File system partiotion of WP76XX


I would like to understand that the file system partiotion of WP76XX.
For example, “/sys” is ROM or RAM.

I read “AirPrime_WP76xx_Product_Technical_Specification_Rev11_0.pdf”, but I could not solve it.

Do you know any documents or information about it?

normally i will use “mount” and “df -h” to check.
I only know the tmpfs is the RAM area, but not quite sure about /sys.