The console is the pair of input and output devices that the OpenBoot firmware uses to communicate with the user (for example, a keyboard and a bit-mapped display). The console devices are selected after probing, allowing the use of plug-in devices for the console. After probing, the drivers for devices named by input-device and output-device are opened, and console input and output is directed to those devices. The ihandles of the open input and output drivers are saved as the values of the stdin and stdout properties in the /chosen node, so that client programs can interact with the user through the console. If either of the specified devices cannot be opened, system-dependent default devices can be used instead of the specified devices.
The console activation process is performed by the install-console command. Normally, install-console is automatically executed during the OpenBoot firmware start-up sequence just after probing, but it can be executed explicitly from an NVRAMRC script if desired.
If you want to change the input and output console configuration, see Set the Input and Output Device.