zephyr: Revamp jerry-port.c, add more functions. (#1411)

The file was named jerry-entry.c and not even built. Rename for clarity,
and add jerry_port_fatal(), jerry_port_get_current_time(),
jerry_port_get_time_zone() functions. User-visible result is that
if Date builtin is enabled (e.g. if building "full" config, its
Date.now() method can be used to measure relative time difference,
e.g. for benchmarking).

JerryScript-DCO-1.0-Signed-off-by: Paul Sokolovsky paul.sokolovsky@linaro.org

targets/zephyr/src/Makefile

@@ -19,4 +19,4 @@ endif
 # Adding path for jerry script APIs
 ZEPHYRINCLUDE += -I$(JERRY_INCLUDE)
 
-obj-y += main-zephyr.o getline-zephyr.o
+obj-y += main-zephyr.o getline-zephyr.o jerry-port.o

targets/zephyr/src/jerry-port.c

@@ -1,4 +1,5 @@
 /* Copyright 2016 Intel Corporation
+ * Copyright 2016 Linaro Limited
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -15,6 +16,8 @@
 
 #include <stdarg.h>
 
+#include <zephyr.h>
+
 #include "jerry-port.h"
 
 /**
@@ -46,3 +49,40 @@ jerry_port_log (jerry_log_level_t level, /**< log level */
   vfprintf (stderr, format, args);
   va_end (args);
 } /* jerry_port_log */
+
+
+/**
+ * Provide fatal message implementation for the engine.
+ */
+void jerry_port_fatal (jerry_fatal_code_t code)
+{
+  jerry_port_log (JERRY_LOG_LEVEL_ERROR, "Jerry Fatal Error!\n");
+  while (true);
+} /* jerry_port_fatal */
+
+/**
+ * Implementation of jerry_port_get_current_time.
+ *
+ * @return current timer's counter value in microseconds
+ */
+double
+jerry_port_get_current_time ()
+{
+  int64_t us = sys_tick_get() * sys_clock_us_per_tick;
+  return (double) us / 1000;
+} /* jerry_port_get_current_time */
+
+/**
+ * Dummy function to get the time zone.
+ *
+ * @return true
+ */
+bool
+jerry_port_get_time_zone (jerry_time_zone_t *tz_p)
+{
+  /* We live in UTC. */
+  tz_p->offset = 0;
+  tz_p->daylight_saving_time = 0;
+
+  return true;
+} /* jerry_port_get_time_zone */