ACPI support

Eric W. Biederman ebiederman at
Thu Mar 11 10:15:01 CET 2004

Stefan Reinauer <stepan at> writes:

> * ron minnich <rminnich at> [040311 15:16]:
> > On 11 Mar 2004, Eric W. Biederman wrote:
> > 
> > > If the BIOS has to implement services an interpreted byte code where the
> > > kernel provides the interpreter at least gives the kernel guys the
> > > option of catching bugs, and working around them.  I completely prefer
> > > AML over BIOS callbacks.
> > 
> > YES!
> In case of broken 16bit bioses there might be a point. But for us I
> don't really see the difference. If it's broken, we can fix it. Even
> when using callbacks, can't we?

We should.  An installed BIOS has an amazing amount of initeria if it is
some little thing.

With AML you can load a new version from the OS without having to flash
you BIOS so it is safer.

Plus there are issues of needed multiple entry points 32bit 64bit and
possibly 16bit depending on which mode the processor is operating in.  With
byte code you only need to provide one version.

Basically byte code seems much more optional than a magic function you
can call.  But in the practical it should be possible to fix the
firmware, and reflash if we did provide callbacks.  I just like to err
as far as possible on the side of caution.

My preference is to provide no code that is run after the OS loads,
and just to specify some static table entries.  The rest is
essentially a fallback position.


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