drivers::chario: Fix reference to non-existent type
k20::uart: Port to ioregs!
app_blink_k20: Test uart
Fix build_docs
rake: Add :debug option
k20::sim: Export regs
ioreg::test: Test gap offset
ioreg: Fix incorrect calculation of gaps
platformtree: Begin fixing tests
k20::uart: Make UART naming consistent with documentation
k20::uart: Enable transmission/reception in set_mode