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From: dhylands@gmail.com (Dave Hylands)
To: kernelnewbies@lists.kernelnewbies.org
Subject: Serial console temporarily garbled
Date: Tue, 22 Nov 2011 10:43:17 -0800	[thread overview]
Message-ID: <CABi1daEoa2q7b--UFF_oyie6yq7He2-i1eSQJRS+Mrr118f2Tw@mail.gmail.com> (raw)
In-Reply-To: <CAGNi4LuPEyAMYCXMSOzKHfw9mkQiVgo9CkHx92zXOtftSRRa6w@mail.gmail.com>

Hi Neil,

On Tue, Nov 22, 2011 at 10:20 AM, Neil Baylis <neil.baylis@gmail.com> wrote:
> I'm working on an embedded system running a 2.6.32 kernel originally derived
> from RHEL6.
>
> The hardware architecture is similar to a PC. The device is a specialized
> server. It uses an 8250 compatible serial port for the console.
>
> When it's booting up, everything looks fine until it initializes the serial
> driver. At that point the output to the console becomes garbled until (I
> think...) getty runs for the console port. Then it's readable again.
>
> It looks as though the initialization of the serial driver is setting the
> wrong baud rate, or perhaps some other configuration. During the boot
> process, this garbled output happens for about 1 second, during which
> probably a few thousand characters of garbage are output.
>
> The grub boot parameter specifies "console=ttys0,57600"

Did you mean ttyS0? The capital S is significant.

The serial ports default to 9600 baud, which is probably what the
garbage coming out is.

> The getty line for the console specifies "T0:23:respawn:/sbin/getty -L ttys0
> 57600 vt100"

This should probably also be ttyS0

-- 
Dave Hylands
Shuswap, BC, Canada
http://www.davehylands.com

  reply	other threads:[~2011-11-22 18:43 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2011-11-22 18:20 Serial console temporarily garbled Neil Baylis
2011-11-22 18:43 ` Dave Hylands [this message]
2011-11-22 18:52   ` Neil Baylis

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