native: added stdin handling for shell

Now the native console driver also handles stdin
so we can drive the shell from the command line,
a pipe or a file

Signed-off-by: Alberto Escolar Piedras <[email protected]>

Author: aescolar

boards/posix/native_posix/Kconfig.board

@@ -3,6 +3,7 @@ config BOARD_NATIVE_POSIX
 	bool "Native POSIX"
 	depends on SOC_POSIX
 	select NATIVE_POSIX_TIMER
+	select NATIVE_POSIX_CONSOLE
 	help
 	  Will produce a console Linux process which can be executed natively.
 	  It provides some minimal needed models:

boards/posix/native_posix/doc/board.rst

@@ -342,16 +342,23 @@ Peripherals
 
 The following peripherals are currently provided with this board:
 
-**Console/printk driver**:
-  A driver is provided that redirects any printk write to the native
-  host application's stdout.
+**Console driver**:
+  A console driver is provided which by default is configured to:
+
+  - Redirect any :c:func:`printk` write to the native host application's
+    `stdout`.
+
+  - Feed any input from the native application `stdin` to a possible
+    running :ref:`Shell`. For more information refer to the section
+    `Shell support`_.
 
 **Simple timer**:
   A simple timer provides the kernel with a 10ms tick.
   This peripheral driver also provides the needed functionality for this
   architecture-specific :c:func:`k_busy_wait`.
 
-  This timer, is configured by default with NATIVE_POSIX_SLOWDOWN_TO_REAL_TIME_
+  This timer, is configured by default with
+  :option:`CONFIG_NATIVE_POSIX_SLOWDOWN_TO_REAL_TIME`
   to slow down the execution to real host time.
   This will provide the illusion that the simulated time is running at the same
   speed as the real host time.
@@ -361,11 +368,66 @@ The following peripherals are currently provided with this board:
   Normally the Zephyr application and HW models run in very little time
   on the host CPU, so this is a good enough approach.
 
-.. _NATIVE_POSIX_SLOWDOWN_TO_REAL_TIME:
-   ../../../../reference/kconfig/CONFIG_NATIVE_POSIX_SLOWDOWN_TO_REAL_TIME.html
-
 **Interrupt controller**:
   A simple yet generic interrupt controller is provided. It can nest interrupts
   and provides interrupt priorities. Interrupts can be individually masked or
   unmasked. SW interrupts are also supported.
 
+Shell support
+*************
+
+When the :ref:`Shell` subsystem is compiled with your application, the native
+standard input (`stdin`) will be redirected to the shell.
+You may use the shell interactively through the console,
+by piping another process output to it, or by feeding it a file.
+
+When using it interactively you may want to select the option
+:option:`CONFIG_NATIVE_POSIX_SLOWDOWN_TO_REAL_TIME`.
+
+When feeding `stdin` from a pipe or file, the console driver will ensure
+reproducibility between runs of the process:
+
+- The execution of the process will be stalled while waiting for new `stdin`
+  data to be ready.
+
+- Commands will be fed to the shell as fast as the shell can process them.
+  To allow controlling the flow of commands to the shell, you may use the
+  driver directive ``!wait <ms>``.
+
+- When the file ends, or the pipe is closed the driver will stop attempting to
+  read it.
+
+Driver directives
+=================
+
+The console driver understands a set of special commands: driver directives.
+These directives are captured by the console driver itself and are not
+forwarded to the shell.
+These directives are:
+
+- ``!wait <ms>``: When received, the driver will pause feeding commands to the
+  shell for `<ms>` milliseconds.
+
+- ``!quit``: When received the driver will cause the application to gracefully
+  exit by calling :c:func:`posix_exit`.
+
+
+Use example
+===========
+
+For example, you can build the shell sample app:
+
+.. zephyr-app-commands::
+   :zephyr-app: samples/subsys/shell/shell_module
+   :host-os: unix
+   :board: native_posix
+   :goals: build
+   :compact:
+
+And feed it the following set of commands through a pipe:
+
+.. code-block:: console
+
+   echo -e \
+   'select kernel\nuptime\n!wait 500\nuptime\n!wait 1000\nuptime\n!quit' \
+   | zephyr/zephyr.exe

drivers/console/Kconfig

@@ -200,12 +200,44 @@ config XTENSA_SIM_CONSOLE
 
 config NATIVE_POSIX_CONSOLE
 	bool
-	prompt "Print to console"
-	depends on BOARD_NATIVE_POSIX
+	prompt "Use native stdin/stdout for console"
+	depends on ARCH_POSIX
 	select CONSOLE_HAS_DRIVER
 	default y
 	help
-	  Use native console to print messages.
+	  Use native stdin and stdout to print messages and get input
+
+config NATIVE_POSIX_STDIN_CONSOLE
+	bool "Use native stdin for console"
+	prompt "Read from native stdin for console"
+	depends on NATIVE_POSIX_CONSOLE
+	default y
+	help
+	  Use native console to get input.
+
+config NATIVE_STDIN_POLL_PERIOD
+	int
+	prompt "Polling period for stdin"
+	depends on NATIVE_POSIX_STDIN_CONSOLE
+	default 20
+	help
+	  In ms, polling period for stdin
+
+config NATIVE_STDIN_PRIO
+	int
+	prompt "Priority of the stdin polling thread"
+	depends on NATIVE_POSIX_STDIN_CONSOLE
+	default 4
+	help
+	  Prioriry of the native stdin polling thread
+
+config NATIVE_POSIX_STDOUT_CONSOLE
+	bool "Use native stdout for console"
+	prompt "Print to native stdout"
+	depends on NATIVE_POSIX_CONSOLE
+	default y
+	help
+	  Use native console (stout) to print messages.
 
 config XTENSA_CONSOLE_INIT_PRIORITY
 	int