One second Openmoko boot?

Wolfgang Spraul wolfgang at qi-hardware.com
Fri Aug 21 06:21:52 CEST 2009


Mickey,

> Not really. Reloading (in the worst case) 128MB from an SD is not exactly fast 
> either.
> 
> The only sane way to substantially improve booting time is to stop booting 
> like a desktop PC, that is move away from starting all services just because 
> you can. Start them on demand and bring only the bare necessities up on boot 
> (filesystems, dbus, X).

Not sure.
What I have seen working usually required much more aggressize optimization,
all the way into hardware.
Two examples:

1. Blackberry (old model, at least 2 years old)
Cold boot only happens when I take out the battery. Otherwise the 'power off'
button will just do some form of suspend (probably suspend to flash).
It takes about 8 seconds to 'turn on' (probably from flash), and the most amazing
thing, it only takes another 3-4 seconds until the first new email arrives in
the Inbox. They probably optimized for this case ALL THE WAY THROUGH the
apps, OS design, HW design, maybe even GSM chipset.
Interestingly, after the first mail it takes maybe 5 seconds or so for the
following mails to arrive, so they optimized the case of 'just get the
first new mail into the Inbox asap' and postpone some other vital
system initialization until after the first mail got delivered.

2. old Palms, late 90's
They kept the whole memory in a low-power self-refresh mode. If you took
out the batteries, you had about 1 minute or so to put new batteries in
(during that time an internal backup battery would keep the RAM alive).
If you didn't do that, all your data on the device was lost (but would
be restored during the next HotSync from your desktop).
Other than that, if you turned the device off you actually didn't turn
it off at all. You only sent the whole system into this super low power
mode where it still would keep the memory alive. It could stay like
this on the battery for about 2-3 weeks.

Wolfgang

On Thu, Aug 20, 2009 at 05:17:25PM +0200, Michael 'Mickey' Lauer wrote:
> On Thursday 20 August 2009 10:02:45 Michal Brzozowski wrote:
> > Any chance suspend to disk, or 'hibernate' would work on openmoko?
> 
> Not really. Reloading (in the worst case) 128MB from an SD is not exactly fast 
> either.
> 
> The only sane way to substantially improve booting time is to stop booting 
> like a desktop PC, that is move away from starting all services just because 
> you can. Start them on demand and bring only the bare necessities up on boot 
> (filesystems, dbus, X).
> 
> I plan to do some proof of concepts when my time allows...
> 
> :M:
> 
> 



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