gallium/docs: Add Galahad

src/gallium/docs/source/debugging.rst

@@ -21,6 +21,10 @@ This option controls if the debug variables should be printed to stderr. This
 is probably the most useful variable, since it allows you to find which
 variables a driver uses.
 
+.. envvar:: GALLIUM_GALAHAD <bool> (false)
+
+Controls if the :ref:`galahad` sanity checker module should be used.
+
 .. envvar:: GALLIUM_RBUG <bool> (false)
 
 Controls if the :ref:`rbug` should be used.

src/gallium/docs/source/distro.rst

@@ -79,6 +79,15 @@ Rbug
 
 Wrapper driver. :ref:`rbug` driver used with stand alone rbug-gui.
 
+.. _galahad:
+
+Galahad
+^^^^^^^
+
+Wrapper driver. Sanity checker for the internal gallium state. Normally
+a driver should n't have to sanity check the input it gets from a state
+tracker. Any wrong state received should be perceived as a state tracker bug.
+
 State Trackers
 --------------