native SDL drivers refactor so they can work with embedded libCs

boards/posix/common/sdl/CMakeLists.txt

@@ -6,11 +6,19 @@ zephyr_library_compile_definitions(NO_POSIX_CHEATS)
 
 find_package(PkgConfig REQUIRED)
 pkg_search_module(SDL2 REQUIRED sdl2)
-zephyr_include_directories(${SDL2_INCLUDE_DIRS})
+
 if (CONFIG_NATIVE_APPLICATION)
  zephyr_link_libraries(${SDL2_LIBRARIES})
+ zephyr_include_directories(${SDL2_INCLUDE_DIRS})
+ zephyr_compile_options(${SDL2_CFLAGS_OTHER})
 else()
  target_link_options(native_simulator INTERFACE "-l${SDL2_LIBRARIES}")
+ target_compile_options(native_simulator INTERFACE "-I${SDL2_INCLUDE_DIRS}" ${SDL2_CFLAGS_OTHER})
 endif()
-zephyr_compile_options(${SDL2_CFLAGS_OTHER})
+
 zephyr_library_sources(sdl_events.c)
+if (CONFIG_NATIVE_APPLICATION)
+ zephyr_library_sources(sdl_events_bottom.c)
+else()
+ target_sources(native_simulator INTERFACE sdl_events_bottom.c)
+endif()

boards/posix/common/sdl/sdl_events.c

@@ -8,53 +8,19 @@
 #include "soc.h"
 #include <zephyr/arch/posix/posix_trace.h>
 #include <zephyr/kernel.h>
-
-#include <SDL.h>
-
-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;
- }
-}
+#include "sdl_events_bottom.h"
 
 static void sdl_handle_events(void *p1, void *p2, void *p3)
 {
- SDL_Event event;
-
  ARG_UNUSED(p1);
  ARG_UNUSED(p2);
  ARG_UNUSED(p3);
 
  for (;;) {
- 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;
- }
+ int rc = sdl_handle_pending_events();
+
+ if (rc != 0) {
+ posix_exit(0);
  }
 
  k_msleep(CONFIG_SDL_THREAD_INTERVAL);
@@ -63,15 +29,14 @@ static void sdl_handle_events(void *p1, void *p2, void *p3)
 
 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());
+ if (sdl_init_video() != 0) {
+ posix_print_error_and_exit("Error on SDL_Init (%s)\n", sdl_get_error());
  }
 }
 
 static void sdl_cleanup(void)
 {
- SDL_Quit();
+ sdl_quit();
 }
 
 NATIVE_TASK(sdl_init, PRE_BOOT_2, 1);

boards/posix/common/sdl/sdl_events_bottom.c

@@ -0,0 +1,86 @@
+/*
+ * Copyright (c) 2018 Jan Van Winkel <jan.van_winkel@dxplore.eu>
+ * Copyright (c) 2023 Nordic Semiconductor ASA
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * "Bottom" of the SDL event handler for the POSIX architecture.
+ * When built with the native_simulator this will be built in the runner context,
+ * that is, with the host C library, and with the host include paths.
+ *
+ * Therefore it cannot include Zephyr headers
+ */
+
+#include <SDL.h>
+
+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;
+ }
+}
+
+/*
+ * Handle all pending display events
+ * Return 1 if the window was closed, 0 otherwise.
+ */
+int sdl_handle_pending_events(void)
+{
+ SDL_Event event;
+
+ while (SDL_PollEvent(&event)) {
+ switch (event.type) {
+ case SDL_WINDOWEVENT:
+ sdl_handle_window_event(&event);
+ break;
+ case SDL_QUIT:
+ return 1;
+ default:
+ break;
+ }
+ }
+ return 0;
+}
+
+/*
+ * Initialize the SDL library
+ *
+ * Returns 0 on success, something else on failure.
+ */
+int sdl_init_video(void)
+{
+ return SDL_Init(SDL_INIT_VIDEO);
+}
+
+/*
+ * Trampoline to SDL_GetError
+ */
+const char *sdl_get_error(void)
+{
+ return SDL_GetError();
+}
+
+/*
+ * Trampoline to SDL_Quit()
+ */
+void sdl_quit(void)
+{
+ SDL_Quit();
+}

boards/posix/common/sdl/sdl_events_bottom.h

@@ -0,0 +1,25 @@
+/*
+ * Copyright (c) 2023 Nordic Semiconductor ASA
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#ifndef BOARDS_POSIX_COMMON_SDL_SDL_EVENTS_BOTTOM_H
+#define BOARDS_POSIX_COMMON_SDL_SDL_EVENTS_BOTTOM_H
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/* Note: None of these functions are public interfaces. But internal to the SDL event handling */
+
+int sdl_handle_pending_events(void);
+int sdl_init_video(void);
+void sdl_quit(void);
+const char *sdl_get_error(void);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* BOARDS_POSIX_COMMON_SDL_SDL_EVENTS_BOTTOM_H */

boards/posix/native_sim/doc/index.rst

@@ -108,16 +108,16 @@ host libC (:kconfig:option:`CONFIG_EXTERNAL_LIBC`).
  bluetooth, userchan, :kconfig:option:`CONFIG_BT_USERCHAN`, host libC
  can, can native posix, :kconfig:option:`CONFIG_CAN_NATIVE_POSIX_LINUX`, host libC
  console backend, POSIX arch console, :kconfig:option:`CONFIG_POSIX_ARCH_CONSOLE`, all
- display, display SDL, :kconfig:option:`CONFIG_SDL_DISPLAY`, host libC
+ display, display SDL, :kconfig:option:`CONFIG_SDL_DISPLAY`, all
  entropy, native posix entropy, :kconfig:option:`CONFIG_FAKE_ENTROPY_NATIVE_POSIX`, host libC
  eprom, eprom emulator, :kconfig:option:`CONFIG_EEPROM_EMULATOR`, host libC
  ethernet, eth native_posix, :kconfig:option:`CONFIG_ETH_NATIVE_POSIX`, host libC
  flash, flash simulator, :kconfig:option:`CONFIG_FLASH_SIMULATOR`, host libC
  flash, host based flash access, :kconfig:option:`CONFIG_FUSE_FS_ACCESS`, host libC
  gpio, GPIO emulator, :kconfig:option:`CONFIG_GPIO_EMUL`, all
- gpio, SDL GPIO emulator, :kconfig:option:`CONFIG_GPIO_EMUL_SDL`, host libC
+ gpio, SDL GPIO emulator, :kconfig:option:`CONFIG_GPIO_EMUL_SDL`, all
  i2c, I2C emulator, :kconfig:option:`CONFIG_I2C_EMUL`, all
- input, input SDL touch, :kconfig:option:`CONFIG_INPUT_SDL_TOUCH`, host libC
+ input, input SDL touch, :kconfig:option:`CONFIG_INPUT_SDL_TOUCH`, all
  log backend, native backend, :kconfig:option:`CONFIG_LOG_BACKEND_NATIVE_POSIX`, all
  rtc, RTC emul, :kconfig:option:`CONFIG_RTC_EMUL`, all
  serial, uart native posix/PTTY, :kconfig:option:`CONFIG_UART_NATIVE_POSIX`, host libC

drivers/display/CMakeLists.txt

@@ -15,7 +15,6 @@ zephyr_library_sources_ifdef(CONFIG_ILI9488 display_ili9488.c)
 zephyr_library_sources_ifdef(CONFIG_LS0XX ls0xx.c)
 zephyr_library_sources_ifdef(CONFIG_MAX7219 display_max7219.c)
 zephyr_library_sources_ifdef(CONFIG_OTM8009A display_otm8009a.c)
-zephyr_library_sources_ifdef(CONFIG_SDL_DISPLAY display_sdl.c)
 zephyr_library_sources_ifdef(CONFIG_SSD1306 ssd1306.c)
 zephyr_library_sources_ifdef(CONFIG_SSD16XX ssd16xx.c)
 zephyr_library_sources_ifdef(CONFIG_ST7789V display_st7789v.c)
@@ -27,3 +26,12 @@ zephyr_library_sources_ifdef(CONFIG_MICROBIT_DISPLAY
  mb_display.c
  mb_font.c
 )
+
+if (CONFIG_SDL_DISPLAY)
+ zephyr_library_sources(display_sdl.c)
+ if (CONFIG_NATIVE_APPLICATION)
+ zephyr_library_sources(display_sdl_bottom.c)
+ else()
+ target_sources(native_simulator INTERFACE display_sdl_bottom.c)
+ endif()
+endif()

drivers/display/Kconfig.sdl

@@ -7,7 +7,6 @@ menuconfig SDL_DISPLAY
  bool "SDL based emulated display"
  default y
  depends on DT_HAS_ZEPHYR_SDL_DC_ENABLED
- depends on EXTERNAL_LIBC
  select HAS_SDL
  help
  Enable SDL based emulated display compliant with display driver API.