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obiwac
 Post subject: Getting GRUB video pointer
PostPosted: Fri Apr 28, 2017 10:16 am 
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I know that I should have done this a LONG time ago, but I kind of forgot to do it when I implemented the graphics for my OS. I only realized that I had hard coded the graphics pointer when I tried running my OS in QEMU, instead of VirtualBox.
I'm passing flags to multiboot GRUB so that it can change the graphics mode before switching to pmode.
So, how exactly do I get the video pointer?

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iansjack
 Post subject: Re: Getting GRUB video pointer
PostPosted: Fri Apr 28, 2017 10:51 am 
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The multiboot specifications tell you where to find the information.

https://www.gnu.org/software/grub/manua ... cification
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osdever
 Post subject: Re: Getting GRUB video pointer
PostPosted: Fri Apr 28, 2017 11:31 am 
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You need to get a Multiboot structure that GRUB passes, video info is included in it along with a ton of other very useful info.

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eryjus
 Post subject: Re: Getting GRUB video pointer
PostPosted: Fri Apr 28, 2017 11:40 pm 
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iansjack wrote:
The multiboot specifications tell you where to find the information.

https://www.gnu.org/software/grub/manua ... cification


I actually found the source to be more valuable. https://github.com/coreos/grub/blob/mas ... ultiboot.h

it contains some undocumented extensions which I found to be implemented in my grub2 loader.

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The name is fitting: Century Hobby OS -- At this rate, it's gonna take me that long!
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"Sometimes things just don't make sense until you figure them out." -- Phil Stahlheber

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obiwac
 Post subject: Re: Getting GRUB video pointer
PostPosted: Sat Apr 29, 2017 9:52 am 
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Ok thanks! It be working now!

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