Initial scripts with Toradex? /etc/init.d/rcS

Hello,
I am using Colibri iMX7, built an image with Yocto. But I can not see /etc/init.d/rcS scripts. When my Linux starts i want to run some scripts. How can i do that? Is there any easy way? Thank you.

Nowadays, our BSP does use systemd.

https://developer.toradex.com/knowledge-base/how-to-autorun-application-at-the-start-up-in-linux#Systemd