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Diffstat (limited to 'doc')
| -rw-r--r-- | doc/README.SNTP | 17 |
1 files changed, 17 insertions, 0 deletions
diff --git a/doc/README.SNTP b/doc/README.SNTP new file mode 100644 index 0000000..fd6f209 --- /dev/null +++ b/doc/README.SNTP @@ -0,0 +1,17 @@ +To use SNTP support, add a define CFG_CMD_SNTP to CONFIG_COMMANDS in +the configuration file of the board. + +The "sntp" command gets network time from NTP time server and +syncronize RTC of the board. This command needs the command line +parameter of server's IP address or environment variable +"ntpserverip". The network time is sent as UTC. So if you want to +set local time to RTC, set the offset in second from UTC to the +enviroment variable "time offset". + +If the DHCP server provides time server's IP or time offset, you +don't need to set the above environment variables yourself. + +Current limitations of SNTP support: +1. The roundtrip time is ignored. +2. Only the 1st NTP server IP, in the option ntp-servers of DHCP, will + be used. |