I've been recently working on resolving issues with Xorg's autoconfiguration mechanism with respect to non-PCI based graphic cards. Although Xorg -configure currently can handle these types of devices (assuming the individual driver probes work correctly that is), there is no automatic mechanism in xf86AutoConfig.c to handle non-PCI cards on Linux (there is a little bit of support on Sun by reading the framebuffer device).
The main issue I'm trying to resolve is that on the ARM architecture, many boards which do have video out often have it hooked directly to the processor or otherwise bypassing a carded bus like PCI. In these cases, autoconfiguration fails since there is no mechanism for these devices. To further complicate the matter, there also is no standardized interface for seeing these type of display devices. What I would like to implement is a lookup mechanism similar to PCI based lookup files, expect it would use the information available from /proc/fb, or /proc/cpuinfo to associate a display device with a specific video driver. For instance, on X startup, it would probe /proc/fb, read the ID tag of the framebuffer device, and then load the correct driver based off that. The drawback of checking /proc/fb however is that it depends on the framebuffer driver being present in the kernel. To avoid this, since on ARM we're dealing with an architecture that is often space limited, the lookup could fall back upon /proc/cpuinfo, and read the Hardware and Revision tags from there, and then look up against another set of data files. As many ARM boards have a one board == one video device relationship, this works well for a vast majority of boards without requiring framebuffer devices compiled into the running kernel. Since this work will benefit the users of X on ARM in general, I'd like to get the work I do merged upstream, and have it in a way that will be acceptable for merging at the get-go. Any comments or criticisms of the design are greatly welcomed. Michael _______________________________________________ xorg mailing list [email protected] http://lists.freedesktop.org/mailman/listinfo/xorg
