[PATCH] console: Add option to keep it silent until env is loaded

[Simon Glass]

Hi Harald,

On Tue, 12 Jul 2022 at 05:58, Harald Seiler <hws at denx.de> wrote:
>
> Hi Simon,
>
> On Tue, 2022-07-12 at 04:58 -0600, Simon Glass wrote:
> > Hi Harald,
> >
> > On Wed, 6 Jul 2022 at 05:19, Harald Seiler <hws at denx.de> wrote:
> > >
> > > Add a config-option which forces the console to stay silent until the
> > > proper environment is loaded from flash.
> > >
> > > This is important when the default environment does not silence the
> > > console but no output must be printed when 'silent' is set in the flash
> > > environment.
> > >
> > > After the environment from flash is loaded, the console will be
> > > silenced/unsilenced depending on it.  If PRE_CONSOLE_BUFFER is also
> > > used, the buffer will now be flushed if the console should not be
> > > silenced.
> > >
> > > Signed-off-by: Harald Seiler <hws at denx.de>
> > > ---
> > >  common/Kconfig   | 10 ++++++++++
> > >  common/console.c |  5 +++++
> > >  2 files changed, 15 insertions(+)
> >
> > This seems OK to me. You might want to implement the silent-console
> > device tree property in console_update_silent() too, which was dropped
> > in the conversion to driver model.
>
> This looks interesting, I'll have to look into it.
>
> Do you know if there's any effort towards supporting such a flag in the
> kernel as well?  I had to remove the serial console property from my DT
> and instead pass console info via cmdline to make the silent console
> work.  A "pure DT" solution of any sort would have been nicer of
> course...

The console's 'silent' flag is propagated to Linux by dropping the
'console=' text from the bootargs. See fixup_silent_linux().

Regards,
Simon


>
> --
> Harald