support.c

这个是LINUX下的GDB调度工具的源码

/* support routines for interpreted instructions
   Copyright (C) 1992, 1993 Free Software Foundation, Inc.

This file is part of Z8KSIM

Z8KSIM 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, or (at your option)
any later version.

Z8KSIM 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 Z8KZIM; if not, write to the Free Software
Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.  */

#include "config.h"

#include <ansidecl.h>
#include <signal.h>
#include <errno.h>

#include "tm.h"
#include "sim.h"
#include "mem.h"
#include <stdio.h>
#ifdef HAVE_TIME_H
#include <time.h>
#endif
#ifdef HAVE_SYS_TIMES_H
#include <sys/times.h>
#endif
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/param.h>
#include "gdb/callback.h"
#include "gdb/remote-sim.h"
#include "syscall.h"

static int get_now PARAMS ((void));
static int now_persec PARAMS ((void));
static int put_long PARAMS ((sim_state_type * context, int ptr, int value));
static int put_short PARAMS ((sim_state_type * context, int ptr, int value));

int sim_z8001_mode;

static int
get_now ()
{
#ifdef HAVE_SYS_TIMES_H
  struct tms b;

  times (&b);
  return b.tms_utime + b.tms_stime;
#else
  return time (0);
#endif
}

static int
now_persec ()
{
  return 50;
}


/* #define LOG /* define this to print instruction use counts */

#ifdef __GNUC__
#define INLINE __inline__
#include "inlines.h"
#else
#include "inlines.h"
#endif

/* This holds the entire cpu context */
static sim_state_type the_state;

int
fail (context, dummy)
     sim_state_type *context;
     int dummy;
{
  context->exception = SIM_BAD_INST;
  return 1;
}

void
sfop_bad1 (context)
     sim_state_type *context;
{
  context->exception
    = SIM_BAD_INST;
}

void
bfop_bad1 (context)
     sim_state_type *context;
{
  context->exception
    = SIM_BAD_INST;
}

void
fop_bad (context)
     sim_state_type *context;
{
  context->exception =
    SIM_BAD_INST;
}

/* Table of bit counts for all byte values */

char the_parity[256] =
{
  0, 1, 1, 2, 1, 2, 2, 3, 1, 2, 2, 3, 2, 3, 3, 4, 1, 2, 2, 3, 2, 3, 3,
  4, 2, 3, 3, 4, 3, 4, 4, 5, 1, 2, 2, 3, 2, 3, 3, 4, 2, 3, 3, 4, 3, 4,
  4, 5, 2, 3, 3, 4, 3, 4, 4, 5, 3, 4, 4, 5, 4, 5, 5, 6, 1, 2, 2, 3, 2,
  3, 3, 4, 2, 3, 3, 4, 3, 4, 4, 5, 2, 3, 3, 4, 3, 4, 4, 5, 3, 4, 4, 5,
  4, 5, 5, 6, 2, 3, 3, 4, 3, 4, 4, 5, 3, 4, 4, 5, 4, 5, 5, 6, 3, 4, 4,
  5, 4, 5, 5, 6, 4, 5, 5, 6, 5, 6, 6, 7, 1, 2, 2, 3, 2, 3, 3, 4, 2, 3,
  3, 4, 3, 4, 4, 5, 2, 3, 3, 4, 3, 4, 4, 5, 3, 4, 4, 5, 4, 5, 5, 6, 2,
  3, 3, 4, 3, 4, 4, 5, 3, 4, 4, 5, 4, 5, 5, 6, 3, 4, 4, 5, 4, 5, 5, 6,
  4, 5, 5, 6, 5, 6, 6, 7, 2, 3, 3, 4, 3, 4, 4, 5, 3, 4, 4, 5, 4, 5, 5,
  6, 3, 4, 4, 5, 4, 5, 5, 6, 4, 5, 5, 6, 5, 6, 6, 7, 3, 4, 4, 5, 4, 5,
  5, 6, 4, 5, 5, 6, 5, 6, 6, 7, 4, 5, 5, 6, 5, 6, 6, 7, 5, 6, 6, 7, 6,
  7, 7, 8};


int read ();
int write ();
int open ();
int close ();
int open ();
int close ();

int link ();
int fstat ();

static int
put_short (context, ptr, value)
     sim_state_type *context;
     int ptr;
     int value;
{
  put_word_mem_da (context, ptr, value);
  return ptr + 2;
}

static int
put_long (context, ptr, value)
     sim_state_type *context;
     int
       ptr;
     int value;
{
  put_long_mem_da (context, ptr, value);
  return ptr + 4;
}

#define aptr(x) ((sitoptr(x)) + (char *)(context->memory))

static int args[3];
static int arg_index;		/* Translate a z8k system call into a host system call */
void
support_call (context, sc)
     sim_state_type *context;
     int sc;
{
  extern int errno;
  int ret;
  int retnext = 0;
  int fd;

  int olderrno = errno;
  errno = 0;
  switch (sc)
    {
    case SYS_ARG:
      args[arg_index++] = context->regs[0].word << 16 | context->regs[1].word;
      break;
    case SYS_exit:
      context->exception = SIM_DONE;
      ret = args[0];
      arg_index = 0;
      break;
    case SYS_close:
      ret = close ((int) (args[0]));
      arg_index = 0;
      break;
    case SYS_creat:
      ret = creat (aptr (args[0]), args[1]);
      arg_index = 0;
      break;
    case SYS_isatty:
      ret = isatty (args[0]);
      arg_index = 0;
      break;
    case SYS_open:
      ret = open (aptr (args[0]), args[1], args[2]);
      arg_index = 0;
      break;
    case SYS_lseek:
      ret = lseek (args[0], (off_t) args[1], args[2]);
      arg_index = 0;
      break;
    case SYS_read:
      ret = read (args[0], aptr (args[1]), args[2]);
      arg_index = 0;
      break;
    case SYS_write:
      ret = write (args[0],aptr (args[1]), args[2]);
      arg_index = 0;
      break;
    case SYS_time:
      {
	int dst = args[0];

	ret = time (0);
	if (dst)
	  {
	    put_long_mem_da (context,
			     sitoptr (dst), ret);
	  }
	retnext = ret;
	ret = retnext >> 16;
	arg_index = 0;
      }
      break;
    case SYS_fstat:
      {
	int buf;
	struct stat host_stat;
	fd = args[0];
	buf = sitoptr (args[1]);
	ret = fstat (fd, &host_stat);
	buf = put_short (context, buf, host_stat.st_dev);
	buf = put_short (context, buf, host_stat.st_ino);
	/* FIXME: Isn't mode_t 4 bytes?  */
	buf = put_short (context, buf, host_stat.st_mode);
	buf = put_short (context, buf, host_stat.st_nlink);
	buf = put_short (context, buf, host_stat.st_uid);
	buf = put_short (context, buf, host_stat.st_uid);
	buf = put_short (context, buf, host_stat.st_rdev);
	buf = put_long (context, buf, host_stat.st_size);
	buf = put_long (context, buf, host_stat.st_atime);
	arg_index = 0;
      } break;
    default:
    case SYS_link:
      context->exception = SIM_BAD_SYSCALL;
      arg_index = 0;
      break;
    }
  context->regs[2].word = ret;
  context->regs[3].word = retnext;
  context->regs[5].word = errno;


  /* support for the stdcall calling convention */
  context->regs[6].word = retnext;
  context->regs[7].word = ret;

  errno = olderrno;
}

#undef get_word_mem_da

int
get_word_mem_da (context, addr)
     sim_state_type *context;
     int addr;
{
  return (get_byte_mem_da (context, addr) << 8) | (get_byte_mem_da (context, addr + 1));

}

#undef get_word_reg
int 
get_word_reg (context, reg) sim_state_type
* context;
     int reg;
{
  return context->regs[reg].word;
}

#ifdef LOG
int log[64 * 1024];

#endif

void
tm_store_register (regno, value)
     int regno;
     int value;
{
  switch
    (regno)
    {
    case REG_PC:
      the_state.sometimes_pc = value;
      break;

    default:
      put_word_reg (&the_state, regno, value);
    }
}

void
swap_long (buf, val)
     char *buf;
     int val;
{
  buf[0] = val >> 24;
  buf[1] = val >> 16;
  buf[2] = val >> 8;
  buf[3] = val >> 0;
}

void
swap_word (buf, val)
     char *buf;
     int val;
{
  buf[0] = val >> 8;
  buf[1] = val >> 0;
}

void
tm_fetch_register (regno, buf)
     int regno;
     char *buf;
{
  switch
    (regno)
    {
    case REG_CYCLES:
      swap_long (buf, the_state.cycles);
      break;
    case REG_INSTS:
      swap_long (buf, the_state.insts);
      break;
      case
    REG_TIME:
      swap_long (buf, the_state.ticks);
      break;
    case REG_PC:
      swap_long (buf, the_state.sometimes_pc);
      break;
    case REG_SP:
      {
	if (sim_z8001_mode)
	  {
	    swap_long (buf, get_long_reg (&the_state, 14));
	  }
	else
	  {
	    swap_long (buf, get_word_reg (&the_state, 15));
	  }
      }
      break;
      case
    REG_FP:
      {
	if (sim_z8001_mode)
	  {
	    swap_long (buf, get_long_reg
		       (&the_state, 10));
	  }
	else
	  {
	    swap_long (buf,
		       get_word_reg (&the_state, 10));
	  }
      }
      break;
    default:
      {
	swap_word (buf,
		   get_word_reg (&the_state, regno));
      }
    }
}

void
tm_resume (step)
     int step;
{
  int now = get_now ();
  struct op_info