| Author |
Message |
ssubbarayan
Guest
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 Posted:
Fri Dec 16, 2005 9:15 am Post subject:
Help me Plz!Debugging RAM version of build,produces rt outpu |
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Gurus,
I have worked in Lots of RTOS projects for consumer electronics
applications.I have encountered the following problem in couple of
instances and till now not able to track the reason behind it,because
each time my solution varies.Given below is my brief of the problem:
We have a consumer electronics appliance in which when the Target boots
up and puts a logo screen,when the user presses a key in the remote,the
target crashes.This happens in the ROM version of build.
When we debug it in RAM version,it never happens.I am clueless what
could be possible reason for this.
My little knowledge of RTOS says that this should be due to some timing
implications which when we step through debugger in RAM version makes
it work and since ROM version is non debuggable,we dont get required
delay for it to work.Is this understanding correct?
I am wondering how experts around here have solved these sorts of
problems where a RAM version when debugged works and ROM version of
same software fails!
In another case I encountered similar problem and traced the route
cause for an first enum parameter which was initialised to 1 instead of
zero and when we set the initial param to zero,it worked.I was clue
less how this made the Debugged RAM version work and fail in ROM
version.
It would be helpful if anyone can share their experience on how they
tackle such problems and whats the best way to debug such problems.
Advanced thanks to all your replys and looking farward for your pearls
of wisdom,
Regards,
s.subbarayan |
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Paul Carpenter
Guest
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| Posted:
Fri Dec 16, 2005 10:54 am Post subject:
Re: Help me Plz!Debugging RAM version of build,produces rt o |
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On 15 Dec, in article
<1134708837.542201.170420@o13g2000cwo.googlegroups.com>
ssubba@gmail.com "ssubbarayan" wrote:
| Quote: | Gurus,
I have worked in Lots of RTOS projects for consumer electronics
applications.I have encountered the following problem in couple of
instances and till now not able to track the reason behind it,because
each time my solution varies.Given below is my brief of the problem:
We have a consumer electronics appliance in which when the Target boots
up and puts a logo screen,when the user presses a key in the remote,the
target crashes.This happens in the ROM version of build.
When we debug it in RAM version,it never happens.I am clueless what
could be possible reason for this.
My little knowledge of RTOS says that this should be due to some timing
implications which when we step through debugger in RAM version makes
it work and since ROM version is non debuggable,we dont get required
delay for it to work.Is this understanding correct?
|
Probably, or even some variable that should be in RAM actually being in
ROM or not waiting for hardware correctly, not intialising ports correctly
(including serial ones), that happens to work in RAM versions.
RAM based debugger does things that are not done without debugger.
| Quote: | I am wondering how experts around here have solved these sorts of
problems where a RAM version when debugged works and ROM version of
same software fails!
|
Use a scope/logic analyser to see what happens when, or toggle LED, or
even send messages to a serial port.
| Quote: | In another case I encountered similar problem and traced the route
cause for an first enum parameter which was initialised to 1 instead of
zero and when we set the initial param to zero,it worked.I was clue
less how this made the Debugged RAM version work and fail in ROM
version.
|
Sounds more like you have RAM based variables that your code assumes are
zeroed, but your startup code does not initialise them to zero. This could
easily be the difference between your RAM based debugger and ROM version.
| Quote: | It would be helpful if anyone can share their experience on how they
tackle such problems and whats the best way to debug such problems.
Advanced thanks to all your replys and looking farward for your pearls
of wisdom,
|
Your scenarios suggest that you have spent time in hosted Application
Programming and transferred to embedded programming, without understanding
the differences.
Without knowing if these are all on the same RTOS, or host processor
anything other than the above general hand waving.
| Quote: | Regards,
s.subbarayan
|
--
Paul Carpenter | paul@pcserviceselectronics.co.uk
<http://www.pcserviceselectronics.co.uk/> PC Services
<http://www.gnuh8.org.uk/> GNU H8 & mailing list info
<http://www.badweb.org.uk/> For those web sites you hate |
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Hans-Bernhard Broeker
Guest
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| Posted:
Fri Dec 16, 2005 3:24 pm Post subject:
Re: Help me Plz!Debugging RAM version of build,produces rt o |
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[F'up2 cut down --- neglected by OP]
In comp.arch.embedded ssubbarayan <ssubba@gmail.com> wrote:
| Quote: | We have a consumer electronics appliance in which when the Target boots
up and puts a logo screen,when the user presses a key in the remote,the
target crashes.This happens in the ROM version of build.
When we debug it in RAM version,it never happens.I am clueless what
could be possible reason for this.
|
Given the minimal amount of information you give, it's pretty much
guaranteed that nobody else can have more of a clue than you do.
[...]
| Quote: | since ROM version is non debuggable,
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And why would that be? There's no particularly strict reason ROM
builds of a program should be non-debuggable. They may well be
*harder* to debug than RAM builds, because some of the usual
techniques (e.g. run-time code modifications) aren't immediately
applicable to ROM programs. But it's not generally impossible.
Or, to put it more provocatively: if your project and CPU is fat
enough that investing in an RTOS makes sense, how come you don't have
JTAG debugging?
And how is that ROM build actually different from the RAM build? The
one special case you mentioned hints that you didn't understand your
tools well enough to turn on all needed options for them to support a
feature of the standardized language like static initializers.
--
Hans-Bernhard Broeker (broeker@physik.rwth-aachen.de)
Even if all the snow were burnt, ashes would remain. |
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