When presented with problems like this I start by replacing all the
default handlers with handlers that log a hit. Since you have NVR that
you can read and write this should be easy... I use my User Page Flash
for the same purpose. This will help you divide-and-conquer.
__
Steve
.
On 8/20/2018 1:13 PM, Keith Rubow wrote:
I am using lwip 2.0.3 with NO_SYS = 1 on a bare metal 386ex processor
with a Wiznet IIM7010A ethernet interface operating in MAC RAW mode.
Yes, this hardware is REALLY old, but we have lots of hardware out in
the field and need to fix a problem, and lwip seems like the best way
to fix it.
My hardware has a hardware watchdog timer that will reset the
processor if not refreshed at least every 5 seconds. Since
implementing lwip I am experiencing extremely infrequent system
crashes. My debugging indicates that I call sys_check_timeouts, and
then the watchdog timer times out, resetting the system. Normally the
watchdog timer is getting refreshed many times per second around the
main program loop. It appears that sys_check_timeouts is taking at
least 5 seconds to execute.
This crash (or watchdog timer reset) is happening very infrequently.
The system will run flawlessly for 2-3 days before crashing.
Unfortunately I do not have source level debugging capability on this
old hardware. It is possible a memory exception could be vectoring me
to a default exception handler that simply hangs in a loop until the
watchdog timer resets the system (but proper code should never cause a
memory exception). Or the sys_check_timeouts could simply be taking
too long to execute. Can it ever take >5 seconds to execute
sys_check_timeouts?
My IIM7010A ethernet interface is being operated in polled mode. My
main loop operates as follows:
for (;;) {
if (received ethernet frame available in wiznet) {
ethernetif_input(); // this will read and process the
ethernet frame for this interface
}
sys_check_timeouts();
if (I have data to send) {
size = size of my data to send; // size is never more than 128 bytes
if (tcp_sndbuf(userinfo.pcb) >= size) { // if enough free space
to send it
if (tcp_write(userinfo.pcb, mybuffer, size, TCP_WRITE_FLAG_COPY)
== ERR_OK) { // if send is successful
tcp_output(userinfo.pcb); // initiate sending of data
}
}
}
do other stuff not related to lwip or tcp/ip // none of it is
very time consuming, should take only a few 10's of milliseconds
reset_watchdog_timer();
}
I use ipv4 with fixed ip address. I have a single TCP/IP connection
up, use callback function for received data, and everything is working
perfectly except for the occasional crashes. My debugging ability is
limited to setting debug variables to values in a region of memory
that is preserved across reboots. My debug variables always show that
the last thing I did was call sys_check_timeouts before the restart,
and I never returned from sys_check_timeouts. Any ideas?
Keith
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