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Re: Porting to 80386ex...
- To: Jonathan Larmour <jlarmour at redhat dot com>
- Subject: Re: [ECOS] Porting to 80386ex...
- From: "Lewin A.R.W. Edwards" <larwe at larwe dot com>
- Date: Mon, 26 Feb 2001 14:21:03 -0500
- Cc: "ecos-discuss at sources dot redhat dot com" <ecos-discuss at sources dot redhat dot com>
- References: <200102250307.TAA14041@cygnus.com>
> > Then if 386ex runs in System Mangement Mode, is it a architecture HAL
> porting , or just a platform HAL porting ,since there are additional registers.
>
>By this do you mean ring 0 versus ring1/2 ?
SMM is a special mode. Essentially it freezes the states of all virtual
machines and flips some "extra" memory into the address space that is not
normally accessible.
Typical use would be when you hit the suspend-to-disk button on a portable
PC. The CPU is whacked into SMM, and it jumps into code that saves hardware
register contents and display RAM, then displays a "saving to disk" message
and writes out all the contents of everything to the hard disk.
=== Lewin A.R.W. Edwards (Embedded Engineer)
Work: http://www.digi-frame.com/
Personal: http://www.zws.com/ and http://www.larwe.com/
"Und setzet ihr nicht das Leben ein,
Nie wird euch das Leben gewonnen sein."