I mentioned APM because it seemed the simplest.
Realisticaly you'd want to follow the LinuxBIOS approach and do minimal
stuff at the BIOS level and move most of the information to a linux
driver. So really all the BIOS portion has to detect and support
are the conditions where the CPU goes through reset. This should
only be the suspend to ram and the suspend to disk states.
So how about a new simple LinuxBIOS PM interface?
Jordan
At 05:18 PM 11/26/2003 +0100, Stefan Reinauer wrote:
* jarcher@pobox.com
<jarcher@pobox.com> [031126 16:32]:
> I'll raise the question to the next level....
>
> Has there been any discussion of putting any power management
support into
> the LinuxBIOS. I've got a possible need for some basics, like
suspend to
> RAM. Classic APM might be enough and simple to
implement. ACPI would be a
> good choice, but I'm not sure about how much ROM foot print would be
needed.
Since ACPI is, similar to FCode, an interface based on abstracted
binary
code, it would probably be easier to add ACPI support to LinuxBIOS
than
supporting APM which needs code hooks.
The ACPI tables could be a) generated by or b) stored in LinuxBIOS as
is
and will be found and interpreted by the Linux Kernel. But besides
the
technical issues there's also a legal question when including ACPI
tables
(some are patented by MS and not freely usable iirc, others might
be
copyrighted by Awkward & Co.)
There are also kernel patches for Linux that allow attaching some of
the
ACPI tables to an initial ramdisk. This can be used to override
broken
bios ACPI tables with corrected ones without reflashing the
bios.
Stefan
--
Stefan Reinauer, SUSE LINUX AG
Teamleader Architecture Development