Re: [Qemu-devel] [PATCH v3 1/2] hw/misc/arm_sp810: Create SP810 device

[Peter Maydell]

On 22 August 2014 09:38, Aggeler  Fabian <address@hidden> wrote:
>
> On 19 Aug 2014, at 16:03, Peter Maydell <address@hidden> wrote:
>> Which input signals in the hardware do these properties
>> correspond to? I can't figure out what the mapping is.
>> As far as I can tell from the documentation the bits
>> in SCCTRL are just always reset to 0 and are not
>> controlled by external signals (which is what qdev
>> properties should typically correspond to).
>
> Actually I don’t know how it is done in hardware. My goal was
> to reflect the default speed of the SP804 timer in QEMU’s vexpress
> emulation in the SCCTRL. What do you suggest in this case?

Well, fundamentally you have to find out what the hardware
does, and do that. We can't model anything else.

> I could remove the QOM properties and set the reset value of the
> TimerEnXSel bits in SCCTRL to 1 (TIMCLK) to match the SCCTRL
> with the speed of the SP804.

The h/w docs suggest the reset value is 0.
I have a feeling you may be attempting to make QEMU's
hardware model include behaviour which is the result of
firmware code setting register values before booting the
kernel...

thanks
-- PMM