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Firmware corruption
Posted: Tue Aug 26, 2008 4:21 am
by shameem
I was reading over at msefi -
http://www.msefi.com/viewtopic.php?f=38&t=32809
So how do stock systems avoid firmware corruption due to crazy power cycling? Do they have soft on/off method or does it have something to do with the constant 12v?
Re: Firmware corruption
Posted: Tue Aug 26, 2008 7:32 am
by Fred
That's strange, unless he had "AMC" on or something like that it shouldn't be possible to corrupt the flash memory. I guess a suitably bad power supply + alternator keeps producing power and battery is isolated could have forced damage by spiking somehow, but the chip is still behind the reg etc.
Anyway, check this out for a start : an3289
Re: Firmware corruption
Posted: Tue Aug 26, 2008 11:44 am
by shameem
It is strange and doesnt seem like a power issue - rather feels like "windows not shut down properly" kinda issue.......
Could there be similar consequences if the processor is powered down somehow "during" boot up -
Is it possible to make the processor do a check sum verification on boot and indicate if firmware is corrupted (like flashing led or fuel pump cycling or something)
The ideal would be to have another copy of firmware stashed away at some other memory location and load that copy in case checksum verification fails......
Re: Firmware corruption
Posted: Tue Aug 26, 2008 12:20 pm
by Fred
shameem wrote:Could there be similar consequences if the processor is powered down somehow "during" boot up -
Not unless it is currently writing to flash, which shouldn't happen when it's not being tuned.
Is it possible to make the processor do a check sum verification on boot and indicate if firmware is corrupted (like flashing led or fuel pump cycling or something)
Yes. I have a function header, but have not done anything with it yet. Likely it would only cover code and not tune though. Tune could be done with the external software though.
Fred.