Can I configure EtherCAT slave as S/W?

I am looking at EtherCAT.
I am using embedded Linux.
etherlab and SOEM have been compiled to test that the EtherCAT master functionality is possible.
But I could not find anything about the EtherCAT slave(S/W).

First of all, etherlab had only master function.
SOES also required specific hardware(Lan9252, twrk60).(https://github.com/OpenEtherCATsociety/SOES/tree/master/soes/hal)

I think ethercat slave is also possible if ethercat master is available with ethernet port.
Is EtherCAT slave a physical hardware (device) unconditionally required, unlike the EtherCAT master?

EtherCAT Slave requires physical ESC(EtherCAT Slave Controller).