Domain Name System
  -------------------------------------------
  
  The Domain Name System (DNS) is a hierarchical naming system for computers,
  services, or any resource participating in the Internet. It associates various
  information with domain names assigned to each of the participants. Most
  importantly, it translates domain names meaningful to humans into the numerical
  (binary) identifiers associated with networking equipment for the purpose of
  locating and addressing these devices world-wide. An often used analogy to
  explain the Domain Name System is that it serves as the "phone book" for the
  Internet by translating human-friendly computer hostnames into IP addresses.
  For example, www.example.com translates to 208.77.188.166.
  
  For more information on DNS - http://en.wikipedia.org/wiki/Domain_Name_System

  U-Boot and DNS
  ------------------------------------------
  
  CONFIG_CMD_DNS - controls if the 'dns' command is compiled in. If it is, it

  		 will send name lookups to the dns server (env var 'dnsip')
  		 Turning this option on will about abou 1k to U-Boot's size.

  		 Example:

  
  bfin> print dnsip
  dnsip=192.168.0.1
  
  bfin> dns www.google.com
  66.102.1.104

  		 By default, dns does nothing except print the IP number on
  		 the default console - which by itself, would be pretty
  		 useless. Adding a third argument to the dns command will
  		 use that as the environment variable to be set.

  		 Example:

  
  bfin> print googleip
  ## Error: "googleip" not defined
  bfin> dns www.google.com googleip
  64.233.161.104
  bfin> print googleip
  googleip=64.233.161.104
  bfin> ping ${googleip}
  Using Blackfin EMAC device
  host 64.233.161.104 is alive

  		 In this way, you can lookup, and set many more meaningful
  		 things.

  
  bfin> sntp
  ntpserverip not set
  bfin> dns pool.ntp.org ntpserverip
  72.18.205.156
  bfin> sntp

  Date: 2009-07-18 Time:	4:06:57

  		 For some helpful things that can be related to DNS in U-Boot,
  		 look at the top level README for these config options:
  		    CONFIG_CMD_DHCP
  		    CONFIG_BOOTP_DNS
  		    CONFIG_BOOTP_DNS2