Fwd: [9fans] VBE 1.2/2.0+ functions for Plan9

Fwd: [9fans] VBE 1.2/2.0+ functions for Plan9

[Bob Hartley]

Please correct me if I am wrong on this:
Is it true that the XFree86 device driver modules are platform 
portable, as long as they are for the same instruction set 
architecture?  For some rason I thought the Linux and BSD mobs could 
swap video drivers around amoungst themselves.

If so, would it be possible to create some sort of adapter code that 
would wrap the x11 device drivers for Plan9 use?

Sorry if this is a naive/misbegotten thought,

regards,

Robert

> On Nov 25, 2004, at 1:57 PM, Devon H. O'Dell wrote:
>
>> rog@vitanuova.com wrote:
>>>> I got some tips to look in Inferno code, since Roger Peppe had
>>>> implemented a VESA driver there.  After looking through the Inferno
>>>> source, it appears that any VESA code has been left out of the 
>>>> public
>>>> source.
>>> the code is here:
>>> 	http://www.vitanuova.com/dist/vesa.tgz
>
> <snip>
>
>>>   cheers,
>>>     rog.
>>
>> Thanks for this code, Roger! I'm definitely going to take a look at 
>> it. I think I'm going to start with a VBE3.0 driver, since that can 
>> be implemented fully in protected mode, and then look at implementing 
>> some kind of emulation (similar to what XFree86 might do) for VBE 1.2 
>> and 2.0. This is a real help for that, in any case. You'll definitely 
>> hear from me if I've got questions :).
>>
>> Kind regards,
>>
>> Devon H. O'Dell
>>
>

Re: [9fans] VBE 1.2/2.0+ functions for Plan9

[boyd, rounin]

> If so, would it be possible to create some sort of adapter code that 
> would wrap the x11 device drivers for Plan9 use?

two words:  hideous mess

Re: [9fans] VBE 1.2/2.0+ functions for Plan9

[Russ Cox]

> Please correct me if I am wrong on this:
> Is it true that the XFree86 device driver modules are platform
> portable, as long as they are for the same instruction set
> architecture?  For some rason I thought the Linux and BSD mobs could
> swap video drivers around amoungst themselves.

As long as you want to use them for X.

> If so, would it be possible to create some sort of adapter code that
> would wrap the x11 device drivers for Plan9 use?

Possible?  Yes.  Particularly easy?  Nowhere close.
The X interface is much more complicated than the
Plan 9 interface, and the interface is very different.
In particular Plan 9 splits the job between user space
and the kernel, while X goes through some hoops to
do everything in user space.  I doubt I would want to load
X modules into the kernel, even if someone did do the
huge amount of work to pull it off.

I wonder if instead there is a way to pull the relevant
information out of the code and generate a Plan 9
driver in its place.  That would still be a lot of work, but
the final pieces might be better for our use.

Russ

Re: [9fans] VBE 1.2/2.0+ functions for Plan9

[Bob Hartley]

Oh well, I was hoping it would be something nice the way the new 
FreeBSD allows loading Windows NIC drivers, except we have access to 
the sources for X11.

I will take a look at this in case some of the drivers are simply table 
driven list of port numbers and data values to write.

Thanks anyways,

Rob

On Nov 25, 2004, at 10:08 PM, Russ Cox wrote:

>> Please correct me if I am wrong on this:
>> Is it true that the XFree86 device driver modules are platform
>> portable, as long as they are for the same instruction set
>> architecture?  For some rason I thought the Linux and BSD mobs could
>> swap video drivers around amoungst themselves.
>
> As long as you want to use them for X.
>
>> If so, would it be possible to create some sort of adapter code that
>> would wrap the x11 device drivers for Plan9 use?
>
> Possible?  Yes.  Particularly easy?  Nowhere close.
> The X interface is much more complicated than the
> Plan 9 interface, and the interface is very different.
> In particular Plan 9 splits the job between user space
> and the kernel, while X goes through some hoops to
> do everything in user space.  I doubt I would want to load
> X modules into the kernel, even if someone did do the
> huge amount of work to pull it off.
>
> I wonder if instead there is a way to pull the relevant
> information out of the code and generate a Plan 9
> driver in its place.  That would still be a lot of work, but
> the final pieces might be better for our use.
>
> Russ
>

Re: [9fans] VBE 1.2/2.0+ functions for Plan9

[Devon H. O'Dell]

Bob Hartley wrote:
> Oh well, I was hoping it would be something nice the way the new FreeBSD 
> allows loading Windows NIC drivers, except we have access to the sources 
> for X11.
> 
> I will take a look at this in case some of the drivers are simply table 
> driven list of port numbers and data values to write.
> 
> Thanks anyways,
> 
> Rob

Well, in any case, DragonFly BSD and FreeBSD have quite clean VESA 
implementations supporting versions 1.2 and above (and only what's in 
the spec, all drawing functions will have to be written from scratch). 
I'm in the process of getting a work environment set up, and I think 
that I can get at least the spec accomplished in a relatively short 
amount of time.

WRT other drivers, the only ones that are really of interest would be 
the DRM drivers, these are included and actively developed in FreeBSD 
and DragonFly BSD. X11 drivers are pretty .... unpretty.

I'll keep the list updated on my progress!

--Devon

> On Nov 25, 2004, at 10:08 PM, Russ Cox wrote:
> 
>>> Please correct me if I am wrong on this:
>>> Is it true that the XFree86 device driver modules are platform
>>> portable, as long as they are for the same instruction set
>>> architecture?  For some rason I thought the Linux and BSD mobs could
>>> swap video drivers around amoungst themselves.
>>
>>
>> As long as you want to use them for X.
>>
>>> If so, would it be possible to create some sort of adapter code that
>>> would wrap the x11 device drivers for Plan9 use?
>>
>>
>> Possible?  Yes.  Particularly easy?  Nowhere close.
>> The X interface is much more complicated than the
>> Plan 9 interface, and the interface is very different.
>> In particular Plan 9 splits the job between user space
>> and the kernel, while X goes through some hoops to
>> do everything in user space.  I doubt I would want to load
>> X modules into the kernel, even if someone did do the
>> huge amount of work to pull it off.
>>
>> I wonder if instead there is a way to pull the relevant
>> information out of the code and generate a Plan 9
>> driver in its place.  That would still be a lot of work, but
>> the final pieces might be better for our use.
>>
>> Russ
>>
> 
> 
>