binutils-gdb/gdb/dsrec.c

/* S-record download support for GDB, the GNU debugger.
   Copyright (C) 1995-2013 Free Software Foundation, Inc.

   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 3 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, see <http://www.gnu.org/licenses/>.  */

#include "defs.h"
#include "serial.h"
#include "srec.h"
#include <sys/time.h>
#include <time.h>
#include "gdb_assert.h"
#include "gdb_string.h"
#include "gdb_bfd.h"

extern int remote_debug;

static int make_srec (char *srec, CORE_ADDR targ_addr, bfd * abfd,
		      asection * sect, int sectoff, int *maxrecsize,
		      int flags);

/* Download an executable by converting it to S records.  DESC is a
   `struct serial *' to send the data to.  FILE is the name of the
   file to be loaded.  LOAD_OFFSET is the offset into memory to load
   data into.  It is usually specified by the user and is useful with
   the a.out file format.  MAXRECSIZE is the length in chars of the
   largest S-record the host can accomodate.  This is measured from
   the starting `S' to the last char of the checksum.  FLAGS is
   various random flags, and HASHMARK is non-zero to cause a `#' to be
   printed out for each record loaded.  WAITACK, if non-NULL, is a
   function that waits for an acknowledgement after each S-record, and
   returns non-zero if the ack is read correctly.  */

void
load_srec (struct serial *desc, const char *file, bfd_vma load_offset,
	   int maxrecsize,
	   int flags, int hashmark, int (*waitack) (void))
{
  bfd *abfd;
  asection *s;
  char *srec;
  int i;
  int reclen;
  struct timeval start_time, end_time;
  unsigned long data_count = 0;
  struct cleanup *cleanup;

  srec = (char *) alloca (maxrecsize + 1);

  abfd = gdb_bfd_open (file, NULL, -1);
  if (!abfd)
    {
      printf_filtered (_("Unable to open file %s\n"), file);
      return;
    }

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

  gettimeofday (&start_time, NULL);

  /* Write a type 0 header record. no data for a type 0, and there
     is no data, so len is 0.  */

  reclen = maxrecsize;
  make_srec (srec, 0, NULL, (asection *) 1, 0, &reclen, flags);
  if (remote_debug)
    {
      srec[reclen] = '\0';
      puts_debug ("sent -->", srec, "<--");
    }
  serial_write (desc, srec, reclen);

  for (s = abfd->sections; s; s = s->next)
    if (s->flags & SEC_LOAD)
      {
	int numbytes;

	bfd_vma addr = bfd_get_section_vma (abfd, s) + load_offset;
	bfd_size_type size = bfd_get_section_size (s);
	char *section_name = (char *) bfd_get_section_name (abfd, s);
	/* Both GDB and BFD have mechanisms for printing addresses.
           In the below, GDB's is used so that the address is
           consistent with the rest of GDB.  BFD's printf_vma() could
           have also been used.  cagney 1999-09-01 */
	printf_filtered ("%s\t: %s .. %s  ",
			 section_name,
			 paddress (target_gdbarch (), addr),
			 paddress (target_gdbarch (), addr + size));
	gdb_flush (gdb_stdout);

	data_count += size;

	for (i = 0; i < size; i += numbytes)
	  {
	    reclen = maxrecsize;
	    numbytes = make_srec (srec, (CORE_ADDR) (addr + i), abfd, s,
				  i, &reclen, flags);

	    if (remote_debug)
	      {
		srec[reclen] = '\0';
		puts_debug ("sent -->", srec, "<--");
	      }

	    /* Repeatedly send the S-record until a good
	       acknowledgement is sent back.  */
	    do
	      {
		serial_write (desc, srec, reclen);
		if (deprecated_ui_load_progress_hook)
		  if (deprecated_ui_load_progress_hook (section_name,
							(unsigned long) i))
		    error (_("Canceled the download"));
	      }
	    while (waitack != NULL && !waitack ());

	    if (hashmark)
	      {
		putchar_unfiltered ('#');
		gdb_flush (gdb_stdout);
	      }
	  }			/* Per-packet (or S-record) loop.  */

	if (deprecated_ui_load_progress_hook)
	  if (deprecated_ui_load_progress_hook (section_name,
						(unsigned long) i))
	    error (_("Canceled the download"));
	putchar_unfiltered ('\n');
      }

  if (hashmark)
    putchar_unfiltered ('\n');

  gettimeofday (&end_time, NULL);

  /* Write a terminator record.  */

  reclen = maxrecsize;
  make_srec (srec, abfd->start_address, NULL, NULL, 0, &reclen, flags);

  if (remote_debug)
    {
      srec[reclen] = '\0';
      puts_debug ("sent -->", srec, "<--");
    }

  serial_write (desc, srec, reclen);

  /* Some monitors need these to wake up properly.  (Which ones? -sts)  */
  serial_write (desc, "\r\r", 2);
  if (remote_debug)
    puts_debug ("sent -->", "\r\r", "<---");

  serial_flush_input (desc);

  print_transfer_performance (gdb_stdout, data_count, 0,
			      &start_time, &end_time);
  do_cleanups (cleanup);
}

/*
 * make_srec -- make an srecord.  This writes each line, one at a
 *      time, each with it's own header and trailer line.
 *      An srecord looks like this:
 *
 * byte count-+     address
 * start ---+ |        |       data        +- checksum
 *          | |        |                   |
 *        S01000006F6B692D746573742E73726563E4
 *        S315000448600000000000000000FC00005900000000E9
 *        S31A0004000023C1400037DE00F023604000377B009020825000348D
 *        S30B0004485A0000000000004E
 *        S70500040000F6
 *
 *      S<type><length><address><data><checksum>
 *
 *      Where
 *      - length
 *        is the number of bytes following upto the checksum.  Note
 *        that this is not the number of chars following, since it
 *        takes two chars to represent a byte.
 *      - type
 *        is one of:
 *        0) header record
 *        1) two byte address data record
 *        2) three byte address data record
 *        3) four byte address data record
 *        7) four byte address termination record
 *        8) three byte address termination record
 *        9) two byte address termination record
 *       
 *      - address
 *        is the start address of the data following, or in the case of
 *        a termination record, the start address of the image
 *      - data
 *        is the data.
 *      - checksum
 *        is the sum of all the raw byte data in the record, from the length
 *        upwards, modulo 256 and subtracted from 255.
 *
 * This routine returns the length of the S-record.
 *
 */

static int
make_srec (char *srec, CORE_ADDR targ_addr, bfd *abfd, asection *sect,
	   int sectoff, int *maxrecsize, int flags)
{
  unsigned char checksum;
  int tmp;
  static const char hextab[] = "0123456789ABCDEF";
  static const char data_code_table[] = "123";
  static const char term_code_table[] = "987";
  static const char header_code_table[] = "000";
  char const *code_table;
  int addr_size;
  int payload_size;
  char *binbuf;
  char *p;

  if (sect)
    {
      tmp = flags;		/* Data or header record */
      code_table = abfd ? data_code_table : header_code_table;
      binbuf = alloca (*maxrecsize / 2);
    }
  else
    {
      tmp = flags >> SREC_TERM_SHIFT;	/* Term record */
      code_table = term_code_table;
      binbuf = NULL;
    }

  if ((tmp & SREC_2_BYTE_ADDR) && (targ_addr <= 0xffff))
    addr_size = 2;
  else if ((tmp & SREC_3_BYTE_ADDR) && (targ_addr <= 0xffffff))
    addr_size = 3;
  else if (tmp & SREC_4_BYTE_ADDR)
    addr_size = 4;
  else
    internal_error (__FILE__, __LINE__,
		    _("make_srec:  Bad address (%s), or bad flags (0x%x)."),
		    paddress (target_gdbarch (), targ_addr), flags);

  /* Now that we know the address size, we can figure out how much
     data this record can hold.  */

  if (sect && abfd)
    {
      payload_size = (*maxrecsize - (1 + 1 + 2 + addr_size * 2 + 2)) / 2;
      payload_size = min (payload_size, bfd_get_section_size (sect) - sectoff);

      bfd_get_section_contents (abfd, sect, binbuf, sectoff, payload_size);
    }
  else
    payload_size = 0;		/* Term or header packets have no payload.  */

  /* Output the header.  */
  snprintf (srec, (*maxrecsize) + 1, "S%c%02X%0*X",
	    code_table[addr_size - 2],
	    addr_size + payload_size + 1,
	    addr_size * 2, (int) targ_addr);

  /* Note that the checksum is calculated on the raw data, not the
     hexified data.  It includes the length, address and the data
     portions of the packet.  */

  checksum = 0;

  checksum += (payload_size + addr_size + 1	/* Packet length */
	       + (targ_addr & 0xff)		/* Address...  */
	       + ((targ_addr >> 8) & 0xff)
	       + ((targ_addr >> 16) & 0xff)
	       + ((targ_addr >> 24) & 0xff));

  /* NOTE: cagney/2003-08-10: The equation is old.  Check that the
     recent snprintf changes match that equation.  */
  gdb_assert (strlen (srec) == 1 + 1 + 2 + addr_size * 2);
  p = srec + 1 + 1 + 2 + addr_size * 2;

  /* Build the Srecord.  */
  for (tmp = 0; tmp < payload_size; tmp++)
    {
      unsigned char k;

      k = binbuf[tmp];
      *p++ = hextab[k >> 4];
      *p++ = hextab[k & 0xf];
      checksum += k;
    }

  checksum = ~checksum;

  *p++ = hextab[checksum >> 4];
  *p++ = hextab[checksum & 0xf];
  *p++ = '\r';

  *maxrecsize = p - srec;
  return payload_size;
}