Re: Handling power failure - MPC5200

In message [ref] you wrote:

Capacitors on the supply provide me with some milliseconds to repond to 
power failure, which I would
like to use to do as much cleanup as possible before power is totally 
gone.  In particular, I am concerned

How many is "some"? If it's not >100 or so it is probably  not  worht
the effort...

with trying to prevent damage to filesystems.  The board has Compact Flash
and onboard flash which
are used as filesystems.  The board will be used as an industrial 
controller.

Can anyone point me to examples of how this can be handled ?

Use the standard methods: use the CF card read-only  (many  CF  cards
can  be  damaged  [beyond  repair]  when  you power off while a write
operation is in progress). Use a filesystem  on  the  ob-board  flash
which knows how to handle a loss of power (i. e., use JFFS2).

Can anyone share experience of a similar setup, which filesystems to 
select etc ?

We usually use ext2 read-only on the CF, JFFS2 for the writable parts
on the on-board flash, cramfs for all  parts  that  need  not  to  be
written  on  a  regular  base (most of your root filesystem including
application  code,  libraries  etc.),  and  a  FiST   based   overlay
filesystem in case of software patches need to be added.

Best regards,

Wolfgang Denk

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