Hello,
There is some mismatch in the documentation:
Board layout (
http://8devices.com/media/files/Carambola2.pdf page 3)
lists S1 as hardware reset button,
Board schematic (
http://8devices.com/media/files/8dev-07 ... sb_SCH.pdf page 2)
draws S2 as hardware reset button, which seems to be right.