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 Post subject: Generic screen output post BIOS
PostPosted: Fri Jul 19, 2019 8:02 am 
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Hi guys,

As I'm sure you are all aware BIOS is getting a long anticipated death relatively shortly. That means no VGA/VESA. What is the UEFI future for hobbyist graphics output? I know there is GOP but apparently that goes away after boot ends unless I've misunderstood something.

Is there a generic way to get hold of, initialise and map a framebuffer that persists post UEFI boot? If there is I'll probably create my graphics module with VESA as just one of many framebuffers it can get. If it needs card specific drivers then that is obviously more complicated.


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 Post subject: Re: Generic screen output post BIOS
PostPosted: Fri Jul 19, 2019 8:55 am 
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The framebuffer acquired from GOP (and older UGA) can still be used after ExitBootServices .


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 Post subject: Re: Generic screen output post BIOS
PostPosted: Fri Jul 19, 2019 10:36 am 
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MichaelPetch wrote:
The framebuffer acquired from GOP (and older UGA) can still be used after ExitBootServices .

I agree in principle, but UGA doesn't provide you with a framebuffer address. This shouldn't matter too much, as this should apply only to Macs.

The Linux way of getting a framebuffer address with UGA is determining the machine via SMBIOS (= DMI?) and looking up the address in a table.

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 Post subject: Re: Generic screen output post BIOS
PostPosted: Sat Jul 20, 2019 4:18 am 
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Thanks guys. I might bite the bullet and look to just move everything to UEFI. Seems like it gives broader resolution support and multimonitor. The only loss seems to be inability to change resolution dynamically but I can live with fixed resolution mode until I have a proper driver.


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 Post subject: Re: Generic screen output post BIOS
PostPosted: Sat Jul 20, 2019 7:56 am 
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I'm unaware of multi-monitor support in UEFI, where did you get this from? I'd be quite interested if true, although I remember it to not be possible ...

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 Post subject: Re: Generic screen output post BIOS
PostPosted: Sat Jul 20, 2019 9:28 am 
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The article below claims it is possible.

https://github.com/rust-osdev/uefi-rs/w ... t-Protocol


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 Post subject: Re: Generic screen output post BIOS
PostPosted: Sat Jul 20, 2019 10:27 am 
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A quick Google search doesn't really yield any results, but I might try this out. Anyone with experience with this is invited to share their thoughts.

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 Post subject: Re: Generic screen output post BIOS
PostPosted: Sat Jul 20, 2019 12:38 pm 
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Here's a post on this forum implying multi monitor is a reason to use UEFI over BIOS.

viewtopic.php?f=11&t=32279&p=278257&hilit=Uefi+gop+monitors#p278257


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