[PATCH v6 2/6] drm/log: Introduce a new boot logger to draw the kmsg on the screen

[John Ogness]

On 2024-11-05, Jocelyn Falempe <jfalempe at redhat.com> wrote:
> drm_log is a simple logger that uses the drm_client API to print the
> kmsg boot log on the screen. This is not a full replacement to fbcon,
> as it will only print the kmsg. It will never handle user input, or a
> terminal because this is better done in userspace.
>
> Design decisions:
>  * It uses the drm_client API, so it should work on all drm drivers
>    from the start.
>  * It doesn't scroll the message, that way it doesn't need to redraw
>    the whole screen for each new message.
>    It also means it doesn't have to keep drawn messages in memory, to
>    redraw them when scrolling.
>  * It uses the new non-blocking console API, so it should work well
>    with PREEMPT_RT.
>
> This patch also adds a Kconfig menu to select the drm client to use.
> It can be overwritten on the kernel command line with:
> drm_client_lib.default=log or drm_client_lib.default=fbdev
>
> Signed-off-by: Jocelyn Falempe <jfalempe at redhat.com>

Reviewed-by: John Ogness <john.ogness at linutronix.de> # console API