scramble: add RKW firmware file format encoder

Change-Id: I8057d6186724c3e8a319a262f45c12da7afb722e

tools/rkw.c

@@ -0,0 +1,166 @@
+/***************************************************************************
+ *             __________               __   ___.
+ *   Open      \______   \ ____   ____ |  | _\_ |__   _______  ___
+ *   Source     |       _//  _ \_/ ___\|  |/ /| __ \ /  _ \  \/  /
+ *   Jukebox    |    |   (  <_> )  \___|    < | \_\ (  <_> > <  <
+ *   Firmware   |____|_  /\____/ \___  >__|_ \|___  /\____/__/\_ \
+ *                     \/            \/     \/    \/            \/
+ *
+ * Copyright (C) 2012 Marcin Bukat
+ *
+ * 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 2
+ * of the License, or (at your option) any later version.
+ *
+ * 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>
+#include <stdint.h>
+
+#define RKLD_MAGIC 0x4c44524b
+#define RKW_HEADER_SIZE 0x2c
+
+/* slightly modified version from crc32.c in rockbox */
+static uint32_t rkw_crc32(const void *src, uint32_t len)
+{
+    const unsigned char *buf = (const unsigned char *)src;
+
+    /* polynomial 0x04c10db7 */
+    static const uint32_t crc32_lookup[16] =
+    {   /* lookup table for 4 bits at a time is affordable */
+        0x00000000, 0x04C10DB7, 0x09821B6E, 0x0D4316D9,
+        0x130436DC, 0x17C53B6B, 0x1A862DB2, 0x1E472005,
+        0x26086DB8, 0x22C9600F, 0x2F8A76D6, 0x2B4B7B61,
+        0x350C5B64, 0x31CD56D3, 0x3C8E400A, 0x384F4DBD
+    };
+
+    uint32_t crc32 = 0;
+    unsigned char byte;
+    uint32_t t;
+
+    while (len--)
+    {
+        byte = *buf++; /* get one byte of data */
+
+        /* upper nibble of our data */
+        t = crc32 >> 28; /* extract the 4 most significant bits */
+        t ^= byte >> 4; /* XOR in 4 bits of data into the extracted bits */
+        crc32 <<= 4; /* shift the CRC register left 4 bits */
+        crc32 ^= crc32_lookup[t]; /* do the table lookup and XOR the result */
+
+        /* lower nibble of our data */
+        t = crc32 >> 28; /* extract the 4 most significant bits */
+        t ^= byte & 0x0F; /* XOR in 4 bits of data into the extracted bits */
+        crc32 <<= 4; /* shift the CRC register left 4 bits */
+        crc32 ^= crc32_lookup[t]; /* do the table lookup and XOR the result */
+    }
+
+    return crc32;
+}
+
+static void int2le(unsigned int val, unsigned char* addr)
+{
+    addr[0] = val & 0xFF;
+    addr[1] = (val >> 8) & 0xff;
+    addr[2] = (val >> 16) & 0xff;
+    addr[3] = (val >> 24) & 0xff;
+}
+
+int rkw_encode(char *iname, char *oname, unsigned long modelnum)
+{
+    size_t len;
+    int length;
+    int rkwlength;
+    FILE *file;
+    uint32_t binary_crc, header_crc;
+    unsigned char *outbuf;
+
+    file = fopen(iname, "rb");
+    if (!file)
+    {
+       perror(iname);
+       return -1;
+    }
+
+    fseek(file,0,SEEK_END);
+    length = ftell(file);
+    
+    fseek(file,0,SEEK_SET);
+
+    /* length of the RKW header + binary length + 4 bytes of CRC */
+    rkwlength = (length + RKW_HEADER_SIZE + 4);
+
+    outbuf = malloc(rkwlength);
+
+    if (!outbuf)
+    {
+       printf("out of memory!\n");
+       fclose(file);
+       return -1;
+    }
+
+    /* Clear the buffer to zero */
+    memset(outbuf, 0, rkwlength);
+
+    /* Build the RKW header */
+    int2le(RKLD_MAGIC, outbuf);                /* magic */
+    int2le(RKW_HEADER_SIZE, outbuf+0x04);      /* header size */
+    int2le(0x60000000, outbuf+0x08);           /* base address */
+    int2le(0x60000000, outbuf+0x0c);           /* load address */
+    int2le(0x60000000+length, outbuf+0x10);    /* end address */
+    int2le(0x6035a5e4, outbuf+0x14);           /* points to some unknown struct */
+    int2le(modelnum, outbuf+0x18);             /* reserved (we abuse the format
+                                                * to store modelnum here
+                                                */
+    int2le(0, outbuf+0x1c);                    /* reserved */
+    int2le(0x60000000, outbuf+0x20);           /* entry point */
+    int2le(0xe0000000, outbuf+0x24);           /* flags */
+
+    header_crc = rkw_crc32(outbuf, RKW_HEADER_SIZE - 4);
+
+    int2le(header_crc, outbuf+0x28);           /* header CRC */
+
+    /* Copy the binary */
+    len = fread(outbuf + RKW_HEADER_SIZE, 1, length, file);
+    if(len < (size_t)length)
+    {
+        perror(iname);
+        free(outbuf);
+        fclose(file);
+        return -2;
+    }
+    fclose(file);
+
+    /* calc binary CRC and put at the end */
+    binary_crc = rkw_crc32 (outbuf + RKW_HEADER_SIZE, length);
+    int2le(binary_crc, outbuf + rkwlength - 4);
+
+    file = fopen(oname, "wb");
+    if (!file)
+    {
+        perror(oname);
+        free(outbuf);
+        return -3;
+    }
+    
+    len = fwrite(outbuf, 1, rkwlength, file);
+    if(len < (size_t)length)
+    {
+        perror(oname);
+        fclose(file);
+        free(outbuf);
+        return -4;
+    }
+
+    fclose(file);
+    free(outbuf);
+    fprintf(stderr, "File encoded successfully\n" );
+
+    return 0;
+}