[LinuxBIOS] [RFC] Payload selector method

[Alex Beregszaszi]

Hi,

After playing around with lbmenu, I came up with the following idea to
select payloads in a clean way.

1a, linuxbios parses the payload number cmos position, and starts the
selected payload

or

1b, linuxbios loads a payload (lbmenu), and passes control to it

2, lbmenu parses the lar
3, the user selects which payload to run
4, lbmenu writes the payloads number (position in lar) to a cmos
variable and gives back control (point 1a)

Imho it is better to have always the 1a, way running, but we have to be
sure the cmos contains a valid value.

Of course with this method payload selection can be repeated as much
times as we want in a single run.