;
365 {
366   int whatregs = 0;
367 
368   if (regno == -1)
369     whatregs = WHATREGS_FLOAT | WHATREGS_GEN | WHATREGS_STACK;
370   else if (regno >= L0_REGNUM && regno <= I7_REGNUM)
371     whatregs = WHATREGS_STACK;
372   else if (regno >= FP0_REGNUM && regno < FP0_REGNUM + 32)
373     whatregs = WHATREGS_FLOAT;
374   else if (regno == SP_REGNUM)
375     whatregs = WHATREGS_STACK | WHATREGS_GEN;
376   else
377     whatregs = WHATREGS_GEN;
378 
379   if (whatregs & WHATREGS_GEN)
380     {
381       struct econtext ec;		/* general regs */
382       int retval;
383 
384       ec.tbr = read_register (TBR_REGNUM);
385       memcpy (&ec.g1, &registers[REGISTER_BYTE (G1_REGNUM)],
386 	      4 * REGISTER_RAW_SIZE (G1_REGNUM));
387 
388       ec.psr = read_register (PS_REGNUM);
389       ec.y = read_register (Y_REGNUM);
390       ec.pc = read_register (PC_REGNUM);
391       ec.npc = read_register (NPC_REGNUM);
392       ec.wim = read_register (WIM_REGNUM);
393 
394       memcpy (ec.o, &registers[REGISTER_BYTE (O0_REGNUM)],
395 	      8 * REGISTER_RAW_SIZE (O0_REGNUM));
396 
397       errno = 0;
398       retval = ptrace (PTRACE_SETREGS, inferior_pid, (PTRACE_ARG3_TYPE) &ec,
399 		       0);
400       if (errno)
401 	perror_with_name ("ptrace(PTRACE_SETREGS)");
402     }
403 
404   if (whatregs & WHATREGS_STACK)
405     {
406       int regoffset;
407       CORE_ADDR sp;
408 
409       sp = read_register (SP_REGNUM);
410 
411       if (regno == -1 || regno == SP_REGNUM)
412 	{
413 	  if (!register_valid[L0_REGNUM+5])
414 	    abort();
415 	  target_xfer_memory (sp + FRAME_SAVED_I0,
416 			      &registers[REGISTER_BYTE (I0_REGNUM)],
417 			      8 * REGISTER_RAW_SIZE (I0_REGNUM), 1);
418 
419 	  target_xfer_memory (sp + FRAME_SAVED_L0,
420 			      &registers[REGISTER_BYTE (L0_REGNUM)],
421 			      8 * REGISTER_RAW_SIZE (L0_REGNUM), 1);
422 	}
423       else if (regno >= L0_REGNUM && regno <= I7_REGNUM)
424 	{
425 	  if (!register_valid[regno])
426 	    abort();
427 	  if (regno >= L0_REGNUM && regno <= L0_REGNUM + 7)
428 	    regoffset = REGISTER_BYTE (regno) - REGISTER_BYTE (L0_REGNUM)
429 	      + FRAME_SAVED_L0;
430 	  else
431 	    regoffset = REGISTER_BYTE (regno) - REGISTER_BYTE (I0_REGNUM)
432 	      + FRAME_SAVED_I0;
433 	  target_xfer_memory (sp + regoffset, &registers[REGISTER_BYTE (regno)],
434 			      REGISTER_RAW_SIZE (regno), 1);
435 	}
436     }
437 
438   if (whatregs & WHATREGS_FLOAT)
439     {
440       struct fcontext fc;		/* fp regs */
441       int retval;
442 
443 /* We read fcontext first so that we can get good values for fq_t... */
444       errno = 0;
445       retval = ptrace (PTRACE_GETFPREGS, inferior_pid, (PTRACE_ARG3_TYPE) &fc,
446 		       0);
447       if (errno)
448 	perror_with_name ("ptrace(PTRACE_GETFPREGS)");
449 
450       memcpy (fc.f.fregs, &registers[REGISTER_BYTE (FP0_REGNUM)],
451 	      32 * REGISTER_RAW_SIZE (FP0_REGNUM));
452 
453       fc.fsr = read_register (FPS_REGNUM);
454 
455       errno = 0;
456       retval = ptrace (PTRACE_SETFPREGS, inferior_pid, (PTRACE_ARG3_TYPE) &fc,
457 		       0);
458       if (errno)
459 	perror_with_name ("ptrace(PTRACE_SETFPREGS)");
460       }
461 }
462 #endif /* SPARC */
463 
464 #if defined (I386) || defined (M68K) || defined (rs6000)
465 
466 /* Return the offset relative to the start of the per-thread data to the
467    saved context block.  */
468 
469 static unsigned long
470 registers_addr(pid)
471      int pid;
472 {
473   CORE_ADDR stblock;
474   int ecpoff = offsetof(st_t, ecp);
475   CORE_ADDR ecp;
476 
477   errno = 0;
478   stblock = (CORE_ADDR) ptrace (PTRACE_THREADUSER, pid, (PTRACE_ARG3_TYPE)0,
479 				0);
480   if (errno)
481     perror_with_name ("ptrace(PTRACE_THREADUSER)");
482 
483   ecp = (CORE_ADDR) ptrace (PTRACE_PEEKTHREAD, pid, (PTRACE_ARG3_TYPE)ecpoff,
484 			    0);
485   if (errno)
486     perror_with_name ("ptrace(PTRACE_PEEKTHREAD)");
487 
488   return ecp - stblock;
489 }
490 
491 /* Fetch one or more registers from the inferior.  REGNO == -1 to get
492    them all.  We actually fetch more than requested, when convenient,
493    marking them as valid so we won't fetch them again.  */
494 
495 void
496 fetch_inferior_registers (regno)
497      int regno;
498 {
499   int reglo, reghi;
500   int i;
501   unsigned long ecp;
502 
503   if (regno == -1)
504     {
505       reglo = 0;
506       reghi = NUM_REGS - 1;
507     }
508   else
509     reglo = reghi = regno;
510 
511   ecp = registers_addr (inferior_pid);
512 
513   for (regno = reglo; regno <= reghi; regno++)
514     {
515       char buf[MAX_REGISTER_RAW_SIZE];
516       int ptrace_fun = PTRACE_PEEKTHREAD;
517 
518 #ifdef M68K
519       ptrace_fun = regno == SP_REGNUM ? PTRACE_PEEKUSP : PTRACE_PEEKTHREAD;
520 #endif
521 
522       for (i = 0; i < REGISTER_RAW_SIZE (regno); i += sizeof (int))
523 	{
524 	  unsigned int reg;
525 
526 	  errno = 0;
527 	  reg = ptrace (ptrace_fun, inferior_pid,
528 			(PTRACE_ARG3_TYPE) (ecp + regmap[regno] + i), 0);
529 	  if (errno)
530 	    perror_with_name ("ptrace(PTRACE_PEEKUSP)");
531 
532 	  *(int *)&buf[i] = reg;
533 	}
534       supply_register (regno, buf);
535     }
536 }
537 
538 /* Store our register values back into the inferior.
539    If REGNO is -1, do this for all registers.
540    Otherwise, REGNO specifies which register (so we can save time).  */
541 
542 /* Registers we shouldn't try to store.  */
543 #if !defined (CANNOT_STORE_REGISTER)
544 #define CANNOT_STORE_REGISTER(regno) 0
545 #endif
546 
547 void
548 store_inferior_registers (regno)
549      int regno;
550 {
551   int reglo, reghi;
552   int i;
553   unsigned long ecp;
554 
555   if (regno == -1)
556     {
557       reglo = 0;
558       reghi = NUM_REGS - 1;
559     }
560   else
561     reglo = reghi = regno;
562 
563   ecp = registers_addr (inferior_pid);
564 
565   for (regno = reglo; regno <= reghi; regno++)
566     {
567       int ptrace_fun = PTRACE_POKEUSER;
568 
569       if (CANNOT_STORE_REGISTER (regno))
570 	continue;
571 
572 #ifdef M68K
573       ptrace_fun = regno == SP_REGNUM ? PTRACE_POKEUSP : PTRACE_POKEUSER;
574 #endif
575 
576       for (i = 0; i < REGISTER_RAW_SIZE (regno); i += sizeof (int))
577 	{
578 	  unsigned int reg;
579 
580 	  reg = *(unsigned int *)&registers[REGISTER_BYTE (regno) + i];
581 
582 	  errno = 0;
583 	  ptrace (ptrace_fun, inferior_pid,
584 		  (PTRACE_ARG3_TYPE) (ecp + regmap[regno] + i), reg);
585 	  if (errno)
586 	    perror_with_name ("ptrace(PTRACE_POKEUSP)");
587 	}
588     }
589 }
590 #endif /* defined (I386) || defined (M68K) || defined (rs6000) */
591 
592 /* Wait for child to do something.  Return pid of child, or -1 in case
593    of error; store status through argument pointer OURSTATUS.  */
594 
595 int
596 child_wait (pid, ourstatus)
597      int pid;
598      struct target_waitstatus *ourstatus;
599 {
600   int save_errno;
601   int thread;
602   union wait status;
603 
604   while (1)
605     {
606       int sig;
607 
608       set_sigint_trap();	/* Causes SIGINT to be passed on to the
609 				   attached process. */
610       pid = wait (&status);
611 
612       save_errno = errno;
613 
614       clear_sigint_trap();
615 
616       if (pid == -1)
617 	{
618 	  if (save_errno == EINTR)
619 	    continue;
620 	  fprintf_unfiltered (gdb_stderr, "Child process unexpectedly missing: %s.\n",
621 		   safe_strerror (save_errno));
622 	  /* Claim it exited with unknown signal.  */
623 	  ourstatus->kind = TARGET_WAITKIND_SIGNALLED;
624 	  ourstatus->value.sig = TARGET_SIGNAL_UNKNOWN;
625 	  return -1;
626 	}
627 
628       if (pid != PIDGET (inferior_pid))	/* Some other process?!? */
629 	continue;
630 
631       thread = status.w_tid;	/* Get thread id from status */
632 
633       /* Initial thread value can only be acquired via wait, so we have to
634 	 resort to this hack.  */
635 
636       if (TIDGET (inferior_pid) == 0 && thread != 0)
637 	{
638 	  inferior_pid = BUILDPID (inferior_pid, thread);
639 	  add_thread (inferior_pid);
640 	}
641 
642       pid = BUILDPID (pid, thread);
643 
644       /* We've become a single threaded process again.  */
645       if (thread == 0)
646 	inferior_pid = pid;
647 
648       /* Check for thread creation.  */
649       if (WIFSTOPPED(status)
650 	  && WSTOPSIG(status) == SIGTRAP
651 	  && !in_thread_list (pid))
652 	{
653 	  int realsig;
654 
655 	  realsig = ptrace (PTRACE_GETTRACESIG, pid, (PTRACE_ARG3_TYPE)0, 0);
656 
657 	  if (realsig == SIGNEWTHREAD)
658 	    {
659 	      /* It's a new thread notification.  We don't want to much with
660 		 realsig -- the code in wait_for_inferior expects SIGTRAP. */
661 	      ourstatus->kind = TARGET_WAITKIND_SPURIOUS;
662 	      ourstatus->value.sig = TARGET_SIGNAL_0;
663 	      return pid;
664 	    }
665 	  else
666 	    error ("Signal for unknown thread was not SIGNEWTHREAD");
667 	}
668 
669       /* Check for thread termination.  */
670       else if (WIFSTOPPED(status)
671 	       && WSTOPSIG(status) == SIGTRAP
672 	       && in_thread_list (pid))
673 	{
674 	  int realsig;
675 
676 	  realsig = ptrace (PTRACE_GETTRACESIG, pid, (PTRACE_ARG3_TYPE)0, 0);
677 
678 	  if (realsig == SIGTHREADEXIT)
679 	    {
680 	      ptrace (PTRACE_CONT, PIDGET (pid), (PTRACE_ARG3_TYPE)0, 0);
681 	      continue;
682 	    }
683 	}
684 
685 #ifdef SPARC
686       /* SPARC Lynx uses an byte reversed wait status; we must use the
687 	 host macros to access it.  These lines just a copy of
688 	 store_waitstatus.  We can't use CHILD_SPECIAL_WAITSTATUS
689 	 because target.c can't include the Lynx <sys/wait.h>.  */
690       if (WIFEXITED (status))
691 	{
692 	  ourstatus->kind = TARGET_WAITKIND_EXITED;
693 	  ourstatus->value.integer = WEXITSTATUS (status);
694 	}
695       else if (!WIFSTOPPED (status))
696 	{
697 	  ourstatus->kind = TARGET_WAITKIND_SIGNALLED;
698 	  ourstatus->value.sig =
699 	    target_signal_from_host (WTERMSIG (status));
700 	}
701       else
702 	{
703 	  ourstatus->kind = TARGET_WAITKIND_STOPPED;
704 	  ourstatus->value.sig =
705 	    target_signal_from_host (WSTOPSIG (status));
706 	}
707 #else
708       store_waitstatus (ourstatus, status.w_status);
709 #endif
710 
711       return pid;
712     }
713 }
714 
715 /* Return nonzero if the given thread is still alive.  */
716 int
717 child_thread_alive (pid)
718      int pid;
719 {
720   /* Arggh.  Apparently pthread_kill only works for threads within
721      the process that calls pthread_kill.
722 
723      We want to avoid the lynx signal extensions as they simply don't
724      map well to the generic gdb interface we want to keep.
725 
726      All we want to do is determine if a particular thread is alive;
727      it appears as if we can just make a harmless thread specific
728      ptrace call to do that.  */
729   return (ptrace (PTRACE_THREADUSER, pid, 0, 0) != -1);
730 }
731 
732 /* Resume execution of the inferior process.
733    If STEP is nonzero, single-step it.
734    If SIGNAL is nonzero, give it that signal.  */
735 
736 void
737 child_resume (pid, step, signal)
738      int pid;
739      int step;
740      enum target_signal signal;
741 {
742   int func;
743 
744   errno = 0;
745 
746   /* If pid == -1, then we want to step/continue all threads, else
747      we only want to step/continue a single thread.  */
748   if (pid == -1)
749     {
750       pid = inferior_pid;
751       func = step ? PTRACE_SINGLESTEP : PTRACE_CONT;
752     }
753   else
754     func = step ? PTRACE_SINGLESTEP_ONE : PTRACE_CONT_ONE;
755 
756 
757   /* An address of (PTRACE_ARG3_TYPE)1 tells ptrace to continue from where
758      it was.  (If GDB wanted it to start some other way, we have already
759      written a new PC value to the child.)
760 
761      If this system does not support PT_STEP, a higher level function will
762      have called single_step() to transmute the step request into a
763      continue request (by setting breakpoints on all possible successor
764      instructions), so we don't have to worry about that here.  */
765 
766   ptrace (func, pid, (PTRACE_ARG3_TYPE) 1, target_signal_to_host (signal));
767 
768   if (errno)
769     perror_with_name ("ptrace");
770 }
771 
772 /* Convert a Lynx process ID to a string.  Returns the string in a static
773    buffer.  */
774 
775 char *
776 lynx_pid_to_str (pid)
777      int pid;
778 {
779   static char buf[40];
780 
781   sprintf (buf, "process %d thread %d", PIDGET (pid), TIDGET (pid));
782 
783   return buf;
784 }
785 
786 /* Extract the register values out of the core file and store
787    them where `read_register' will find them.
788 
789    CORE_REG_SECT points to the register values themselves, read into memory.
790    CORE_REG_SIZE is the size of that area.
791    WHICH says which set of registers we are handling (0 = int, 2 = float
792          on machines where they are discontiguous).
793    REG_ADDR is the offset from u.u_ar0 to the register values relative to
794             core_reg_sect.  This is used with old-fashioned core files to
795 	    locate the registers in a large upage-plus-stack ".reg" section.
796 	    Original upage address X is at location core_reg_sect+x+reg_addr.
797  */
798 
799 static void
800 fetch_core_registers (core_reg_sect, core_reg_size, which, reg_addr)
801      char *core_reg_sect;
802      unsigned core_reg_size;
803      int which;
804      CORE_ADDR reg_addr;
805 {
806   struct st_entry s;
807   unsigned int regno;
808 
809   for (regno = 0; regno < NUM_REGS; regno++)
810     if (regmap[regno] != -1)
811       supply_register (regno, core_reg_sect + offsetof (st_t, ec)
812 		       + regmap[regno]);
813 
814 #ifdef SPARC
815 /* Fetching this register causes all of the I & L regs to be read from the
816    stack and validated.  */
817 
818   fetch_inferior_registers (I0_REGNUM);
819 #endif
820 }
821 
822 
823 /* Register that we are able to handle lynx core file formats.
824    FIXME: is this really bfd_target_unknown_flavour? */
825 
826 static struct core_fns lynx_core_fns =
827 {
828   bfd_target_unknown_flavour,
829   fetch_core_registers,
830   NULL
831 };
832 
833 void
834 _initialize_core_lynx ()
835 {
836   add_core_fns (&lynx_core_fns);
837 }
838