Today I was able to re-acquire a Logic i.MX31 Development kit and rerun the same tests on the development kit. The development kit had Lolo version 2.4.0, slightly earlier version than our production units (Lolo 2.4.12) although I had no problem in consistently reproducing the problem.
1) Connected the development kit ethernet port to a powered non-managed switch (Netgear FS108).
2) Created a fatal loop on the ethernet switch by directly connecting two of the switches ports together with a patch cable.
3) Connected a serial connection to a PC running TeraTerm.
4) Powered on the developement kit and instantly exited the configuration script by pressing "Q".
5) At the Losh prompt entered "ifconfig sm0 dhcp".
6) As the echo "Starting DHCP on sm0.." is received, Lolo appears to freeze at this point and a high activity can be observed on the ethernet switch communication leds.
7) The TeraTerm output below shows two tests that were ran. The first test is without the fatal loop connected. The first test responds as expected with a "error: ifconfig: unable to get ip address; still trying (sm0)" message. For the second test, the fatal loop was connected prior to powering on the development kit. Once the losh command "ifconfig sm0 dhcp" was entered, the development kit remained at the "Starting DHCP on sm0 .." message for at least 5 minutes. My assumption is that the DHCP function sends out a broadcast message which gets trapped in a switch loop and causes a broadcast storm. This broadcast storm causes excessive interrupts that overload the CPU. Our main concern is not with Lolo but that this same condition happens during normal operation in the WinCE 5.0 operating system.
LogicLoader
(c) Copyright 2002-2006, Logic Product Development, Inc.
All Rights Reserved.
Version 2.4.0-IMX31_10 0001
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losh> ifconfig sm0 dhcp
Starting DHCP on sm0 ..........
error: ifconfig: unable to get ip address; still trying (sm0)
losh> }}
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LogicLoader
(c) Copyright 2002-2006, Logic Product Development, Inc.
All Rights Reserved.
Version 2.4.0-IMX31_10 0001
*****************************************************************
losh> ifconfig sm0 dhcp
Starting DHCP on sm0 ..