Is OLPC going for ACPI support?

[Manish Regmi]

On 3/3/07, Mitch Bradley <wmb at firmworks.com> wrote:

>
> The OLPC OS does not use the ACPI interface, nor does the OLPC firmware
> support it .  The OS drivers perform the appropriate power management
> operations directly, with full knowledge of the behavior of the hardware
> on which they operate.  The firmware exports a low-level suspend-to-RAM
> function in the form of a subroutine.  The OS, after doing whatever
> driver work is necessary, calls that subroutine.  The firmware then
> saves the core state and puts the hardware into a low-power state with
> RAM powered in self-refresh mode.  Upon a wakeup event, the firmware
> restores the core state and returns from the subroutine.
>
> The current size of the firmware suspend/resume code is about 1K.  It is
> written in assembly language, optimized to do its job as quickly as
> possible.  We hope to be able to do "micro sleeps" so fast that the user
> will not realize that the system is sleeping.
>
> OLPC has special hardware features for retaining the image on the screen
> and for performing wireless mesh routing while the main processor is
> powered off.

Thank you very much for such a nice explanation.
In the code i saw a lot of "magic" port numbers. Is there any
documentation describing them (esp. ones not found in traditional PC).


-- 
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Manish Regmi
Volunteer
OLPC Nepal