I'm currently working a project that involves setting up a PC/104 stack and running Ubuntu 8.04 LTS. We need to use the PC/104 stack because its an embedded application - and we're required to use a DeviceNet peripheral card to communicate to other devices. (DeviceNet is just a protocol on top of CAN.)

Anyway, the following hardware is on the stack:

• Kontron MOPSPM104 with a 1GHz Intel Celeron processor
• ConnectTech FlashDrive/104 4GB Industrial Temp (-40 to +85 C)
• Woodhead (Molex) PC104DVNIO DeviceNet card
• A run of the mill 104 power supply

The Kontron Board offers two serial ports, one VGA out, and two USB ports. The DeviceNet card is an ISA card. Because of this (per the User's Guide for the Kontron Board), I have manually set the IRQs in the BIOS to be appropriately configured, and turned off ACPI in both the BIOS and passed the appropriate flag in GRUB. I've installed Ubuntu 8.04 desktop, 32 bit.

The problem that I'm having is that, from time to time, the entire 104 stack locks up. This only seems to happen in two cases, both of which we're running GNOME. We have a custom application that uses the DeviceNet card, and the system will lock up, or (more frequently) when we're running Firefox and either surfing for some information or trying to test it - typically by streaming video from a IP-camera.

The reason I ask this questions is I cannot determine the root cause of this lockup. The IRQs appear to correctly configured in the BIOS and as the Kernel sees them, and nothing is logged to dmesg. If you all could help me determine the root cause of this lockup, I would greatly appreciate it. Thanks.