[ELDK] about NFS log in

[wolfking]

Dear All:
  I have a freescale's 8641d hpcn board. I install eldk 4.2 and the newest linux (3.1).
  I have successfully run the linux using NFS by mounting the RFS to the host. 
  But when the linux finishes booting, it asks for log in. That is, I have to enter
the user name and password. But I don't know when and where I have set the user information.
Can someone tell me how to solve this? Thanks!