passing module parameters in 2.6

["sanjayk" <tousanjay@xxxxxxxxxxxxxx>]

Hi all
I have a confusion about the usage of parameter passing mechanism to modules in linux kernel 2.6.
In kernel 2.4.x, we use MODULE_PARM giving name and type of variable.
In 2.6 we have a similar macro besides we also have (particularly 2.6.5)
module_param_string(name, string, len, perm).
I couldn't understand how this macro works?

TIA
sanjayk