Serial console temporarily garbled

[Dave Hylands]

Hi Neil,

On Tue, Nov 22, 2011 at 10:20 AM, Neil Baylis <neil.baylis at 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