kernel code reading: pci sysfs entry vendor/device/resource
kernel code test: move test function in test file
kernel code test: pci resource assign

Did an interesting test, even the start address is bigger then 0, it still
works.
kernel code test: pci resource assign

This is similar with the previous one.

When the start address is bigger, it also works.
kernel code test: fix one issue.
kernel code reading: pci init on x86

on x86, the BAR resource is assigned according to the BIOS value first.
kernel code reading: net dev
kernel code reading: netlink protocol