Eric Sultan wrote: > > How does a device driver know that it's a primary device? It doesn't, really, nor is it required for this project. This project only provides identification of the primary graphics controller to user space. We didn't make it an implementation requirement this property existed prior to the first attach so that the driver could query.
There are tricks on both the SPARC and x86 platforms for the character driver to figure this out. > There's no harm, is there, if a driver fails to publish this property? Correct, nor is the character driver bound to the graphics controller responsible for publishing this property. > > One of the emails said that on SPARC the default graphics device is > the first graphics device found that can be controlled by the > probe-list words. Do I assume correctly that this isn't necessarily > so, for example when the console device is a graphics device specified > by the OpenBoot NVRAM parameter output-device? > I thought I wrote that in the context of the console output device being something other than one of the graphics controllers but now that I've reread it, I didn't make that clear. In the case where the graphics controller is the console output device, it is also the primary device.
