/************************************************************************************
 * configs/ea3131/tools/lpchdr.c
 *
 *   Copyright (C) 2010-2011 Gregory Nutt. All rights reserved.
 *   Author: Gregory Nutt <gnutt@nuttx.org>
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 * 3. Neither the name NuttX nor the names of its contributors may be
 *    used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
 * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
 * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
 * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 *
 ************************************************************************************/

/************************************************************************************
 * Included Files
 ************************************************************************************/

#include <sys/types.h>
#include <sys/stat.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <stdint.h>
#include <string.h>
#include <fcntl.h>
#include <errno.h>
#include "lpchdr.h"

/************************************************************************************
 * Pre-processor Definitions
 ************************************************************************************/

#define IO_BUF_SIZE  1024
#define HDR_SIZE     0x80
#define HDR_CRC_SIZE 0x6c

/************************************************************************************
 * Private Data
 ************************************************************************************/

static const char *g_infile;
static const char *g_outfile;

/************************************************************************************
 * Private Functions
 ************************************************************************************/

static void show_usage(const char *progname, int exitcode)
{
  fprintf(stderr, "%s -o <outfile> <infile>\n", progname);
  exit(exitcode);
}

static void parse_args(int argc, char **argv)
{
  int ch;

  while ((ch = getopt(argc, argv, ":o:")) >= 0)
    {
      switch (ch)
        {
          case 'o':
            g_outfile = optarg;
            break;

          case ':':
            fprintf(stderr, "Missing option argumen\n");
            show_usage(argv[0], 1);

          case '?':
          default:
            fprintf(stderr, "Unrecognized option\n");
            show_usage(argv[0], 1);
        }
    }

  if (optind >= argc)
    {
      fprintf(stderr, "Missing binary input file name\n");
      show_usage(argv[0], 1);
    }

  g_infile = argv[optind];
  optind++;

  if (optind < argc)
    {
      fprintf(stderr, "Garbage at the end of the command line\n");
      show_usage(argv[0], 1);
    }
}

static inline uint32_t infilecrc32(int infd, size_t len, size_t padlen)
{
  off_t offset;
  uint8_t buffer[IO_BUF_SIZE];
  ssize_t nbytes;
  size_t bytesread;
  uint32_t crc;

  offset = lseek(infd, 0, SEEK_SET);
  if (offset == (off_t)-1)
    {
      fprintf(stderr, "lseek failed: %s\n", strerror(errno));
      exit(4);
    }

  crc = 0;
  for (bytesread = 0; bytesread < len; bytesread += nbytes)
    {
      nbytes = read(infd, buffer, IO_BUF_SIZE);
      if (nbytes < 0)
        {
          fprintf(stderr, "read failed: %s\n", strerror(errno));
          exit(4);
        }
      else if (nbytes == 0)
        {
          fprintf(stderr, "Unexpected end-of-file: %s\n", strerror(errno));
          exit(4);
        }
      else
        {
          crc = crc32part(buffer, nbytes, crc);
        }
    }

  /* Add the zero-padding at the end of the binary in the CRC */

  memset(buffer, 0, IO_BUF_SIZE);
  return crc32part(buffer, padlen, crc);
}

static inline void writefile(int infd, int outfd, size_t len, size_t padlen)
{
  off_t offset;
  uint8_t buffer[IO_BUF_SIZE];
  ssize_t nbytesread;
  ssize_t nbyteswritten;
  size_t totalread;

  offset = lseek(infd, 0, SEEK_SET);
  if (offset == (off_t)-1)
    {
      fprintf(stderr, "lseek failed: %s\n", strerror(errno));
      exit(4);
    }

  for (totalread = 0; totalread < len; totalread += nbytesread)
    {
      nbytesread = read(infd, buffer, IO_BUF_SIZE);
      if (nbytesread < 0)
        {
          fprintf(stderr, "read failed: %s\n", strerror(errno));
          exit(4);
        }
      else if (nbytesread == 0)
        {
          fprintf(stderr, "Unexpected end-of-file: %s\n", strerror(errno));
          exit(4);
        }
      else
        {
          nbyteswritten = write(outfd, buffer, nbytesread);
          if (nbyteswritten < 0)
            {
              fprintf(stderr, "write failed: %s\n", strerror(errno));
              exit(4);
            }
          else if (nbyteswritten != nbytesread)
            {
              fprintf(stderr, "Short writes not handled\n");
              exit(4);
            }
        }
    }

  /* Write the zero-padding at the end of the binary */

  memset(buffer, 0, IO_BUF_SIZE);
  nbyteswritten = write(outfd, buffer, padlen);
  if (nbyteswritten < 0)
    {
      fprintf(stderr, "write failed: %s\n", strerror(errno));
      exit(4);
    }
  else if (nbyteswritten != padlen)
    {
      fprintf(stderr, "Short writes not handled\n");
      exit(4);
    }
}

/************************************************************************************
 * Public Functions
 ************************************************************************************/

int main(int argc, char **argv, char **envp)
{
  struct lpc31_header_s g_hdr;
  struct stat buf;
  ssize_t nbytes;
  size_t padlen;
  int infd;
  int outfd;
  int ret;

  /* Parse arguments */

  parse_args(argc, argv);

  /* Open files */

  infd = open(g_infile, O_RDONLY);
  if (infd < 0)
    {
      fprintf(stderr, "Failed to open %s for reading: %s\n", g_infile, strerror(errno));
      exit(2);
    }

  outfd = open(g_outfile, O_WRONLY|O_CREAT|O_TRUNC, 0644);
  if (outfd < 0)
    {
      fprintf(stderr, "Failed to open %s for writing: %s\n", g_outfile, strerror(errno));
      exit(2);
    }

  /* Get the size of the binary file */

  ret = fstat(infd, &buf);
  if (ret < 0)
    {
      fprintf(stderr, "stat of %s failed: %s\n", g_infile, strerror(errno));
      exit(3);
    }

  /* Initialize the header */

  memset(&g_hdr, 0, sizeof(struct lpc31_header_s));
  g_hdr.vector          = 0xea00001e;  /* b 0x11029080 */
  g_hdr.magic           = 0x41676d69;
#if 1 /* CRC doesn't seem to be functional */
  g_hdr.imageType       = 0x0000000a;
#else
  g_hdr.imageType       = 0x0000000b;
#endif
  g_hdr.imageLength     = (buf.st_size + sizeof(struct lpc31_header_s) + 511) & ~0x1ff;

  /* This is how much we must pad at the end of the binary image. */

  padlen                = g_hdr.imageLength - buf.st_size;

  /* Calculate CRCs */
 
  g_hdr.execution_crc32 = infilecrc32(infd, buf.st_size, padlen);
  g_hdr.header_crc32    = crc32((const uint8_t*)&g_hdr, HDR_CRC_SIZE);

  /* Write the header */

  nbytes = write(outfd, &g_hdr, HDR_SIZE);
  if (nbytes != 0x80)
    {
      fprintf(stderr, "write of header to of %s failed: %s\n", g_outfile, strerror(errno));
      exit(4);
    }

  /* Copy the input file to the output */

  writefile(infd, outfd, buf.st_size, padlen);
  close(infd);
  close(outfd);
  return 0;
}