Linux Kernel Module Cheat

Enable graphic mode with:

./run --graphic

Outcome: you see a penguin due to CONFIG_LOGO.

For a more exciting GUI experience, see: Section 14.4, “X11 Buildroot”

Text mode is the default due to the following considerable advantages:

copy and paste commands and stdout output to / from host
get full panic traces when you start making the kernel crash :-) See also: https://unix.stackexchange.com/questions/208260/how-to-scroll-up-after-a-kernel-panic
have a large scroll buffer, and be able to search it, e.g. by using tmux on host
one less window floating around to think about in addition to your shell :-)
graphics mode has only been properly tested on x86_64.

Text mode has the following limitations over graphics mode:

you can’t see graphics such as those produced by X11 Buildroot
very early kernel messages such as early console in extract_kernel only show on the GUI, since at such early stages, not even the serial has been setup.

x86_64 has a VGA device enabled by default, as can be seen as:

./qemu-monitor info qtree

and the Linux kernel picks it up through the fbdev graphics system as can be seen from:

cat /dev/urandom > /dev/fb0