[ECOS] Erroneous Network Traffic Affects Ethernet Debugging on PowerPC

["Mike Arthur" <arth2219 at gmail dot com>]

We have an in house HAL for a PowerPC target that can be fatally
affected by erroneous network traffic while debugging over the
ethernet.

If there is network traffic going to the RedBoot IP (i.e. ping
flooding the RedBoot IP) or there are network broadcasts during tests
such as heaptest, the target will become unresponsive to the point
that GDB will lose its connection to the target.  We are not sure what
is causing GDB to timeout from the target.

It appears the target gets stuck in the RedBoot ethernet code
processing packets; we have determined this by the use of a JTAG.
This of course does not happen if the host and target are on an
isolated network without any other traffic besides GDB packets going
to RedBoot.  Debugging works great over ethernet on an isolated
network.

Does anybody have any ideas of where the bug could reside?  Could the
bug be in the ethernet drivers, in the stand alone stack, somewhere in
the variant or platform HALs?

Has anyone ever ran into problems with network traffic during network
debug sessions?  What caused the problem?

Any tips on how to debug problems with ethernet debugging?

The target becomes unresponsive at different points depending on the template.


Here is how far the target gets with the 'default' template running heaptest:
---------------------------------------------------------------------------------------------------------
(gdb) load
Loading section .text, size 0x15950 lma 0x100000
Loading section .rodata, size 0x103c lma 0x115950
Loading section .eh_frame, size 0x84 lma 0x116990
Loading section .data, size 0x3a40 lma 0x116a18
Start address 0x100000, load size 107600
Transfer rate: 286933 bits/sec, 505 bytes/write.
(gdb) c
Continuing.
INFO: <code from 0x00100000 -> 0x00115950, CRC a75f>
INFO:<Starting heaptest - testing all memory usable as heap>
INFO:<Any failures reported may indicate failing RAM hardware,>
INFO:<or an invalid memory map>
INFO:<Testing memory at 0x00125c18 of size 1072538588 for 10 iterations>
PASS:<all zeroes>



Here is how far the target gets with the 'net' template running heaptest:
----------------------------------------------------------------------------------------------------
(gdb) load
Loading section .text, size 0x63958 lma 0x100000
Loading section .rodata, size 0x310c lma 0x163958
Loading section .eh_frame, size 0x84 lma 0x166a68
Loading section .data, size 0x4988 lma 0x166af0
Start address 0x100000, load size 439408
Transfer rate: 292938 bits/sec, 510 bytes/write.
(gdb) c
Continuing.
[cyg_net_init] Init: mbinit(0x00000000)
Remote communication error: No route to host.


Thanks,
Mike

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