gallium/docs: Document the OS module.

diff --git a/src/gallium/docs/source/distro.rst b/src/gallium/docs/source/distro.rst
index 0ef9fe2645c56eb418ea5f811c7ba137e72eba0e..0fabb639ad32303726c449b5d9a51ca3392891a9 100644 (file)
--- a/src/gallium/docs/source/distro.rst
+++ b/src/gallium/docs/source/distro.rst
@@ -103,6 +103,22 @@ Xorg XFree86 DDX
 Auxiliary
 ---------
 
+OS
+^^
+
+The OS module contains the abstractions for basic operating system services:
+
+* memory allocation
+* simple message logging
+* obtaining run-time configuration option
+* threading primitives
+
+This is the bare minimum required to port Gallium to a new platform.
+
+The OS module already provides the implementations of these abstractions for
+the most common platforms.  When targeting an embedded platform no
+implementation will be provided -- these must be provided separately.
+
 CSO Cache
 ^^^^^^^^^