The RTC includes 128 bytes of NVRAM which can be used for custom applications. The utility 'nvramctl' can be used to read/write the NVRAM. The source for this utility is available from our ts4900-utils github.
The utility reads/writes a byte at a time, and returns the value in hex.
nvramctl --addr 10 --set 0x40 nvramctl --addr 10 --get # Returns "nvram10=0x40". # This can also be used with eval eval $(nvramctl --addr 10 --get) echo $nvram10 # Returns "0x40"
The NVRAM code can be included in your application by using these two files: