Q24PL001 (657f00gg) Exceptions


#1

Given the poor exception documentation, this post is probably a long shot but perhaps someone has seen these exceptions or something similar.

Recently, we received a number of backtraces from a customer in the field and the majority of the decoded responses make little sense (see below).

Trace L3RR 1 rrc_ChooseCellsFromWorkBa : can’t choose cells from a NOT computed WorkBa
ADS Bckt -> Unresolved symbol : 0x00059371
ADS Bckt -> Unresolved symbol : 0x000CBF17
ADS Bckt -> Unresolved symbol : 0x000F1999
ADS Bckt -> Unresolved symbol : 0x0011DAC9
ADS Bckt -> Unresolved symbol : 0x00182627
ADS Bckt -> Unresolved symbol : 0x00181D4D
ADS Bckt -> Unresolved symbol : 0x0015E693
ADS Bckt -> Unresolved symbol : 0x0015E903
ADS Bckt -> Unresolved symbol : 0x0017D7C5
ADS Bckt -> Unresolved symbol : 0x0001F33D
ADS Bckt -> Unresolved symbol : 0x0001F2B7
ADS Bckt -> Unresolved symbol : 0x0005806B
ADS Bckt -------> ADS BACK TRACE <-------
ADS Bckt The function corresponding to this address : 0x55555555, is not in the .axf file

Trace SPV 3 Near ==> Far impossible c6
ADS Bckt -> Unresolved symbol : 0x00059CF7
ADS Bckt -> Unresolved symbol : 0x000A2D03
ADS Bckt -> Unresolved symbol : 0x000A1BD5
ADS Bckt -> Unresolved symbol : 0x000D16BF
ADS Bckt -> Unresolved symbol : 0x000558DD
ADS Bckt -> Unresolved symbol : 0x0001F33D
ADS Bckt -> Unresolved symbol : 0x0001F20F
ADS Bckt -> Unresolved symbol : 0x0005806B
ADS Bckt -------> ADS BACK TRACE <-------
ADS Bckt The function corresponding to this address : 0x55555555, is not in the .axf file

Trace HWL 1 Arm exception 1 121e34a 900
ADS Bckt -> Unresolved symbol : 0x000A9745
ADS Bckt -> Unresolved symbol : 0x000547C9
ADS Bckt -> Unresolved symbol : 0x00053234
ADS Bckt -> Unresolved symbol : 0x00058487
ADS Bckt -> Unresolved symbol : 0x0001F33D
ADS Bckt -> Unresolved symbol : 0x0001F21B
ADS Bckt -> Unresolved symbol : 0x00058113
ADS Bckt -------> ADS BACK TRACE <-------
ADS Bckt The function corresponding to this address : 0x1aba24, is not in the .axf file

In the case of the two exceptions referring to address 0x55555555, I have carefully reviewed my m file and there is no functions/symbols remotely near this address. As for the third exception, I have checked the addresses 121e34a and 0x1aba24 and neither address is listed or close to anything in my m file.

Any suggestions or observations would be greatly appreciated. Unfortunately, I have not had much luck with my Sierra Wireless rep (partial answers or no response). Thank you.

-gpcoakley


#2

Well, my Sierra Wireless Rep finally responded to my inquires after a week of waiting. In this case, the response was to connect the Target Monitoring Tool to the module and recreate the exception with certain traces enabled. Since these modules are located in different states and in the hands of customers, this is an unrealistic approach to resolving these exceptions. When I first read about the backtrace functionality, I assumed this feature could be used to resolve/debug exceptions discovered by customers in the field which may not be easy to replicate (if possible) in the lab or at my desk.

Unfortunately, this is no the first time I have received this kind of response from Sierra Wireless (or Wavecom) regarding diagnosing issues with modules (Q24PL001, Q26, and WMP100) and leads me to the conclusion that the backtrace functionality is completely useless in it’s current form. I know this post is unlikely to trigger a response from Sierra Wireless, but I hope it serves as warning to fellow customers regarding the backtrace functionality.


#3

It is, indeed, very sad that there is no way to monitor the traces remotely. :angry:

I don’t think it’s completely useless - but could be more useful.

Unquestionably, the poor documentaion severely limits what usefulness it has.
(and it’s even worse now that M2MStudio has removed what little documentation there was!)

See also: https://forum.sierrawireless.com/t/exception-documentation-is-still-poor/1900/7
forum.sierrawireless.com/viewtop … =47&t=1135

This is what I managed to work out regarding analysing backtrace files (note that it’s pre-M2MStudio):
antronics.co.uk/downloads/OA … _Files.pdf

Note that the backtrace is effectively a stack dump - it shows you where stuff happened, but not what happened.