Symphony Utility Functions. These are probably useful.
uint16_t crc16 
( 
char * 
ptr, 


int 
count 

) 
 
Calculate a 16bit CRC Checksum.
 Parameters

[in]  ptr  The data you want to calculate the checksum for. 
[in]  count  The number of bytes to included the CRC calculation. 
 Returns
 The 16bit CRC Checksum.
source: Amulet Technologies, LLC (MIT)
uint32_t crc32 
( 
uint32_t 
crc, 


uint8_t * 
buf, 


size_t 
len 

) 
 
Calculate a 32bit CRC Checksum.
 Parameters

[in]  crc  Initial value for CRC Calculation. Commonly 0. 
[in]  buf  The data you want to calculate the checksum for. 
[in]  len  The number of bytes included in the CRC calculation. 
 Returns
 The 32bit CRC Checksum.
source: Zlib
int32_t ll_difftime 
( 
struct time * 
a, 


struct time * 
b 

) 
 
Get the diffrence between two times in seconds.
 Parameters

[in]  a  The start time. 
[out]  b  The end time. 
 Returns
 The floor of the number of seconds (ba).
int32_t ll_difftime_from_now 
( 
struct time * 
a  ) 

Get the diffrence from a start time and when the functions called.
 Parameters

 Returns
 The floor of the number of seconds (nowa).