Lpc2000

Hi Mike,

While looking at the boot loader implementation, I noticed a segment of 
code in the Command String Interpreter (CSI) did not look right.  I 
confirmed it was a bug by crafting an input line and observing boot loader 
crash in response.

This sequence of input is not what one would normally enter when one uses 
the ISP to do things in accordance with the user manual.  It perhaps can 
occur when the interacting program (for example during field updates) 
misbehaves.

Such a bug in the CSI poses unacceptable risks when CRP is contemplated.

Where CRP is not needed, you have to consider what happens after the boot 
loader crashes.  These would include:

* Is it always possible to recover?
* Does external reset work?
* Do you need power cycling?
* What happens no recovery is attempted for a length of time?
* Are there any temporal changes?  Can this result in your application 
failing because it relied on the integrity of "reset" state?
* Are there any persistent changes, for example to the contents of on-chip 
flash?

There is no general answer to the above questions because when something 
like this happen, we say what happens is "indeterminate".  We cannot 
determine what happens because too many other factors that we cannot 
control or account for come in to play, including what application code it 
is running and what is the current state of on-chip RAM.

Normally, I do not advocate undertaking such an investigation because it is 
likely to be expensive yet inconclusive.  Fixing the boot loader is the the 
preferred option.  As I do not have access to the source I wrote my own.

Hope this helps.

Jaya

>Message: 7
>    Date: Thu, 23 Feb 2006 10:02:05 -0500
>    From: mfrazier@...
>Subject: Re: Re: Tom's questions for Jaya
>
>You say at will...what exactly are you doing that causes this failure?? We
>also have a project in mid stages of development that use the LPC2292 and
>speaking with other engineers on the project they claim they have not yet
>had any issues.
>
>Thanks,
>Mike

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