How to get SystemMemorySize?

[Deepak Madhusudan]

Hi All,
 In linux driver in order to get the system memory size we can get it using
the following call.
   struct sysinfo si;
   si_meminfo(&si);
   return (si.tatotalram);
Is there any similar call in freebsd to get the following
information.Currently i am using freebsd 6.3.Please let me know.

Thanks and regards,
Deepak