Console devices

Updated: May 06, 2022

System consoles (with VGA-compatible graphics chips in text mode) are managed by the devc-con or devc-con-hid driver. The video display card/screen and the system keyboard are collectively referred to as the physical console.

The devc-con or devc-con-hid driver permits multiple sessions to be run concurrently on a physical console by means of virtual consoles. The devc-con console driver process typically manages more than one set of I/O queues to io-char, which are made available to user processes as a set of character devices with names like /dev/con1, /dev/con2, etc. From the application's point of view, there “really are” multiple consoles available to be used.

Of course, there's only one physical console (screen and keyboard), so only one of these virtual consoles is actually displayed at any one time. The keyboard is “attached” to whichever virtual console is currently visible.

Terminal emulation

The console drivers emulate an ANSI terminal.