ok setenv boot-device device-specifier
where the device-specifier is one of the following:
Note - The Solaris OS modifies the boot-device variable to its full path name, not the alias name. If you choose a nondefault boot-device variable, the Solaris OS specifies the full device path of the boot device.
Note - You can specify the name of the program to be booted as well as the way the boot program operates. For more information, refer to the OpenBoot Command Reference Manual for your specific Solaris OS release.
If you want to specify a network interface other than an on-board Ethernet interface as the default boot device, you can determine the full path name of each interface by typing either of the following commands:
ok show-devs ok show-nets
The show-devs command lists the system devices and displays the full path name of each PCI device.
OpenBoot Command Reference Manual