Need help about porting bind-9.7.0 to ARM board

Hi all!
I am trying to port bind-9.7.0-p2 to ARM board. According to configure help, my configuration is:

./configure CC= /usr/local/arm/3.4.1/bin/arm-linux-gcc --host=arm-s3c2410-linux --build=i686-pc-linux --with-openssl=no --prefix=/mnt/bind --enable-static --enable-thread --enable-epoll

but i met configure error:

checking for /dev/random... configure: error: cannot check for file existence when cross compiling.

I know there is an option. It is --with-randomdev=<path>. And i have read related information in bind9 mannual:

random-device The source of entropy to be used by the server. Entropy is primarily needed for DNSSEC operations, such as TKEY transactions and dynamic update of signed zones. This options specifies
the device (or file) from which to read entropy. If this is a file, operations requiring entropy will fail when the file has been exhausted. If not specified, the default value is /dev/random (or equivalent) when present, and none otherwise. The random-device option takes effect during the initial configuration load at server startup time and is ignored on subsequent reloads.

However, it is still difficult for me to understand how to specify the random device path. I really need help.
Thanks!!

OK! i should add --with-randomdev=/dev/random in ./configure