How the LXC container root file system is created

I am new to the lxc container and coming from virtualisation world and sorry for asking the basic stuff here. I have used lxc-create to create the Ubuntu container and noticed that the rootfile system created and it is not clear what is schema to include the system resource? I required this information because I have the requirement to create the lxc container which shall run on TEE but it is not clear how to create it what are system resources it will consider to run and how restrict the system resources like memory, cpu no of threads pps cgroups etc?

See on how to create a container image that you can use with either LXC or LXD.

Restricting system resources is performed when you launch the container out of the container image.

Thanks. That gives the clarification.

I have another question in similar type, I have to build LXC support in my build environment for armv7 for 4.0.9 kernel. In order to build I have to enable the namespace in kernel (I am not able to find this support in kernel config) where can i find the name space support? and were can i get the lxc patch to build for my kernel.