High resolutions without specialized graphics driver

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oli2
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High resolutions without specialized graphics driver

Post by oli2 »

Is there any way I can get a higher resolution on my display without specialized graphics drivers? Maybe there’s a better framebuffer than 0xA0000?
Octocontrabass
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Re: High resolutions without specialized graphics driver

Post by Octocontrabass »

Which bootloader are you using? Most existing bootloaders can set up a high resolution framebuffer for you.

If you're writing your own BIOS bootloader, you can use VBE.

If you're writing your own UEFI bootloader, you can use GOP.
oli2
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Re: High resolutions without specialized graphics driver

Post by oli2 »

I was looking at GOP, but I can’t seem to find much documentation on how to get the frame buffer address from GRUB.
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Re: High resolutions without specialized graphics driver

Post by Octocontrabass »

GRUB supports Multiboot and Multiboot2. You can use either of those to get a framebuffer.
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AndrewAPrice
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Re: High resolutions without specialized graphics driver

Post by AndrewAPrice »

I use Grub and it works great. It passes the framebuffer, resolution and other metadata to the kernel via the multiboot header.
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Re: High resolutions without specialized graphics driver

Post by klange »

AndrewAPrice wrote:I use Grub and it works great. It passes the framebuffer, resolution and other metadata to the kernel via the multiboot header.
Grub still generally relies on mechanisms like VBE or GOP (or UGA, or OpenFirmware...) to obtain that framebuffer, so it can still suffer from the common issue of not being able to set up a native panel resolution when VBE/GOP don't have one - a bizarre curse of early boot on many laptops where you would think the one known panel resolution would have been included! My ThinkPad T410 has a native resolution of 1440x900, yet the VBE firmware only supports 1280x800!

Grub does have a few specialized drivers - such as one for the Cirrus chipset QEMU used to default to emulating, one for the Bochs BGA (looks like only port-IO versions), ones for some Radeon cards used in Lemote machines...
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