Add support for the generic Telechips firmware format checksums - use -tcc=sum if the header just contains a single checksum, or -tcc=crc if the header contains two 32-bit CRCs. Credit goes to Hein-Pieter van Braam for his work on identifying the (reverse) CRC32 algorithm used when calculating the two CRCs
git-svn-id: svn://svn.rockbox.org/rockbox/trunk@14917 a1c6a512-1295-4272-9138-f99709370657
diff --git a/docs/CREDITS b/docs/CREDITS
index 8396793..0f09162 100644
--- a/docs/CREDITS
+++ b/docs/CREDITS
@@ -336,6 +336,7 @@
Pinitnun Shanasabang
Ken Fazzone
David Bishop
+Hein-Pieter van Braam
The libmad team
The wavpack team
diff --git a/tools/Makefile b/tools/Makefile
index 74d82af..bbb9b0d 100644
--- a/tools/Makefile
+++ b/tools/Makefile
@@ -16,15 +16,16 @@
all:
@echo "Run make in your build directory!"
-scramble: scramble.o iriver.o mi4.o gigabeat.o gigabeats.o
+scramble: scramble.o iriver.o mi4.o gigabeat.o gigabeats.o telechips.o
descramble: descramble.o iriver.o gigabeat.o
-scramble.o: scramble.c iriver.h mi4.h gigabeat.h
+scramble.o: scramble.c iriver.h mi4.h gigabeat.h telechips.h
descramble.o: descramble.c iriver.h gigabeat.h
iriver.o: iriver.c iriver.h
gigabeat.o: gigabeat.c gigabeat.h
gigabeats.o: gigabeats.c gigabeats.h
mi4.o: mi4.c mi4.h
+telechips.o: telechips.c telechips.h
sh2d: sh2d.c
diff --git a/tools/scramble.c b/tools/scramble.c
index 8534d41..ad12883 100644
--- a/tools/scramble.c
+++ b/tools/scramble.c
@@ -25,6 +25,7 @@
#include "gigabeat.h"
#include "gigabeats.h"
#include "mi4.h"
+#include "telechips.h"
int iaudio_encode(char *iname, char *oname, char *idstring);
int ipod_encode(char *iname, char *oname, int fw_ver, bool fake_rsrc);
@@ -102,6 +103,7 @@
"\t -model=XXXX where XXXX is the model id string\n"
"\t -type=XXXX where XXXX is a string indicating the \n"
"\t type of binary, eg. RBOS, RBBL\n"
+ "\t-tcc=X Telechips generic firmware format (X values: sum, crc)\n"
"\t-add=X Rockbox generic \"add-up\" checksum format\n"
"\t (X values: h100, h120, h140, h300, ipco, nano, ipvd, mn2g\n"
"\t ip3g, ip4g, mini, iax5, h10, h10_5gb, tpj2,\n"
@@ -127,7 +129,7 @@
unsigned long modelnum;
char modelname[5];
int model_id;
- enum { none, scramble, xor, add } method = scramble;
+ enum { none, scramble, xor, tcc_sum, tcc_crc, add } method = scramble;
model_id = ARCHOS_PLAYER;
@@ -186,6 +188,20 @@
return -1;
}
}
+ else if(!strncmp(argv[1], "-tcc=", 4)) {
+ headerlen = 0;
+ iname = argv[2];
+ oname = argv[3];
+
+ if(!strcmp(&argv[1][5], "sum"))
+ method = tcc_sum;
+ else if(!strcmp(&argv[1][5], "crc"))
+ method = tcc_crc;
+ else {
+ fprintf(stderr, "unsupported TCC method: %s\n", &argv[1][5]);
+ return 2;
+ }
+ }
else if(!strncmp(argv[1], "-add=", 5)) {
iname = argv[2];
oname = argv[3];
@@ -409,7 +425,7 @@
break;
}
- if(method != add) {
+ if((method == none) || (method == scramble) || (method == xor)) {
/* calculate checksum */
for (i=0;i<length;i++)
crc += inbuf[i];
@@ -426,6 +442,17 @@
headerlen = 8;
}
break;
+
+ case tcc_sum:
+ memcpy(outbuf, inbuf, length); /* the input buffer to output*/
+ telechips_encode_sum(outbuf, length);
+ break;
+
+ case tcc_crc:
+ memcpy(outbuf, inbuf, length); /* the input buffer to output*/
+ telechips_encode_crc(outbuf, length);
+ break;
+
case scramble:
if (headerlen == 6) {
int2be(length, header);
@@ -488,9 +515,11 @@
perror(oname);
return -1;
}
- if ( !fwrite(header,headerlen,1,file) ) {
- perror(oname);
- return -1;
+ if (headerlen > 0) {
+ if ( !fwrite(header,headerlen,1,file) ) {
+ perror(oname);
+ return -1;
+ }
}
if ( !fwrite(outbuf,length,1,file) ) {
perror(oname);
diff --git a/tools/telechips.c b/tools/telechips.c
new file mode 100644
index 0000000..5b6f3c2
--- /dev/null
+++ b/tools/telechips.c
@@ -0,0 +1,156 @@
+/***************************************************************************
+ * __________ __ ___.
+ * Open \______ \ ____ ____ | | _\_ |__ _______ ___
+ * Source | _// _ \_/ ___\| |/ /| __ \ / _ \ \/ /
+ * Jukebox | | ( <_> ) \___| < | \_\ ( <_> > < <
+ * Firmware |____|_ /\____/ \___ >__|_ \|___ /\____/__/\_ \
+ * \/ \/ \/ \/ \/
+ * $Id$
+ *
+ * Telechips firmware checksum support for scramble
+ *
+ * Copyright (C) 2007 Dave Chapman
+ *
+ * Thanks to Hein-Pieter van Braam for his work in identifying the
+ * CRC algorithm used.
+ *
+ * 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 <unistd.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <stdint.h>
+#include <stdlib.h>
+
+static uint32_t crctable[256];
+
+/* Simple implementation of a function to reverse the bottom n bits in x */
+static uint32_t bitreverse(uint32_t x,int n)
+{
+ int i;
+ uint32_t mask = 1<<(n-1);
+ uint32_t res = 0;
+
+ for (i=0; i<n; i++)
+ {
+ if (x & 1)
+ res |= mask;
+
+ x >>= 1;
+ mask >>= 1;
+ }
+ return res;
+}
+
+/* Generate a lookup table for a reverse CRC32 */
+static void gentable(uint32_t poly)
+{
+ int i;
+ uint32_t r;
+ uint32_t index;
+
+ for (index = 0; index < 256; index++)
+ {
+ r = bitreverse(index,8) << 24;
+ for (i=0; i<8; i++)
+ {
+ if (r & (1 << 31))
+ r = (r << 1) ^ poly;
+ else
+ r<<=1;
+ }
+ crctable[index] = bitreverse(r,32);
+ }
+}
+
+/* Perform a reverse CRC32 */
+static uint32_t calc_crc(unsigned char *message, int size)
+{
+ uint32_t crc = 0;
+ int i;
+
+ for (i=0; i < size; i++){
+ if ((i < 0x10) || (i >= 0x18)) {
+ crc = crctable[((crc ^ (message[i])) & 0xff)] ^ (crc >> 8);
+ }
+ }
+
+ return crc;
+}
+
+/* Endian-safe functions to read/write a 32-bit little-endian integer */
+
+static uint32_t get_uint32le(unsigned char* p)
+{
+ return p[0] | (p[1] << 8) | (p[2] << 16) | (p[3] << 24);
+}
+
+static void put_uint32le(unsigned char* p, uint32_t x)
+{
+ p[0] = x & 0xff;
+ p[1] = (x >> 8) & 0xff;
+ p[2] = (x >> 16) & 0xff;
+ p[3] = (x >> 24) & 0xff;
+}
+
+/* A simple checksum - seems to be used by the TCC76x firmwares */
+void telechips_encode_sum(unsigned char* buf, int length)
+{
+ uint32_t sum;
+ int i;
+
+ /* Set checksum field to 0 */
+ put_uint32le(buf + 0x10, 0);
+
+ /* Perform a simple sum, treating the file as a series of 32-bit
+ little-endian integers */
+ sum = 0;
+ for (i=0; i < length; i+=4) {
+ sum += get_uint32le(buf + i);
+ }
+ /* Negate the sum - this means that the sum of the whole file
+ (including this value) will be equal to zero */
+ sum = -sum;
+
+ /* Set the checksum field */
+ put_uint32le(buf + 0x10, sum);
+}
+
+
+/* Two reverse CRC32 checksums - seems to be used by the TCC77x firmwares */
+void telechips_encode_crc(unsigned char* buf, int length)
+{
+ uint32_t crc1,crc2;
+
+ /* Generate the CRC table */
+ gentable(0x8001801BL);
+
+ /* Clear the existing CRC values */
+ put_uint32le(buf+0x10, 0);
+ put_uint32le(buf+0x18, 0);
+
+ /* Write the length */
+ put_uint32le(buf+0x1c, length);
+
+ /* Calculate the first CRC - over the entire file */
+ crc1 = calc_crc(buf, length);
+
+ /* What happens next depends on the filesize */
+ if (length >= 128*1024)
+ {
+ put_uint32le(buf+0x18, crc1);
+
+ crc2 = calc_crc(buf, 128*1024);
+ put_uint32le(buf+0x10, crc2);
+ } else {
+ put_uint32le(buf+0x10, crc1);
+ }
+}
diff --git a/tools/telechips.h b/tools/telechips.h
new file mode 100644
index 0000000..7854da0
--- /dev/null
+++ b/tools/telechips.h
@@ -0,0 +1,26 @@
+/***************************************************************************
+ * __________ __ ___.
+ * Open \______ \ ____ ____ | | _\_ |__ _______ ___
+ * Source | _// _ \_/ ___\| |/ /| __ \ / _ \ \/ /
+ * Jukebox | | ( <_> ) \___| < | \_\ ( <_> > < <
+ * Firmware |____|_ /\____/ \___ >__|_ \|___ /\____/__/\_ \
+ * \/ \/ \/ \/ \/
+ * $Id$
+ *
+ * Copyright (C) 2007 Dave Chapman
+ *
+ * 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.
+ *
+ ****************************************************************************/
+
+#ifndef _TELECHIPS_H
+#define _TELECHIPS_H
+
+void telechips_encode_sum(unsigned char* buf, int length);
+void telechips_encode_crc(unsigned char* buf, int length);
+
+#endif