[gnu.gdb.bug] gdb isi support

adam@UUNET.UU.NET (Adam de Boor) (07/14/89)

I noticed the fix for reading registers for the ISI in the 3.2 patch set and
that reminded me of the isi-dep.c file I worked up to make the whole thing
work correctly, as raw 3.1 failed miserably at that task, being unable to read
registers from a core file or a running process. Below is an isi-dep.c and
m-isi.h that will work with the 4.3 distribution from ISI. I don't know
about their 4.2 dist, as we nuked that long ago, so I can't test it. Do
with these files as you see fit.

The dep file is taken wholesale from sun3-dep.c, but passes "non-standard"
parameters to REGISTER_U_ADDR. It seems safer to me to use u_ar0 itself to
locate the registers rather than relying on various fudge factors and
whatnot (BLOCKFUDGE and KERNEL_U_ADDR) whose origin is undocumented.

a

ps. you can ignore/delete the ATTACH_DETACH stuff in isi-dep.c -- it comes from
a kludge I worked into the ISI kernel to allow me to attach to a running
process, something I'd become fond of on the sun.

=================================
isi-dep.c
=================================
/* Low level interface to ptrace, for GDB when running under Unix.
   Copyright (C) 1988 Free Software Foundation, Inc.

GDB is distributed in the hope that it will be useful, but WITHOUT ANY
WARRANTY.  No author or distributor accepts responsibility to anyone
for the consequences of using it or for whether it serves any
particular purpose or works at all, unless he says so in writing.
Refer to the GDB General Public License for full details.

Everyone is granted permission to copy, modify and redistribute GDB,
but only under the conditions described in the GDB General Public
License.  A copy of this license is supposed to have been given to you
along with GDB so you can know your rights and responsibilities.  It
should be in a file named COPYING.  Among other things, the copyright
notice and this notice must be preserved on all copies.

In other words, go ahead and share GDB, but don't try to stop
anyone else from sharing it farther.  Help stamp out software hoarding!
*/

#include "defs.h"
#include "param.h"
#include "frame.h"
#include "inferior.h"

#ifdef USG
#include <sys/types.h>
#endif

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

#ifdef COFF_ENCAPSULATE
#include "a.out.encap.h"
#else
#include <a.out.h>
#endif
#ifndef N_SET_MAGIC
#define N_SET_MAGIC(exec, val) ((exec).a_magic = (val))
#endif
#include <sys/file.h>
#include <sys/stat.h>

#include <sys/ptrace.h>
#ifdef ATTACH_DETACH
static int  oldParent;
extern int  attach_flag;
#endif /* ATTACH_DETACH */

/*
 * Mapping of register numbers to their position in the stack
 */
#include <machine/reg.h>
int rloc[] = {
    R0, R1, R2, R3, R4, R5, R6, R7, R8, R9, R10, R11, R12, R13, FP, SP, PS, PC
};

extern int errno;

/* This function simply calls ptrace with the given arguments.  
   It exists so that all calls to ptrace are isolated in this 
   machine-dependent file. */
int
call_ptrace (request, pid, arg3, arg4)
     int request, pid, arg3, arg4;
{
  return ptrace (request, pid, arg3, arg4);
}

#ifdef ATTACH_DETACH
/* Start debugging the process whose number is PID.  */

attach (pid)
     int pid;
{
  errno = 0;
  oldParent = ptrace (PT_ATTACH, pid, 0, 0);
  if (errno)
    perror_with_name ("ptrace");
  attach_flag = 1;
  return pid;
}

/* Stop debugging the process whose number is PID
   and continue it with signal number SIGNAL.
   SIGNAL = 0 means just continue it.  */

void
detach (signal)
     int signal;
{
  errno = 0;
  ptrace (PT_DETACH, inferior_pid, signal, oldParent);
  if (errno)
    perror_with_name ("ptrace");
  attach_flag = 0;
}

#endif /* ATTACH_DETACH */

kill_inferior ()
{
  if (remote_debugging)
    return;
  if (inferior_pid == 0)
    return;

#ifdef ATTACH_DETACH
  if (attach_flag) {
      /*
       * Need to detach so the old parent gets notified of the death.
       */
      detach(SIGKILL);
  } else {
#endif /* ATTACH_DETACH */
      ptrace (PT_KILL, inferior_pid, 0, 0);
      wait (0);
#ifdef ATTACH_DETACH
  }
#endif /* ATTACH_DETACH */
  inferior_died ();
}

/* This is used when GDB is exiting.  It gives less chance of error.*/

kill_inferior_fast ()
{
  if (remote_debugging)
    return;
  if (inferior_pid == 0)
    return;
#ifdef ATTACH_DETACH
  if (attach_flag) {
      detach(SIGKILL);
  } else {
#endif /* ATTACH_DETACH */
      ptrace (PT_KILL, inferior_pid, 0, 0);
      wait (0);
#ifdef ATTACH_DETACH
  }
#endif /* ATTACH_DETACH */
}

/* Resume execution of the inferior process.
   If STEP is nonzero, single-step it.
   If SIGNAL is nonzero, give it that signal.  */

void
resume (step, signal)
     int step;
     int signal;
{
  errno = 0;
  if (remote_debugging)
    remote_resume (step, signal);
  else
    {
      ptrace (step ? PT_STEP : PT_CONTINUE, inferior_pid, 1, signal);
      if (errno)
	perror_with_name ("ptrace");
    }
}

void
fetch_inferior_registers ()
{
  register int regno;
  register unsigned int regaddr;
  char buf[MAX_REGISTER_RAW_SIZE];
  register int i;

  struct user u;
  unsigned int offset = (char *) &u.u_ar0 - (char *) &u;
  offset = ptrace (3, inferior_pid, offset, 0) - KERNEL_U_ADDR;

  for (regno = 0; regno < NUM_REGS; regno++)
    {
      regaddr = register_addr (regno, offset);
      for (i = 0; i < REGISTER_RAW_SIZE (regno); i += sizeof (int))
 	{
 	  *(int *) &buf[i] = ptrace (3, inferior_pid, regaddr, 0);
 	  regaddr += sizeof (int);
 	}
      supply_register (regno, buf);
    }
}

/* 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).  */

store_inferior_registers (regno)
     int regno;
{
  register unsigned int regaddr;
  char buf[80];

  struct user u;
  unsigned int offset = (char *) &u.u_ar0 - (char *) &u;
  offset = ptrace (3, inferior_pid, offset, 0) - KERNEL_U_ADDR;

  if (regno >= 0)
    {
      regaddr = register_addr (regno, offset);
      errno = 0;
      ptrace (6, inferior_pid, regaddr, read_register (regno));
      if (errno != 0)
	{
	  sprintf (buf, "writing register number %d", regno);
	  perror_with_name (buf);
	}
    }
  else for (regno = 0; regno < NUM_REGS; regno++)
    {
      regaddr = register_addr (regno, offset);
      errno = 0;
      ptrace (6, inferior_pid, regaddr, read_register (regno));
      if (errno != 0)
	{
	  sprintf (buf, "writing register number %d", regno);
	  perror_with_name (buf);
	}
    }
}

/* Copy LEN bytes from inferior's memory starting at MEMADDR
   to debugger memory starting at MYADDR. 
   On failure (cannot read from inferior, usually because address is out
   of bounds) returns the value of errno. */

int
read_inferior_memory (memaddr, myaddr, len)
     CORE_ADDR memaddr;
     char *myaddr;
     int len;
{
  register int i;
  /* Round starting address down to longword boundary.  */
  register CORE_ADDR addr = memaddr & - sizeof (int);
  /* Round ending address up; get number of longwords that makes.  */
  register int count
    = (((memaddr + len) - addr) + sizeof (int) - 1) / sizeof (int);
  /* Allocate buffer of that many longwords.  */
  register int *buffer = (int *) alloca (count * sizeof (int));
  extern int errno;

  /* Read all the longwords */
  for (i = 0; i < count; i++, addr += sizeof (int))
    {
      errno = 0;
      if (remote_debugging)
	buffer[i] = remote_fetch_word (addr);
      else
	buffer[i] = ptrace (1, inferior_pid, addr, 0);
      if (errno)
	return errno;
    }

  /* Copy appropriate bytes out of the buffer.  */
  bcopy ((char *) buffer + (memaddr & (sizeof (int) - 1)), myaddr, len);
  return 0;
}

/* Copy LEN bytes of data from debugger memory at MYADDR
   to inferior's memory at MEMADDR.
   On failure (cannot write the inferior)
   returns the value of errno.  */

int
write_inferior_memory (memaddr, myaddr, len)
     CORE_ADDR memaddr;
     char *myaddr;
     int len;
{
  register int i;
  /* Round starting address down to longword boundary.  */
  register CORE_ADDR addr = memaddr & - sizeof (int);
  /* Round ending address up; get number of longwords that makes.  */
  register int count
    = (((memaddr + len) - addr) + sizeof (int) - 1) / sizeof (int);
  /* Allocate buffer of that many longwords.  */
  register int *buffer = (int *) alloca (count * sizeof (int));
  extern int errno;

  /* Fill start and end extra bytes of buffer with existing memory data.  */

  if (remote_debugging)
    buffer[0] = remote_fetch_word (addr);
  else
    buffer[0] = ptrace (1, inferior_pid, addr, 0);

  if (count > 1)
    {
      if (remote_debugging)
	buffer[count - 1]
	  = remote_fetch_word (addr + (count - 1) * sizeof (int));
      else
	buffer[count - 1]
	  = ptrace (1, inferior_pid,
		    addr + (count - 1) * sizeof (int), 0);
    }

  /* Copy data to be written over corresponding part of buffer */

  bcopy (myaddr, (char *) buffer + (memaddr & (sizeof (int) - 1)), len);

  /* Write the entire buffer.  */

  for (i = 0; i < count; i++, addr += sizeof (int))
    {
      errno = 0;
      if (remote_debugging)
	remote_store_word (addr, buffer[i]);
      else
	ptrace (4, inferior_pid, addr, buffer[i]);
      if (errno)
	return errno;
    }

  return 0;
}

/* Work with core dump and executable files, for GDB. 
   This code would be in core.c if it weren't machine-dependent. */

/* Recognize COFF format systems because a.out.h defines AOUTHDR.  */
#ifdef AOUTHDR
#define COFF_FORMAT
#endif

#ifndef N_TXTADDR
#define N_TXTADDR(hdr) 0
#endif /* no N_TXTADDR */

#ifndef N_DATADDR
#define N_DATADDR(hdr) hdr.a_text
#endif /* no N_DATADDR */

/* Make COFF and non-COFF names for things a little more compatible
   to reduce conditionals later.  */

#ifdef COFF_FORMAT
#define a_magic magic
#endif

#ifndef COFF_FORMAT
#define AOUTHDR struct exec
#endif

extern char *sys_siglist[];


/* Hook for `exec_file_command' command to call.  */

extern void (*exec_file_display_hook) ();
   
/* File names of core file and executable file.  */

extern char *corefile;
extern char *execfile;

/* Descriptors on which core file and executable file are open.
   Note that the execchan is closed when an inferior is created
   and reopened if the inferior dies or is killed.  */

extern int corechan;
extern int execchan;

/* Last modification time of executable file.
   Also used in source.c to compare against mtime of a source file.  */

extern int exec_mtime;

/* Virtual addresses of bounds of the two areas of memory in the core file.  */

extern CORE_ADDR data_start;
extern CORE_ADDR data_end;
extern CORE_ADDR stack_start;
extern CORE_ADDR stack_end;

/* Virtual addresses of bounds of two areas of memory in the exec file.
   Note that the data area in the exec file is used only when there is no core file.  */

extern CORE_ADDR text_start;
extern CORE_ADDR text_end;

extern CORE_ADDR exec_data_start;
extern CORE_ADDR exec_data_end;

/* Address in executable file of start of text area data.  */

extern int text_offset;

/* Address in executable file of start of data area data.  */

extern int exec_data_offset;

/* Address in core file of start of data area data.  */

extern int data_offset;

/* Address in core file of start of stack area data.  */

extern int stack_offset;

#ifdef COFF_FORMAT
/* various coff data structures */

extern FILHDR file_hdr;
extern SCNHDR text_hdr;
extern SCNHDR data_hdr;

#endif /* not COFF_FORMAT */

/* a.out header saved in core file.  */
  
extern AOUTHDR core_aouthdr;

/* a.out header of exec file.  */

extern AOUTHDR exec_aouthdr;

extern void validate_files ();

core_file_command (filename, from_tty)
     char *filename;
     int from_tty;
{
  int val;
  extern char registers[];

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

  if (corefile)
    free (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)
    {
      if (have_inferior_p ())
	error ("To look at a core file, you must kill the inferior with \"kill\".");
      corechan = open (filename, O_RDONLY, 0);
      if (corechan < 0)
	perror_with_name (filename);
      /* 4.2-style (and perhaps also sysV-style) core dump file.  */
      {
	struct user u;

	int reg_offset;

	val = myread (corechan, &u, sizeof u);
	if (val < 0)
	  perror_with_name (filename);
	data_start = exec_data_start;

	data_end = data_start + NBPG * u.u_dsize;
	stack_start = stack_end - NBPG * u.u_ssize;
	data_offset = NBPG * UPAGES;
	stack_offset = NBPG * (UPAGES + u.u_dsize);
	reg_offset = (int) u.u_ar0 - KERNEL_U_ADDR;

	/* I don't know where to find this info.
	   So, for now, mark it as not available.  */
	N_SET_MAGIC (core_aouthdr, 0);

	/* Read the register values out of the core file and store
	   them where `read_register' will find them.  */

	{
	  register int regno;

	  for (regno = 0; regno < NUM_REGS; regno++)
	    {
	      char buf[MAX_REGISTER_RAW_SIZE];

	      val = lseek (corechan, register_addr (regno, reg_offset), 0);
	      if (val < 0)
		perror_with_name (filename);

 	      val = myread (corechan, buf, sizeof buf);
	      if (val < 0)
		perror_with_name (filename);
	      supply_register (regno, buf);
	    }
	}
      }
      if (filename[0] == '/')
	corefile = savestring (filename, strlen (filename));
      else
	{
	  corefile = concat (current_directory, "/", filename);
	}

      set_current_frame ( create_new_frame (read_register (FP_REGNUM),
					    read_pc ()));
      select_frame (get_current_frame (), 0);
      validate_files ();
    }
  else if (from_tty)
    printf ("No core file now.\n");
}

exec_file_command (filename, from_tty)
     char *filename;
     int from_tty;
{
  int val;

  /* Eliminate all traces of old exec file.
     Mark text segment as empty.  */

  if (execfile)
    free (execfile);
  execfile = 0;
  data_start = 0;
  data_end -= exec_data_start;
  text_start = 0;
  text_end = 0;
  exec_data_start = 0;
  exec_data_end = 0;
  if (execchan >= 0)
    close (execchan);
  execchan = -1;

  /* Now open and digest the file the user requested, if any.  */

  if (filename)
    {
      execchan = openp (getenv ("PATH"), 1, filename, O_RDONLY, 0,
			&execfile);
      if (execchan < 0)
	perror_with_name (filename);

#ifdef COFF_FORMAT
      {
	int aout_hdrsize;
	int num_sections;

	if (read_file_hdr (execchan, &file_hdr) < 0)
	  error ("\"%s\": not in executable format.", execfile);

	aout_hdrsize = file_hdr.f_opthdr;
	num_sections = file_hdr.f_nscns;

	if (read_aout_hdr (execchan, &exec_aouthdr, aout_hdrsize) < 0)
	  error ("\"%s\": can't read optional aouthdr", execfile);

	if (read_section_hdr (execchan, _TEXT, &text_hdr, num_sections) < 0)
	  error ("\"%s\": can't read text section header", execfile);

	if (read_section_hdr (execchan, _DATA, &data_hdr, num_sections) < 0)
	  error ("\"%s\": can't read data section header", execfile);

	text_start = exec_aouthdr.text_start;
	text_end = text_start + exec_aouthdr.tsize;
	text_offset = text_hdr.s_scnptr;
	exec_data_start = exec_aouthdr.data_start;
	exec_data_end = exec_data_start + exec_aouthdr.dsize;
	exec_data_offset = data_hdr.s_scnptr;
	data_start = exec_data_start;
	data_end += exec_data_start;
	exec_mtime = file_hdr.f_timdat;
      }
#else /* not COFF_FORMAT */
      {
	struct stat st_exec;

#ifdef HEADER_SEEK_FD
	HEADER_SEEK_FD (execchan);
#endif
	
	val = myread (execchan, &exec_aouthdr, sizeof (AOUTHDR));

	if (val < 0)
	  perror_with_name (filename);

        text_start = N_TXTADDR (exec_aouthdr);
        exec_data_start = N_DATADDR (exec_aouthdr);

	text_offset = N_TXTOFF (exec_aouthdr);
	exec_data_offset = N_TXTOFF (exec_aouthdr) + exec_aouthdr.a_text;

	text_end = text_start + exec_aouthdr.a_text;
        exec_data_end = exec_data_start + exec_aouthdr.a_data;
	data_start = exec_data_start;
	data_end += exec_data_start;

	fstat (execchan, &st_exec);
	exec_mtime = st_exec.st_mtime;
      }
#endif /* not COFF_FORMAT */

      validate_files ();
    }
  else if (from_tty)
    printf ("No exec file now.\n");

  /* Tell display code (if any) about the changed file name.  */
  if (exec_file_display_hook)
    (*exec_file_display_hook) (filename);
}

=========================================
m-isi.h
=========================================
/* Definitions to make GDB run on an ISI Optimum V (3.05) under 4.3bsd.
   Copyright (C) 1987, 1989 Free Software Foundation, Inc.

This file is part of GDB.

GDB 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 1, or (at your option)
any later version.

GDB 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 GDB; see the file COPYING.  If not, write to
the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.  */

/*
Date: Thu, 2 Apr 87 00:02:42 EST
From: crl@maxwell.physics.purdue.edu (Charles R. LaBrec)
Message-Id: <8704020502.AA01744@maxwell.physics.purdue.edu>
To: bug-gdb@prep.ai.mit.edu
Subject: gdb for ISI Optimum V

Here is an m-isi-ov.h file for gdb version 2.1.  It supports the 68881
registers, and tracks down the function prologue (since the ISI cc
puts it at the end of the function and branches to it if not
optimizing).  Also included are diffs to core.c, findvar.c, and
inflow.c, since the original code assumed that registers are an int in
the user struct, which isn't the case for 68020's with 68881's (and
not using the NEW_SUN_PTRACE).  I have not fixed the bugs associated
with the other direction (writing registers back to the user struct).
I have also included a diff that turns m68k-pinsn.c into isi-pinsn.c,
which is needed since the 3.05 release of as does not understand
floating point ops, and it compiles incorrectly under "cc -20"

I have used gdb for a while now, and it seems to work relatively well,
but I do not guarantee that it is perfect.  The more that use it, the
faster the bugs will get shaken out.  One bug I know of is not in gdb,
but in the assembler.  It seems to screw up the .stabs of variables.
For externs, this is not important since gdb uses the global symbol
value, but for statics, this makes gdb unable to find them.  I am
currently trying to track it down.

As an aside, I notice that only global functions are used as symbols
to print as relative addresses, i.e. "<function + offset>", and not
static functions, which end up printing as large offsets from the last
global one.  Would there be a problem if static functions were also
recorded as misc functions in read_dbx_symtab?

Charles LaBrec
crl @ maxwell.physics.purdue.edu  */

/* Identify this machine */
#ifndef ISI68K
#define ISI68K
#endif

/* Define the bit, byte, and word ordering of the machine.  */
#define BITS_BIG_ENDIAN
#define BYTES_BIG_ENDIAN
#define WORDS_BIG_ENDIAN

/* Define this if the C compiler puts an underscore at the front
   of external names before giving them to the linker.  */

#define NAMES_HAVE_UNDERSCORE

/* Debugger information will be in DBX format.  */

#define READ_DBX_FORMAT

/* Support kludged attach/detach */

#define ATTACH_DETACH

/* Offset from address of function to start of its code.
   Zero on most machines.  */

#define FUNCTION_START_OFFSET 0

/* Advance PC across any function entry prologue instructions
   to reach some "real" code.  */

#define SKIP_PROLOGUE(pc)   \
{ register int op = read_memory_integer (pc, 2);	\
  if (op == 0047126)					\
    pc += 4;   /* Skip link #word */			\
  else if (op == 0044016)				\
    pc += 6;   /* Skip link #long */			\
  else if (op == 0060000)				\
    pc += 4;   /* Skip bra #word */			\
  else if (op == 00600377)				\
    pc += 6;   /* skip bra #long */			\
  else if ((op & 0177400) == 0060000)			\
    pc += 2;   /* skip bra #char */			\
}


/* Immediately after a function call, return the saved pc.
   Can't always go through the frames for this because on some machines
   the new frame is not set up until the new function executes
   some instructions.  */

#define SAVED_PC_AFTER_CALL(frame) \
read_memory_integer (read_register (SP_REGNUM), 4)

/* This is the amount to subtract from u.u_ar0
   to get the offset in the core file of the register values.  */

/*#define KERNEL_U_ADDR 0x10800000*/
#define KERNEL_U_ADDR 0

/* Address of end of stack space.  */

/*#define STACK_END_ADDR 0x10000000*/
#define STACK_END_ADDR 0xfffe000

/* Stack grows downward.  */

#define INNER_THAN <

/* Sequence of bytes for breakpoint instruction.  */

#define BREAKPOINT {0x4e, 0x4f}

/* Data segment starts at etext rounded up to DATAROUND in {N,Z}MAGIC files */

#define DATAROUND	0x20000
#define N_DATADDR(hdr)	(hdr.a_magic != OMAGIC ? \
	(hdr.a_text + DATAROUND) & ~(DATAROUND-1) : hdr.a_text)

/* Text segment starts at sizeof (struct exec) in {N,Z}MAGIC files */

#define N_TXTADDR(hdr)	(hdr.a_magic != OMAGIC ? sizeof (struct exec) : 0)

/* Amount PC must be decremented by after a breakpoint.
   This is often the number of bytes in BREAKPOINT
   but not always.
   On the ISI, the kernel resets the pc to the trap instr */

#define DECR_PC_AFTER_BREAK 0

/* Nonzero if instruction at PC is a return instruction.  */

#define ABOUT_TO_RETURN(pc) (read_memory_integer (pc, 2) == 0x4e75)

/* Return 1 if P points to an invalid floating point value.  */

#define INVALID_FLOAT(p, len) 0   /* Just a first guess; not checked */

/* Largest integer type */
#define LONGEST long

/* Name of the builtin type for the LONGEST type above. */
#define BUILTIN_TYPE_LONGEST builtin_type_long

/* Say how long registers are.  */

#define REGISTER_TYPE long

/* Number of machine registers */
/* If you've got a 68881, more power to you -- define ISI68881. For those
 * unfortunate schmucks, though, referencing the registers causes instant
 * death as it tries to convert fp registers to fp constants using fp
 * instructions, which the machine can't handle (q.v. convert_from_68881).
 * To get around this, only tell gdb we've got the first 18 registers */

#ifdef ISI68881
#define NUM_REGS 29
#else
#define NUM_REGS 18
#endif /* ISI68881 */

/* Initializer for an array of names of registers.
   There should be NUM_REGS strings in this initializer.  */

#define REGISTER_NAMES  \
 {"d0", "d1", "d2", "d3", "d4", "d5", "d6", "d7", \
  "a0", "a1", "a2", "a3", "a4", "a5", "fp", "sp", \
  "ps", "pc",  \
  "fp0", "fp1", "fp2", "fp3", "fp4", "fp5", "fp6", "fp7", \
  "fpcontrol", "fpstatus", "fpiaddr" }

/* Register numbers of various important registers.
   Note that some of these values are "real" register numbers,
   and correspond to the general registers of the machine,
   and some are "phony" register numbers which are too large
   to be actual register numbers as far as the user is concerned
   but do serve to get the desired values when passed to read_register.  */

#define FP_REGNUM 14		/* Contains address of executing stack frame */
#define SP_REGNUM 15		/* Contains address of top of stack */
#define PS_REGNUM 16		/* Contains processor status */
#define PC_REGNUM 17		/* Contains program counter */
#define FP0_REGNUM 18		/* Floating point register 0 */
#define FPC_REGNUM 26		/* 68881 control register */

/* expects blockend to be u.u_ar0 */
extern int rloc[];  	/* Defined in isi-dep.c */
#define REGISTER_U_ADDR(addr, blockend, regno)                  \
{       blockend &= UPAGES*NBPG - 1;                            \
	if (regno < 18) addr = (int)blockend + rloc[regno]*4;  	\
        else if (regno < 26) addr = (int) &((struct user *)0)->u_68881_regs \
            + (regno - 18) * 12;                                \
        else if (regno < 29) addr = (int) &((struct user *)0)->u_68881_regs \
            + 8 * 12 + (regno - 26) * 4;                        \
}

/* Total amount of space needed to store our copies of the machine's
   register state, the array `registers'.  */
#define REGISTER_BYTES (16*4+8*12+8+20)

/* Index within `registers' of the first byte of the space for
   register N.  */

#define REGISTER_BYTE(N)  \
 ((N) >= FPC_REGNUM ? (((N) - FPC_REGNUM) * 4) + 168	\
  : (N) >= FP0_REGNUM ? (((N) - FP0_REGNUM) * 12) + 72	\
  : (N) * 4)

/* Number of bytes of storage in the actual machine representation
   for register N.  On the 68000, all regs are 4 bytes
   except the floating point regs which are 12 bytes.  */

#define REGISTER_RAW_SIZE(N) (((unsigned)(N) - FP0_REGNUM) < 8 ? 12 : 4)

/* Number of bytes of storage in the program's representation
   for register N.  On the 68000, all regs are 4 bytes
   except the floating point regs which are 8-byte doubles.  */

#define REGISTER_VIRTUAL_SIZE(N) (((unsigned)(N) - FP0_REGNUM) < 8 ? 8 : 4)

/* Largest value REGISTER_RAW_SIZE can have.  */

#define MAX_REGISTER_RAW_SIZE 12

/* Largest value REGISTER_VIRTUAL_SIZE can have.  */

#define MAX_REGISTER_VIRTUAL_SIZE 8

/* Nonzero if register N requires conversion
   from raw format to virtual format.  */

#define REGISTER_CONVERTIBLE(N) (((unsigned)(N) - FP0_REGNUM) < 8)

/* Convert data from raw format for register REGNUM
   to virtual format for register REGNUM.  */

#define REGISTER_CONVERT_TO_VIRTUAL(REGNUM,FROM,TO)	\
{ if ((REGNUM) >= FP0_REGNUM && (REGNUM) < FPC_REGNUM)	\
    convert_from_68881 ((FROM), (TO));	\
  else					\
    bcopy ((FROM), (TO), 4); }

/* Convert data from virtual format for register REGNUM
   to raw format for register REGNUM.  */

#define REGISTER_CONVERT_TO_RAW(REGNUM,FROM,TO)	\
{ if ((REGNUM) >= FP0_REGNUM && (REGNUM) < FPC_REGNUM)	\
    convert_to_68881 ((FROM), (TO));	\
  else					\
    bcopy ((FROM), (TO), 4); }

/* Return the GDB type object for the "standard" data type
   of data in register N.  */

#define REGISTER_VIRTUAL_TYPE(N) \
 (((unsigned)(N) - FP0_REGNUM) < 8 ? builtin_type_double : builtin_type_int)

/* Store the address of the place in which to copy the structure the
   subroutine will return.  This is called from call_function. */

#define STORE_STRUCT_RETURN(ADDR, SP) \
  { write_register (9, (ADDR)); }

/* Extract from an array REGBUF containing the (raw) register state
   a function return value of type TYPE, and copy that, in virtual format,
   into VALBUF.  */

#define EXTRACT_RETURN_VALUE(TYPE,REGBUF,VALBUF) \
  bcopy (REGBUF, VALBUF, TYPE_LENGTH (TYPE))

/* Write into appropriate registers a function return value
   of type TYPE, given in virtual format.  */

#define STORE_RETURN_VALUE(TYPE,VALBUF) \
  write_register_bytes (0, VALBUF, TYPE_LENGTH (TYPE))

/* Extract from an array REGBUF containing the (raw) register state
   the address in which a function should return its structure value,
   as a CORE_ADDR (or an expression that can be used as one).  */

#define EXTRACT_STRUCT_VALUE_ADDRESS(REGBUF) (*(int *)(REGBUF))

/* Describe the pointer in each stack frame to the previous stack frame
   (its caller).  */

/* FRAME_CHAIN takes a frame's nominal address
   and produces the frame's chain-pointer.

   FRAME_CHAIN_COMBINE takes the chain pointer and the frame's nominal address
   and produces the nominal address of the caller frame.

   However, if FRAME_CHAIN_VALID returns zero,
   it means the given frame is the outermost one and has no caller.
   In that case, FRAME_CHAIN_COMBINE is not used.  */

/* In the case of the ISI, the frame's nominal address
   is the address of a 4-byte word containing the calling frame's address.  */

#define FRAME_CHAIN(thisframe)  \
  ((thisframe)->pc >= first_object_file_end ? \
   read_memory_integer ((thisframe)->frame, 4) :\
   0)

#define FRAME_CHAIN_VALID(chain, thisframe) \
  (chain != 0 && (FRAME_SAVED_PC (thisframe) >= first_object_file_end))

#define FRAME_CHAIN_COMBINE(chain, thisframe) (chain)

/* Define other aspects of the stack frame.  */

/* A macro that tells us whether the function invocation represented
   by FI does not have a frame on the stack associated with it.  If it
   does not, FRAMELESS is set to 1, else 0.  */
#define FRAMELESS_FUNCTION_INVOCATION(FI, FRAMELESS) \
{							\
  CORE_ADDR func_start, after_prologue;			\
  func_start = (get_pc_function_start ((FI)->pc) +	\
		FUNCTION_START_OFFSET);			\
  after_prologue = func_start;				\
  SKIP_PROLOGUE (after_prologue);			\
  (FRAMELESS) = (after_prologue == func_start);		\
}

#define FRAME_SAVED_PC(FRAME) (read_memory_integer ((FRAME)->frame + 4, 4))

#define FRAME_ARGS_ADDRESS(fi) ((fi)->frame)

#define FRAME_LOCALS_ADDRESS(fi) ((fi)->frame)

/* Return number of args passed to a frame.
   Can return -1, meaning no way to tell.  */

#define FRAME_NUM_ARGS(val, fi)  \
{ register CORE_ADDR pc = FRAME_SAVED_PC (fi);			\
  register int insn = 0177777 & read_memory_integer (pc, 2);	\
  val = 0;							\
  if (insn == 0047757 || insn == 0157374)  /* lea W(sp),sp or addaw #W,sp */ \
    val = read_memory_integer (pc + 2, 2);			\
  else if ((insn & 0170777) == 0050217 /* addql #N, sp */	\
	   || (insn & 0170777) == 0050117)  /* addqw */		\
    { val = (insn >> 9) & 7; if (val == 0) val = 8; }		\
  else if (insn == 0157774) /* addal #WW, sp */			\
    val = read_memory_integer (pc + 2, 4);			\
  val >>= 2; }

/* Return number of bytes at start of arglist that are not really args.  */

#define FRAME_ARGS_SKIP 8

/* Put here the code to store, into a struct frame_saved_regs,
   the addresses of the saved registers of frame described by FRAME_INFO.
   This includes special registers such as pc and fp saved in special
   ways in the stack frame.  sp is even more special:
   the address we return for it IS the sp for the next frame.  */

#define FRAME_FIND_SAVED_REGS(frame_info, frame_saved_regs)		\
{ register int regnum;							\
  register int regmask;							\
  register CORE_ADDR next_addr;						\
  register CORE_ADDR pc;						\
  register int insn;							\
  register int offset;							\
  bzero (&frame_saved_regs, sizeof frame_saved_regs);			\
  if ((frame_info)->pc >= (frame_info)->frame - CALL_DUMMY_LENGTH - FP_REGNUM*4 - 8*12 - 4 \
      && (frame_info)->pc <= (frame_info)->frame)				\
    { next_addr = (frame_info)->frame;					\
      pc = (frame_info)->frame - CALL_DUMMY_LENGTH - FP_REGNUM * 4 - 8*12 - 4; }\
  else   								\
    { pc = get_pc_function_start ((frame_info)->pc); 			\
      /* Verify we have a link a6 instruction next,			\
	 or a branch followed by a link a6 instruction;			\
	 if not we lose.  If we win, find the address above the saved   \
	 regs using the amount of storage from the link instruction.  */\
retry:									\
      insn = read_memory_integer (pc, 2);				\
      if (insn == 044016)						\
	next_addr = (frame_info)->frame - read_memory_integer (pc += 2, 4), pc+=4; \
      else if (insn == 047126)						\
	next_addr = (frame_info)->frame - read_memory_integer (pc += 2, 2), pc+=2; \
      else if ((insn & 0177400) == 060000)	/* bra insn */		\
	{ offset = insn & 0377;						\
          pc += 2;				/* advance past bra */	\
	  if (offset == 0)			/* bra #word */		\
	    offset = read_memory_integer (pc, 2), pc += 2;		\
	  else if (offset == 0377)		/* bra #long */		\
	    offset = read_memory_integer (pc, 4), pc += 4;		\
	  pc += offset;							\
	  goto retry;							\
      } else goto lose;							\
      /* If have an addal #-n, sp next, adjust next_addr.  */		\
      if ((0177777 & read_memory_integer (pc, 2)) == 0157774)		\
	next_addr += read_memory_integer (pc += 2, 4), pc += 4;		\
    }									\
  /* next should be a moveml to (sp) or -(sp) or a movl r,-(sp) */	\
  insn = read_memory_integer (pc, 2), pc += 2;				\
  regmask = read_memory_integer (pc, 2);				\
  if ((insn & 0177760) == 022700)	/* movl rn, (sp) */		\
    (frame_saved_regs).regs[(insn&7) + ((insn&010)?8:0)] = next_addr;	\
  else if ((insn & 0177760) == 024700)	/* movl rn, -(sp) */		\
    (frame_saved_regs).regs[(insn&7) + ((insn&010)?8:0)] = next_addr-=4; \
  else if (insn == 0044327)		/* moveml mask, (sp) */		\
    { pc += 2;								\
      /* Regmask's low bit is for register 0, the first written */	\
      next_addr -= 4;							\
      for (regnum = 0; regnum < 16; regnum++, regmask >>= 1)		\
	if (regmask & 1)						\
          (frame_saved_regs).regs[regnum] = (next_addr += 4);		\
  } else if (insn == 0044347)		/* moveml mask, -(sp) */	\
    { pc += 2;								\
      /* Regmask's low bit is for register 15, the first pushed */	\
      for (regnum = 15; regnum >= 0; regnum--, regmask >>= 1)		\
	if (regmask & 1)						\
          (frame_saved_regs).regs[regnum] = (next_addr -= 4); }		\
  /* clrw -(sp); movw ccr,-(sp) may follow.  */				\
  if (read_memory_integer (pc, 2) == 041147 				\
      && read_memory_integer (pc+2, 2) == 042347)			\
    (frame_saved_regs).regs[PS_REGNUM] = (next_addr -= 4);		\
  lose: ;								\
  (frame_saved_regs).regs[SP_REGNUM] = (frame_info)->frame + 8;		\
  (frame_saved_regs).regs[FP_REGNUM] = (frame_info)->frame;		\
  (frame_saved_regs).regs[PC_REGNUM] = (frame_info)->frame + 4;		\
}

/* Compensate for lack of `vprintf' function.  */
#define vprintf(format, ap) _doprnt (format, ap, stdout)

/* Things needed for making the inferior call functions.  */

/* Push an empty stack frame, to record the current PC, etc.  */

#define PUSH_DUMMY_FRAME \
{ register CORE_ADDR sp = read_register (SP_REGNUM);			\
  register int regnum;							\
  char raw_buffer[12];							\
  sp = push_word (sp, read_register (PC_REGNUM));			\
  sp = push_word (sp, read_register (FP_REGNUM));			\
  write_register (FP_REGNUM, sp);					\
  for (regnum = FP0_REGNUM + 7; regnum >= FP0_REGNUM; regnum--)		\
    { read_register_bytes (REGISTER_BYTE (regnum), raw_buffer, 12);	\
      sp = push_bytes (sp, raw_buffer, 12); }				\
  for (regnum = FP_REGNUM - 1; regnum >= 0; regnum--)			\
    sp = push_word (sp, read_register (regnum));			\
  sp = push_word (sp, read_register (PS_REGNUM));			\
  write_register (SP_REGNUM, sp);  }

/* Discard from the stack the innermost frame, restoring all registers.  */

#define POP_FRAME  \
{ register FRAME frame = get_current_frame ();			 	\
  register CORE_ADDR fp;					 	\
  register int regnum;							\
  struct frame_saved_regs fsr;						\
  struct frame_info *fi;						\
  char raw_buffer[12];							\
  fi = get_frame_info (frame);					 	\
  fp = fi->frame;						 	\
  get_frame_saved_regs (fi, &fsr);					\
  for (regnum = FP0_REGNUM + 7; regnum >= FP0_REGNUM; regnum--)		\
    if (fsr.regs[regnum])						\
      { read_memory (fsr.regs[regnum], raw_buffer, 12);			\
        write_register_bytes (REGISTER_BYTE (regnum), raw_buffer, 12); }\
  for (regnum = FP_REGNUM - 1; regnum >= 0; regnum--)			\
    if (fsr.regs[regnum])						\
      write_register (regnum, read_memory_integer (fsr.regs[regnum], 4)); \
  if (fsr.regs[PS_REGNUM])						\
    write_register (PS_REGNUM, read_memory_integer (fsr.regs[PS_REGNUM], 4)); \
  write_register (FP_REGNUM, read_memory_integer (fp, 4));		\
  write_register (PC_REGNUM, read_memory_integer (fp + 4, 4));  	\
  write_register (SP_REGNUM, fp + 8);					\
  flush_cached_frames ();						\
  set_current_frame ( create_new_frame (read_register (FP_REGNUM),	\
					read_pc ())); }

/* This sequence of words is the instructions
     fmovem #<f0-f7>,-(sp)
     moveml 0xfffc,-(sp)
     clrw -(sp)
     movew ccr,-(sp)
     /..* The arguments are pushed at this point by GDB;
	no code is needed in the dummy for this.
	The CALL_DUMMY_START_OFFSET gives the position of
	the following jsr instruction.  *../
     jsr @#32323232
     addl #69696969,sp
     bpt
     nop
Note this is 24 bytes.
We actually start executing at the jsr, since the pushing of the
registers is done by PUSH_DUMMY_FRAME.  If this were real code,
the arguments for the function called by the jsr would be pushed
between the moveml and the jsr, and we could allow it to execute through.
But the arguments have to be pushed by GDB after the PUSH_DUMMY_FRAME is done,
and we cannot allow the moveml to push the registers again lest they be
taken for the arguments.  */

#define CALL_DUMMY {0xf227e0ff, 0x48e7fffc, 0x426742e7, 0x4eb93232, 0x3232dffc, 0x69696969, 0x4e4f4e71}

#define CALL_DUMMY_LENGTH 28

#define CALL_DUMMY_START_OFFSET 12

/* Insert the specified number of args and function address
   into a call sequence of the above form stored at DUMMYNAME.  */

#define FIX_CALL_DUMMY(dummyname, pc, fun, nargs, type)     \
{ *(int *)((char *) dummyname + 20) = nargs * 4;  \
  *(int *)((char *) dummyname + 14) = fun; }

/* Interface definitions for kernel debugger KDB.  */

/* Map machine fault codes into signal numbers.
   First subtract 0, divide by 4, then index in a table.
   Faults for which the entry in this table is 0
   are not handled by KDB; the program's own trap handler
   gets to handle then.  */

#define FAULT_CODE_ORIGIN 0
#define FAULT_CODE_UNITS 4
#define FAULT_TABLE    \
{ 0, 0, 0, 0, SIGTRAP, 0, 0, 0, \
  0, SIGTRAP, 0, 0, 0, 0, 0, SIGKILL, \
  0, 0, 0, 0, 0, 0, 0, 0, \
  SIGILL }

/* Start running with a stack stretching from BEG to END.
   BEG and END should be symbols meaningful to the assembler.
   This is used only for kdb.  */

#define INIT_STACK(beg, end)  \
{ asm (".globl end");         \
  asm ("movl $ end, sp");      \
  asm ("clrl fp"); }

/* Push the frame pointer register on the stack.  */
#define PUSH_FRAME_PTR        \
  asm ("movel fp, -(sp)");

/* Copy the top-of-stack to the frame pointer register.  */
#define POP_FRAME_PTR  \
  asm ("movl (sp), fp");

/* After KDB is entered by a fault, push all registers
   that GDB thinks about (all NUM_REGS of them),
   so that they appear in order of ascending GDB register number.
   The fault code will be on the stack beyond the last register.  */

#define PUSH_REGISTERS        \
{ asm ("clrw -(sp)");	      \
  asm ("pea 10(sp)");	      \
  asm ("movem $ 0xfffe,-(sp)"); }

/* Assuming the registers (including processor status) have been
   pushed on the stack in order of ascending GDB register number,
   restore them and return to the address in the saved PC register.  */

#define POP_REGISTERS          \
{ asm ("subil $8,28(sp)");     \
  asm ("movem (sp),$ 0xffff"); \
  asm ("rte"); }