The weight distributions of some product codes

General expressions are derived for the weight distributions of the binary product codes S_m1⊗S_m2, R_m1 ⊗R_m2, S_m1⊗R_m2, E _m1⊗S_m2, and E_m1⊗R_m2 , where S_m is the [2^m-1, m, 2^m-1] simplex code, R_m is the [2^m, m+1, 2^m-1] first order Reed Muller code, and E_m is the [m, m-1, 2] even weight code