GTA04 PMU / Core arch block diagram v1

Harald Welte laforge at
Thu Apr 3 15:37:27 CEST 2008

On Tue, Apr 01, 2008 at 06:43:14PM -0300, Werner Almesberger wrote:
> Andy Green wrote:
> > Corner cases like hangup action, reacting to mute, going to handsfree
> > and plugging the headphones in should be instant with no deadtime if the
> > CPU is there or not.
> Hmm, I'm just a bit afraid that we may end up building yet another
> u-boot if the MPU gets to do too much. Small tight real-time things
> (such as speaking HDQ), high-frequency events (integration of
> accelerometer results), and low-level power management (PMU bringup),
> yes, by all means, but things like hangup management sound rather
> like the sort of policy best done in user space to me ...

I agree with werner.  You also should keep in mind that if too much
functionality is implemented in the MPU, then more people will feel that
they have to re-program it, resulting in the possibility to brick it,
re-generating the need for some kind of MPU un-bricking feature, just
like we have for the CPU.

- Harald Welte <laforge at>         
Software for the world's first truly open Free Software mobile phone

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