lkml.org 
[lkml]   [2015]   [May]   [7]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: earlycon: no match?
On 05/07/2015 04:14 PM, Maciej W. Rozycki wrote:
> On Thu, 7 May 2015, Peter Hurley wrote:
>
>>> What's the point of having two parameters as synonyms whose syntax is not
>>> compatible to each other in the general case? I'd expect the following
>>> cases to be handled:
>>>
>>> 1. Regular console only (no early console requested) => `console=foo...'.
>>>
>>> 2. Both early and regular console => `earlycon=blah... console=foo...'.
>>>
>>> 3. Early console handing over to regular console => `earlycon=blah...'.
>>
>> 4. Early console only => `earlycon=blah...'
>>
>> How to distinguish between 3 & 4?
>
> Good point. If you want to disable the handover, then it has to be
> handled by the early console driver somehow. Perhaps an option for
> `earlycon=' (e.g. `nohandover') would be required for that. In that case
> the default selection would apply for the regular console, depending on
> the available drivers.
>
> Your concern appears to me unrelated to `earlycon=' vs `console='
> parameter aliasing though. The same observation about the handover
> applies whether the parameters are aliased to each other or not. Have I
> missed anything?
>
>>> Why do you want to support `console=blah...' too (a question to be asked
>>> back in 2007, but better late than never)?
>>
>> Command line is considered to be userspace, so it doesn't really matter
>> what I think about whether console= should have been overloaded like that.
>>
>> The fact is, it was.
>
> The change has not been cast in stone, it can always be reverted if on
> the second thoughts it is concluded to have been wrong.
>
> How does this overload interact with multiple `console=' options being
> present BTW, which one is considered the early console? Or do we support
> driving multiple early consoles in parallel just as we do with regular
> consoles?

Please familiarize yourself with the existing 'console=' and 'earlycon='
command line options documented in Documentation/kernel-parameters.txt
These have not changed with 4.1-rc

Regards,
Peter Hurley




\
 
 \ /
  Last update: 2015-05-07 23:21    [W:0.078 / U:0.492 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site