shell: move shell to its own subsystem

This moves the shell component into its own subsys and groups all
related files and options into a single place.

Additionally, one Kconfig option will now be required to enable the
shell:

 CONFIG_CONSOLE_SHELL=y

The header files was also moved to include/shell/shell.h and can be now
referenced with

 #include <shell/shell.h>

instead of

 #include <misc/shell.h>

Updated documentation as well.

Change-Id: Iffbba4acfa05408055e9fd28dffa213451351f94
Signed-off-by: Anas Nashif <anas.nashif@intel.com>

1 files changed, 24 insertions, 25 deletions

diff --git a/doc/subsystems/shell.rst b/doc/subsystems/shell.rst
index 17eb7c1db..8d2b6d669 100644
--- a/doc/subsystems/shell.rst
+++ b/doc/subsystems/shell.rst
@@ -6,11 +6,11 @@ Shell
 Overview
 ********
 
-Zephyr OS Shell enables multiple Zephyr OS modules to use and expose their
-shell interface simultaneously.
+The Shell enables multiple subsystem to use and expose their shell interface
+simultaneously.
 
-Each module can support shell functionality dynamically by its Kconfig file,
-which enables or disables the shell usage for the module.
+Each subbsystem can support shell functionality dynamically by its Kconfig file,
+which enables or disables the shell usage for the subsystem.
 
 Using shell commands
 ********************
@@ -19,14 +19,19 @@ Use one of the following formats:
 
 Specific module's commands
 ==========================
+
+A shell interface exposing subsystem features is a shell module, multiple
+modules can be available at the same time.
+
 `MODULE_NAME COMMAND`
  One of the available modules is “KERNEL”, for the Kernel module.  More
  information can be found in :c:macro:`SHELL_REGISTER`.
 
 Help commands
 =============
+
 `help`
- Prints the available modules.
+ Prints the list of available modules.
 
 `help MODULE_NAME`
  Prints the names of the available commands for the module.
@@ -37,6 +42,7 @@ Help commands
 
 Select module commands
 ======================
+
 `set_module MODULE_NAME`
  Use this command when using the shell only for one module. After entering this
  command, you will not need to enter module name in further commands. If
@@ -54,40 +60,33 @@ There are two levels of configuration: Infrastructure level and Module level.
 Infrastructure level
 ====================
 
-The default value for ENABLE_SHELL flag should be considered per product.
-This flag enables shell services.
+The option :option:`CONFIG_CONSOLE_SHELL` enables the shell subsystem and enable the
+default features of the shell subsystem.
 
-If it is enabled, kernel shell commands are also available for use.
-See the :option:`CONFIG_ENABLE_SHELL` Kconfig options for more information.
-
-Module level
-============
-Each module using shell service should add a unique flag in its Kconfig file.
+Module/Subsystem level
+======================
+Each subsystem using the shell service should add a unique flag in its Kconfig file.
 
 Example:
 
-CONFIG_SAMPLE_MODULE_USE_SHELL=y
-
-In the module’s code, the shell usage depends on this config parameter.
-This module-specific flag should also depend on ENABLE_SHELL flag.
+CONFIG_NET_SHELL=y
 
-Therefore, there is one global flag, in addition to a unique flag per each
-module.
-The default value for ENABLE_SHELL flag should be considered per product.
+In the subsystem’s code, the shell usage depends on this config parameter.
+This subsystem specific flag should also depend on :option:`CONFIG_CONSOLE_SHELL` flag.
 
 Configuration steps to add shell functionality to a module
 ==========================================================
 
- #. Check that ENABLE_SHELL is set to yes.
- #. Add the module unique flag to its Kconfig file.
+ #. Check that :option:`CONFIG_CONSOLE_SHELL` is set to yes.
+ #. Add the subsystem unique flag to its Kconfig file.
 
 Writing a shell module
 **********************
 
-In order to support shell in your module, the application must do the following:
+In order to support shell in your subsystem, the application must do the following:
 
-#. Module configuration flag: Declare a new flag in your module Kconfig file.
-   It should depend on `ENABLE_SHELL` flag.
+#. Module configuration flag: Declare a new flag in your subsystem Kconfig file.
+   It should depend on `:option:`CONFIG_CONSOLE_SHELL`` flag.
 
 #. Module registration to shell: Add your shell identifier and register its
    callback functions in the shell database using :c:macro:`SHELL_REGISTER`.