The default one is Solaris. The default timeout to make selection is 30 seconds. The secondary boot is capable of reading and booting from a UFS file system on a hard disk or CD, or by way of LAN using NFS protocol. It switches the processor to 32-bit, paged, protected mode and performs some limited machine initialization. After that, root file system specified in bootpath eeprom variable is mounted.
Secondary boot is programmable, which makes it very flexible.
Device Configuration Assistant Device Configuration Assistant, or shortly DCA, is used to add, remove and configure device drivers necessary to boot a machine up. DCA is run at the begining of Solaris setup to determine what device drivers need to be load, and to select the device from which the installation software will be loaded. DCA is shipped with Solaris media kit on a floppy disk. The first one, if true, causes DCA to boot Solaris kernel off the device and partition specified in bootpath variable, otherwise presents a list of all devices capable of doing that and waits for a user selection. The list usually contains all hard disk drives, CD-ROMs, and LAN adapters.