Re: [PATCH v2] bootconfig: Apply early options from embedded config

[Masami Hiramatsu (Google) <mhiramat@kernel.org>]

On Wed, 15 Apr 2026 04:15:57 -0700
Breno Leitao <leitao@debian.org> wrote:

> On Tue, Apr 07, 2026 at 03:19:09AM -0700, Breno Leitao wrote:
> > On Fri, Apr 03, 2026 at 11:45:19AM +0900, Masami Hiramatsu wrote:
> > > > I'm still uncertain about this approach. The goal is to identify and
> > > > categorize the early parameters that are parsed prior to bootconfig
> > > > initialization.
> > >
> > > Yes, if we support early parameters in bootconfig, we need to clarify
> > > which parameters are inherently unsupportable, and document it.
> > > Currently it is easy to say that it does not support the parameter
> > > defined with "early_param()". Similary, maybe we should introduce
> > > "arch_param()" or something like it (or support all of them).
> > >
> > > >
> > > > Moreover, this work could become obsolete if bootconfig's initialization
> > > > point shifts earlier or later in the boot sequence, necessitating
> > > > another comprehensive analysis.
> > >
> > > If we can init it before calling setup_arch(), yes, we don't need to
> > > check it. So that is another option. Do you think it is feasible to
> > > support all of them? (Of course, theologically we can do, but the
> > > question is the use case and requirements.)
> >
> > I don't believe all early parameters can be supported by bootconfig.
> > Some are inherently incompatible as far as I understand, while others
> > depend on bootconfig's initialization point in the boot sequence.
> 
> I've developed a patch series that relocates bootconfig initialization
> to occur before setup_arch().
> 
> Adopting this approach would streamline the categorization considerably,
> as only a small subset of kernel parameters are parsed before
> setup_arch() is called.
> 
> This enables a clearer distinction: parameters processed *before*
> setup_arch() versus those handled afterward, rather than classifying
> based on what occurs before bootconfig initialization.
> 
> Just to close the look and link both discussion together, the proposed
> patch series is available at:
> 
> https://lore.kernel.org/all/20260415-bootconfig_earlier-v1-0-cf160175de5e@debian.org/


Thanks for working on this series!! Let me review the series.

BTW, I found that the current __setup(), early_param(), module_param()
are a bit complicated, for example, __setup() and early_param() are
stored in the different array of module_param(), and those can use
the same parameter (e.g. console).

And as you found some of early_param() options are only applied via
command line. Maybe we can introduce another special macro which is
only for command line.

Thanks,

-- 
Masami Hiramatsu (Google) <mhiramat@kernel.org>