docs/manual/ccache-support.txt: document the new BR2_USE_CCACHE variable
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>
Signed-off-by: Yann E. MORIN <yann.morin.1998@free.fr>
diff --git a/docs/manual/ccache-support.txt b/docs/manual/ccache-support.txt
index ea64628..ab4f10b 100644
--- a/docs/manual/ccache-support.txt
+++ b/docs/manual/ccache-support.txt
@@ -55,3 +55,15 @@
See https://ccache.samba.org/manual.html#_compiling_in_different_directories[the
ccache manual's section on "Compiling in different directories"] for
more details about this rewriting of absolute paths.
+
+When +ccache+ is enabled in Buildroot using the +BR2_CCACHE=y+ option:
+
+* +ccache+ is used during the Buildroot build itself
+
+* +ccache+ is not used when building outside of Buildroot, for example
+ when directly calling the cross-compiler or using the SDK
+
+One can override this behavior using the +BR2_USE_CCACHE+ environment
+variable: when set to +1+, usage of ccache is enabled (default during
+the Buildroot build), when unset or set to a value different from +1+,
+usage of ccache is disabled.
