xref: /openbmc/u-boot/doc/README.SNTP (revision 8e6f1a8e)
1To use SNTP support, add a define CFG_CMD_SNTP to CONFIG_COMMANDS in
2the configuration file of the board.
3
4The "sntp" command gets network time from NTP time server and
5syncronize RTC of the board. This command needs the command line
6parameter of server's IP address or environment variable
7"ntpserverip". The network time is sent as UTC. So if you want to
8set local time to RTC, set the offset in second from UTC to the
9enviroment variable "time offset".
10
11If the DHCP server provides time server's IP or time offset, you
12don't need to set the above environment variables yourself.
13
14Current limitations of SNTP support:
151. The roundtrip time is ignored.
162. Only the 1st NTP server IP, in the option ntp-servers of DHCP, will
17   be used.
18