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Re: why scrub memory?
This seems reasonable enough... however, isnt all memory that is going to be
used written to before it is used? Does Ecos/Redboot assume that the memory
has been written with zeros when it uses memory?
thanks,
Aaron
On Friday 20 June 2003 02:38 pm, Mark Salter wrote:
> >>>>> Aaron Richardson writes:
> >
> > I see on several platforms (including the one that I am working on) that
> > memory scrubbing is occuring. Why is this done and can I remove it? I
> > am tired of waiting the time for this occur. I have 256 MB of memory
> > right now, but plan on having much more in the future.
>
> When the ECC memory is first powered on, it must be written to
> before it is read. This syncs the ECC code bits with the data
> bits. The simplest approach is taken and all of memory is
> scrubbed before any is used. If the application that RedBoot
> boots (or the standalone eCos app) is not going to muck with
> the MMU, then the HAL could be enhanced to defer scrubbing a
> given memory page until that page is first touched. But only
> if that's not a performance problem for the app.
>
> --Mark
--
Aaron Richardson
aarichar@cisco.com
512-378-1286
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