nanogui: does framebuffer driver make everything greenish ?
Subject:
Re: [nanogui] does framebuffer driver make everything greenish ?
From:
"Greg Haerr" ####@####.####
Date:
2 Jul 2008 00:49:37 -0000
Message-Id: <0eba01c8dbdd$b51114b0$2f01a8c0@HaydenLake>
: GdOpenScreen(): no of colors currently supported = 16777216 [psd->ncolors]
: No. of planes = 1 [psd->planes]
: bpp = 24 [psd->bpp]
: Size of memory allocated = 2764800 [psd->size]
: address of fb memory = 0x29558000 [psd->addr]
: etc....
:
: It also says that true color is used, not any palette.
:
: According to the h/w manufacturer the graphics chip used has 3 graphics
: plane and 1 cursor plane.
:
: Then why GdOpenScreen() is reporting there is only one plane?
: Does 'psd->planes' mean that graphics plane only or something else?
The fb driver is using one plane of 24 bits per pixel, three bytes
per color. Simple, really.
:
: As here is 3 graphics planes, might be one of the plane is filled with
green
: color and causing the greenish effect on final display. Just guessing...
Not likely if you can see the image. This means that the image is
displayed using the correct byte-order contents.
Like I mentioned earlier, if you boot the system and its
got a green tinge, then your kernel is not configured properly
for the display.
: Is it the limitation of frame buffer driver because of which Microwindows
: can't support more than one graphics plane?
:
If you're using the fb driver in microwindows, then yes it only
supports one plane. You would have to write a special driver,
this would require a new kernel interface. Lots of work.
Regards,
Greg
:
: Microwindow supports only one graphics plane. Can I get the control of
other
: planes somehow? (just to clean other planes.... )
:: How is each graphics plane identified by the fb driver?
:
: Regards,
: Aveek
:
:
:
: -----Original Message-----
: From: Greg Haerr ####@####.####
: Sent: Tuesday, July 01, 2008 1:33 AM
: To: Aveek Adhya; ####@####.####
: Subject: Re: [nanogui] does framebuffer driver make everything greenish ?
:
:: Is there any generic application (like fbset) to query the frame buffer
:: driver to get graphics h/w information (bpp, no. of graphics planes,
alpha
:: support etc.) of my target system?
:
: fbset won't tell you this. But look at the code in
: microwindows' driver/scr_fb.c, this queries the framebuffer,
: as well as deals with palette issues with the kernel.
:
: It would help to know your framebuffer format, its hard
: to guess an answer for you with so little information. For
: instance, on palettized displays, your problem is simple,
: the master palette is incorrect.
:
: If your kernel is booting and shows a greenish shade, then
: its obvious the problem hasn't to do with microwindows, but
: instead with your kernel config/fb setup.
:
: Regards,
:
: Greg
:
:
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