D'oh! I forgot the last part of my message. Those of you who are *really* paying attention must be wondering about the active translator setting on the outer root's /servers/exec. Previously the exec server set itself as active translator on /servers/exec after receiving exec_init. But exec_init doesn't come until the outer bootfs gets fsys_init from the inner bootfs, after the servers are all running. So now the exec server acts more like a normal passive translator: the bootstrap filesystem sets the active translator on /servers/exec after receiving the fsys_startup RPC from exec.
A wart in the code is that for --boot-command to be parsed properly by the diskfs argp code, every bootstrap filesystem must use the ARGP_IN_ORDER flag in its argp_parse call.
