We have a kiosk application that runs matchbox on top of linux, and has only a barcode scanner for input (no keyboard). It would be great to be able to print a barcode that--when scanned--sent commands like SysRq R etc, so that one could REISUB without having to disassemble the unit.

If there is not an existing way, could you patch the barcode driver to interpret a certain set of symbols and initiate the sequence?