[U-Boot-Users] Flash environment vs EEPROM environment

Wolfgang Denk wd at denx.de
Tue Feb 1 23:15:40 CET 2005

In message <41FFD322.4030401 at smiths-aerospace.com> you wrote:
> If you do a lot of flash erase/writing and glitch the power rapidly and 
> repeatedly during the flash activity, you _will_ have corrupted flash at 
> _unpredictable_ (i.e. not necessarily the block you were intending to 
> write/erase) locations.  Guaranteed.  Want to see the scars :-)?

I know that this is true. But we don't discuss if this is possible at
all,  the  question  was  how  this  might  affect  U-Boot  and   the
envrionment storage.

Assuming that we use redundant flash sectors, than the worst thing to
happen is that one copy of the environment gets corrupted. This  will
leave you with the other, good copy.

You could say that with redundant flash sectors a write operation  to
the  environment  storage  in flash has transaction character: either
you will see the state before the write operation was started, or the
state after it has completed. I think we're pretty safe against  data
loss or corruption.

Best regards,

Wolfgang Denk

Software Engineering:  Embedded and Realtime Systems,  Embedded Linux
Phone: (+49)-8142-66989-10 Fax: (+49)-8142-66989-80 Email: wd at denx.de
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