Re: 2.6.0-test1: Framebuffer problem

From: Geert Uytterhoeven (
Date: Mon Jul 21 2003 - 15:14:17 EST

On 19 Jul 2003, Alan Cox wrote:
> On Sad, 2003-07-19 at 07:02, Geert Uytterhoeven wrote:
> > No, that's not so simple, because vesafb requests the linear frame buffer,
> > while vga16fb requests the VGA region.

  - vesafb uses
      o request_mem_region() on the linear frame buffer
      o request_region() on the 32 VGA registers (but the return code is
        ignored because of vgacon)
  - vga16fb doesn't use resource management (ugh)
  - vgacon uses
      o request_region() on the MDA/CGA/EGA/VGA registers

> In standard usage mode both of them use the vga registers for palette control..

Vesafb may use a protected mode BIOS call instead.

An additional complexity is that not only vesafb/vga16fb may claim the VGA
registers, but also vgacon. And it's allowed for vesafb/vga16fb to take over



Geert Uytterhoeven -- There's lots of Linux beyond ia32 --

In personal conversations with technical people, I call myself a hacker. But when I'm talking to journalists I just say "programmer" or something like that. -- Linus Torvalds

- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to More majordomo info at Please read the FAQ at

This archive was generated by hypermail 2b29 : Wed Jul 23 2003 - 22:00:44 EST