Port-hpcarm archive

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index][Old Index]

Re: HP Jornada 728 for everyday life?



From:  <otto.waltari%kolumbus.fi@localhost>

> "Valeriy E. Ushakov" [uwe%stderr.spb.ru@localhost] wrote: 
> > On Thu, Dec 11, 2008 at 18:05:35 +0100, Emanuele Santoro wrote:
> > As far as I can tell it's not possible to support proper suspend in
> > principle for the 7xx series.  The problem is that ARM CPU wakes up by
> > doing a kind of reset, jumping to memory address 0, where WinCE ROM is
> > located (and it is really read-only), so there's no way you can handle
> > wake up.
> 
> Which turns out to be a quite annoying issue. Originally the device was 
designed
> to suspend by taking the power off everything except the RAM, in order to 
keep
> it's state. When the device is then turned back on, all the ram is there 
and the state
> returns to where it was when we powered off. But while running a 
different os, the
> WinCE loader at 0 has no clue about anything else than it's own business. 
Due to
> the nature of ROM, the WinCE loader cannot be overwritten. 
> 

If someone is really motivated there is another option - implement 
hibernate:
 - save the state to flash and power off
 - have wince run the NetBSD bootloader on start
 - have the NetBSD bootloader check for and load the saved state

You need to have real pmf support for the hardware so device state can be 
saved and restored fully (or in some cases just reset), but you get 
~indefinite battery life...


Home | Main Index | Thread Index | Old Index