Recall that the printk output might go to up to three locations:
- The first being the kernel memory log buffer (always)
- The second being non-volatile log files
- The last one (that we'll address here): the console device
Traditionally, the console device is a pure kernel feature, the initial Terminal window that the superuser logs into (/dev/console) in a non-graphical environment. Interestingly, on Linux, we can define several consoles – a teletype terminal (tty) window (such as /dev/console), a text-mode VGA, a framebuffer, or even a serial port served over USB (this being common on embedded systems during development; see more on Linux consoles in the Further reading section of this chapter).
For example, when we connect a Raspberry Pi to an x86-64 laptop via a USB-to-RS232 TTL UART (USB-to-serial) cable (see the Further reading section of this chapter for a blog article on this very useful accessory...
