[gpm] What come out /dev/mouse ??

[JohnnyRun]

Hi all!

I'm going to discover how mouses (ps2) work in linux. 
I would like to know what kind of signals mouse send to host and how gpm
manage it.
hexdumping /dev/psaux I receive something like:

000ce0 1804 01ec ed38 38fd f8ec ef38 38f3 ecf2
0000cf0 f438 38e9 eaf5 f738 38ed f2f8 fd38 38f3
0000d00 f1ff 0228 28f2 f303 0628 28f5 f705 0528

Gpm use this kind of data? If so, where?
What is the rawest information that gpm receive?

Thanks for attention.
Byebye
JohnnyRun