env: Explain how to use #include files in text environment

Provide documentation on how to share common settings among boards.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> # Intel Edison
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>

diff --git a/doc/usage/environment.rst b/doc/usage/environment.rst
index 91dc07b17bce42bf929dedb7f9ce48bc3dc56961..c6439dde6689391ad1e58b8c58f405a7fab9f849 100644 (file)
--- a/doc/usage/environment.rst
+++ b/doc/usage/environment.rst
@@ -81,6 +81,12 @@ Example::
         echo CONFIG_SYS_BOARD boot failed - please check your image
         echo Load address is CONFIG_SYS_LOAD_ADDR
 
+Settings which are common to a group of boards can use #include to bring in
+a common file in the `include/env` directory, containing environment
+settings. For example::
+
+   #include <env/ti/mmc.env>
+
 If CONFIG_ENV_SOURCE_FILE is empty and the default filename is not present, then
 the old-style C environment is used instead. See below.