SDL based display emulation driver

boards/posix/native_posix/CMakeLists.txt

@@ -12,6 +12,15 @@ zephyr_library_sources(
 	cmdline.c
 	)
 
+if(CONFIG_HAS_SDL)
+	find_package(PkgConfig REQUIRED)
+	pkg_search_module(SDL2 REQUIRED sdl2)
+	zephyr_include_directories(${SDL2_INCLUDE_DIRS})
+	zephyr_link_libraries(${SDL2_LIBRARIES})
+	zephyr_compile_options(${SDL2_CFLAGS_OTHER})
+	zephyr_library_sources(sdl_events.c)
+endif()
+
 zephyr_ld_options(
   -lm
 )

boards/posix/native_posix/Kconfig

@@ -15,4 +15,9 @@ config NATIVE_POSIX_SLOWDOWN_TO_REAL_TIME
 	  case the zephyr kernel and application cannot tell the difference unless they
 	  interact with some other driver/device which runs at real time.
 
+config HAS_SDL
+	bool
+	help
+	  This option specifies that the target board has SDL support
+
 endif

boards/posix/native_posix/Kconfig.defconfig

@@ -72,4 +72,11 @@ config UART_CONSOLE
 
 endif #CONSOLE
 
+if DISPLAY
+
+config SDL_DISPLAY
+	default y
+
+endif # DISPLAY
+
 endif # BOARD_NATIVE_POSIX

boards/posix/native_posix/doc/board.rst

@@ -519,6 +519,23 @@ 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).
 
+**Display driver**:
+  A display driver is provided that creates a window on the host machine to
+  render display content.
+
+  This driver requires a 32-bit version of the `SDL2`_ library on the host
+  machine and ``pkg-config`` settings to correctly pickup the SDL2 install path
+  and compiler flags.
+
+  On a Ubuntu 18.04 host system, for example, install the ``pkg-config`` and
+  ``libsdl2-dev:i386`` packages, and configure the pkg-config search path with
+  these commands::
+
+    $ sudo apt-get install pkg-config libsdl2-dev:i386
+    $ export PKG_CONFIG_PATH=/usr/lib/i386-linux-gnu/pkgconfig
+
+.. _SDL2:
+   https://www.libsdl.org/download-2.0.php
 
 UART
 *****

boards/posix/native_posix/hw_models_top.c

@@ -12,12 +12,16 @@
 #include <stdint.h>
 #include <signal.h>
 #include <stddef.h>
+#include <stdlib.h>
+#include <pthread.h>
 #include "hw_models_top.h"
 #include "timer_model.h"
 #include "irq_ctrl.h"
 #include "posix_board_if.h"
 #include "posix_soc_if.h"
 #include "posix_arch_internal.h"
+#include "sdl_events.h"
+#include <misc/util.h>
 
 
 static u64_t simu_time; /* The actual time as known by the HW models */
@@ -26,21 +30,33 @@ static u64_t end_of_time = NEVER; /* When will this device stop */
 /* List of HW model timers: */
 extern u64_t hw_timer_timer; /* When should this timer_model be called */
 extern u64_t irq_ctrl_timer;
-
-static enum { HWTIMER = 0, IRQCNT, NUMBER_OF_TIMERS, NONE }
-	next_timer_index = NONE;
+#ifdef CONFIG_HAS_SDL
+extern u64_t sdl_event_timer;
+#endif
+
+static enum {
+	HWTIMER = 0,
+	IRQCNT,
+#ifdef CONFIG_HAS_SDL
+	SDLEVENTTIMER,
+#endif
+	NUMBER_OF_TIMERS,
+	NONE
+} next_timer_index = NONE;
 
 static u64_t *Timer_list[NUMBER_OF_TIMERS] = {
 	&hw_timer_timer,
-	&irq_ctrl_timer
+	&irq_ctrl_timer,
+#ifdef CONFIG_HAS_SDL
+	&sdl_event_timer,
+#endif
 };
 
 static u64_t next_timer_time;
 
 /* Have we received a SIGTERM or SIGINT */
 static volatile sig_atomic_t signaled_end;
 
-
 /**
  * Handler for SIGTERM and SIGINT
  */
@@ -95,7 +111,6 @@ static void hwm_sleep_until_next_timer(void)
 	if (signaled_end || (simu_time > end_of_time)) {
 		posix_print_trace("\nStopped at %.3Lfs\n",
 				((long double)simu_time)/1.0e6);
-
 		posix_exit(0);
 	}
 }
@@ -134,6 +149,11 @@ void hwm_main_loop(void)
 		case IRQCNT:
 			hw_irq_ctrl_timer_triggered();
 			break;
+#ifdef CONFIG_HAS_SDL
+		case SDLEVENTTIMER:
+			sdl_handle_events();
+			break;
+#endif
 		default:
 			/* LCOV_EXCL_START */
 			posix_print_error_and_exit(

boards/posix/native_posix/sdl_events.c

@@ -0,0 +1,75 @@
+/*
+ * Copyright (c) 2018 Jan Van Winkel <[email protected]>
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#include <SDL.h>
+#include "posix_board_if.h"
+#include "posix_trace.h"
+#include "posix_arch_internal.h"
+#include "soc.h"
+#include "hw_models_top.h"
+
+u64_t sdl_event_timer;
+
+static void sdl_handle_window_event(const SDL_Event *event)
+{
+	SDL_Window *window;
+	SDL_Renderer *renderer;
+
+	switch (event->window.event) {
+	case SDL_WINDOWEVENT_EXPOSED:
+
+		window = SDL_GetWindowFromID(event->window.windowID);
+		if (window == NULL) {
+			return;
+		}
+
+		renderer = SDL_GetRenderer(window);
+		if (renderer == NULL) {
+			return;
+		}
+		SDL_RenderPresent(renderer);
+		break;
+	default:
+		break;
+	}
+}
+
+void sdl_handle_events(void)
+{
+	SDL_Event event;
+
+	sdl_event_timer = hwm_get_time() + 10000;
+
+	while (SDL_PollEvent(&event)) {
+		switch (event.type) {
+		case SDL_WINDOWEVENT:
+			sdl_handle_window_event(&event);
+			break;
+		case SDL_QUIT:
+			posix_exit(0);
+			break;
+		default:
+			break;
+		}
+	}
+
+}
+
+static void sdl_init(void)
+{
+	if (SDL_Init(SDL_INIT_VIDEO) != 0) {
+		posix_print_error_and_exit("Error on SDL_Init (%s)\n",
+				SDL_GetError());
+	}
+}
+
+static void sdl_cleanup(void)
+{
+	SDL_Quit();
+}
+
+NATIVE_TASK(sdl_init, PRE_BOOT_2, 1);
+NATIVE_TASK(sdl_cleanup, ON_EXIT, 2);

boards/posix/native_posix/sdl_events.h

@@ -0,0 +1,14 @@
+/*
+ * Copyright (c) 2018 Jan Van Winkel <[email protected]>
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+#ifndef ZEPHYR_BOARD_POSIX_NATIVE_POSIX_SDL_EVENTS_H
+#define ZEPHYR_BOARD_POSIX_NATIVE_POSIX_SDL_EVENTS_H
+
+#include <zephyr/types.h>
+
+void sdl_handle_events(void);
+
+#endif /* ZEPHYR_BOARD_POSIX_NATIVE_POSIX_SDL_EVENTS_H */
+

drivers/display/CMakeLists.txt

@@ -10,3 +10,6 @@ zephyr_sources_ifdef(CONFIG_ILI9340_LCD_ADAFRUIT_1480
 )
 zephyr_sources_ifdef(CONFIG_SSD1306 ssd1306.c)
 zephyr_sources_ifdef(CONFIG_SSD1673 ssd1673.c)
+
+zephyr_sources_ifdef(CONFIG_SDL_DISPLAY display_sdl.c)
+

drivers/display/Kconfig

@@ -20,8 +20,8 @@ source "subsys/logging/Kconfig.template.log_config"
 source "drivers/display/Kconfig.grove"
 
 source "drivers/display/Kconfig.microbit"
-
 source "drivers/display/Kconfig.ili9340"
+source "drivers/display/Kconfig.sdl"
 
 source "drivers/display/Kconfig.ssd1306"
 

drivers/display/Kconfig.sdl

@@ -0,0 +1,30 @@
+# Kconfig - SDL based emulated display configuration options
+
+#
+# Copyright (c) 2018 Jan Van Winkel <[email protected]>
+#
+# SPDX-License-Identifier: Apache-2.0
+#
+
+menuconfig SDL_DISPLAY
+	bool "SDL based emulated display"
+	depends on BOARD_NATIVE_POSIX
+	select HAS_SDL
+	help
+	  Enable SDL based emulated display compliant with display driver API.
+
+if SDL_DISPLAY
+
+config SDL_DISPLAY_DEV_NAME
+	string "SDL display device name"
+	default "SDL_DISPLAY"
+
+config SDL_DISPLAY_X_RES
+	int "X resolution for SDL display"
+	default 320
+
+config SDL_DISPLAY_Y_RES
+	int "Y resolution for SDL display"
+	default 240
+
+endif #SDL_DISPLAY