The processing of the rc.boot script can be suppressed by specifying the -b option on the boot command line.
When an automatic reboot is in progress, rc and rc.boot are invoked with the argument autoboot and run a fsck with option -p to ``preen'' all the disks of minor inconsistencies resulting from the last system shutdown and to check for serious inconsistencies caused by hardware or software failure. If this auto-check and repair succeeds, then the second part of rc is run.
The second part of rc, which is run after a auto-reboot succeeds and also if rc is invoked when a single user shell terminates (see init(8)), starts all the daemons on the system, preserves editor files and clears the scratch directory /tmp. Rc.local is executed immediately before any other commands after a successful fsck. Normally, the first commands placed in the rc.local file define the machine's name, using hostname(1), and save any possible core image that might have been generated as a result of a system crash, savecore(8). The latter command is included in the rc.local file because the directory in which core dumps are saved is usually site specific.