Re: [POWER] battery calibration parameters from sysfs

From: Pavel Machek
Date: Sun Dec 13 2009 - 08:19:41 EST


> One of the things we're facing is Android, which has
> its userspace in plain Java JNI at the end of this link:
> http://android.git.kernel.org/?p=platform/frameworks/base.git;a=blob;f=s
> ervices/jni/com_android_server_BatteryService.cpp;h=8e7cadc6b680fc420d34
> 1faa094c71922946fdab;hb=HEAD
>
> If you browse down to line 275 you can see it parse the sysfs
> attribute "capacity", then this propagates up to the battery
> status indicator on *all* Android phones out there. So if
> you want to run Android unmodified, this is what you need to
> provide. They are effectively using the power sysfs as
> their hardware abstraction layer in this case.
>
> Note: I'm not claiming that Android is doing it right or that
> we can't modify this code or so, it's just that this is the way
> a few million Android devices out there are actually doing it.

Users can't modify them, so they don't count...

...but then there are all the systems that rely on /proc/apm
emulation, like openembedded popular on sharp zaurus...

Pavel
--
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(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html
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