The time is is preserved by battery powered clock chip. The time is read
from the chip when you boot. When you change the time you changes it in 2
places - in the OS and in the RTC chip. Neither involves writing to disc.
Therefore EWF is irrelevant.
The RTC also contains a small ammonut or RAM that is preserved by the
battery. The BIOS settings come from there. Depending on the board that you
are using there might be parts of the RAM that are not used, and that you
could get access to. You could store paramters there if you want - but be
careful.
To read and write the CMOS you need to be able to access I/O ports 0x70 and
0x71 directly. I tried this using DLPortIO, but, although other ports were
accessable, writing 0x70 didn't work, and I thought of a better way of doing
it.
The simplest way of storing permanent changes is to use the set-up suggested
by Heidi Linda. In this there is a small C: drive - which is unprotected,
and a larger D: drive that is protected by EWF. I can now happily write
configiration data onto C: without worrying about ewfmgr and its foibles.
However, I would recommend that you have a mechanism to check the data you
are reading from C: and means of restoring defaults if it is corrupt.
HTH
Simon