/***************************************************************************
 *             __________               __   ___.
 *   Open      \______   \ ____   ____ |  | _\_ |__   _______  ___
 *   Source     |       _//  _ \_/ ___\|  |/ /| __ \ /  _ \  \/  /
 *   Jukebox    |    |   (  <_> )  \___|    < | \_\ (  <_> > <  <
 *   Firmware   |____|_  /\____/ \___  >__|_ \|___  /\____/__/\_ \
 *                     \/            \/     \/    \/            \/
 * $Id: mkboot.c,v 1.4 2005-11-18 23:00:40 linus Exp $
 *
 * Copyright (C) 2005 by Linus Nielsen Feltzing
 *
 * All files in this archive are subject to the GNU General Public License.
 * See the file COPYING in the source tree root for full license agreement.
 *
 * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
 * KIND, either express or implied.
 *
 ****************************************************************************/
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

void usage(void)
{
    printf("usage: mkboot <-iax5|-h100|-h300> <firmware file> <boot file> <output file>\n");

    exit(1);
}


int main(int argc, char *argv[])
{
    if(argc != 5)
    {
        usage();
        return 0;
    }

    if ( ! strcmp(argv[1], "-h100"))
        return iriver_main(argv[2], argv[3], argv[4], 0x1f0000);
    
    if ( ! strcmp(argv[1], "-h300"))
        return iriver_main(argv[2], argv[3], argv[4], 0x3f0000);
    
    if ( ! strcmp(argv[1], "-iax5"))
        return iaudio_main(argv[2], argv[3], argv[4]);

    usage();
    return 0;
}

unsigned char image[0x400000 + 0x220 + 0x400000/0x200];

int iriver_main(const char infile[], const char bootfile[], const char outfile[], int origin)
{
    FILE *f;
    long pos;
    int i;
    int file_length;
    int len;
    int actual_length, total_length, binary_length, num_chksums;

    memset(image, 0xff, sizeof(image));

    /* First, read the iriver original firmware into the image */
    f = fopen(infile, "rb");
    if(!f) {
        perror(infile);
        exit(1);
    }

    i = fread(image, 1, 16, f);
    if(i < 16) {
        perror(infile);
        exit(1);
    }

    /* This is the length of the binary image without the scrambling
       overhead (but including the ESTFBINR header) */
    binary_length = image[4] + (image[5] << 8) +
        (image[6] << 16) + (image[7] << 24);

    /* Read the rest of the binary data, but not the checksum block */
    len = binary_length+0x200-16;
    i = fread(image+16, 1, len, f);
    if(i < len) {
        perror(infile);
        exit(1);
    }
    
    fclose(f);

    /* Now, read the boot loader into the image */
    f = fopen(bootfile, "rb");
    if(!f) {
        perror(bootfile);
        exit(1);
    }

    fseek(f, 0, SEEK_END);
    len = ftell(f);

    fseek(f, 0, SEEK_SET);

    i = fread(image+0x220 + origin, 1, len, f);
    if(i < len) {
        perror(bootfile);
        exit(1);
    }

    fclose(f);

    f = fopen(outfile, "wb");
    if(!f) {
        perror(outfile);
        exit(1);
    }

    /* Patch the reset vector to start the boot loader */
    image[0x220 + 4] = image[origin + 0x220 + 4];
    image[0x220 + 5] = image[origin + 0x220 + 5];
    image[0x220 + 6] = image[origin + 0x220 + 6];
    image[0x220 + 7] = image[origin + 0x220 + 7];

    /* This is the actual length of the binary, excluding all headers */
    actual_length = origin + len;

    /* Patch the ESTFBINR header */
    image[0x20c] = (actual_length >> 24) & 0xff;
    image[0x20d] = (actual_length >> 16) & 0xff;
    image[0x20e] = (actual_length >> 8) & 0xff;
    image[0x20f] = actual_length & 0xff;
    
    image[0x21c] = (actual_length >> 24) & 0xff;
    image[0x21d] = (actual_length >> 16) & 0xff;
    image[0x21e] = (actual_length >> 8) & 0xff;
    image[0x21f] = actual_length & 0xff;

    /* This is the length of the binary, including the ESTFBINR header and
       rounded up to the nearest 0x200 boundary */
    binary_length = (actual_length + 0x20 + 0x1ff) & 0xfffffe00;

    /* The number of checksums, i.e number of 0x200 byte blocks */
    num_chksums = binary_length / 0x200;

    /* The total file length, including all headers and checksums */
    total_length = binary_length + num_chksums + 0x200;

    /* Patch the scrambler header with the new length info */
    image[0] = total_length & 0xff;
    image[1] = (total_length >> 8) & 0xff;
    image[2] = (total_length >> 16) & 0xff;
    image[3] = (total_length >> 24) & 0xff;
    
    image[4] = binary_length & 0xff;
    image[5] = (binary_length >> 8) & 0xff;
    image[6] = (binary_length >> 16) & 0xff;
    image[7] = (binary_length >> 24) & 0xff;
    
    image[8] = num_chksums & 0xff;
    image[9] = (num_chksums >> 8) & 0xff;
    image[10] = (num_chksums >> 16) & 0xff;
    image[11] = (num_chksums >> 24) & 0xff;
    
    i = fwrite(image, 1, total_length, f);
    if(i < total_length) {
        perror(outfile);
        exit(1);
    }

    printf("Wrote 0x%x bytes in %s\n", total_length, outfile);
    
    fclose(f);
    
    return 0;
}

#define HEADER_SIZE 0x1030
#define FLASH_START        0x00010000
#define ROCKBOX_BOOTLOADER 0x00150000
#define BOOTLOADER_LIMIT   0x00170000 

int iaudio_main(const char fname[], const char bname[], const char oname[])
{
  size_t flength, blength;
  unsigned char *bbuf, *fbuf, *p;
  const unsigned char fsig[] = { 
    /* jsr 10010 */
    0x4e, 0xb9, 0x00, 0x01, 0x00, 0x10 };
  const unsigned char bsig[] = { 
    /* tst.b 30000000 */
    0x4a, 0x39, 0x30, 0x00, 0x00, 0x00 };
  FILE *ffile, *bfile, *ofile;
  unsigned char sum = 0;
  int i;

  /* read input files */
  if ((bfile = fopen(bname, "rb")) == NULL)
  {
    perror("Cannot open Rockbox bootloader file.\n");
    return -1;
  }

  fseek(bfile, 0, SEEK_END);
  blength = ftell(bfile);
  fseek(bfile, 0, SEEK_SET);

  if (blength + ROCKBOX_BOOTLOADER >= BOOTLOADER_LIMIT)
  {
    perror("Rockbox bootloader is too big.\n");
    return -1;
  }
 
  if ((ffile = fopen(fname, "rb")) == NULL)
  {
    perror("Cannot open original firmware file.\n");
    return -1;
  }
  
  fseek(ffile, 0, SEEK_END);
  flength = ftell(ffile);
  fseek(ffile, 0, SEEK_SET);

  bbuf = malloc(blength);
  fbuf = malloc(flength);

  if (!bbuf || !fbuf)
  {
    perror("Out of memory.\n");
    return -1;
  }

  if (   fread(bbuf, 1, blength, bfile) < blength 
      || fread(fbuf, 1, flength, ffile) < flength)
  {
    perror("Read error.\n");
    return -1;
  }
  fclose(bfile);
  fclose(ffile);

  /* verify format of input files */
  if (blength < 0x10
      || memcmp(bbuf, bsig, sizeof(bsig)))
  {
    perror("Rockbox bootloader format error (is it bootloader.bin?).\n");
    return -1;
  }
  if (flength < HEADER_SIZE-FLASH_START+BOOTLOADER_LIMIT 
      || memcmp(fbuf+HEADER_SIZE, fsig, sizeof(fsig)))
  {
    perror("Original firmware format error (is it x5_fw.bin?).\n");
    return -1;
  }

  /* verify firmware is not overrun */
  for (i = ROCKBOX_BOOTLOADER; i < BOOTLOADER_LIMIT; i++)
  {
    if (fbuf[HEADER_SIZE-FLASH_START+i] != 0xff)
    {
      perror("Original firmware has grown too much.\n");
      return -1;
    }
  }

  /* change jsr 0x10010 to jsr DUAL_BOOTLOADER */
  p = fbuf + HEADER_SIZE + 2;
  *p++ = (ROCKBOX_BOOTLOADER >> 24) & 0xff;
  *p++ = (ROCKBOX_BOOTLOADER >> 16) & 0xff;
  *p++ = (ROCKBOX_BOOTLOADER >>  8) & 0xff;
  *p++ = (ROCKBOX_BOOTLOADER      ) & 0xff;

  p = fbuf + HEADER_SIZE + ROCKBOX_BOOTLOADER - FLASH_START;
  memcpy(p, bbuf, blength);

  /* recalc checksum */
  for (i = HEADER_SIZE; i < flength; i++)
    sum += fbuf[i];
  fbuf[0x102b] = sum;

  /* write output */
  if ((ofile = fopen(oname, "wb")) == NULL)
  {
    perror("Cannot open output file.\n");
    return -1;
  }
  if (fwrite(fbuf, 1, flength, ofile) < flength)
  {
    perror("Write error.\n");
    return -1;
  }
  fclose(ofile);
  free(bbuf);
  free(fbuf);

  return 0;
}