egl: Native Display autodetection
EGL doesnt define howto manage different native platforms.
So mesa has a builtime configurable default platform,
whith non-standard envvar (EGL_PLATFORM) overwrites.
This caused unneeded bugreports, when EGL_PLATFORM was forgotten.
Detection is grouped into basic types of NativeDisplays (which itself
needs to be detected). The final decision is based on characteristcs
of these basic types:
File Desciptor based platforms (fbdev):
- fstat(2) to check for being a fd that belongs to a character device
- check kernel subsystem (todo)
Pointer to structuctures (x11, wayland, drm/gbm):
- mincore(2) to check whether its valid pointer to some memory.
- magic elements (e.g. pointers to exported symbols):
o wayland display stores interface type pointer (first elm.)
o gbm stores pointer to its constructor (first elm.)
o x11 as a fallback (FIXME?)
Reviewed-by: Kristian Høgsberg <krh@bitplanet.net>
5 files changed