[maemo-developers] [maemo-developers] Dream Scenario (Re: Maemo roadmap, SDK improvements...)

From: Dave Neuer dave.neuer at pobox.com
Date: Wed Feb 7 15:40:25 EET 2007
On 2/7/07, Koen Kooi <koen at dominion.kabel.utwente.nl> wrote:
> Did I miss the opensourcing of DSME?

Igor has given me permission to repost the message he sent me when the
list, it addresses this topic, so here it is:

On Thu, 2007-01-18 at 11:40 -0500, ext Dave Neuer wrote:
> On 1/18/07, Igor Stoppa <igor.stoppa at nokia.com> wrote:
> >
> > All the power management stuff is done in kernel, which is pubblicly
> > available, and it has been like that since we launched it.
> >
> > Just go and check the code.
> I'm aware of the clocks stuff in the OMAP kernel.
> >
> > Unless you are bitching about an application which checks if the cover
> > is on and turns off the backlight.
> That's all DSME is?
That's all you need from DSME for power management.

I cannot say more about it for legal reasons that hopefully will be
removed in a near future, but if you are willing to take a friendly
advice, all you need is right under your nose.

> >
> > And this has been stated several times (for example by myself last
> > week), so if the next time you could first inform yourself, before
> > making such statements, you will have my everlasting gratitude.
> I missed that, and I'll look for it, thank you (any pointers, thread
> subject, etc?)

Check maemo-users, the discussion about Battery benchmarking:
--- begin quote ---
> Do I need to catch DBus events to get
> informed that I have to go in some application specific low power mode?

Yes, screen blanked should be enough.
Also because N800 doesn't have a cover, but certainly that doesn't
prevent us to do the very same power saving that was already available
on 770. :-D

The cover would just be the cause for an _immediate_ rather than timed
screen blanking.
--- end quote ---

That's user space power management for you.

> >
> > >
> > > > Specifics please? What code/documentation are you missing and what would you
> > > > create with them? And how are going to do the same things with iPhone?
> > >
> > > Code for the DSME so we can build custom firmware images where the
> > > power mangement works.
> > I would really like you to prove your affirmations.
> Can I, _today_, build a full FIASCO image from source which an
> end-user could install on their tablet and have it just as functional
> as a Nokia-provided FIASCO image?
> If _your_ answer is "no," consider my assertions proved.
as I said already power management is not really turning the backlight
on and off, and all the power management code is in the kernel.
So could you compile a kernel that does sleep_while_idle power saving?
Sure, just go and get the kernel code. That's all you need for power
management. The advanced part of it. The "secret" part that seems to be
missing although it's just there to be downloaded.

> >
> > Just write a script that pings the retu wd every 30s, kill dsme and
> > watch power management still run (yes, the backlighting won't go off,
> > but it's not such a big deal to replace).
> >
> > To give you a hint, check the sysfs entry /sys/power/sleep_while_idle
> > that's your undisclosed, proprietary, hidden power management.
> Look, when I downloaded FIASCO images from Nokia, I had to accept
> terms which included that I could not reverse engineer it. I live in
> the US, so those terms are enforceable, AFAIK. Now, if you're telling
> me that Nokia is hereby waiving those terms, and I can do whatever I
> want to to play around w/ Nokia images to figure out exactly what they
> do and release open-source versions of them, please be explicit about
> it.

AFAIK you can do whatever you want with the kernel code. Like reading
it. You don't really have to hook into sysfs entries to monitor a
running device for understandinig what the code does.

Again, afaik the backlighting driver is open, otherwise we are probably
infringing the license. But I don't think so.

Are you forbidden to read open kernel code and think about it in the US?
Very hard to believe ...

> Your tone, and the content of your message sounds to me like a dare to
> fork maemo.

I couldn't be less worried about that.
It's open, you can do whatever you want with it, as long as it's legal.

I simply don't like unproved assertions that, had they been formulated
as questions, would have received a friendly answer.

Now don't think that the unfriendly answer is less accurate, please.

I don't know who has had this wonderful idea that the power management
is provided by the cover, but I have made it a personal point to kill
the wrong rumor, since apparently it's one of the favourite subjects
used against OSSO deliverables, that they are hiding precious bits of

I simply cannot stand affirmations based on rumors, be them false or
truthfull. That's not engineering, it's marketing.

Cheers, Igor

Igor Stoppa <igor.stoppa at nokia.com>

More information about the maemo-developers mailing list