ref-manual/structure: document the auto.conf file

Add documentation for auto.conf, which is used by external tools for
automatically setting variables.

(From yocto-docs rev: 707b29352838792c635b39c8b5c20c519b10b832)

Signed-off-by: Antonin Godard <antonin.godard@bootlin.com>
(cherry picked from commit 134e54a75e0144c4629f702c6f43e92ed1f12dce)
Signed-off-by: Antonin Godard <antonin.godard@bootlin.com>
Signed-off-by: Steve Sakoman <steve@sakoman.com>

1 files changed, 9 insertions, 0 deletions

diff --git a/documentation/ref-manual/structure.rst b/documentation/ref-manual/structure.rst
index 1bb35da5dc..1301038d5b 100644
--- a/documentation/ref-manual/structure.rst
+++ b/documentation/ref-manual/structure.rst
@@ -328,6 +328,15 @@ Once the build process gets the sample file, it uses ``sed`` to substitute final
 This file indicates the state of the sanity checks and is created during
 the build.
 
+.. _structure-build-conf-auto.conf:
+
+``build/conf/auto.conf``
+------------------------
+
+This file contains configuration variables that are automatically modified by
+tools such as :oe_git:`bitbake-config-build </bitbake/tree/bin/bitbake-config-build>`.
+This file should not be modified manually.
+
 .. _structure-build-downloads:
 
 ``build/downloads/``