Index: share/man/man9/random.9
===================================================================
--- share/man/man9/random.9
+++ share/man/man9/random.9
@@ -26,7 +26,7 @@
 .\"
 .\" $FreeBSD$
 .\" "
-.Dd June 30, 2015
+.Dd July 12, 2015
 .Dt RANDOM 9
 .Os
 .Sh NAME
@@ -34,6 +34,7 @@
 .Nm arc4random ,
 .Nm random ,
 .Nm read_random ,
+.Nm read_random_uio ,
 .Nm srandom
 .Nd supply pseudo-random numbers
 .Sh SYNOPSIS
@@ -50,6 +51,8 @@
 .In sys/random.h
 .Ft int
 .Fn read_random "void *buffer" "int count"
+.Ft int
+.Fn read_random_uio "struct uio *uio" "int flags"
 .Sh DESCRIPTION
 The
 .Fn random
@@ -117,11 +120,26 @@
 that no entropy
 has been returned.
 .Pp
+The
+.Fn read_random_uio
+function behaves identical to
+.Xr read 2
+on
+.Pa /dev/random .
+The
+.Fa uio
+argument points to a buffer where random data should be stored.
+If the random device is unseeded, this function shall block, unless the
+.Fa flags
+argument is equal to
+.Dv O_NONBLOCK .
+.Pp
 All the bits returned by
 .Fn random ,
-.Fn arc4rand
-and
+.Fn arc4rand ,
 .Fn read_random
+and
+.Fn read_random_uio
 are usable.
 For example,
 .Sq Li random()&01
@@ -168,6 +186,11 @@
 function returns
 the number of bytes placed in
 .Fa buffer .
+.Pp
+If successful, the
+.Fn read_random_uio
+function returns zero.
+It returns an error number on failure.
 .Sh AUTHORS
 .An Dan Moschuk
 wrote
Index: sys/compat/cloudabi/cloudabi_random.c
===================================================================
--- sys/compat/cloudabi/cloudabi_random.c
+++ sys/compat/cloudabi/cloudabi_random.c
@@ -26,13 +26,28 @@
 #include <sys/cdefs.h>
 __FBSDID("$FreeBSD$");
 
+#include <sys/types.h>
+#include <sys/random.h>
+#include <sys/uio.h>
+
 #include <compat/cloudabi/cloudabi_proto.h>
 
 int
 cloudabi_sys_random_get(struct thread *td,
     struct cloudabi_sys_random_get_args *uap)
 {
+	struct iovec iov = {
+		.iov_base = uap->buf,
+		.iov_len = uap->nbyte
+	};
+	struct uio uio = {
+		.uio_iov = &iov,
+		.uio_iovcnt = 1,
+		.uio_resid = iov.iov_len,
+		.uio_segflg = UIO_USERSPACE,
+		.uio_rw = UIO_READ,
+		.uio_td = td
+	};
 
-	/* Not implemented. */
-	return (ENOSYS);
+	return (read_random_uio(&uio, 0));
 }
Index: sys/dev/random/randomdev.c
===================================================================
--- sys/dev/random/randomdev.c
+++ sys/dev/random/randomdev.c
@@ -134,6 +134,13 @@
 static int
 randomdev_read(struct cdev *dev __unused, struct uio *uio, int flags)
 {
+
+	return (read_random_uio(uio, flags));
+}
+
+int
+read_random_uio(struct uio *uio, int flags)
+{
 	uint8_t *random_buf;
 	int c, error;
 	ssize_t nbytes;
Index: sys/sys/random.h
===================================================================
--- sys/sys/random.h
+++ sys/sys/random.h
@@ -31,7 +31,10 @@
 
 #ifdef _KERNEL
 
+struct uio;
+
 u_int read_random(void *, u_int);
+int read_random_uio(struct uio *, int);
 
 /*
  * Note: if you add or remove members of random_entropy_source, remember to also update the