[haiku-development] Re: Boot Screen Not Displayed with Various Video Chips
- From: "Axel Dörfler" <axeld@xxxxxxxxxxxxxxxx>
- To: haiku-development@xxxxxxxxxxxxx
- Date: Fri, 31 Oct 2008 10:53:38 +0100 CET
Gerald Zajac <zajacg@xxxxxxxxxxxxx> wrote:
> The VESA driver selects the same mode, and also does not display
> anything because the monitor indicates the mode is out of range.
> AFAIK,
> no key strokes like BeOS has were ever implemented to allow setting a
> lower resolution.
There is a key combination (currently F12 + left command + left control
+ left shift) that would let you fall back to a safe mode, but it's not
yet implemented to do anything.
> All the chips that I have tested that have this problem, are either
> currently supported by the S3 driver, or will be supported by the ATI
> driver when I complete it. Thus, there is no need to blacklist them
> because the VESA driver will not handle them correctly at 1280x1024.
They would only be blacklisted in the boot loader to select a better
mode, and there, a driver is not available anyway.
> > Maybe we just choose the wrong mode option of several, though, as
> > the
> > chips are definitely capable of producing that resolution (and VESA
> > modes should always come out with 60 Hz).
> VESA modes do not always produce 60 Hz refresh rate. They usually do
> with a laptop chip, but this not the case with other video chips.
> For
> example, the S3 Savage chips display the boot screen, but the refresh
> rate is usually 75 Hz.
I remember they always used to do that, and this was a common complaint
about them :-)
But apparently it's only a guide, and the VBE implementations can
choose what to use.
> > It just looks so much better to use the native resolution.
> A 1024x768 boot screen on my 1280x1024 monitor looks very good.
> Maybe
> your monitor does a poor job of expanding a screen. Laptops do a
> particularly poor job of expanding a display image to fill the LCD
> screen. That is why the latest S3 driver no longer allows a laptop
> chip
> to expand a display image to fill the LCD screen.
Which best should be configurable via settings file or even better, the
Screen preferences app.
But a scaled image looks always poor compared to a crisp native
resolution one, no matter how good the scaling works.
> Another possible solution to this problem would be to limit the boot
> screen resolution to 1024x768 if the chip is a VESA 2.0 chip. These
> chips are mostly older chips, and all chips that had this problem
> IIRC
> were VESA 2.0 chips. Later chips at VESA 3.0 or later could continue
> to
> be handled as they are now.
That would be a viable solution. But before we do this, I want to
experiment with the CRTCInfoBlock structure that you can provide mode
switches with to set a specific timing.
If that doesn't help, I'm open for more generic solutions.
I've added the CRTC stuff in r28390, please tell me if that works for
you.
Bye,
Axel.
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