See the top level README for information on where to find the
schematic and programmers reference manual for the ARM processor
on the raspberry pi.  Also find information on how to load and run
these programs.

This example uses the free running ARM timer, not the 64 bit system
timer as in blinker02 but the so called ARM timer.

The system clock appears to come up at 250MHz as documented.  Divide that
by 250 to get 1Mhz on this free running ARM timer.  Then count to four
million ticks between led state changes and the led will change state
every four seconds.