Boxes under /b/sys provide system services that either affect the whole machine or do not fit well on other place.
is used to toggle debug flags in the kernel. Its contents appear to be the set of active debug flags—each one is a character. An string copied into it would either set or clear (if started by "-") the debug flags found in the string. Use grep defdbg on the source to see which debug flags are defined.
is a placeholder used to send system-wide commands to the machine, such as halt. No commands are defined yet.
is the great bit bucket. It discards data copied into, and appears to be always empty when data is copied from it.
is the node time in binary format. It is four bytes with the number of seconds since epoch.
is the node time printed as a string.
contains a random number in binary format (four bytes).
contains the set of boxes advertised to the network by the kernel at this machine (other boxes may be advertised by user processes). Copy a string made of two names (box name, ad name) separated by white space to stablish a new ad. Ads are sent upon request and also every 30 seconds. Ads are requested
every time import(2) is used to mount network ads.