1 files changed, 117 insertions, 0 deletions
diff --git a/doc/usage/cmd/cedit.rst b/doc/usage/cmd/cedit.rst
index 8e1110c7c77..f415b48699e 100644
--- a/doc/usage/cmd/cedit.rst
+++ b/doc/usage/cmd/cedit.rst
@@ -10,6 +10,11 @@ Synopis
 
     cedit load <interface> <dev[:part]> <filename>
     cedit run
+    cedit write_fdt <dev[:part]> <filename>
+    cedit read_fdt <dev[:part]> <filename>
+    cedit write_env [-v]
+    cedit read_env [-v]
+    cedit write_cmos [-v] [dev]
 
 Description
 -----------
@@ -22,6 +27,69 @@ It makes use of the expo subsystem.
 The description is in the form of a devicetree file, as documented at
 :ref:`expo_format`.
 
+See :doc:`../../develop/cedit` for information about the configuration editor.
+
+cedit load
+~~~~~~~~~~
+
+Loads a configuration-editor description from a file. It creates a new cedit
+structure ready for use. Initially no settings are read, so default values are
+used for each object.
+
+cedit run
+~~~~~~~~~
+
+Runs the default configuration-editor event loop. This is very simple, just
+accepting character input and moving through the objects under user control.
+The implementation is at `cedit_run()`.
+
+cedit write_fdt
+~~~~~~~~~~~~~~~
+
+Writes the current user settings to a devicetree file. For each menu item the
+selected ID and its text string are written.
+
+cedit read_fdt
+~~~~~~~~~~~~~~
+
+Reads the user settings from a devicetree file and updates the cedit with those
+settings.
+
+cedit read_env
+~~~~~~~~~~~~~~
+
+Reads the settings from the environment variables. For each menu item `<name>`,
+cedit looks for a variable called `c.<name>` with the ID of the selected menu
+item.
+
+The `-v` flag enables verbose mode, where each variable is printed after it is
+read.
+
+cedit write_env
+~~~~~~~~~~~~~~~
+
+Writes the settings to environment variables. For each menu item the selected
+ID and its text string are written, similar to:
+
+   setenv c.<name> <selected_id>
+   setenv c.<name>-str <selected_id's text string>
+
+The `-v` flag enables verbose mode, where each variable is printed before it is
+set.
+
+cedit write_cmos
+~~~~~~~~~~~~~~~~
+
+Writes the settings to locations in the CMOS RAM. The locations used are
+specified by the schema. See `expo_format_`.
+
+The `-v` flag enables verbose mode, which shows which CMOS locations were
+updated.
+
+Normally the first RTC device is used to hold the data. You can specify a
+different device by name using the `dev` parameter.
+
+
 Example
 -------
 
@@ -29,3 +97,52 @@ Example
 
     => cedit load hostfs - fred.dtb
     => cedit run
+    => cedit write_fdt hostfs - settings.dtb
+
+That results in::
+
+    / {
+        cedit-values {
+            cpu-speed = <0x00000006>;
+            cpu-speed-str = "2 GHz";
+            power-loss = <0x0000000a>;
+            power-loss-str = "Always Off";
+        };
+    }
+
+    => cedit read_fdt hostfs - settings.dtb
+
+This shows settings being stored in the environment::
+
+    => cedit write_env -v
+    c.cpu-speed=7
+    c.cpu-speed-str=2.5 GHz
+    c.power-loss=12
+    c.power-loss-str=Memory
+    => print
+    ...
+    c.cpu-speed=6
+    c.cpu-speed-str=2 GHz
+    c.power-loss=10
+    c.power-loss-str=Always Off
+    ...
+
+    => cedit read_env -v
+    c.cpu-speed=7
+    c.power-loss=12
+
+This shows writing to CMOS RAM. Notice that the bytes at 80 and 84 change::
+
+    => rtc read 80 8
+    00000080: 00 00 00 00 00 2f 2a 08                          ...../*.
+    =>  cedit write_cmos -v
+    Write 2 bytes from offset 80 to 84
+    => rtc read 80 8
+    00000080: 01 00 00 00 08 2f 2a 08                          ...../*.
+    => cedit read_cmos -v
+    Read 2 bytes from offset 80 to 84
+
+Here is an example with the device specified::
+
+    => cedit write_cmos rtc@43
+    =>