Is there any way to set the source,drain area and perimeter parameters from Xschem? Because I am setting them up using parameters and then giving values for those parameters using .param statement but in the generated netlist, it only reads till Width and Length of the MOSFET. It doesn't read Area and Perimeter for some reason, does ngspice/xschem compute those values on its own? I even tried putting the parameters inside curly braces but that doesn't seem to work either.

@Koustubh the pmos4.sym and nmos4.sym are process-agnostic devices, they usually are used in contexts where only W, L, m are given. However there is a catch all

extra

attribute that you can use to define any additional parameter you want: see the image, where additional MOS parameters are defined using the

extra

attribute and the result in the generated netlist for m6: