egl: add EGL_MESA_device_software support

Add a plain software device, which is always available.

We can safely assign it as the first/initial device in _eglGlobals,
although we ensure that's the case with a handful of _eglDeviceSupports
checks throughout the code.

v2:
 - s/_eglFindDevice/_eglAddDevice/ (Eric)
 - s/_eglLookupAllDevices/_eglRefreshDeviceList/ (Eric)
 - move ^^ helpers into a earlier patch (Eric, Mathias)
 - set the SW device on _eglGlobal init. (Eric)
 - add a number of _eglDeviceSupports checks (Mathias)
 - split Device/Display attach to a separate patch

v3:
 - flip inverted asserts (Mathias)
 - s/on-stack/static/ (Mathias)

Signed-off-by: Emil Velikov <[email protected]>
Reviewed-by: Mathias Fröhlich <[email protected]>

1 files changed, 3 insertions, 1 deletions

diff --git a/src/egl/main/egldevice.h b/src/egl/main/egldevice.h
index f8f3fdc1907..74b5ddeee5c 100644
--- a/src/egl/main/egldevice.h
+++ b/src/egl/main/egldevice.h
@@ -38,6 +38,8 @@
 extern "C" {
 #endif
 
+extern _EGLDevice _eglSoftwareDevice;
+
 void
 _eglFiniDevice(void);
 
@@ -57,7 +59,7 @@ _EGLDevice *
 _eglAddDevice(int fd, bool software);
 
 enum _egl_device_extension {
-   EGL_FOOBAR, /* A temporary entry, since enum with zero entries is illegal */
+   _EGL_DEVICE_SOFTWARE,
 };
 
 typedef enum _egl_device_extension _EGLDeviceExtension;