gdb/irix4-nat.c

/* Native support for the SGI Iris running IRIX version 4, for GDB.
   Copyright 1988, 1989, 1990, 1991, 1992, 1993, 1995, 1996, 1999, 2000,
   2001 Free Software Foundation, Inc.
   Contributed by Alessandro Forin(af@cs.cmu.edu) at CMU
   and by Per Bothner(bothner@cs.wisc.edu) at U.Wisconsin.
   Implemented for Irix 4.x by Garrett A. Wollman.

   This file is part of GDB.

   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; either version 2 of the License, or
   (at your option) any later version.

   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with this program; if not, write to the Free Software
   Foundation, Inc., 59 Temple Place - Suite 330,
   Boston, MA 02111-1307, USA.  */

#include "defs.h"
#include "inferior.h"
#include "gdbcore.h"
#include "regcache.h"

#include <sys/time.h>
#include <sys/procfs.h>
#include <setjmp.h>		/* For JB_XXX.  */

/* Prototypes for supply_gregset etc. */
#include "gregset.h"

/* Size of elements in jmpbuf */

#define JB_ELEMENT_SIZE 4

typedef unsigned int greg_t;	/* why isn't this defined? */

static void fetch_core_registers (char *, unsigned int, int, CORE_ADDR);

/*
 * See the comment in m68k-tdep.c regarding the utility of these functions.
 */

void
supply_gregset (gregset_t *gregsetp)
{
  register int regi;
  register greg_t *regp = (greg_t *) (gregsetp->gp_regs);
  char *zerobuf = alloca (max_register_size (current_gdbarch));
  memset (zerobuf, 0, max_register_size (current_gdbarch));

  /* FIXME: somewhere, there should be a #define for the meaning
     of this magic number 32; we should use that. */
  for (regi = 0; regi < 32; regi++)
    supply_register (regi, (char *) (regp + regi));

  supply_register (PC_REGNUM, (char *) &(gregsetp->gp_pc));
  supply_register (HI_REGNUM, (char *) &(gregsetp->gp_mdhi));
  supply_register (LO_REGNUM, (char *) &(gregsetp->gp_mdlo));
  supply_register (CAUSE_REGNUM, (char *) &(gregsetp->gp_cause));

  /* Fill inaccessible registers with zero.  */
  supply_register (BADVADDR_REGNUM, zerobuf);
}

void
fill_gregset (gregset_t *gregsetp, int regno)
{
  int regi;
  register greg_t *regp = (greg_t *) (gregsetp->gp_regs);

  /* same FIXME as above wrt 32 */
  for (regi = 0; regi < 32; regi++)
    if ((regno == -1) || (regno == regi))
      *(regp + regi) = *(greg_t *) & deprecated_registers[REGISTER_BYTE (regi)];

  if ((regno == -1) || (regno == PC_REGNUM))
    gregsetp->gp_pc = *(greg_t *) & deprecated_registers[REGISTER_BYTE (PC_REGNUM)];

  if ((regno == -1) || (regno == CAUSE_REGNUM))
    gregsetp->gp_cause = *(greg_t *) & deprecated_registers[REGISTER_BYTE (CAUSE_REGNUM)];

  if ((regno == -1) || (regno == HI_REGNUM))
    gregsetp->gp_mdhi = *(greg_t *) & deprecated_registers[REGISTER_BYTE (HI_REGNUM)];

  if ((regno == -1) || (regno == LO_REGNUM))
    gregsetp->gp_mdlo = *(greg_t *) & deprecated_registers[REGISTER_BYTE (LO_REGNUM)];
}

/*
 * Now we do the same thing for floating-point registers.
 * We don't bother to condition on FP0_REGNUM since any
 * reasonable MIPS configuration has an R3010 in it.
 *
 * Again, see the comments in m68k-tdep.c.
 */

void
supply_fpregset (fpregset_t *fpregsetp)
{
  register int regi;
  char *zerobuf = alloca (max_register_size (current_gdbarch));
  memset (zerobuf, 0, max_register_size (current_gdbarch));

  for (regi = 0; regi < 32; regi++)
    supply_register (FP0_REGNUM + regi,
		     (char *) &fpregsetp->fp_r.fp_regs[regi]);

  supply_register (FCRCS_REGNUM, (char *) &fpregsetp->fp_csr);

  /* FIXME: how can we supply FCRIR_REGNUM?  SGI doesn't tell us. */
  supply_register (FCRIR_REGNUM, zerobuf);
}

void
fill_fpregset (fpregset_t *fpregsetp, int regno)
{
  int regi;
  char *from, *to;

  for (regi = FP0_REGNUM; regi < FP0_REGNUM + 32; regi++)
    {
      if ((regno == -1) || (regno == regi))
	{
	  from = (char *) &deprecated_registers[REGISTER_BYTE (regi)];
	  to = (char *) &(fpregsetp->fp_r.fp_regs[regi - FP0_REGNUM]);
	  memcpy (to, from, REGISTER_RAW_SIZE (regi));
	}
    }

  if ((regno == -1) || (regno == FCRCS_REGNUM))
    fpregsetp->fp_csr = *(unsigned *) &deprecated_registers[REGISTER_BYTE (FCRCS_REGNUM)];
}


/* Figure out where the longjmp will land.
   We expect the first arg to be a pointer to the jmp_buf structure from which
   we extract the pc (JB_PC) that we will land at.  The pc is copied into PC.
   This routine returns true on success. */

int
get_longjmp_target (CORE_ADDR *pc)
{
  char *buf;
  CORE_ADDR jb_addr;

  buf = alloca (TARGET_PTR_BIT / TARGET_CHAR_BIT);
  jb_addr = read_register (A0_REGNUM);

  if (target_read_memory (jb_addr + JB_PC * JB_ELEMENT_SIZE, buf,
			  TARGET_PTR_BIT / TARGET_CHAR_BIT))
    return 0;

  *pc = extract_address (buf, TARGET_PTR_BIT / TARGET_CHAR_BIT);

  return 1;
}

/* Provide registers to GDB from a core file.

   CORE_REG_SECT points to an array of bytes, which were obtained from
   a core file which BFD thinks might contain register contents. 
   CORE_REG_SIZE is its size.

   Normally, WHICH says which register set corelow suspects this is:
     0 --- the general-purpose register set
     2 --- the floating-point register set
   However, for Irix 4, WHICH isn't used.

   REG_ADDR is also unused.  */

static void
fetch_core_registers (char *core_reg_sect, unsigned core_reg_size,
		      int which, CORE_ADDR reg_addr)
{
  if (core_reg_size != REGISTER_BYTES)
    {
      warning ("wrong size gregset struct in core file");
      return;
    }

  memcpy ((char *) deprecated_registers, core_reg_sect, core_reg_size);
}


/* Register that we are able to handle irix4 core file formats.
   FIXME: is this really bfd_target_unknown_flavour? */

static struct core_fns irix4_core_fns =
{
  bfd_target_unknown_flavour,		/* core_flavour */
  default_check_format,			/* check_format */
  default_core_sniffer,			/* core_sniffer */
  fetch_core_registers,			/* core_read_registers */
  NULL					/* next */
};

void
_initialize_core_irix4 (void)
{
  add_core_fns (&irix4_core_fns);
}