The effect of temporal profile of an ultra-intense, ultrashort few-cycle laser pulse incident normally on a solid surface on harmonics generation (HHG) and attosecond pulse trains has numerically been studied. The results of transformation of initially narrow spectrum of the laser pulse into a broad harmonic spectrum are obtained. The reflected signal has the form of a train of ultrashort pulses of duration ~100 attoseconds for the case of a Ti:sapphire laser. The effect of collisions on electron dynamics has been taken into account