33.3.1 Booting Another OS

If NetBoot is given a pseudo URL-style name at the prompt it will fetch that file and boot it.

The format of the name is as follows:

hostname:path [args]

Where:

hostname

is either an IP-address or a name of a host from which to get the OS. Currently the hostname lookup is fake and depends on hardwired names in the NetBoot code. The OSKit includes resolver code but that code depends on the OSKit BSD socket package, which NetBoot currently does not use.

path

is the path to the desired OS. This directory must be NFS-exported to the machine running NetBoot or the fetch will fail.

args

are optional command line arguments to pass to the booted kernel.

Two args, -h and -f, are handled as toggles. These args are checked for by the default OSKit console startup code and determine if the serial console will be used (-h) and if it runs at 115200 baud (-f). Therefore, if NetBoot was booted with either of these args it will pass them to the booted OS, assuming it wants to use the same console. However, the OS to fetch may be specified with either of these args and they will be removed from the default argument list.

Another arg is placed in the booted OS's argument string before booting. NetBoot passes a flag of the form ``-retaddr hex'' to the booted OS so it can return to this address if it wants to return control to NetBoot. This is normally done by the booted OS's _exit routine.