udev & modalias files

[Muni Sekhar]

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?


How does udev load modules dynamically when a new device is added?
Where should I look for default udev rules?


-- 
Thanks,
Sekhar