Merge pull request tock#355 from alistair23/alistair/gettimeofday

libtock: sys: Implement _gettimeofday

libtock/alarm.h

@@ -31,6 +31,8 @@ extern "C" {
 
 #include "tock.h"
 
+#include <sys/time.h>
+
 /** \brief Opaque handle to a single-shot alarm.
  *
  * An opaque handle to an alarm created by `alarm_at` or `alarm_in`. Memory
@@ -69,6 +71,18 @@ int alarm_at(uint32_t reference, uint32_t dt, subscribe_upcall, void*, alarm_t *
  */
 void alarm_cancel(alarm_t*);
 
+// Use this to implement _gettimeofday yourself as libtock-c doesn't provide
+// an implementation.
+//
+// See https://github.com/tock/libtock-c/pull/355#issuecomment-1841351091 for
+// more details
+//
+// ```c
+// int _gettimeofday(struct timeval *tv, void *tzvp) {
+//   return gettimeasticks(tv, tzvp);
+// }
+// ```
+int gettimeasticks(struct timeval *tv, void *tzvp);
 
 #ifdef __cplusplus
 }

libtock/alarm_timer.c

@@ -211,3 +211,19 @@ int yield_for_with_timeout(bool* cond, uint32_t ms) {
   timer_cancel(&timer);
   return RETURNCODE_SUCCESS;
 }
+
+int gettimeasticks(struct timeval *tv, __attribute__ ((unused)) void *tzvp)
+{
+  uint32_t frequency, now, seconds, remainder;
+
+  alarm_internal_frequency(&frequency);
+  alarm_internal_read(&now);
+
+  seconds   = now / frequency;
+  remainder = now % frequency;
+
+  tv->tv_sec  = seconds;
+  tv->tv_usec = (remainder * 1000 * 1000) / frequency;
+
+  return 0;
+}