Getting GRUB video pointer

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obiwac
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Getting GRUB video pointer

Post by obiwac »

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
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Re: Getting GRUB video pointer

Post by iansjack »

The multiboot specifications tell you where to find the information.

https://www.gnu.org/software/grub/manua ... cification
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osdever
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Re: Getting GRUB video pointer

Post by osdever »

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
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Re: Getting GRUB video pointer

Post by eryjus »

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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obiwac
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Re: Getting GRUB video pointer

Post by obiwac »

Ok thanks! It be working now!
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