Strange BIOS-self-reset and IRQ-conflicts

Hi All,

i have here an small linux with a kernel 2.4.18 (not modular) running at a

3,5"-SBC with VIA Eden Processor. For my application i dont need the parallel port, but many serial ports, so the kernel was built without parport-stuff and no parport devices are in the system. For the serial ports i'm using a 8-port-PC104-Card, which needs at least one IRQ. Because i dont need the parport, i set it off in the BIOS and give the free IRQ 7 to the serial-card and all is running smoothly.

My customer have sold some POS-systems based on the above mentioned system, now he comes with following problem: One of these systems seems to reset its BIOS to its defaults, and this includes: parallel port is active and has IRQ 7. And the system has heavy communication over the serial ports (remember: IRQ 7), so we have a massive performance breakdown.

My questions now are:

  1. Is such a self reset possible? And what could be the reason for such behaviour? Normally there is no keyboard available at the machine to get into the BIOS and load the default settings, so i can exclude some "handmade error" by the service personal.
  2. How can i get the information whether the parallel port is active and using IRQ 7 from inside the running linux? lsmod, cat /proc/interrupts and ksyms doesnt work.

Thanks in Advance, Jens

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Reply to
Jens Nixdorf
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Hi,

"Jens Nixdorf" schrieb:

system,

I assume a hardware fault - the system simply loses it's bios settings ...

See above ...

If you want to check the bios settings, you might want to try the /dev/nvram device

best regards, Reiner

Reply to
Reiner Rosin

I hope so. Until now this is the first and only system which is doing so.

A-ha! I would never come to /dev/nvram of my own! Thank you! Will try this tomorrow at the office.

regards, Jens

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Reply to
Jens Nixdorf

Get the BIOS image off the board. Use the OEM BIOS customization utilities (freely available on the Internet, though theoretically for OEMs only) to customize the BIOS so that the factory default is parallel port off. Flash your customized image onto all boards you ship.

It's in general a risky idea to ship a PC-based embedded system that cannot survive CMOS clearing. Power glitches (rapid power-cycling, for instance), acts of Dog, etc, can all corrupt CMOS and if even one bit goes bad, the BIOS will reset everything to defaults.

Reply to
Lewin A.R.W. Edwards

Lewin A.R.W. Edwards schrieb:

That's a good idea. Thank you.

regards, Jens

Reply to
Jens Nixdorf

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