tools/rkw.c

   1 /***************************************************************************
   2  *             __________               __   ___.
   3  *   Open      \______   \ ____   ____ |  | _\_ |__   _______  ___
   4  *   Source     |       _//  _ \_/ ___\|  |/ /| __ \ /  _ \  \/  /
   5  *   Jukebox    |    |   (  <_> )  \___|    < | \_\ (  <_> > <  <
   6  *   Firmware   |____|_  /\____/ \___  >__|_ \|___  /\____/__/\_ \
   7  *                     \/            \/     \/    \/            \/
   8  *
   9  * Copyright (C) 2012 Marcin Bukat
  10  *
  11  * This program is free software; you can redistribute it and/or
  12  * modify it under the terms of the GNU General Public License
  13  * as published by the Free Software Foundation; either version 2
  14  * of the License, or (at your option) any later version.
  15  *
  16  * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
  17  * KIND, either express or implied.
  18  *
  19  ****************************************************************************/
  20
  21 #include <stdio.h>
  22 #include <stdlib.h>
  23 #include <string.h>
  24 #include <stdint.h>
  25
  26 #define RKLD_MAGIC 0x4c44524b
  27 #define RKW_HEADER_SIZE 0x2c
  28
  29 /* slightly modified version from crc32.c in rockbox */
  30 static uint32_t rkw_crc32(const void *src, uint32_t len)
  31 {
  32     const unsigned char *buf = (const unsigned char *)src;
  33
  34     /* polynomial 0x04c10db7 */
  35     static const uint32_t crc32_lookup[16] =
  36     {   /* lookup table for 4 bits at a time is affordable */
  37         0x00000000, 0x04C10DB7, 0x09821B6E, 0x0D4316D9,
  38         0x130436DC, 0x17C53B6B, 0x1A862DB2, 0x1E472005,
  39         0x26086DB8, 0x22C9600F, 0x2F8A76D6, 0x2B4B7B61,
  40         0x350C5B64, 0x31CD56D3, 0x3C8E400A, 0x384F4DBD
  41     };
  42
  43     uint32_t crc32 = 0;
  44     unsigned char byte;
  45     uint32_t t;
  46
  47     while (len--)
  48     {
  49         byte = *buf++; /* get one byte of data */
  50
  51         /* upper nibble of our data */
  52         t = crc32 >> 28; /* extract the 4 most significant bits */
  53         t ^= byte >> 4; /* XOR in 4 bits of data into the extracted bits */
  54         crc32 <<= 4; /* shift the CRC register left 4 bits */
  55         crc32 ^= crc32_lookup[t]; /* do the table lookup and XOR the result */
  56
  57         /* lower nibble of our data */
  58         t = crc32 >> 28; /* extract the 4 most significant bits */
  59         t ^= byte & 0x0F; /* XOR in 4 bits of data into the extracted bits */
  60         crc32 <<= 4; /* shift the CRC register left 4 bits */
  61         crc32 ^= crc32_lookup[t]; /* do the table lookup and XOR the result */
  62     }
  63
  64     return crc32;
  65 }
  66
  67 static void int2le(unsigned int val, unsigned char* addr)
  68 {
  69     addr[0] = val & 0xFF;
  70     addr[1] = (val >> 8) & 0xff;
  71     addr[2] = (val >> 16) & 0xff;
  72     addr[3] = (val >> 24) & 0xff;
  73 }
  74
  75 int rkw_encode(char *iname, char *oname, unsigned long modelnum)
  76 {
  77     size_t len;
  78     int length;
  79     int rkwlength;
  80     FILE *file;
  81     uint32_t binary_crc, header_crc;
  82     unsigned char *outbuf;
  83
  84     file = fopen(iname, "rb");
  85     if (!file)
  86     {
  87        perror(iname);
  88        return -1;
  89     }
  90
  91     fseek(file,0,SEEK_END);
  92     length = ftell(file);
  93
  94     fseek(file,0,SEEK_SET);
  95
  96     /* length of the RKW header + binary length + 4 bytes of CRC */
  97     rkwlength = (length + RKW_HEADER_SIZE + 4);
  98
  99     outbuf = malloc(rkwlength);
 100
 101     if (!outbuf)
 102     {
 103        printf("out of memory!\n");
 104        fclose(file);
 105        return -1;
 106     }
 107
 108     /* Clear the buffer to zero */
 109     memset(outbuf, 0, rkwlength);
 110
 111     /* Build the RKW header */
 112     int2le(RKLD_MAGIC, outbuf);                /* magic */
 113     int2le(RKW_HEADER_SIZE, outbuf+0x04);      /* header size */
 114     int2le(0x60000000, outbuf+0x08);           /* base address */
 115     int2le(0x60000000, outbuf+0x0c);           /* load address */
 116     int2le(0x60000000+length, outbuf+0x10);    /* end address */
 117     int2le(0x6035a5e4, outbuf+0x14);           /* points to some unknown struct */
 118     int2le(modelnum, outbuf+0x18);             /* reserved (we abuse the format
 119                                                 * to store modelnum here
 120                                                 */
 121     int2le(0, outbuf+0x1c);                    /* reserved */
 122     int2le(0x60000000, outbuf+0x20);           /* entry point */
 123     int2le(0xe0000000, outbuf+0x24);           /* flags */
 124
 125     header_crc = rkw_crc32(outbuf, RKW_HEADER_SIZE - 4);
 126
 127     int2le(header_crc, outbuf+0x28);           /* header CRC */
 128
 129     /* Copy the binary */
 130     len = fread(outbuf + RKW_HEADER_SIZE, 1, length, file);
 131     if(len < (size_t)length)
 132     {
 133         perror(iname);
 134         free(outbuf);
 135         fclose(file);
 136         return -2;
 137     }
 138     fclose(file);
 139
 140     /* calc binary CRC and put at the end */
 141     binary_crc = rkw_crc32 (outbuf + RKW_HEADER_SIZE, length);
 142     int2le(binary_crc, outbuf + rkwlength - 4);
 143
 144     file = fopen(oname, "wb");
 145     if (!file)
 146     {
 147         perror(oname);
 148         free(outbuf);
 149         return -3;
 150     }
 151
 152     len = fwrite(outbuf, 1, rkwlength, file);
 153     if(len < (size_t)length)
 154     {
 155         perror(oname);
 156         fclose(file);
 157         free(outbuf);
 158         return -4;
 159     }
 160
 161     fclose(file);
 162     free(outbuf);
 163     fprintf(stderr, "File encoded successfully\n" );
 164
 165     return 0;
 166 }