To boot picobsd, insert the floppy and reset the machine. The boot procedure is similar to the standard
.Fx boot. Booting from a floppy is normally rather slow (in the order of 1-2 minutes), things are much faster if you store your image on a hard disk, Compact Flash, or CDROM.
You can also use etherboot to load the preloaded, uncompressed kernel image which is a byproduct of the picobsd build. In this case the load time is a matter of a few seconds, even on a 10Mbit/s ethernet.
After booting, picobsd loads the root file system from the memory file system, starts /sbin/init, and passes control to a first startup script, /etc/rc. The latter populates the /etc and /root directories with the default files, then tries to identify the boot device (floppy, hard disk partition) and possibly override the contents of the root file system with files read from the boot device. This allows you to store local configuration on the same media. After this phase the boot device is no longer used, unless the user specifically does it.
After this, control is transferred to a second script, /etc/rc1 (which can be overridden from the boot device). This script tries to associate a hostname to the system by using the MAC address of the first ethernet interface as a key, and /etc/hosts as a lookup table. Then control is passed to the main user configuration script, /etc/rc.conf, which is supposed to override the value of a number of configuration variables which have been pre-set in /etc/rc.conf.defaults. You can use the hostname variable to create different configurations from the same file. After taking control back, /etc/rc1 completes the initializations, and as part of this it configures network interfaces and optionally calls the firewall configuration script, /etc/rc.firewall, where the user can store his own firewall configuration.
Note that by default picobsd runs entirely from main memory, and has no swap space, unless you explicitly request it. The boot device is also not used anymore after /etc/rc1 takes control, again, unless you explicitly request it.
CONFIGURING a PicoBSD system
The operation of a picobsd system can be configured through a few files which are read at boot time, very much like a standard
.Fx system. There are, however, some minor differences to reduce the number of files to store and/or customize, thus saving space. Among the files to configure we have the following: