unknown error while booting

[Clarence <c5666305_(_at_)_hkstar_(_dot_)_com>]

Hello,

I recently found out that there is a messages on my screen while booting
my system (toshiba 1800 on OpenBSD-3.0).  Can anyone tell me the meaning
of it ? How can I fix it ?  Thanks.

Clarence

======= message ========
openbsd (hd0a:/etc/boot.conf) unknown error : code 20
========================