Hi Jakub,

On Mon, Jul 4, 2011 at 1:17 PM, Jakub Jermar <[email protected]> wrote:
> On 4.7.2011 12:30, Artyom Tarasenko wrote:
>> You mean that HelenOS only needs the interrupt controller, and the rest
>> of IOMMU (particularly DVMA) is not necessary?
>
> Exactly, so far, the devices we have supported on sparc64 (and
> everywhere else) were very simple ones using just PIO - mostly serial
> controllers and various buses / interrupt controllers. HelenOS mainline
> can't do any DMA or DVMA yet, just mere PIO.

Ok. Since today qemu has an interrupt controller good enough for booting Linux.
So you might want to consider implementing a SU stdio driver. ;-)

>> Actually Qemu-sparc64 does support hardware interrupts, what it lacks
>> is an interrupt controller (and the rest of IOMMU).
>> Particularly this means there is no general way to disable a certain
>> interrupt without knowing its source, but all other mechanisms -
>> changing pil, or disabling interrupt generation on a device level
>> (timers, serial ports and cmd646 can do it) work fine.
>
> We detect what mondo vector number the device is using by traversing the
> OFW tree, thus we can map the device's parent bus interrupt to the
> system bus interrupt number. We also have auxilliary drivers for OBIO
> (as found on the Ultra 5's Sabre PCI or also on Ultra 60's Psycho PCI)
> to handle the end of interrupt condition in the "interrupt controller".
>
>> So, if the rest of IOMMU is not necessary, it sounds that HelenOS can
>> be modified so that it would work both on a real and qemu sun4u
>> machines.
>
> Could it then be just a matter of providing a small kbd driver and the
> parent bus attachment code that would teach HelenOS to accept a PS2
> keyboard instead of a Sun keyboard attached via a ns16550?
>
> In a similar fashion, adding fb support was a matter of Igor providing a
> small scr driver for QEMU,VGA.
>
>One problem I can immediately see is that there is no `interrupts`
> property in the `keyboard` node.

Does the vanilla 0.4.3 iso have a PS2 keyboard driver?
Since there is a controller, adding a property is trivial:

http://tyom.blogspot.com/2012/05/booting-linuxsparc64-on-todays-openbios.html

Artyom


-- 
Regards,
Artyom Tarasenko

solaris/sparc under qemu blog: http://tyom.blogspot.com/search/label/qemu

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