Subject: Re: framebuffer mmap access
To: Brett D. Slager <firstname.lastname@example.org>
From: Scott Reynolds <scott.reynolds@Plexus.COM>
Date: 03/21/1999 20:58:31
On Sun, 21 Mar 1999, Brett D. Slager wrote:
> 1. Shouldn't wsdisplaymmap allow mapping under both text and
> graphics conditions?
I've run into a similar issue with converting the mac68k port to wscons.
I've got a binary compatibility issue to work out with regard to mmap() due
to the fact that our grf interface allows a display to be mapped regardless
of whether the ite (terminal emulator) is active on the display.
Since it's an application-level thing, though, your problem is trivial to
int mode = WSDISPLAYIO_MODE_MAPPED;
ioctl(f, WSDISPLAYIO_SMODE, &mode);
This will put the display, whether console or not, into mapped mode, and
mmap() will work fine. (To revert back to the emulation, use
> It's perfectly reasonable to want to
> mmap the display on a tga regardless of any text emulations.
For a display that operates exclusively in a bitmapped mode, I'd agree. On
the other hand, the interface as it stands allows the implementor to have a
way to switch between a bitmapped display for framebuffer access and a
hardware-based text mode, and have well-defined results in each case.