avr.c

这是一个非常有价值的参考代码

	 */
        rc = avr_read_byte(pgm, p, mem, addr, &r);
        if (rc != 0) {
          pgm->pgm_led(pgm, OFF);
          pgm->err_led(pgm, ON);
          return -4;
        }
        gettimeofday (&tv, NULL);
        prog_time = (tv.tv_sec * 1000000) + tv.tv_usec;
      } while ((r != data) &&
               ((prog_time-start_time) < mem->max_write_delay));
    }

    /*
     * At this point we either have a valid readback or the
     * max_write_delay is expired.
     */
    
    if (r == data) {
      ready = 1;
    }
    else if (mem->pwroff_after_write) {
      /*
       * The device has been flagged as power-off after write to this
       * memory type.  The reason we don't just blindly follow the
       * flag is that the power-off advice may only apply to some
       * memory bits but not all.  We only actually power-off the
       * device if the data read back does not match what we wrote.
       */
      pgm->pgm_led(pgm, OFF);
      fprintf(stderr,
              "%s: this device must be powered off and back on to continue\n",
              progname);
      if (pgm->pinno[PPI_AVR_VCC]) {
        fprintf(stderr, "%s: attempting to do this now ...\n", progname);
        pgm->powerdown(pgm);
        usleep(250000);
        rc = pgm->initialize(pgm, p);
        if (rc < 0) {
          fprintf(stderr, "%s: initialization failed, rc=%d\n", progname, rc);
          fprintf(stderr, 
                  "%s: can't re-initialize device after programming the "
                  "%s bits\n", progname, mem->desc);
          fprintf(stderr,
                  "%s: you must manually power-down the device and restart\n"
                  "%s:   %s to continue.\n",
                  progname, progname, progname);
          return -3;
        }
        
        fprintf(stderr, "%s: device was successfully re-initialized\n",
                progname);
        return 0;
      }
    }

    tries++;
    if (!ready && tries > 5) {
      /*
       * we wrote the data, but after waiting for what should have
       * been plenty of time, the memory cell still doesn't match what
       * we wrote.  Indicate a write error.
       */
      pgm->pgm_led(pgm, OFF);
      pgm->err_led(pgm, ON);
      
      return -6;
    }
  }

  pgm->pgm_led(pgm, OFF);
  return 0;
}


/*
 * write a byte of data at the specified address
 */
int avr_write_byte(PROGRAMMER * pgm, AVRPART * p, AVRMEM * mem,
                   unsigned long addr, unsigned char data)
{

  unsigned char safemode_lfuse;
  unsigned char safemode_hfuse;
  unsigned char safemode_efuse;
  unsigned char safemode_fuse;
  int rc;

  /* If we write the fuses, then we need to tell safemode that they *should* change */
  safemode_memfuses(0, &safemode_lfuse, &safemode_hfuse, &safemode_efuse, &safemode_fuse);

  if (strcmp(mem->desc, "fuse")==0) {
      safemode_fuse = data;
  }
  if (strcmp(mem->desc, "lfuse")==0) {
      safemode_lfuse = data;
  }
  if (strcmp(mem->desc, "hfuse")==0) {
      safemode_hfuse = data;
  }
  if (strcmp(mem->desc, "efuse")==0) {
      safemode_efuse = data;
  }
  
  safemode_memfuses(1, &safemode_lfuse, &safemode_hfuse, &safemode_efuse, &safemode_fuse);

  if (pgm->write_byte) {
    rc = pgm->write_byte(pgm, p, mem, addr, data);
    if (rc == 0) {
      return rc;
    }
    /* write_byte() method failed, try again with default. */
  }

  return avr_write_byte_default(pgm, p, mem, addr, data);
}


/*
 * Write the whole memory region of the specified memory from the
 * corresponding buffer of the avrpart pointed to by 'p'.  Write up to
 * 'size' bytes from the buffer.  Data is only written if the new data
 * value is different from the existing data value.  Data beyond
 * 'size' bytes is not affected.
 *
 * Return the number of bytes written, or -1 if an error occurs.
 */
int avr_write(PROGRAMMER * pgm, AVRPART * p, char * memtype, int size, 
              int verbose)
{
  int              rc;
  int              wsize;
  unsigned long    i;
  unsigned char    data;
  int              werror;
  AVRMEM         * m;

  m = avr_locate_mem(p, memtype);
  if (m == NULL) {
    fprintf(stderr, "No \"%s\" memory for part %s\n",
            memtype, p->desc);
    return -1;
  }

  pgm->err_led(pgm, OFF);

  werror  = 0;

  wsize = m->size;
  if (size < wsize) {
    wsize = size;
  }
  else if (size > wsize) {
    fprintf(stderr, 
            "%s: WARNING: %d bytes requested, but memory region is only %d"
            "bytes\n"
            "%sOnly %d bytes will actually be written\n",
            progname, size, wsize,
            progbuf, wsize);
  }

  if ((strcmp(m->desc, "flash")==0) || (strcmp(m->desc, "eeprom")==0)) {
    if (pgm->paged_write != NULL) {
      /*
       * the programmer supports a paged mode write, perhaps more
       * efficiently than we can read it directly, so use its routine
       * instead
       */
      return pgm->paged_write(pgm, p, m, m->page_size, size);
    }
  }

  if (pgm->write_setup) {
      pgm->write_setup(pgm, p, m);
  }

  for (i=0; i<wsize; i++) {
    data = m->buf[i];
    report_progress(i, wsize, NULL);

    rc = avr_write_byte(pgm, p, m, i, data);
    if (rc) {
      fprintf(stderr, " ***failed;  ");
      fprintf(stderr, "\n");
      pgm->err_led(pgm, ON);
      werror = 1;
    }

    if (m->paged) {
      /*
       * check to see if it is time to flush the page with a page
       * write
       */
      if (((i % m->page_size) == m->page_size-1) ||
          (i == wsize-1)) {
        rc = avr_write_page(pgm, p, m, i);
        if (rc) {
          fprintf(stderr,
                  " *** page %ld (addresses 0x%04lx - 0x%04lx) failed "
                  "to write\n",
                  i % m->page_size, 
                  i - m->page_size + 1, i);
          fprintf(stderr, "\n");
          pgm->err_led(pgm, ON);
          werror = 1;
        }
      }
    }

    if (werror) {
      /* 
       * make sure the error led stay on if there was a previous write
       * error, otherwise it gets cleared in avr_write_byte()
       */
      pgm->err_led(pgm, ON);
    }
  }

  return i;
}



/*
 * read the AVR device's signature bytes
 */
int avr_signature(PROGRAMMER * pgm, AVRPART * p)
{
  int rc;

  report_progress (0,1,"Reading");
  rc = avr_read(pgm, p, "signature", 0, 0);
  if (rc < 0) {
    fprintf(stderr,
            "%s: error reading signature data for part \"%s\", rc=%d\n",
            progname, p->desc, rc);
    return -1;
  }
  report_progress (1,1,NULL);

  return 0;
}


/*
 * Verify the memory buffer of p with that of v.  The byte range of v,
 * may be a subset of p.  The byte range of p should cover the whole
 * chip's memory size.
 *
 * Return the number of bytes verified, or -1 if they don't match.
 */
int avr_verify(AVRPART * p, AVRPART * v, char * memtype, int size)
{
  int i;
  unsigned char * buf1, * buf2;
  int vsize;
  AVRMEM * a, * b;

  a = avr_locate_mem(p, memtype);
  if (a == NULL) {
    fprintf(stderr, 
            "avr_verify(): memory type \"%s\" not defined for part %s\n",
            memtype, p->desc);
    return -1;
  }

  b = avr_locate_mem(v, memtype);
  if (b == NULL) {
    fprintf(stderr, 
            "avr_verify(): memory type \"%s\" not defined for part %s\n",
            memtype, v->desc);
    return -1;
  }

  buf1  = a->buf;
  buf2  = b->buf;
  vsize = a->size;

  if (vsize < size) {
    fprintf(stderr, 
            "%s: WARNING: requested verification for %d bytes\n"
            "%s%s memory region only contains %d bytes\n"
            "%sOnly %d bytes will be verified.\n",
            progname, size,
            progbuf, memtype, vsize,
            progbuf, vsize);
    size = vsize;
  }

  for (i=0; i<size; i++) {
    if (buf1[i] != buf2[i]) {
      fprintf(stderr, 
              "%s: verification error, first mismatch at byte 0x%04x\n"
              "%s0x%02x != 0x%02x\n",
              progname, i, 
              progbuf, buf1[i], buf2[i]);
      return -1;
    }
  }

  return size;
}


int avr_get_cycle_count(PROGRAMMER * pgm, AVRPART * p, int * cycles)
{
  AVRMEM * a;
  unsigned int cycle_count = 0;
  unsigned char v1;
  int rc;
  int i;

  a = avr_locate_mem(p, "eeprom");
  if (a == NULL) {
    return -1;
  }

  for (i=4; i>0; i--) {
    rc = avr_read_byte(pgm, p, a, a->size-i, &v1);
  if (rc < 0) {
    fprintf(stderr, "%s: WARNING: can't read memory for cycle count, rc=%d\n",
            progname, rc);
    return -1;
  }
    cycle_count = (cycle_count << 8) | v1;
  }

   /*
   * If the EEPROM is erased, the cycle count reads 0xffffffff.
   * In this case we return a cycle_count of zero.
   * So, the calling function don't have to care about whether or not
   * the cycle count was initialized.
   */
  if (cycle_count == 0xffffffff) {
    cycle_count = 0;
  }

  *cycles = (int) cycle_count;

  return 0;
}


int avr_put_cycle_count(PROGRAMMER * pgm, AVRPART * p, int cycles)
{
  AVRMEM * a;
  unsigned char v1;
  int rc;
  int i;

  a = avr_locate_mem(p, "eeprom");
  if (a == NULL) {
    return -1;
  }

  for (i=1; i<=4; i++) {
    v1 = cycles & 0xff;
    cycles = cycles >> 8;

    rc = avr_write_byte(pgm, p, a, a->size-i, v1);
    if (rc < 0) {
      fprintf(stderr, "%s: WARNING: can't write memory for cycle count, rc=%d\n",
              progname, rc);
      return -1;
    }
  }

  return 0;
  }

int avr_chip_erase(PROGRAMMER * pgm, AVRPART * p)
{
  int cycles;
  int rc;

  if (do_cycles) {
    rc = avr_get_cycle_count(pgm, p, &cycles);
    /*
     * Don't update the cycle counter, if read failed
     */
    if(rc != 0) {
      do_cycles = 0;
    }
  }

  rc = pgm->chip_erase(pgm, p);

  /*
   * Don't update the cycle counter, if erase failed
   */
  if (do_cycles && (rc == 0)) {
    cycles++;
    fprintf(stderr, "%s: erase-rewrite cycle count is now %d\n",
            progname, cycles);
    avr_put_cycle_count(pgm, p, cycles);
  }

  return rc;
}