Re: Device detection?
On Sun, 14 Mar 1999, Jonathan P Tomer wrote:
> > checkpointing doesn't have to thrash the harddisk. consider this -- if you
> > have a program that flushes output to disk for each line it writes to a file,
> > does it thrash the harddisk?
> >
> > checkpointing is needed for lots of apps... it doesn't necessary cause any
> > thrashing.
>
> windows checkpointing thrashes because they explicitly turn off caching
> and writes after each device tested for. that's a lot of devices, and
> it's very quick to test for each -- quicker than it is to write the
> checkpoint info. but they decided it's worth it in order to have
> bulletproof autodetection. it's not, imho.
Maybe it is because hardware hackers are scarce around here,
or maybe it is just too hairy or even impossible to implement...
Is there any non-volatile memory that can be used during an
installation, even if that means saving and then restoring the contents
automatically when the system is stable[1] (or via the rescue disk or
native system if the installation is aborted)?
You wouldn't need much, enough for an index (label?) to the test being
performed when the system crashed, and some junk (id, checksum, ...)
to make sure you are not reading garbage after a reset.
If I was up to speed on hardware I would probably know the answer to
this... are there any differences between cycling the power and hitting
the reset button that could be used? I'm thinking both of hardware
issues (cache, memory, or registers that remain stable during a reset),
and as a flag (for new and resumed runs of the installation).
- Bruce
[1] I'm crude enough to advocate shutting down the hw clock and using
its registers if it is possible and all there is to work with.
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