Re: port-macppc/48600

[Michael <macallan%netbsd.org@localhost>]

The following reply was made to PR port-macppc/48600; it has been noted by GNATS.

From: Michael <macallan%netbsd.org@localhost>
To: gnats-bugs%NetBSD.org@localhost
Cc: 
Subject: Re: port-macppc/48600
Date: Sat, 22 Nov 2014 10:35:18 -0500

 Hello,
 
 On Sat, 22 Nov 2014 15:15:00 +0000 (UTC)
 scole_mail <scole_mail%gmx.com@localhost> wrote:
 
 >  Guess I don't understand the difference between MAPPED and DUMBFB.  If
 >  I do
 >  		    case WSDISPLAYIO_MODE_EMUL:
 >  		  //case WSDISPLAYIO_MODE_MAPPED:
 >   		    case WSDISPLAYIO_MODE_DUMBFB:
 >  
 >  X always starts in 8 bit, so it seems like I need to set depth when MAPPED ?
 
 Many drivers treat them the same, The difference is this:
 In WSDISPLAYIO_MODE_DUMBFB we can map the framebuffer at offset 0, and nothing else. This is what xf86-video-wsfb uses.
 In WSDISPLAYIO_MODE_MAPPED we can map the actual hardware, at their respective bus addresses ( for PCI cards for example ) or something similar. A few drivers use this, for example xf86-video-crime ( for the SGI O2's onboard graphics hardware ). This is intended for hardware that can not or should not be mapped in other ways.
 They're kept separate since the framebuffer at 0 may overlap with bus addresses used by the hardware.
 
 have fun
 Michael