Restructured the lwip raw comat code.

Added replacements for the time functions on ESP8266.

replacements/time.c

@@ -0,0 +1,147 @@
+/*
+ * time.c - ESP8266-specific functions for SNTP
+ * Copyright (c) 2015 Peter Dobler. All rights reserved.
+ * This file is part of the esp8266 core for Arduino environment.
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
+ * See the GNU Lesser General Public License for more details.
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
+ *
+ */
+
+#include <time.h>
+#include <sntp.h>
+
+extern uint32_t system_get_time(void);
+extern uint64_t system_mktime(uint32_t year, uint32_t mon, uint32_t day, uint32_t hour, uint32_t min, uint32_t sec);
+
+static int errno_var = 0;
+
+int* __errno(void) {
+    // DEBUGV("__errno is called last error: %d (not current)\n", errno_var);
+    return &errno_var;
+}
+
+unsigned long millis(void)
+{
+	return system_get_time() / 1000UL;
+}
+
+unsigned long micros(void)
+{
+	return system_get_time();
+}
+
+#ifndef _TIMEVAL_DEFINED
+#define _TIMEVAL_DEFINED
+struct timeval {
+  time_t      tv_sec;
+  suseconds_t tv_usec;
+};
+#endif
+
+extern char* sntp_asctime(const struct tm *t);
+extern struct tm* sntp_localtime(const time_t *clock);
+
+// time gap in seconds from 01.01.1900 (NTP time) to 01.01.1970 (UNIX time)
+#define DIFF1900TO1970 2208988800UL
+
+static int s_daylightOffset_sec = 0;
+static long s_timezone_sec = 0;
+static time_t s_bootTime = 0;
+
+// calculate offset used in gettimeofday
+static void ensureBootTimeIsSet()
+{
+    if (!s_bootTime)
+    {
+        time_t now = sntp_get_current_timestamp();
+        if (now)
+        {
+            s_bootTime =  now - millis() / 1000;
+        }
+    }
+}
+
+static void setServer(int id, const char* name_or_ip)
+{
+    if (name_or_ip)
+    {
+        //TODO: check whether server is given by name or IP
+        sntp_setservername(id, (char*) name_or_ip);
+    }
+}
+
+void configTime(int timezone, int daylightOffset_sec, const char* server1, const char* server2, const char* server3)
+{
+    sntp_stop();
+
+    setServer(0, server1);
+    setServer(1, server2);
+    setServer(2, server3);
+
+    s_timezone_sec = timezone;
+    s_daylightOffset_sec = daylightOffset_sec;
+    sntp_set_timezone(timezone/3600);
+    sntp_init();
+}
+
+int clock_gettime(clockid_t unused, struct timespec *tp)
+{
+    tp->tv_sec  = millis() / 1000;
+    tp->tv_nsec = micros() * 1000;
+    return 0;
+}
+
+// seconds since 1970
+time_t mktime(struct tm *t)
+{
+    // system_mktime expects month in range 1..12
+    #define START_MONTH 1
+    return DIFF1900TO1970 + system_mktime(t->tm_year, t->tm_mon + START_MONTH, t->tm_mday, t->tm_hour, t->tm_min, t->tm_sec);
+}
+
+time_t time(time_t * t)
+{
+    time_t seconds = sntp_get_current_timestamp();
+    if (t)
+    {
+        *t = seconds;
+    }
+    return seconds;
+}
+
+char* asctime(const struct tm *t)
+{
+    return sntp_asctime(t);
+}
+
+struct tm* localtime(const time_t *clock)
+{
+    return sntp_localtime(clock);
+}
+
+char* ctime(const time_t *t)
+{
+    struct tm* p_tm = localtime(t);
+    char* result = asctime(p_tm);
+    return result;
+}
+
+int gettimeofday(struct timeval *tp, void *tzp)
+{
+    if (tp)
+    {
+        ensureBootTimeIsSet();
+        tp->tv_sec  = (s_bootTime + millis()) / 1000;
+        tp->tv_usec = micros() * 1000;
+    }
+    return 0;
+}