Problems with serial console on a i386 machine

From: Heiko Gerstung (heiko.gerstung_removeme__at_meinberg.de)
Date: 10/20/04

  • Next message: Jules: "Re: where to buy cheap, low power, small, diskless systems for thin clients and network appliances?" 
    Date: Wed, 20 Oct 2004 10:36:05 +0200

    Hi y'all!

    We use a SBC with a Geode CPU (i386 compatible) and now wanted to switch
    off VGA console support (and the onboard graphics as well). As a console
    can be handy sometimes, we planned to use a serial console and built a
    kernel (2.4.20 with PPSKit patches) supporting this.

    Now, when we boot the system everything works fine, console messages can
    be read over the serial port, but when the kernel finished its first
    initialization and init bangs in, the serial output begins to crawl.

    After every 16 characters the output sleeps for approx. 10 seconds, this
    leads to a boot up time of 15 minutes (compared to less than 1 minute
    with a VGA console enabled).

    Afterwards the system runs with normal speed, but everytime I try to
    output something on the serial port I use as a console, the output is as
    slow as described above.

    We wonder if this is a problem with the signal pins or something like
    that. We tried ZOC as a terminal program as well as one or two others
    without a change.

    If we do not use the serial port as a console, it works flawlessy.

    It would be great if anyone could point us into the right direction.

    Thanks in advance,
    kind regards,

    Heiko 

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