[lkml]   [2019]   [Mar]   [28]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
Messages in this thread
SubjectRe: [PATCH v2 7/7] x86/boot: Support nocfg parameter for earlyprintk
On Thu, Mar 28, 2019 at 02:03:17PM +0100, Borislav Petkov wrote:
> On Tue, Mar 19, 2019 at 09:43:25PM +0300, Andy Shevchenko wrote:
> > If by BIOS or by other means the serial port is configured
> > user might want to skip reconfiguration in the boot code.
> That needs more explanation: how can that happen?

I didn't get what is 'that' here? You mean that serial interface becomes
configured before kernel even starts? See below.

> How is the user
> supposed to know whether the serial port is configured in order to use
> this cmdline param?

If the connection to the target is done via serial interface and
firmware and / or bootloader already did necessary configuration.

> Why can't the kernel detect whether the serial port is configured and
> not touch that configuration?

Because it can't at this stage. We simple can't afford to move all serial
drivers (even partially) to the _boot_ part of the kernel.

> A lot of why's and head scratching...

What other why's should be answered?

With Best Regards,
Andy Shevchenko

 \ /
  Last update: 2019-03-28 14:22    [W:0.127 / U:61.644 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site