remote-hms.c

早期freebsd实现

/* Remote debugging interface for Hitachi HMS Monitor Version 1.0
   Copyright 1992 Free Software Foundation, Inc.
   Contributed by Cygnus Support.  Written by Steve Chamberlain
   ([e-mail]).

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., 675 Mass Ave, Cambridge, MA 02139, USA.  */

#include "defs.h"
#include "inferior.h"
#include "wait.h"
#include "value.h"
#include <string.h>
#include <ctype.h>
#include <fcntl.h>
#include <signal.h>
#include <setjmp.h>
#include <errno.h>
#include "terminal.h"
#include "target.h"
#include "gdbcore.h"

/* External data declarations */
extern int stop_soon_quietly;           /* for wait_for_inferior */

/* Forward data declarations */
extern struct target_ops hms_ops;		/* Forward declaration */

/* Forward function declarations */
static void hms_fetch_registers ();
static int  hms_store_registers ();
static void hms_close ();
static int  hms_clear_breakpoints();

extern struct target_ops hms_ops;

static int quiet = 1;

/***********************************************************************/
/* Caching stuff stolen from remote-nindy.c  */

/* The data cache records all the data read from the remote machine
   since the last time it stopped.

   Each cache block holds LINE_SIZE bytes of data
   starting at a multiple-of-LINE_SIZE address.  */


#define LINE_SIZE_POWER 4
#define LINE_SIZE (1<<LINE_SIZE_POWER)     /* eg 1<<3 == 8 */
#define LINE_SIZE_MASK ((LINE_SIZE-1))      /* eg 7*2+1= 111*/
#define DCACHE_SIZE 64		/* Number of cache blocks */
#define XFORM(x)  ((x&LINE_SIZE_MASK)>>2)
struct dcache_block {
	struct dcache_block *next, *last;
	unsigned int addr;	/* Address for which data is recorded.  */
	int data[LINE_SIZE/sizeof(int)];
};

struct dcache_block dcache_free, dcache_valid;

/* Free all the data cache blocks, thus discarding all cached data.  */ 
static
void
dcache_flush ()
{
  register struct dcache_block *db;

  while ((db = dcache_valid.next) != &dcache_valid)
    {
      remque (db);
      insque (db, &dcache_free);
    }
}

/*
 * If addr is present in the dcache, return the address of the block
 * containing it.
 */
static
struct dcache_block *
dcache_hit (addr)
     unsigned int addr;
{
  register struct dcache_block *db;

  if (addr & 3)
    abort ();

  /* Search all cache blocks for one that is at this address.  */
  db = dcache_valid.next;
  while (db != &dcache_valid)
    {
      if ((addr & ~LINE_SIZE_MASK)== db->addr)
	return db;
      db = db->next;
    }
  return NULL;
}

/*  Return the int data at address ADDR in dcache block DC.  */
static
int
dcache_value (db, addr)
     struct dcache_block *db;
     unsigned int addr;
{
  if (addr & 3)
    abort ();
  return (db->data[XFORM(addr)]);
}

/* Get a free cache block, put or keep it on the valid list,
   and return its address.  The caller should store into the block
   the address and data that it describes, then remque it from the
   free list and insert it into the valid list.  This procedure
   prevents errors from creeping in if a ninMemGet is interrupted
   (which used to put garbage blocks in the valid list...).  */
static
struct dcache_block *
dcache_alloc ()
{
  register struct dcache_block *db;

  if ((db = dcache_free.next) == &dcache_free)
    {
      /* If we can't get one from the free list, take last valid and put
	 it on the free list.  */
      db = dcache_valid.last;
      remque (db);
      insque (db, &dcache_free);
    }

  remque (db);
  insque (db, &dcache_valid);
  return (db);
}

/* Return the contents of the word at address ADDR in the remote machine,
   using the data cache.  */
static
int
dcache_fetch (addr)
     CORE_ADDR addr;
{
  register struct dcache_block *db;

  db = dcache_hit (addr);
  if (db == 0)
    {
      db = dcache_alloc ();
      immediate_quit++;
      hms_read_inferior_memory(addr & ~LINE_SIZE_MASK, (unsigned char *)db->data, LINE_SIZE);
      immediate_quit--;
      db->addr = addr & ~LINE_SIZE_MASK;
      remque (db);			/* Off the free list */
      insque (db, &dcache_valid);	/* On the valid list */
    }
  return (dcache_value (db, addr));
}

/* Write the word at ADDR both in the data cache and in the remote machine.  */
static void
dcache_poke (addr, data)
     CORE_ADDR addr;
     int data;
{
  register struct dcache_block *db;

  /* First make sure the word is IN the cache.  DB is its cache block.  */
  db = dcache_hit (addr);
  if (db == 0)
  {
    db = dcache_alloc ();
    immediate_quit++;
    hms_write_inferior_memory(addr & ~LINE_SIZE_MASK, (unsigned char *)db->data, LINE_SIZE);
    immediate_quit--;
    db->addr = addr & ~LINE_SIZE_MASK;
    remque (db);		/* Off the free list */
    insque (db, &dcache_valid);	/* On the valid list */
  }

  /* Modify the word in the cache.  */
  db->data[XFORM(addr)] = data;

  /* Send the changed word.  */
  immediate_quit++;
  hms_write_inferior_memory(addr, (unsigned char *)&data, 4);
  immediate_quit--;
}

/* The cache itself. */
struct dcache_block the_cache[DCACHE_SIZE];

/* Initialize the data cache.  */
static void
dcache_init ()
{
  register i;
  register struct dcache_block *db;

  db = the_cache;
  dcache_free.next = dcache_free.last = &dcache_free;
  dcache_valid.next = dcache_valid.last = &dcache_valid;
  for (i=0;i<DCACHE_SIZE;i++,db++)
    insque (db, &dcache_free);
}


/***********************************************************************
 * I/O stuff stolen from remote-eb.c
 ***********************************************************************/

static int timeout = 2;

static const char *dev_name;


/* Descriptor for I/O to remote machine.  Initialize it to -1 so that
   hms_open knows that we don't have a file open when the program
   starts.  */


int is_open = 0;
int check_open()
{
  if (!is_open)
  {
    error("remote device not open");
  }
}

#define ON	1
#define OFF	0

/* Read a character from the remote system, doing all the fancy
   timeout stuff.  */
static int
readchar ()
{
  int buf;
  buf = serial_readchar(timeout);

  if (buf < 0)
   error ("Timeout reading from remote system.");

  if (!quiet)
   printf("%c",buf);
  
  return buf & 0x7f;
}

static int
readchar_nofail ()
{
  int buf;
  buf = serial_readchar(timeout);
  if (buf < 0) buf = 0;
  if (!quiet)
   printf("%c",buf);
  
  return buf & 0x7f;

}

/* Keep discarding input from the remote system, until STRING is found. 
   Let the user break out immediately.  */
static void
expect (string)
     char *string;
{
  char *p = string;


  immediate_quit = 1;
  while (1)
    {
      if (readchar() == *p)
	{
	  p++;
	  if (*p == '\0')
	    {
	      immediate_quit = 0;
	      return;
	    }
	}
      else
	p = string;
    }
}

/* Keep discarding input until we see the hms prompt.

   The convention for dealing with the prompt is that you
   o give your command
   o *then* wait for the prompt.

   Thus the last thing that a procedure does with the serial line
   will be an expect_prompt().  Exception:  hms_resume does not
   wait for the prompt, because the terminal is being handed over
   to the inferior.  However, the next thing which happens after that
   is a hms_wait which does wait for the prompt.
   Note that this includes abnormal exit, e.g. error().  This is
   necessary to prevent getting into states from which we can't
   recover.  */
static void
expect_prompt ()
{
  expect ("HMS>");
}

/* Get a hex digit from the remote system & return its value.
   If ignore_space is nonzero, ignore spaces (not newline, tab, etc).  */
static int
get_hex_digit (ignore_space)
     int ignore_space;
{
  int ch;
  while (1)
    {
      ch = readchar ();
      if (ch >= '0' && ch <= '9')
	return ch - '0';
      else if (ch >= 'A' && ch <= 'F')
	return ch - 'A' + 10;
      else if (ch >= 'a' && ch <= 'f')
	return ch - 'a' + 10;
      else if (ch == ' ' && ignore_space)
	;
      else
	{
	  expect_prompt ();
	  error ("Invalid hex digit from remote system.");
	}
    }
}

/* Get a byte from hms_desc and put it in *BYT.  Accept any number
   leading spaces.  */
static void
get_hex_byte (byt)
     char *byt;
{
  int val;

  val = get_hex_digit (1) << 4;
  val |= get_hex_digit (0);
  *byt = val;
}

/* Read a 32-bit hex word from the hms, preceded by a space  */
static long 
get_hex_word()
{
  long val;
  int j;
      
  val = 0;
  for (j = 0; j < 8; j++)
	val = (val << 4) + get_hex_digit (j == 0);
  return val;
}
/* Called when SIGALRM signal sent due to alarm() timeout.  */



/* Number of SIGTRAPs we need to simulate.  That is, the next
   NEED_ARTIFICIAL_TRAP calls to hms_wait should just return
   SIGTRAP without actually waiting for anything.  */

static int need_artificial_trap = 0;

void
hms_kill(arg,from_tty)
char	*arg;
int	from_tty;
{

}



/*
 * Download a file specified in 'args', to the hms. 
 */
static void
hms_load(args,fromtty)
char	*args;
int	fromtty;
{
  bfd	*abfd;
  asection *s;
  int	n;
  char	buffer[1024];

  check_open();

  dcache_flush();
  inferior_pid = 0;  
  abfd = bfd_openr(args,"coff-h8300");
  if (!abfd) 
  {
    printf_filtered("Unable to open file %s\n", args);
    return;
  }

  if (bfd_check_format(abfd, bfd_object) ==0) 
  {
    printf_filtered("File is not an object file\n");
    return ;
  }

  s = abfd->sections;
  while (s != (asection *)NULL) 
  {
    if (s->flags & SEC_LOAD) 
    {
      int i;

      
#define DELTA 1024
      char *buffer = xmalloc(DELTA);
      printf_filtered("%s\t: 0x%4x .. 0x%4x  ",s->name, s->vma, s->vma + s->_raw_size);
      for (i = 0; i < s->_raw_size; i+= DELTA) 
      {
	int delta = DELTA;
	if (delta > s->_raw_size - i)
	 delta = s->_raw_size - i ;

	bfd_get_section_contents(abfd, s, buffer, i, delta);
	hms_write_inferior_memory(s->vma + i, buffer, delta);
	printf_filtered("*");
	fflush(stdout);
      }
      printf_filtered(  "\n");      
      free(buffer);
    }
    s = s->next;
  }
  sprintf(buffer, "r PC=%x", abfd->start_address);
  hms_write_cr(buffer);
  expect_prompt();
}

/* This is called not only when we first attach, but also when the
   user types "run" after having attached.  */
void
hms_create_inferior (execfile, args, env)
     char *execfile;
     char *args;
     char **env;
{
  int entry_pt;
  char buffer[100];    

  if (args && *args)
   error ("Can't pass arguments to remote hms process.");

  if (execfile == 0 || exec_bfd == 0)
   error ("No exec file specified");

  entry_pt = (int) bfd_get_start_address (exec_bfd);
  check_open();


  hms_kill(NULL,NULL);	 
  hms_clear_breakpoints();
  init_wait_for_inferior ();
  hms_write_cr("");
  expect_prompt();

  insert_breakpoints ();	/* Needed to get correct instruction in cache */
  proceed(entry_pt, -1, 0);
}


/* Open a connection to a remote debugger.
   NAME is the filename used for communication, then a space,
   then the baud rate.
 */

static char *
find_end_of_word(s)
char *s;
{
  while (*s && !isspace(*s))
   s++;
  return s;
}

static char *get_word(p)
char **p;
{
  char *s = *p;
  char *word ;
  char *copy;
  size_t len;

  while (isspace(*s))
   s++;

  word = s;

  len = 0;

  while (*s && !isspace(*s)) 
  {
    s++;
    len++;
  
  }
  copy = xmalloc(len+1);
  memcpy(copy, word, len);
  copy[len] = 0;
  *p = s;
  return copy;
}

static int baudrate = 9600;

static int
is_baudrate_right()
{
  int ok;
  /* Put this port into NORMAL mode, send the 'normal' character */

  hms_write("\001", 1);		/* Control A */
  hms_write("\r", 1);		/* Cr */
  
  while (1) 
  {
    ok = serial_readchar(timeout);
    if (ok < 0) break;
  }

  hms_write("r",1);

  if (readchar_nofail() == 'r')  
   return 1;

  /* Not the right baudrate, or the board's not on */
  return 0;
}
static void
set_rate()
{
  if (!serial_setbaudrate(baudrate))
   error("Can't set baudrate");
}

static void
get_baudrate_right()
{
#if 0
  while (!is_baudrate_right()) 
  {
    baudrate = serial_nextbaudrate(baudrate);
    if (baudrate == 0) {
      printf_filtered("Board not yet in sync\n");
      break;
    }
    printf_filtered("Board not responding, trying %d baud\n",baudrate);
    QUIT;
    serial_setbaudrate(baudrate);
  }
#endif
}

static void
hms_open (name, from_tty)
     char *name;
     int from_tty;
{

  unsigned int prl;
  char *p;
  
  if(name == 0) 
  {
    name = "";
  }
  if (is_open)  
    hms_close (0);
  if (name && strlen(name))
    dev_name = strdup(name);
  if (!serial_open(dev_name))
    perror_with_name ((char *)dev_name);
  serial_raw();
  is_open = 1;

  dcache_init();

  get_baudrate_right();
  
  /* Hello?  Are you there?  */
  serial_write("\r",1);
  expect_prompt ();

  /* Clear any break points */
  hms_clear_breakpoints();

  printf_filtered("Connected to remote H8/300 HMS system.\n");
}

/* Close out all files and local state before this target loses control. */

static void
hms_close (quitting)
     int quitting;
{


  /* Clear any break points */
  hms_clear_breakpoints();

  /* Put this port back into REMOTE mode */ 
  sleep(1);			/* Let any output make it all the way back */
  serial_write("R\r", 2);
  serial_close();
  is_open = 0;
}

/* Terminate the open connection to the remote debugger.
   Use this when you want to detach and do something else
   with your gdb.  */
void
hms_detach (args,from_tty)
     char *args;
     int from_tty;
{
  if (is_open)
  { 
	hms_clear_breakpoints();
  }
 
  pop_target();		/* calls hms_close to do the real work */
  if (from_tty)
    printf_filtered ("Ending remote %s debugging\n", target_shortname);
}
 
/* Tell the remote machine to resume.  */

void
hms_resume (step, sig)
     int step, sig;
{
  dcache_flush();
  
  if (step)	
  {
    hms_write_cr("s");
    expect("Step>");
    
    /* Force the next hms_wait to return a trap.  Not doing anything
       about I/O from the target means that the user has to type
       "continue" to see any.  FIXME, this should be fixed.  */
    need_artificial_trap = 1;
  }
  else
  {
    hms_write_cr("g");
    expect("g");
  }
}

/* Wait until the remote machine stops, then return,
   storing status in STATUS just as `wait' would.  */

int
hms_wait (status)
     WAITTYPE *status;
{
  /* Strings to look for.  '?' means match any single character.  
     Note that with the algorithm we use, the initial character
     of the string cannot recur in the string, or we will not
     find some cases of the string in the input.  */
  
  static char bpt[] = "At breakpoint:";
  /* It would be tempting to look for "\n[__exit + 0x8]\n"
     but that requires loading symbols with "yc i" and even if
     we did do that we don't know that the file has symbols.  */
  static char exitmsg[] = "HMS>";
  char *bp = bpt;
  char *ep = exitmsg;

  /* Large enough for either sizeof (bpt) or sizeof (exitmsg) chars.  */
  char swallowed[50];
  /* Current position in swallowed.  */
  char *swallowed_p = swallowed;

  int ch;