console vs earlycon ?

Arnd Bergmann arnd at arndb.de
Wed Oct 21 15:54:28 PDT 2015


On Wednesday 21 October 2015 15:24:41 Peter Hurley wrote:
> On 10/21/2015 03:00 PM, Arnd Bergmann wrote:

> > Yes, I see this as a tradeoff: we want the console to be as early as
> > possible in order to report boot-time errors to the user, but not so early
> > to require hacks that can cause problems themselves. earlycon has to
> > do some scary stuff and is relatively recent, while the hacks
> > necessary for console_init() are much older and better tested.
> 
> I assume you mean the hacks necessary to get _earlycon_ working at
> console_init() time, because the hacks necessary to get non-8250
> serial consoles working at console_init() would be extensive and
> brand new.
> 

No, I was just being slow and assumed that the 51 drivers that come with
a console_initcall() do something in there to actually start the console,
but you are right that most of them don't actually do that. They just
call register_console() and wait for the device to show up later.

	Arnd



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