UART for POSIX_ARCH

arch/posix/CMakeLists.txt

@@ -23,7 +23,7 @@ if (CONFIG_ASAN)
 	zephyr_ld_options(-fsanitize=address)
 endif ()
 
-zephyr_compile_definitions(_POSIX_C_SOURCE=200809 _XOPEN_SOURCE _XOPEN_SOURCE_EXTENDED)
+zephyr_compile_definitions(_POSIX_C_SOURCE=200809 _XOPEN_SOURCE=600 _XOPEN_SOURCE_EXTENDED)
 
 zephyr_ld_options(
   -ldl

boards/posix/native_posix/Kconfig.defconfig

@@ -38,10 +38,17 @@ endchoice
 
 endif # BT_HCI
 
+if SERIAL
+
+config UART_NATIVE_POSIX
+	def_bool y
+
+endif # SERIAL
+
 if LOG
 
 config LOG_BACKEND_NATIVE_POSIX
-	def_bool y
+	def_bool y if !SERIAL
 
 # For native_posix we can log immediately without any problem
 # Doing so will be nicer for debugging
@@ -55,4 +62,14 @@ config LOG_PROCESS_THREAD
 
 endif # LOG
 
+if CONSOLE
+
+config NATIVE_POSIX_CONSOLE
+	def_bool y if !SERIAL
+
+config UART_CONSOLE
+	def_bool y if SERIAL
+
+endif #CONSOLE
+
 endif # BOARD_NATIVE_POSIX

boards/posix/native_posix/doc/board.rst

@@ -19,6 +19,9 @@ you use native host tools for compiling, debugging, and analyzing your
 Zephyr application, eliminating the need for architecture-specific
 target hardware in the early phases of development.
 
+This board provides a few peripherals such as an Ethernet driver and UART.
+See `Peripherals`_ for more information.
+
 Host system dependencies
 ========================
 
@@ -458,8 +461,8 @@ The following peripherals are currently provided with this board:
     ``stdout``.
 
   - Feed any input from the native application ``stdin`` to a possible
-    running :ref:`Shell`. For more information refer to the section
-    `Shell support`_.
+    running legacy shell. For more information refer to the section
+    `Legacy shell support`_.
 
 **Clock, timer and system tick model**
   This model provides the system tick timer. By default
@@ -538,11 +541,40 @@ The following peripherals are currently provided with this board:
   must be powered down and support Bluetooth Low Energy (i.e. support the
   Bluetooth specification version 4.0 or greater).
 
-Shell support
-*************
+**UART**
+  An optional UART driver can be compiled with native_posix.
+  For more information refer to the section `UART`_.
+
+
+UART
+*****
+
+This driver can be configured to either create and link the UART to a new
+pseudoterminal (i.e. ``/dev/pts<nbr>``), or to map the UART input and
+output to the executable's ``stdin`` and ``stdout``.
+This is chosen by selecting either
+:option:`CONFIG_NATIVE_UART_0_ON_OWN_PTY` or
+:option:`CONFIG_NATIVE_UART_0_ON_STDINOUT`
+Note that for interactive use, the first option should be chosen. The
+second option is only intended for automated testing or feeding/piping other
+processes output to the UART.
+
+When :option:`CONFIG_NATIVE_UART_0_ON_OWN_PTY` is chosen, the name of the
+newly created UART pseudo-terminal will be displayed in the console.
+You may also chose to automatically attach a terminal emulator to it by
+passing the command line option ``-attach_uart`` to the executable.
+The command used for attaching to the new shell can be set with the command line
+option ``-attach_uart_cmd=<"cmd">``. Where the default command is given by
+:option:`CONFIG_NATIVE_UART_AUTOATTACH_DEFAULT_CMD`.
+Note that the default command assumes both ``xterm`` and ``screen`` are
+installed in the system.
+
+
+Legacy shell support
+********************
 
-When the :ref:`Shell` subsystem is compiled with your application, the native
-standard input (``stdin``) will be redirected to the shell.
+When the legacy :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.
 
@@ -580,16 +612,8 @@ These directives are:
 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:
+For example, after you have built an application with the legacy shell, you
+can feed it the following set of commands through a pipe:
 
 .. code-block:: console
 

boards/posix/native_posix/native_posix_defconfig

@@ -2,5 +2,4 @@ CONFIG_ARCH_POSIX=y
 CONFIG_SOC_POSIX=y
 CONFIG_BOARD_NATIVE_POSIX=y
 CONFIG_CONSOLE=y
-CONFIG_SERIAL=y
 CONFIG_SYS_CLOCK_HW_CYCLES_PER_SEC=1000000

drivers/console/Kconfig

@@ -255,15 +255,14 @@ config NATIVE_POSIX_CONSOLE
 	bool "Use the host terminal for console"
 	depends on ARCH_POSIX
 	select CONSOLE_HAS_DRIVER
-	default y
 	help
 	  Use the host terminal (where the native_posix binary was launched) for the
 	  Zephyr console
 
 config NATIVE_POSIX_STDIN_CONSOLE
 	bool "Use the host terminal stdin"
 	depends on NATIVE_POSIX_CONSOLE
-	default y
+	default y if !NATIVE_UART_0_ON_STDINOUT
 	help
 	  Feed the host terminal stdin to the Zephyr console/shell.
 

drivers/serial/CMakeLists.txt

@@ -26,3 +26,8 @@ zephyr_library_sources_if_kconfig(usart_mcux_lpc.c)
 zephyr_library_sources_if_kconfig(uart_psoc6.c)
 
 zephyr_library_sources_ifdef(CONFIG_USERSPACE   uart_handlers.c)
+
+if(CONFIG_UART_NATIVE_POSIX)
+  zephyr_library_compile_definitions(NO_POSIX_CHEATS)
+  zephyr_library_sources(uart_native_posix.c)
+endif()

drivers/serial/Kconfig

@@ -71,6 +71,8 @@ source "drivers/serial/Kconfig.imx"
 
 source "drivers/serial/Kconfig.stellaris"
 
+source "drivers/serial/Kconfig.native_posix"
+
 source "drivers/serial/Kconfig.nsim"
 
 source "drivers/serial/Kconfig.usart_sam"

drivers/serial/Kconfig.native_posix

@@ -0,0 +1,59 @@
+config UART_NATIVE_POSIX
+	bool "UART driver for native_posix"
+	select SERIAL_HAS_DRIVER
+	depends on ARCH_POSIX
+	help
+	  This enables a UART driver for the POSIX ARCH. The driver can be configured
+	  to either connect to the terminal from which native_posix was run, or into
+	  one decicated pseudoterminal for this UART.
+
+if UART_NATIVE_POSIX
+
+config UART_NATIVE_POSIX_PORT_0_NAME
+	string "Port 0 Device Name"
+	default "UART_0"
+	depends on UART_NATIVE_POSIX
+	help
+	  This is the device name for UART, and is included in the device
+	  struct.
+
+choice
+	prompt "Native UART Port 0 connection"
+	default NATIVE_UART_0_ON_OWN_PTY
+
+config NATIVE_UART_0_ON_OWN_PTY
+	bool "Connect the UART to its own pseudo terminal"
+	help
+	  Connect the UART to its own pseudoterminal. This is the preferred option
+	  for users who want to use Zephyr's shell.
+	  Moreover this option does not conflict with any other native_posix backend
+	  which may use the calling shell standard input/output.
+
+config NATIVE_UART_0_ON_STDINOUT
+	bool "Connect the UART to the invoking shell stdin/stdout"
+	help
+	  Connect the UART to the stdin & stdout of the calling shell/terminal which
+	  invoked the native_posix executable. This is good enough for automated
+	  testing, or when feeding from a file/pipe.
+	  Note that other, non UART messages, will also be printed to the terminal.
+	  This option should NOT be used in conjunction with the legacy shell
+	  native_posix backend (NATIVE_POSIX_STDIN_CONSOLE)
+	  It is strongly discouraged to try to use this option with the new shell
+	  interactively, as the default terminal configuration is NOT appropriate
+	  for interactive use.
+
+endchoice
+
+config NATIVE_UART_AUTOATTACH_DEFAULT_CMD
+	string "Default command to attach the UART to a new terminal"
+	default "xterm -e screen %s &"
+	help
+	  If the native_posix executable is called with the --attach_uart command line
+	  option, this will be the default command which will be run to attach a new
+	  terminal to it.
+	  Note that this command must have one, and only one, '%s' as placeholder for
+	  the pseudoterminal device name (e.g. /dev/pts/35)
+	  This is only applicable if a UART is configured to use its own PTY with
+	  NATIVE_UART_x_ON_OWN_PTY.
+
+endif #UART_NATIVE_POSIX