bbswitch is a kernel module which automatically detects the required ACPI calls
for two kinds of Optimus laptops. It has been verified to work with "real"
Optimus and "legacy" Optimus laptops (at least, that is how I call them). The
machines on which these tests has performed are:

- Clevo B7130 - GT 425M ("real" Optimus, Lekensteyns laptop)
- Dell Vostro 3500 - GT 310M ("legacy" Optimus, Samsagax' laptop)

(note: there is no need to add more supported laptops here as the universal
calls should work for every laptop model supporting either Optimus calls)

It's preferred over manually hacking with the acpi_call module because it can
detect the correct handle preceding _DSM and has some built-in safeguards:

- You're not allowed to disable a card if a driver (nouveau, nvidia) is loaded.
- Before suspend, the card is automatically enabled. When resuming, it's
disabled again if that was the case before suspending. Hibernation should
work, but it not tested.