On Fri, Jun 03, 2016 at 10:02:02PM +0530, Muni Sekhar wrote:

Hi,

I see lot of modalias files under /sys directory.

For e.g:

# cat /sys/devices/pci0000:00/0000:00:1c.0/0000:02:00.0/modalias

pci:v00001556d00005555sv00004000sd00000000bc08sc05i01



I would like to know which part of the kernel module creates sysfs
modalias file?

The kernel bus code for the device that the bus is on creates this.  For
this example, the PCI bus code does this work.

How does udev load modules dynamically when a new device is added?

The book, "Linux Device Drivers, version 3", free online, has a whole
section on this, I suggest reading it.

Where should I look for default udev rules?

In the udev or systemd package on your machine.  Specific ways to do
this depends on your distro.

greg k-h