nanogui: Re: Microwindows 0.87pre2 released for RTEMS
Subject:
Re: FW: Microwindows 0.87pre2 released for RTEMS
From:
Rosimildo daSilva ####@####.####
Date:
15 Dec 1999 01:16:51 -0000
Message-Id: <199912150111.RAA30843@www1.xoommail.com>
Joel Sherrill wrote:
>
Fisrt, thanks Greg for the hard work to get the RTEMS merged.
>
> Greg Haerr wrote:
> >
> > Since Mark and Joel may not be on the NanoGUI list, I am
> > forwarding this message FYI. - Greg
>
> Thanks for cc'ing us. This is an exciting development at least
> from the RTEMS perspective. :)
>
> This is more a question for Rosilmido:
>
> What is the best way to deal with the various drivers for
> Microwindows/RTEMS?
> My concern is that this could explode in Greg's face. There are about
> 40 BSPs
> in RTEMS for 9 CPU families. Most of these can't support Microwindows
> but
> there is still the possibility for a LOT of variations.
>
> I suppose that they are dependent on Microwindows at least as much as
> RTEMS.
I understand your concern. I guess we have to abstract the
devices: Kbd, Mouse and Video in such a way that they look the
same for Microwindows independently of which RTEMS BSP/ CPU is
involved.
For Kbd and Mouse, they "char" oriented devices and they match
perfectly with RTEMS devices:
Let's say:
handle_kbd = open( "/dev/rtems_kbd" ),
handle_mouse = open( "/dev/rtems_ps2_mouse" ),
handle_screen = open( "/dev/rtems_lcd_display" ),
ioctls( handle_screen, GET_SCREEN_CAPABILITIES, &screen_cap );
For the video, I need some help from Greg on how we should
abstract it, because the overhead of a driver could be un-acceptable.
Peharps the driver should returns its features via ioctls() including
a pointer to the "video buffer". We might want to follow the frame
buffer approach.
With this method, Microwindows would be opening standard devices
and reading/writing to/from them. This would be the same for each
CPU/BSP.
I need to think about this a bit more. I'll try to eleborate it
more over the weekend.
Rosimildo.
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