gdb/sun386-nat.c

/* Native support for Sun 386i's for GDB, the GNU debugger.
   Copyright 1986, 1987, 1989, 1991, 1992, 1993, 1995, 1999, 2000, 2001
   Free Software Foundation, Inc.
   Changes for sun386i by Jean Daniel Fekete (jdf@litp.univ-p6-7.fr),
   C2V Paris, April 89.

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

#include <sys/param.h>
#include <sys/dir.h>
#include <sys/user.h>
#include <signal.h>
#include <sys/ioctl.h>
#include <fcntl.h>

#include <sys/ptrace.h>
#include <machine/reg.h>

#include <sys/file.h>
#include "gdb_stat.h"
#include <sys/core.h>


/* Machine-dependent code which would otherwise be in corefile.c */
/* Work with core files, for GDB. */


void
core_file_command (char *filename, int from_tty)
{
  int val;

  /* Discard all vestiges of any previous core file
     and mark data and stack spaces as empty.  */

  if (corefile)
    xfree (corefile);
  corefile = 0;

  if (corechan >= 0)
    close (corechan);
  corechan = -1;

  data_start = 0;
  data_end = 0;
  stack_start = STACK_END_ADDR;
  stack_end = STACK_END_ADDR;

  /* Now, if a new core file was specified, open it and digest it.  */

  if (filename)
    {
      filename = tilde_expand (filename);
      make_cleanup (xfree, filename);

      if (have_inferior_p ())
	error ("To look at a core file, you must kill the program with \"kill\".");
      corechan = open (filename, O_RDONLY, 0);
      if (corechan < 0)
	perror_with_name (filename);

      {
	struct core corestr;

	val = myread (corechan, &corestr, sizeof corestr);
	if (val < 0)
	  perror_with_name (filename);
	if (corestr.c_magic != CORE_MAGIC)
	  error ("\"%s\" does not appear to be a core dump file (magic 0x%x, expected 0x%x)",
		 filename, corestr.c_magic, (int) CORE_MAGIC);
	else if (sizeof (struct core) != corestr.c_len)
	    error ("\"%s\" has an invalid struct core length (%d, expected %d)",
		   filename, corestr.c_len, (int) sizeof (struct core));

	data_start = exec_data_start;
	data_end = data_start + corestr.c_dsize;
	stack_start = stack_end - corestr.c_ssize;
	data_offset = sizeof corestr;
	stack_offset = sizeof corestr + corestr.c_dsize;

	memcpy (registers, &corestr.c_regs, sizeof corestr.c_regs);

	memcpy (&registers[REGISTER_BYTE (FP0_REGNUM)],
		corestr.c_fpu.f_fpstatus.f_st,
		sizeof corestr.c_fpu.f_fpstatus.f_st);
	memcpy (&registers[REGISTER_BYTE (FPC_REGNUM)],
		&corestr.c_fpu.f_fpstatus.f_ctrl,
		sizeof corestr.c_fpu.f_fpstatus -
		sizeof corestr.c_fpu.f_fpstatus.f_st);

	/* the struct aouthdr of sun coff is not the struct exec stored
	   in the core file. */
	memcpy (&core_aouthdr, &corestr.c_aouthdr, sizeof (struct exec));
#ifndef COFF_ENCAPSULATE
	core_aouthdr.magic = corestr.c_aouthdr.a_info;
	core_aouthdr.vstamp = /*SUNVERSION */ 31252;
#endif
	printf_unfiltered ("Core file is from \"%s\".\n", corestr.c_cmdname);
	if (corestr.c_signo > 0)
	  printf_unfiltered ("Program terminated with signal %d, %s.\n",
			 corestr.c_signo, safe_strsignal (corestr.c_signo));
      }
      if (filename[0] == '/')
	corefile = savestring (filename, strlen (filename));
      else
	{
	  corefile = concat (current_directory, "/", filename, NULL);
	}

      flush_cached_frames ();
      select_frame (get_current_frame (), 0);

      validate_files ();
    }
  else if (from_tty)
    printf_unfiltered ("No core file now.\n");
}

i387_to_double (char *from, char *to)
{
  long *lp;
  /* push extended mode on 387 stack, then pop in double mode

   * first, set exception masks so no error is generated -
   * number will be rounded to inf or 0, if necessary 
   */
  asm ("pushl %eax");		/* grab a stack slot */
  asm ("fstcw (%esp)");		/* get 387 control word */
  asm ("movl (%esp),%eax");	/* save old value */
  asm ("orl $0x3f,%eax");	/* mask all exceptions */
  asm ("pushl %eax");
  asm ("fldcw (%esp)");		/* load new value into 387 */

  asm ("movl 8(%ebp),%eax");
  asm ("fldt (%eax)");		/* push extended number on 387 stack */
  asm ("fwait");
  asm ("movl 12(%ebp),%eax");
  asm ("fstpl (%eax)");		/* pop double */
  asm ("fwait");

  asm ("popl %eax");		/* flush modified control word */
  asm ("fnclex");		/* clear exceptions */
  asm ("fldcw (%esp)");		/* restore original control word */
  asm ("popl %eax");		/* flush saved copy */
}

double_to_i387 (char *from, char *to)
{
  /* push double mode on 387 stack, then pop in extended mode
   * no errors are possible because every 64-bit pattern
   * can be converted to an extended
   */
  asm ("movl 8(%ebp),%eax");
  asm ("fldl (%eax)");
  asm ("fwait");
  asm ("movl 12(%ebp),%eax");
  asm ("fstpt (%eax)");
  asm ("fwait");
}

void
fetch_inferior_registers (int regno)
{
  struct regs inferior_registers;
  struct fp_state inferior_fp_registers;

  registers_fetched ();

  ptrace (PTRACE_GETREGS, inferior_pid,
	  (PTRACE_ARG3_TYPE) & inferior_registers);
  ptrace (PTRACE_GETFPREGS, inferior_pid,
	  (PTRACE_ARG3_TYPE) & inferior_fp_registers);

  memcpy (registers, &inferior_registers, sizeof inferior_registers);

  memcpy (&registers[REGISTER_BYTE (FP0_REGNUM)], inferior_fp_registers.f_st,
	  sizeof inferior_fp_registers.f_st);
  memcpy (&registers[REGISTER_BYTE (FPC_REGNUM)],
	  &inferior_fp_registers.f_ctrl,
	  sizeof inferior_fp_registers - sizeof inferior_fp_registers.f_st);
}

/* Store our register values back into the inferior.
   If REGNO is -1, do this for all registers.
   Otherwise, REGNO specifies which register (so we can save time).  */

void
store_inferior_registers (int regno)
{
  struct regs inferior_registers;
  struct fp_state inferior_fp_registers;

  memcpy (&inferior_registers, registers, 20 * 4);

  memcpy (inferior_fp_registers.f_st,
	  &registers[REGISTER_BYTE (FP0_REGNUM)],
	  sizeof inferior_fp_registers.f_st);
  memcpy (&inferior_fp_registers.f_ctrl,
	  &registers[REGISTER_BYTE (FPC_REGNUM)],
	  sizeof inferior_fp_registers - sizeof inferior_fp_registers.f_st);

#ifdef PTRACE_FP_BUG
  if (regno == FP_REGNUM || regno == -1)
    /* Storing the frame pointer requires a gross hack, in which an
       instruction that moves eax into ebp gets single-stepped.  */
    {
      int stack = inferior_registers.r_reg[SP_REGNUM];
      int stuff = ptrace (PTRACE_PEEKDATA, inferior_pid,
			  (PTRACE_ARG3_TYPE) stack);
      int reg = inferior_registers.r_reg[EAX];
      inferior_registers.r_reg[EAX] =
	inferior_registers.r_reg[FP_REGNUM];
      ptrace (PTRACE_SETREGS, inferior_pid,
	      (PTRACE_ARG3_TYPE) & inferior_registers);
      ptrace (PTRACE_POKEDATA, inferior_pid, (PTRACE_ARG3_TYPE) stack,
	      0xc589);
      ptrace (PTRACE_SINGLESTEP, inferior_pid, (PTRACE_ARG3_TYPE) stack,
	      0);
      wait (0);
      ptrace (PTRACE_POKEDATA, inferior_pid, (PTRACE_ARG3_TYPE) stack,
	      stuff);
      inferior_registers.r_reg[EAX] = reg;
    }
#endif
  ptrace (PTRACE_SETREGS, inferior_pid,
	  (PTRACE_ARG3_TYPE) & inferior_registers);
  ptrace (PTRACE_SETFPREGS, inferior_pid,
	  (PTRACE_ARG3_TYPE) & inferior_fp_registers);
}