Can XPe Shutdown too fast for CF Cards?

[Tony]

Hi all,

I have a simple test system here that is producing some interesting results.
This system has an XPe OS running on a CF card. I created a batch file that
is run on startup that does "shutdown -r -t 0". The system just cycles
reboots and I've been watching what its failure behaviour is.

When the system has its EWF turned on, it seems to reboot continuously
without any problems. However, when I turn the EWF off, the system will
eventually come up and indicate that "cmd.exe is corrupt". Manually trying
to launch cmd.exe confirms Windows thinks it is corrupt. However, if I just
cycle the power on the system, then everything runs again for a while until
the same error comes up.

Given that turning the EWF on remedies the problem makes me think that
somehow the system is restarting before data is safely written to the disk
(whatever that data may be). I still find it curious though, since I
thought using the shutdown command would commence a "graceful" shutdown, and
I wasn't expecting to see any problems.

Why would just cycling the power fix the corrupt file? Are there
buffer/cache settings I should be looking at in Windows? Any BIOS settings
that may be causing problems?

Anyone have any thoughts or insights?

Regards,

Tony

 

[jimt]

Looks like your problem happens when writes are going to the CF. When I was
researching CFs I found out that writes are handled specially within the CF.
Some CF's fail badly if power is removed while wear leveling is going on,
for example.

I would be tempted to experiment a little, and try a CF from one of the OEM
vendors like M-Systems or Silicon Systems. Or repeat the experiment with a
HDD in place of the CF. This way you could rule out the CF.

Good luck,

 

[Guest]

Tony,
I have tried to reproduce your experiment with my own setup. I left five
embedded devices rebooting over the weekend. I used the task scheduler to run
a batch file at system startup. None of the devices failed. I was however
only using a fairly light image (in that there was nothing else set to run
except for the shutdown command). Can you tell me, was there anything else
set to run at startup on your image? Can you also tell me whether your flash
cards were formatted with FAT or NTFS (I am trying both at the moment). I am
also using various sizes of flash card (256Mb, 512Mb and 1Gb).

When you said that you were reliably getting failures, what sort of
timescale were you talking about?

As an aside, I have noticed a great deal of difference in the speed of
supposedly identical flash cards. It could be that only certain flash cards
are prone to this error, and if you happen to get a good flash card then all
will be hunky dory.

John