XPe on read-only Compact Flash? (newbie)

[Jay]

I'm trying decide between Windows XP Embedded and Linux.

I want to build a Windows XP Embedded system and deploy it
to compact flash. Then, flip a switch on our board (we
provide the switch) that disables writes to the flash
memory. Power up again, booting and running Windows XP
Embedded entirely from read-only flash. Can we do this?

Is it true that Windows XP Embedded could create a ram
drive for temporary storage ? Then we could send files
that need permanent storage over a network connection to
somewhere else.

I've briefly reviewed the instructions on EWF
configuration options - there doesn't seem to be a totally
read-only option. Am I missing something ?

Thanks !

 

[KM]

Jay,

You were looking into the right direction - EWF is probably what you need.
Just to answer you question with an example - EWF is used to boot XPE image
from CD-ROMs.

As a second option, you may consider booting the image into a ramdisk -
local boot.ini /rdpath switch (search this NG archive for details). However,
EWF would be better and less memory consuming solution.

KM

 

[Heidi Linda eMVP]

EWF can be turned off - but if you delete the EWF manager app they're going
to have a hard time doing it...

 

[Slobodan Brcin]

Jay,

In your specific case there is totally read only solution.
RAM EWF is started before file system is mounted and it will overlay every
write to read only medium.
If someone tried to disable(commit) changes it will happen during the
shutdown phase. Since your CF is read only changes won't be written.

So no one can disable EWF on your device unless he enables write to CF.


BTW:
Is there any standard CF reader that has integrated switch?


Regards,
Slobodan

 

[Jay]

Slobodan,

Thank you very much for answering my question.

Your question about CF adapters pointed out an additional
error we had: Our hardware designers thought we could
pull the WriteEnable# line to the CF part with a switch,
but unfortunately that signal is ignored when the CF is in
IDE mode. So we still have a problem to solve. I
haven't yet been able to find any CF adapters that provide
an integrated switch.

I do believe that I can use the procedure identified in
the MSDN article titled "Using Compact Flash (CF) with the
Enhanced Write Filter (EWF)" to at least provide a
software-level of protection. This stores the EWF
parameters in the registry.

I'm not sure what we will do (if anything) about the
physical protection yet.

Thanks for your help,
Jay