Index: head/sys/compat/cloudabi/cloudabi_clock.c
===================================================================
--- head/sys/compat/cloudabi/cloudabi_clock.c	(revision 285753)
+++ head/sys/compat/cloudabi/cloudabi_clock.c	(revision 285754)
@@ -1,47 +1,125 @@
 /*-
  * Copyright (c) 2015 Nuxi, https://nuxi.nl/
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
  *    documentation and/or other materials provided with the distribution.
  *
  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  * SUCH DAMAGE.
  */
 
 #include <sys/cdefs.h>
 __FBSDID("$FreeBSD$");
 
+#include <sys/param.h>
+#include <sys/proc.h>
+#include <sys/stdint.h>
+#include <sys/syscallsubr.h>
+
 #include <compat/cloudabi/cloudabi_proto.h>
+#include <compat/cloudabi/cloudabi_syscalldefs.h>
+#include <compat/cloudabi/cloudabi_util.h>
 
+/* Converts a CloudABI clock ID to a FreeBSD clock ID. */
+static int
+cloudabi_convert_clockid(cloudabi_clockid_t in, clockid_t *out)
+{
+	switch (in) {
+	case CLOUDABI_CLOCK_MONOTONIC:
+		*out = CLOCK_MONOTONIC;
+		return (0);
+	case CLOUDABI_CLOCK_PROCESS_CPUTIME_ID:
+		*out = CLOCK_PROCESS_CPUTIME_ID;
+		return (0);
+	case CLOUDABI_CLOCK_REALTIME:
+		*out = CLOCK_REALTIME;
+		return (0);
+	case CLOUDABI_CLOCK_THREAD_CPUTIME_ID:
+		*out = CLOCK_THREAD_CPUTIME_ID;
+		return (0);
+	default:
+		return (EINVAL);
+	}
+}
+
+/* Converts a struct timespec to a CloudABI timestamp. */
 int
+cloudabi_convert_timespec(const struct timespec *in, cloudabi_timestamp_t *out)
+{
+	cloudabi_timestamp_t s, ns;
+
+	if (in->tv_sec < 0) {
+		/* Timestamps from before the Epoch cannot be expressed. */
+		*out = 0;
+		return (EOVERFLOW);
+	}
+	s = in->tv_sec;
+	ns = in->tv_nsec;
+	if (s > UINT64_MAX / 1000000000 ||
+	    (s == UINT64_MAX / 1000000000 && ns > UINT64_MAX % 1000000000)) {
+		/* Addition of seconds and nanoseconds would overflow. */
+		*out = UINT64_MAX;
+		return (EOVERFLOW);
+	}
+	*out = s * 1000000000 + ns;
+	return (0);
+}
+
+int
 cloudabi_sys_clock_res_get(struct thread *td,
     struct cloudabi_sys_clock_res_get_args *uap)
 {
+	struct timespec ts;
+	cloudabi_timestamp_t cts;
+	int error;
+	clockid_t clockid;
 
-	/* Not implemented. */
-	return (ENOSYS);
+	error = cloudabi_convert_clockid(uap->clock_id, &clockid);
+	if (error != 0)
+		return (error);
+	error = kern_clock_getres(td, clockid, &ts);
+	if (error != 0)
+		return (error);
+	error = cloudabi_convert_timespec(&ts, &cts);
+	if (error != 0)
+		return (error);
+	td->td_retval[0] = cts;
+	return (0);
 }
 
 int
 cloudabi_sys_clock_time_get(struct thread *td,
     struct cloudabi_sys_clock_time_get_args *uap)
 {
+	struct timespec ts;
+	cloudabi_timestamp_t cts;
+	int error;
+	clockid_t clockid;
 
-	/* Not implemented. */
-	return (ENOSYS);
+	error = cloudabi_convert_clockid(uap->clock_id, &clockid);
+	if (error != 0)
+		return (error);
+	error = kern_clock_gettime(td, clockid, &ts);
+	if (error != 0)
+		return (error);
+	error = cloudabi_convert_timespec(&ts, &cts);
+	if (error != 0)
+		return (error);
+	td->td_retval[0] = cts;
+	return (0);
 }
Index: head/sys/compat/cloudabi/cloudabi_util.h
===================================================================
--- head/sys/compat/cloudabi/cloudabi_util.h	(revision 285753)
+++ head/sys/compat/cloudabi/cloudabi_util.h	(revision 285754)
@@ -1,36 +1,41 @@
 /*-
  * Copyright (c) 2015 Nuxi, https://nuxi.nl/
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
  *    documentation and/or other materials provided with the distribution.
  *
  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  * SUCH DAMAGE.
  *
  * $FreeBSD$
  */
 
 #ifndef _CLOUDABI_UTIL_H_
 #define	_CLOUDABI_UTIL_H_
 
 #include <compat/cloudabi/cloudabi_syscalldefs.h>
 
+struct timespec;
+
 /* Converts a FreeBSD errno to a CloudABI errno. */
 cloudabi_errno_t cloudabi_convert_errno(int);
+
+/* Converts a struct timespec to a CloudABI timestamp. */
+int cloudabi_convert_timespec(const struct timespec *, cloudabi_timestamp_t *);
 
 #endif