drivers: entropy native: Refactor to support embedded libCs

Refactor the host libC accesses to use the native simulator host trampolines when building for the native_simulator. For native_posix we keep accessing the host libC directly. In this way we support building this driver with embedded libCs. Signed-off-by: Alberto Escolar Piedras <alberto.escolar.piedras@nordicsemi.no>
zephyrproject-rtos · Jul 5, 2023 · d736e94 · d736e94
1 parent c3dc01d
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Showing 3 changed files with 12 additions and 4 deletions.
diff --git a/boards/posix/native_sim/doc/index.rst b/boards/posix/native_sim/doc/index.rst
@@ -109,7 +109,7 @@ host libC (:kconfig:option:`CONFIG_EXTERNAL_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
-     entropy, native posix entropy, :kconfig:option:`CONFIG_FAKE_ENTROPY_NATIVE_POSIX`, host libC
+     entropy, native posix entropy, :kconfig:option:`CONFIG_FAKE_ENTROPY_NATIVE_POSIX`, all
      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

diff --git a/drivers/entropy/Kconfig.native_posix b/drivers/entropy/Kconfig.native_posix
@@ -4,7 +4,6 @@ config FAKE_ENTROPY_NATIVE_POSIX
 	bool "Native posix entropy driver"
 	default y
 	depends on DT_HAS_ZEPHYR_NATIVE_POSIX_RNG_ENABLED
-	depends on EXTERNAL_LIBC
 	select ENTROPY_HAS_DRIVER
 	help
 	  This option enables the test random number generator for the

diff --git a/drivers/entropy/fake_entropy_native_posix.c b/drivers/entropy/fake_entropy_native_posix.c
@@ -23,6 +23,15 @@
 #include "soc.h"
 #include "cmdline.h" /* native_posix command line options header */
 
+#if defined(CONFIG_NATIVE_LIBRARY)
+#include "nsi_host_trampolines.h"
+#define host_random() nsi_host_random()
+#define host_srandom(x) nsi_host_srandom(x)
+#else
+#define host_random() random()
+#define host_srandom(x) srandom(x)
+#endif /* defined(CONFIG_NATIVE_LIBRARY) */
+
 static unsigned int seed = 0x5678;
 
 static int entropy_native_posix_get_entropy(const struct device *dev,
@@ -36,7 +45,7 @@ static int entropy_native_posix_get_entropy(const struct device *dev,
 		 * Note that only 1 thread (Zephyr thread or HW models), runs at
 		 * a time, therefore there is no need to use random_r()
 		 */
-		long int value = random();
+		long value = host_random();
 
 		size_t to_copy = MIN(length, sizeof(long int));
 
@@ -64,7 +73,7 @@ static int entropy_native_posix_get_entropy_isr(const struct device *dev,
 static int entropy_native_posix_init(const struct device *dev)
 {
 	ARG_UNUSED(dev);
-	srandom(seed);
+	host_srandom(seed);
 	posix_print_warning("WARNING: "
 			    "Using a test - not safe - entropy source\n");
 	return 0;