[core] Implement POSIX gettimeofday() and settimeofday()

arduino/libretuya/core/LibreTuyaConfig.h

@@ -77,6 +77,11 @@
 #define LT_UART_DEFAULT_SERIAL LT_UART_DEFAULT_PORT
 #endif
 
+// Misc options
+#ifndef LT_USE_TIME
+#define LT_USE_TIME 0
+#endif
+
 // Per-module logging output - applies to all loglevels
 #ifndef LT_DEBUG_ALL
 #define LT_DEBUG_ALL 0

arduino/libretuya/core/main.cpp

@@ -41,6 +41,12 @@ void runPeriodicTasks() {
 		periodicTasks[0] = millis();
 	}
 #endif
+#if LT_USE_TIME
+	if (millis() - periodicTasks[1] > 10000) {
+		gettimeofday(NULL, NULL);
+		periodicTasks[1] = millis();
+	}
+#endif
 }
 
 int main(void) {

arduino/libretuya/posix/lt_posix_api.h

@@ -1,5 +1,7 @@
 /* Copyright (c) Kuba Szczodrzyński 2022-05-16. */
 
+#include <sys/time.h>
+
 extern char *strdup(const char *);
 extern int strcasecmp(const char *s1, const char *s2);
 extern int strncasecmp(const char *s1, const char *s2, size_t n);

arduino/libretuya/posix/time.c

@@ -0,0 +1,50 @@
+/* Copyright (c) Kuba Szczodrzyński 2022-09-03. */
+
+#include <Arduino.h>
+#include <errno.h>
+
+static uint32_t reset_epoch	 = 0; // epoch corresponding to millis() == 0
+static uint32_t reset_millis = 0; // millis() when epoch reset was performed
+
+int __wrap_gettimeofday(struct timeval *tv, void *tz) {
+	if (millis() < reset_millis) {
+		// the clock overflowed
+		reset_epoch += UINT32_MAX / 1000;
+		reset_millis = millis();
+	}
+	if (!tv) {
+		errno = EINVAL;
+		return -1;
+	}
+	unsigned long m = millis();
+	tv->tv_sec		= reset_epoch + (m / 1000);
+	tv->tv_usec		= (m % 1000) * 1000;
+	return 0;
+}
+
+int __wrap_settimeofday(const struct timeval *tv, const struct timezone *tz) {
+	if (!tv) {
+		errno = EINVAL;
+		return -1;
+	}
+	unsigned long m = millis();
+	reset_epoch		= tv->tv_sec - (m / 1000);
+	reset_millis	= m;
+	return 0;
+}
+
+int gettimeofday(struct timeval *tv, void *tz) {
+	return __wrap_gettimeofday(tv, tz);
+}
+
+int settimeofday(const struct timeval *tv, const struct timezone *tz) {
+	return __wrap_settimeofday(tv, tz);
+}
+
+int _gettimeofday(struct timeval *tv, void *tz) {
+	return __wrap_gettimeofday(tv, tz);
+}
+
+int _settimeofday(const struct timeval *tv, const struct timezone *tz) {
+	return __wrap_settimeofday(tv, tz);
+}

builder/arduino-common.py

@@ -30,6 +30,9 @@ env.Append(
         # wrappers from port/printf/
         "-Wl,-wrap,putchar",
         "-Wl,-wrap,puts",
+        # wrappers from posix/time.c
+        "-Wl,-wrap,gettimeofday",
+        "-Wl,-wrap,settimeofday",
     ],
 )
 # Arduino core uses __libc_init_array

docs/reference/config.md

@@ -107,3 +107,7 @@ The meaning of most flags is as follows:
 - `LT_ARD_HAS_MD5` - MD5 library implemented, `MD5Impl.h` available
 - `LT_ARD_HAS_WIFI` - WiFi library implemented, `WiFiData.h` available
 - `LT_HEAP_FUNC` - function name used to get available heap size (for `LT_HEAP_I()`)
+
+### Misc options
+
+- `LT_USE_TIME` - enables implementation of `gettimeofday()` and `settimeofday()`; checks for `millis()` overflows periodically