fix syscalls
fix warning
move printf here from irq_cpu
fix uart0_puts
make printf use uart0_puts
fix syscalls
implement socket io, WIP
fix unix socket io, handle close/reconnect
Parametrize uart0 behaviour

move the task of uart initialization from board to cpu
parametrize uart initialization
move stdio/stderr redirection initialization here from cpu
make stdio/stderr redirection optional
fixup