hak5
/
openwrt
mirror of https://github.com/hak5/openwrt.git
1
0
Fork 0
Code Issues Packages Projects Releases Wiki Activity

tools/firmware-utils: Allow changing the CRC32 poly value in mkbrnimg 

VGV7519 is currently the only device with brnboot support. It seems to
be happy with 0x2083b8ed as CRC32 poly. However, VGV7510KW22 fails to
validate the checksum - it requires 0x04c11db7 instead.

I have built an brnboot image manually on the command line, once with
the old code and then with the new code but passing the old CRC32
poly value. Both resulted in a brnboot image with the same sha1sum.

Signed-off-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>

SVN-Revision: 45881
lede-17.01
John Crispin 2015-06-03 13:58:48 +00:00
parent f9f093baa3
commit 5d3f0eea1c
1 changed files with 13 additions and 7 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

20
tools/firmware-utils/src/mkbrnimg.c
View File

@ -32,9 +32,14 @@
static uint32_t crc32[1<<BPB];
static char *output_file = "default-brnImage";
static uint32_t magic = 0x12345678;
static char *signature = "BRNDTW502";
static uint32_t crc32_poly = 0x2083b8ed;
static void init_crc32()
{
const uint32_t poly = ntohl(0x2083b8ed);
const uint32_t poly = ntohl(crc32_poly);
int n;
for (n = 0; n < 1<<BPB; n++) {
@ -61,21 +66,17 @@ static void usage(const char *) __attribute__ (( __noreturn__ ));
static void usage(const char *mess)
{
fprintf(stderr, "Error: %s\n", mess);
fprintf(stderr, "Usage: mkbrnimg [-o output_file] [-m magic] [-s signature] kernel_file [additional files]\n");
fprintf(stderr, "Usage: mkbrnimg [-o output_file] [-m magic] [-s signature] [-p crc32 poly] kernel_file [additional files]\n");
fprintf(stderr, "\n");
exit(1);
}
static char *output_file = "default-brnImage";
static uint32_t magic = 0x12345678;
static char *signature = "BRNDTW502";
static void parseopts(int *argc, char ***argv)
{
char *endptr;
int res;
while ((res = getopt(*argc, *argv, "o:m:s:")) != -1) {
while ((res = getopt(*argc, *argv, "o:m:s:p:")) != -1) {
switch (res) {
default:
usage("Unknown option");
@ -91,6 +92,11 @@ static void parseopts(int *argc, char ***argv)
case 's':
signature = optarg;
break;
case 'p':
crc32_poly = strtoul(optarg, &endptr, 0);
if (endptr == optarg || *endptr != 0)
usage("'crc32 poly' must be a decimal or hexadecimal 32-bit value");
break;
}
}
*argc -= optind;