Analysis of information sources in references of the Wikipedia article "Linux console" in English language version.
The system console is the device which receives all kernel messages and warnings and which allows logins in single user mode. If you answer Y here, a virtual terminal (the device used to interact with a physical terminal) can be used as system console.
If you say Y here, it will be possible to use a serial port as the system console (the system console is the device which receives all kernel messages and warnings and which allows logins in single user mode). This could be useful if some terminal or printer is connected to that serial port.
If you say Y here, it will be possible to use a USB to serial converter port as the system console (the system console is the device which receives all kernel messages and warnings and which allows logins in single user mode). This could be useful if some terminal or printer is connected to that serial port.
Saying Y here will allow you to use Linux in text mode through a display that complies with the generic VGA standard. Virtually everyone wants that.
CONFIG_VT is the kernel configuration option that enables virtual terminals in the kernel. Initially written by Linus himself, it has been around since 1991.
The framebuffer console (fbcon), as its name implies, is a text console running on top of the framebuffer device. It has the functionality of any standard text console driver, such as the VGA console, with the added features that can be attributed to the graphical nature of the framebuffer. In the x86 architecture, the framebuffer console is optional, and some even treat it as a toy. For other architectures, it is the only available display device, text or graphical. What are the features of fbcon? The framebuffer console supports high resolutions, varying font types, display rotation, primitive multihead, etc. Theoretically, multi-colored fonts, blending, aliasing, and any feature made available by the underlying graphics card are also possible.
The system console is the device which receives all kernel messages and warnings and which allows logins in single user mode.
If you say Y here, you will get support for terminal devices with display and keyboard devices. These are called "virtual" because you can run several virtual terminals (also called virtual consoles) on one physical terminal. This is rather useful, for example one virtual terminal can collect system messages and warnings, another one can be used for a text-mode user session, and a third could run an X session, all in parallel. Switching between virtual terminals is done with certain key combinations, usually Alt-<function key>.
Announced yesterday was the release of kmscon, a terminal emulator for Linux that's similar to what's offered inside the kernel, but instead it's in user-space and relies upon the kernel's DRM interfaces as well as Mesa.
CONFIG_VT has been part of the Linux kernel going back to the early 90s but hasn't really advanced much in that time. David Herrmann, a developer that got going on this new initiative as a student part of Google Summer of Code, wants a new solution that's built with multi-seat and multiple monitors in mind, incorporates Unicode font rendering, XKB-like keyboard handling, graphics hardware acceleration, VT220-VT510 compatibility, and other features.
