Re: [9fans] Scrolling considered harmful

[erik quanstrom <quanstro@labs.coraid.com>]

> I have retrieved atom aux/realemu and I will have to test.
>
> But before, I will have to read the aux/vga sources to understand what
> it expects. Because aux/vga -p gives me all the informations about the
> vesa supported modes of the card, and even the monitor settings (I
> wonder that the problem is here, that is monitor and card "discuss" and
> the software is not part of the discussion). The informations (vesa: the
> RADEON card; edid: the monitor 1600x900):

the problem is that the VBE calls that are used to set up
various video modes jump to vendor-provided real mode
code that is often buggy.  the reason for emulation is
(a) to avoid problems associated with real-mode code
triggering interrupts the partial real-mode implementation

the 9 kernels provide is not prepared to handle, and
(b) to avoid invalid accesses caused by buggy real-mode
code.

yes it sounds implausable that the vendor code could be
that broken, but it's true!

- erik