the usage of cover and cover point, and how to coordinate with backend.

[zhao-denghui]

Hi,
There is ccover invoked in ICache, DCache, TLB, and PTW of Rocket-Chip. The purpose of these is to generate cover-points for verification. But these points did not generate. Is there any method to generate the coverage file?
In a word, I want to know the usage of cover and cover point, and how to coordinate with backend. I'll be appreciate if someone can help me.

[sequencer]

cover should be migrate to the new world LTL landed in Chisel6, but we current don't have enough resource to sort it out.