restored the BIOS configuration to the default settings by upgrade the BIOS.
1: Get the upgrade file (such as RMSIV060.bin) and ipmctool from support.e website;
2: Power off the server, and keep the server in the standby state;
3: Use winscp to transfer the upgrade file and ipmctool to tmp
folder of the BMC;
4: Log in to the BMC over Telnet, run cd tmp to go to the tmp directory, and run chmod 777 ipmctool to change the ipmctool to an executable file.
5: Run the ./ipmctool 14 RMSIV060.bin
command to upgrade the management engine (ME).
6: If information similar to the following is displayed, the upgrade is complete.
7: Reboot the server,then we can login the BIOS without password.