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: c16beccd7fa836a6bc77bb0a9d3274508bd3c6ff)

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 2190f5b90e..b92d9bb411 100644
--- a/documentation/ref-manual/structure.rst
+++ b/documentation/ref-manual/structure.rst
@@ -344,6 +344,15 @@ This configuration file is generated by :doc:`bblock </dev-manual/bblock>` and
 contains the signatures locked by ``bblock``. By default, it does not exist
 and will be created upon the first invocation of ``bblock``.
 
+.. _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/``