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mallard wrote:

bzt wrote:It is not. See The Incredible Machine for example.

Slight nitpick; that game actually runs at 640x400, allowing it to double-buffer within the standard 256KB VGA memory, which certainly affects (perceived) performance.

I've previously posted the available options for "better-than-VGA" graphics in protected mode. Personally, I use the x86 emulator route (via the excellent designed-for-exactly-this-purpose libx86emu).

Probably redundant idea now, but did anyone ever "wrap up" libx86emu in to a c library that could be used as a basic VBE graphics driver?

I've spent days fighting with GRUB2, and getting nowhere... I think I'm going to have to bite the bullet, move into the21st century and get my kernel booting via EFI if I want graphics

bloodline wrote: I've spent days fighting with GRUB2, and getting nowhere... I think I'm going to have to bite the bullet, move into the21st century and get my kernel booting via EFI if I want graphics

With GRUB2, you can set an initial VESA video mode in two ways:

• By setting `gfxpayload` to a known supported resolution (such as `800x600x32`) in your `grub.cfg` file; though I consider this more as a hack rather than a proper solution but it can still be used for early kernel development. Here is an example:

  Code: Select all

  menuentry 'MyOS' {
    load_video
    set gfxpayload=800x600x32
    multiboot2 /path/to/kernel.elf
    boot arg_a arg_b...
  }
  

  Note that although you specified a given resolution, this doesn't mean the actual boot manager will always set the video mode to the requested resolution (especially if they're non-standard). You got to also check the presence of the `framebuffer-info` tag in the given taglist (see EFI i386 machine state with boot services enabled) to ensure that the boot loader did the actual work of setting a video mode in addition of receiving the actual framebuffer address & video mode properties.
• By specifing a `framebuffer` tag to your Multiboot 2 compliant kernel header. Has the advantage of being handled by all Multiboot 2 compliant boot managers. Just like the first method, you will need to check the presence & the contents of the `framebuffer-info` tag to be sure that the boot manager has set the correct resolution

crosssans wrote:

bloodline wrote: I've spent days fighting with GRUB2, and getting nowhere... I think I'm going to have to bite the bullet, move into the21st century and get my kernel booting via EFI if I want graphics

With GRUB2, you can set an initial VESA video mode in two ways:

• By setting `gfxpayload` to a known supported resolution (such as `800x600x32`) in your `grub.cfg` file; though I consider this more as a hack rather than a proper solution but it can still be used for early kernel development. Here is an example:

  Code: Select all

  menuentry 'MyOS' {
    load_video
    set gfxpayload=800x600x32
    multiboot2 /path/to/kernel.elf
    boot arg_a arg_b...
  }
  

  Note that although you specified a given resolution, this doesn't mean the actual boot manager will always set the video mode to the requested resolution (especially if they're non-standard). You got to also check the presence of the `framebuffer-info` tag in the given taglist (see EFI i386 machine state with boot services enabled) to ensure that the boot loader did the actual work of setting a video mode in addition of receiving the actual framebuffer address & video mode properties.
• By specifing a `framebuffer` tag to your Multiboot 2 compliant kernel header. Has the advantage of being handled by all Multiboot 2 compliant boot managers. Just like the first method, you will need to check the presence & the contents of the `framebuffer-info` tag to be sure that the boot manager has set the correct resolution

Thanks for this, I am quite familiar with GRUB Legacy (used it around 15 to 20 years ago ), so that is what I have been using, but for some reason I can't get the version (0.92?) I'm using to set a frame buffer... I figured it's just too old, so I'm trying to install GRUB 2 but it keeps throwing me to the Rescue shell...

It's entirely my fault, I'm sure I'm getting the install parameters wrong, the grub documentation is abysmal...

Ok, so it is my grub2 config that is at fault... I booted my with Debian image, and then at the grub command line I typed:
grub> multiboot (hd1,msdos1)/kernel.elf
grub>boot

And my framebuffer test pattern was displayed!!! Now I need to figure out how to get my grub2 config right... the Debian grub-mkconfig script just keeps wanting to set up linux

My Kernel disk image just keeps failing with:
error: no such device: blah blah blah blah some random uuid

-EDIT- Ok... got there in the end... I now have it booting to a 800x600x16 display... time to write a proper gfx library!