diff --git a/sys/compat/mach/files.mach b/sys/compat/mach/files.mach
index b00c47c645e3..1baa7057ca75 100644
--- a/sys/compat/mach/files.mach
+++ b/sys/compat/mach/files.mach
@@ -1,4 +1,4 @@
-#	$NetBSD: files.mach,v 1.9 2002/12/07 21:23:03 manu Exp $
+#	$NetBSD: files.mach,v 1.10 2002/12/12 23:18:20 manu Exp $
 #
 # Config file description for machine-independent Mach compat code.
 # Included by ports that need it.
@@ -15,6 +15,7 @@ file	compat/mach/mach_misc.c		compat_mach | compat_darwin
 file	compat/mach/mach_message.c	compat_mach | compat_darwin
 file	compat/mach/mach_namemap.c	compat_mach | compat_darwin
 file	compat/mach/mach_port.c		compat_mach | compat_darwin
+file	compat/mach/mach_semaphore.c	compat_mach | compat_darwin
 file	compat/mach/mach_syscalls.c	compat_mach | compat_darwin
 file	compat/mach/mach_sysent.c	compat_mach | compat_darwin
 file	compat/mach/mach_task.c		compat_mach | compat_darwin
diff --git a/sys/compat/mach/mach_exec.c b/sys/compat/mach/mach_exec.c
index 0d6e78a5af1a..8d66dd5559e9 100644
--- a/sys/compat/mach/mach_exec.c
+++ b/sys/compat/mach/mach_exec.c
@@ -1,4 +1,4 @@
-/*	$NetBSD: mach_exec.c,v 1.13 2002/12/07 15:33:01 manu Exp $	 */
+/*	$NetBSD: mach_exec.c,v 1.14 2002/12/12 23:18:20 manu Exp $	 */
 
 /*-
  * Copyright (c) 2001 The NetBSD Foundation, Inc.
@@ -37,12 +37,13 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: mach_exec.c,v 1.13 2002/12/07 15:33:01 manu Exp $");
+__KERNEL_RCSID(0, "$NetBSD: mach_exec.c,v 1.14 2002/12/12 23:18:20 manu Exp $");
 
 #include <sys/param.h>
 #include <sys/systm.h>
 #include <sys/proc.h>
 #include <sys/exec.h>
+#include <sys/queue.h>
 #include <sys/exec_macho.h>
 #include <sys/malloc.h>
 
@@ -52,6 +53,8 @@ __KERNEL_RCSID(0, "$NetBSD: mach_exec.c,v 1.13 2002/12/07 15:33:01 manu Exp $");
 #include <uvm/uvm_param.h>
 
 #include <compat/mach/mach_types.h>
+#include <compat/mach/mach_message.h>
+#include <compat/mach/mach_semaphore.h>
 #include <compat/mach/mach_exec.h>
 
 static void mach_e_proc_exec(struct proc *, struct exec_package *);
@@ -224,6 +227,10 @@ mach_e_proc_init(p, vmspace)
 	med = (struct mach_emuldata *)p->p_emuldata;
 	med->med_p = 0;
 
+	/* Initialize semaphores if needed. Not the best place for that... */
+	if (mach_semaphore_cold == 1)
+		mach_semaphore_init();
+
 	return;
 }
 
@@ -234,5 +241,7 @@ mach_e_proc_exit(p)
 	free(p->p_emuldata, M_EMULDATA);
 	p->p_emuldata = NULL;
 
+	mach_semaphore_cleanup(p);
+
 	return;
 }
diff --git a/sys/compat/mach/mach_exec.h b/sys/compat/mach/mach_exec.h
index 236811300101..4513ed6059fa 100644
--- a/sys/compat/mach/mach_exec.h
+++ b/sys/compat/mach/mach_exec.h
@@ -1,4 +1,4 @@
-/*	$NetBSD: mach_exec.h,v 1.6 2002/12/07 15:33:01 manu Exp $	 */
+/*	$NetBSD: mach_exec.h,v 1.7 2002/12/12 23:18:20 manu Exp $	 */
 
 /*-
  * Copyright (c) 2001 The NetBSD Foundation, Inc.
@@ -45,6 +45,7 @@
 
 struct mach_emuldata {
 	mach_cproc_t med_p;
+	int med_thpri;
 };
 
 int exec_mach_copyargs(struct proc *, struct exec_package *, 
diff --git a/sys/compat/mach/mach_misc.c b/sys/compat/mach/mach_misc.c
index a64707763081..b6f25cf8775d 100644
--- a/sys/compat/mach/mach_misc.c
+++ b/sys/compat/mach/mach_misc.c
@@ -1,4 +1,4 @@
-/*	$NetBSD: mach_misc.c,v 1.14 2002/11/29 17:08:16 manu Exp $	 */
+/*	$NetBSD: mach_misc.c,v 1.15 2002/12/12 23:18:21 manu Exp $	 */
 
 /*-
  * Copyright (c) 2001 The NetBSD Foundation, Inc.
@@ -43,7 +43,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: mach_misc.c,v 1.14 2002/11/29 17:08:16 manu Exp $");
+__KERNEL_RCSID(0, "$NetBSD: mach_misc.c,v 1.15 2002/12/12 23:18:21 manu Exp $");
 
 #include <sys/param.h>
 #include <sys/systm.h>
@@ -85,17 +85,6 @@ __KERNEL_RCSID(0, "$NetBSD: mach_misc.c,v 1.14 2002/11/29 17:08:16 manu Exp $");
 #include <compat/mach/mach_clock.h>
 #include <compat/mach/mach_syscallargs.h>
 
-int
-mach_sys_semaphore_signal_trap(struct proc *p, void *v, register_t *r) {
-#ifdef DEBUG_MACH
-	struct mach_sys_semaphore_signal_trap_args *ap = v;
-#endif
-	*r = 0;
-	DPRINTF(("mach_sys_semaphore_signal_trap(0x%x);\n",
-	    SCARG(ap, signal_name)));
-	return 0;
-}
-
 
 int
 mach_sys_semaphore_signal_all_trap(struct proc *p, void *v, register_t *r) {
@@ -121,18 +110,6 @@ mach_sys_semaphore_signal_thread_trap(struct proc *p, void *v, register_t *r) {
 }
 
 
-int
-mach_sys_semaphore_wait_trap(struct proc *p, void *v, register_t *r) {
-#ifdef DEBUG_MACH
-	struct mach_sys_semaphore_wait_trap_args *ap = v;
-#endif
-	*r = 0;
-	DPRINTF(("mach_sys_semaphore_wait_trap(0x%x);\n",
-	    SCARG(ap, wait_name)));
-	return 0;
-}
-
-
 int
 mach_sys_semaphore_wait_signal_trap(struct proc *p, void *v, register_t *r) {
 #ifdef DEBUG_MACH
@@ -260,18 +237,6 @@ mach_sys_swtch(struct proc *p, void *v, register_t *r) {
 }
 
 
-int
-mach_sys_syscall_thread_switch(struct proc *p, void *v, register_t *r) {
-#ifdef DEBUG_MACH
-	struct mach_sys_syscall_thread_switch_args *ap = v;
-#endif
-	*r = 0;
-	DPRINTF(("mach_sys_syscall_thread_switch(0x%x, %d, %d);\n",
-	    SCARG(ap, thread_name), SCARG(ap, option), SCARG(ap, option_time)));
-	return 0;
-}
-
-
 int
 mach_sys_wait_until(struct proc *p, void *v, register_t *r) {
 #ifdef DEBUG_MACH
diff --git a/sys/compat/mach/mach_namemap.c b/sys/compat/mach/mach_namemap.c
index fba25eda58e8..14f6cf3510a2 100644
--- a/sys/compat/mach/mach_namemap.c
+++ b/sys/compat/mach/mach_namemap.c
@@ -1,4 +1,4 @@
-/*	$NetBSD: mach_namemap.c,v 1.10 2002/12/12 00:29:24 manu Exp $ */
+/*	$NetBSD: mach_namemap.c,v 1.11 2002/12/12 23:18:21 manu Exp $ */
 
 /*-
  * Copyright (c) 2002 The NetBSD Foundation, Inc.
@@ -37,7 +37,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: mach_namemap.c,v 1.10 2002/12/12 00:29:24 manu Exp $");
+__KERNEL_RCSID(0, "$NetBSD: mach_namemap.c,v 1.11 2002/12/12 23:18:21 manu Exp $");
 
 #include <sys/types.h>
 #include <sys/param.h>
@@ -50,6 +50,7 @@ __KERNEL_RCSID(0, "$NetBSD: mach_namemap.c,v 1.10 2002/12/12 00:29:24 manu Exp $
 #include <compat/mach/mach_port.h>
 #include <compat/mach/mach_task.h>
 #include <compat/mach/mach_thread.h>
+#include <compat/mach/mach_semaphore.h>
 #include <compat/mach/mach_vm.h>
 
 struct mach_subsystem_namemap mach_namemap[] = {
@@ -70,6 +71,8 @@ struct mach_subsystem_namemap mach_namemap[] = {
 	{ 3409, mach_task_get_special_port, "task_get_special_port" },
 	{ 3410, mach_task_set_special_port, "task_set_special_port" },
 	{ 3412, mach_thread_create_running, "thread_create_running" },
+	{ 3418, mach_semaphore_create, "semaphore_create" },
+	{ 3419, mach_semaphore_destroy, "semaphore_destroy" },
 	{ 3616, mach_thread_policy, "thread_policy" },
 	{ 3801, mach_vm_allocate, "vm_allocate" },
 	{ 3802, mach_vm_deallocate, "vm_deallocate" },
diff --git a/sys/compat/mach/mach_semaphore.c b/sys/compat/mach/mach_semaphore.c
new file mode 100644
index 000000000000..dff36de36cf1
--- /dev/null
+++ b/sys/compat/mach/mach_semaphore.c
@@ -0,0 +1,309 @@
+/*	$NetBSD: mach_semaphore.c,v 1.1 2002/12/12 23:18:21 manu Exp $ */
+
+/*-
+ * Copyright (c) 2002 The NetBSD Foundation, Inc.
+ * All rights reserved.
+ *
+ * This code is derived from software contributed to The NetBSD Foundation
+ * by Emmanuel Dreyfus
+ *
+ * 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.
+ * 3. All advertising materials mentioning features or use of this software
+ *    must display the following acknowledgement:
+ *        This product includes software developed by the NetBSD
+ *        Foundation, Inc. and its contributors.
+ * 4. Neither the name of The NetBSD Foundation nor the names of its
+ *    contributors may be used to endorse or promote products derived
+ *    from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. 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 FOUNDATION 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>
+__KERNEL_RCSID(0, "$NetBSD: mach_semaphore.c,v 1.1 2002/12/12 23:18:21 manu Exp $");
+
+#include <sys/types.h>
+#include <sys/param.h>
+#include <sys/systm.h>
+#include <sys/signal.h>
+#include <sys/pool.h>
+#include <sys/lock.h>
+#include <sys/malloc.h>
+#include <sys/proc.h>
+
+#include <compat/mach/mach_types.h>
+#include <compat/mach/mach_message.h>
+#include <compat/mach/mach_semaphore.h>
+#include <compat/mach/mach_clock.h>
+#include <compat/mach/mach_syscallargs.h>
+
+/* Semaphore list, lock, pools and inited flag */
+static LIST_HEAD(mach_semaphore_list, mach_semaphore) mach_semaphore_list; 
+static struct lock mach_semaphore_list_lock;
+static struct pool mach_semaphore_list_pool;
+static struct pool mach_waiting_proc_pool;
+int mach_semaphore_cold = 1; 
+
+/* Function to manipulate them */
+static struct mach_semaphore *mach_semaphore_get(int, int);
+static void mach_semaphore_put(struct mach_semaphore *);
+static struct mach_waiting_proc *mach_waiting_proc_get
+    (struct proc *, struct mach_semaphore *);
+static void mach_waiting_proc_put
+    (struct mach_waiting_proc *, struct mach_semaphore *, int);
+
+int
+mach_sys_semaphore_wait_trap(p, v, retval)
+	struct proc *p;
+	void *v;
+	register_t *retval;
+{
+	struct mach_sys_semaphore_wait_trap_args /* {
+		syscallarg(mach_port_name_t) wait_name;
+	} */ *uap = v;
+	struct mach_semaphore *ms;
+	struct mach_waiting_proc *mwp;
+	int blocked = 0;
+
+	ms = (struct mach_semaphore *)SCARG(uap, wait_name);
+
+	lockmgr(&ms->ms_lock, LK_EXCLUSIVE, NULL);	
+	ms->ms_value--;
+	if (ms->ms_value < 0)
+		blocked = 1;
+	lockmgr(&ms->ms_lock, LK_RELEASE, NULL);	
+
+	if (blocked != 0) {
+		mwp = mach_waiting_proc_get(p, ms);	
+		while (ms->ms_value < 0)
+			tsleep(mwp, PZERO, "sem_wait", 0);
+		mach_waiting_proc_put(mwp, ms, 0);
+	}
+	return 0;
+}
+
+int
+mach_sys_semaphore_signal_trap(p, v, retval)
+	struct proc *p;
+	void *v;
+	register_t *retval;
+{
+	struct mach_sys_semaphore_signal_trap_args /* {
+		syscallarg(mach_port_name_t) signal_name;
+	} */ *uap = v;
+	struct mach_semaphore *ms;
+	struct mach_waiting_proc *mwp;
+	int unblocked = 0;
+
+	ms = (struct mach_semaphore *)SCARG(uap, signal_name);
+
+	lockmgr(&ms->ms_lock, LK_EXCLUSIVE, NULL);	
+	ms->ms_value++;
+	if (ms->ms_value >= 0)
+		unblocked = 1;
+	lockmgr(&ms->ms_lock, LK_RELEASE, NULL);	
+
+	if (unblocked != 0) {
+		lockmgr(&ms->ms_lock, LK_SHARED, NULL);	
+		mwp = TAILQ_FIRST(&ms->ms_waiting);
+		wakeup(mwp);
+		lockmgr(&ms->ms_lock, LK_RELEASE, NULL);	
+	}
+	return 0;
+}
+
+int 
+mach_semaphore_create(p, msgh, maxlen, dst)
+	struct proc *p;
+	mach_msg_header_t *msgh;
+	size_t maxlen;
+	mach_msg_header_t *dst;
+{
+	mach_semaphore_create_request_t req;
+	mach_semaphore_create_reply_t rep;
+	struct mach_semaphore *ms;
+	int error;
+
+	if ((error = copyin(msgh, &req, sizeof(req))) != 0)
+		return error;
+
+	ms = mach_semaphore_get(req.req_value, req.req_policy);
+	
+	bzero(&rep, sizeof(rep));
+
+	rep.rep_msgh.msgh_bits =
+	    MACH_MSGH_REPLY_LOCAL_BITS(MACH_MSG_TYPE_MOVE_SEND_ONCE);
+	rep.rep_msgh.msgh_size = sizeof(rep) - sizeof(rep.rep_trailer);
+	rep.rep_msgh.msgh_local_port = req.req_msgh.msgh_local_port;
+	rep.rep_msgh.msgh_id = req.req_msgh.msgh_id + 100;
+	rep.rep_sem.name = (mach_port_t)ms; /* Waiting for better */
+	rep.rep_trailer.msgh_trailer_size = 8;
+
+	return MACH_MSG_RETURN(p, &rep, msgh, sizeof(rep), maxlen, dst);
+}
+
+int 
+mach_semaphore_destroy(p, msgh, maxlen, dst)
+	struct proc *p;
+	mach_msg_header_t *msgh;
+	size_t maxlen;
+	mach_msg_header_t *dst;
+{
+	mach_semaphore_destroy_request_t req;
+	mach_semaphore_destroy_reply_t rep;
+	struct mach_semaphore *ms;
+	int error;
+
+	if ((error = copyin(msgh, &req, sizeof(req))) != 0)
+		return error;
+
+	ms = (struct mach_semaphore *)req.req_sem.name;
+	mach_semaphore_put(ms);
+	
+	bzero(&rep, sizeof(rep));
+
+	rep.rep_msgh.msgh_bits =
+	    MACH_MSGH_REPLY_LOCAL_BITS(MACH_MSG_TYPE_MOVE_SEND_ONCE);
+	rep.rep_msgh.msgh_size = sizeof(rep) - sizeof(rep.rep_trailer);
+	rep.rep_msgh.msgh_local_port = req.req_msgh.msgh_local_port;
+	rep.rep_msgh.msgh_id = req.req_msgh.msgh_id + 100;
+	rep.rep_trailer.msgh_trailer_size = 8;
+
+	return MACH_MSG_RETURN(p, &rep, msgh, sizeof(rep), maxlen, dst);
+}
+
+void
+mach_semaphore_init(void)
+{
+	LIST_INIT(&mach_semaphore_list);
+	lockinit(&mach_semaphore_list_lock, PZERO|PCATCH, "mach_sem", 0, 0);
+	pool_init(&mach_semaphore_list_pool, sizeof (struct mach_semaphore),
+	    0, 0, 128, "mach_sem_pool", NULL);
+	pool_init(&mach_waiting_proc_pool, sizeof (struct mach_waiting_proc),
+	    0, 0, 128, "mach_waitp_pool", NULL);
+	mach_semaphore_cold = 0;
+
+	return;
+}
+
+static struct mach_semaphore *
+mach_semaphore_get(value, policy)
+	int value;
+	int policy;
+{
+	struct mach_semaphore *ms;
+
+	ms = (struct mach_semaphore *)pool_get(&mach_semaphore_list_pool,
+	    M_WAITOK);
+	ms->ms_value = value;
+	ms->ms_policy = policy;
+	TAILQ_INIT(&ms->ms_waiting);
+	lockinit(&ms->ms_lock, PZERO|PCATCH, "mach_waitp", 0, 0);
+
+	lockmgr(&mach_semaphore_list_lock, LK_EXCLUSIVE, NULL);
+	LIST_INSERT_HEAD(&mach_semaphore_list, ms, ms_list);
+	lockmgr(&mach_semaphore_list_lock, LK_RELEASE, NULL);
+
+	return ms;
+}
+
+static void
+mach_semaphore_put(ms)
+	struct mach_semaphore *ms;
+{
+	struct mach_waiting_proc *mwp;
+
+	lockmgr(&ms->ms_lock, LK_EXCLUSIVE, NULL);	
+	while ((mwp = TAILQ_FIRST(&ms->ms_waiting)) != NULL) 
+		mach_waiting_proc_put(mwp, ms, 0);
+	lockmgr(&ms->ms_lock, LK_RELEASE, NULL);	
+	lockmgr(&ms->ms_lock, LK_DRAIN, NULL);	
+
+	lockmgr(&mach_semaphore_list_lock, LK_EXCLUSIVE, NULL);
+	LIST_REMOVE(ms, ms_list);
+	lockmgr(&mach_semaphore_list_lock, LK_RELEASE, NULL);
+
+	pool_put(&mach_semaphore_list_pool, ms);
+
+	return;
+}
+
+static struct mach_waiting_proc *
+mach_waiting_proc_get(p, ms)
+	struct proc *p;
+	struct mach_semaphore *ms;
+{
+	struct mach_waiting_proc *mwp;
+
+	mwp = (struct mach_waiting_proc *)pool_get(&mach_waiting_proc_pool,
+	    M_WAITOK);
+	mwp->mwp_p = p;
+
+	lockmgr(&ms->ms_lock, LK_EXCLUSIVE, NULL);	
+	TAILQ_INSERT_TAIL(&ms->ms_waiting, mwp, mwp_list);
+	lockmgr(&ms->ms_lock, LK_RELEASE, NULL);	
+
+	return mwp;
+}
+
+static void
+mach_waiting_proc_put(mwp, ms, locked)
+	struct mach_waiting_proc *mwp;
+	struct mach_semaphore *ms;
+	int locked;
+{
+	if (!locked)
+		lockmgr(&ms->ms_lock, LK_EXCLUSIVE, NULL);	
+	TAILQ_REMOVE(&ms->ms_waiting, mwp, mwp_list);
+	if (!locked)
+		lockmgr(&ms->ms_lock, LK_RELEASE, NULL);	
+	pool_put(&mach_waiting_proc_pool, mwp);
+
+	return;
+}
+
+/* 
+ * Cleanup after process exit. Need improvements, there 
+ * can be some memory leaks here.
+ */
+void
+mach_semaphore_cleanup(p)
+	struct proc *p;
+{
+	struct mach_semaphore *ms;
+	struct mach_waiting_proc *mwp;
+
+	lockmgr(&mach_semaphore_list_lock, LK_SHARED, NULL);
+	LIST_FOREACH(ms, &mach_semaphore_list, ms_list) {
+		lockmgr(&ms->ms_lock, LK_SHARED, NULL);
+		TAILQ_FOREACH(mwp, &ms->ms_waiting, mwp_list) 
+			if (mwp->mwp_p == p) {
+				lockmgr(&ms->ms_lock, LK_UPGRADE, NULL);
+				mach_waiting_proc_put(mwp, ms, 0);
+				ms->ms_value++;
+				if (ms->ms_value >= 0)
+					wakeup(TAILQ_FIRST(&ms->ms_waiting));
+			}
+		lockmgr(&ms->ms_lock, LK_RELEASE, NULL);
+	}
+	lockmgr(&mach_semaphore_list_lock, LK_RELEASE, NULL);
+	
+	return;
+}
diff --git a/sys/compat/mach/mach_semaphore.h b/sys/compat/mach/mach_semaphore.h
new file mode 100644
index 000000000000..8ceb01dd4df4
--- /dev/null
+++ b/sys/compat/mach/mach_semaphore.h
@@ -0,0 +1,102 @@
+/*	$NetBSD: mach_semaphore.h,v 1.1 2002/12/12 23:18:21 manu Exp $ */
+
+/*-
+ * Copyright (c) 2002 The NetBSD Foundation, Inc.
+ * All rights reserved.
+ *
+ * This code is derived from software contributed to The NetBSD Foundation
+ * by Emmanuel Dreyfus
+ *
+ * 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.
+ * 3. All advertising materials mentioning features or use of this software
+ *    must display the following acknowledgement:
+ *        This product includes software developed by the NetBSD
+ *        Foundation, Inc. and its contributors.
+ * 4. Neither the name of The NetBSD Foundation nor the names of its
+ *    contributors may be used to endorse or promote products derived
+ *    from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. 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 FOUNDATION 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.
+ */
+
+#ifndef	_MACH_SEMAPHORE_H_
+#define	_MACH_SEMAPHORE_H_
+
+#include <sys/lock.h>
+#include <sys/queue.h>
+
+extern int mach_semaphore_cold;
+
+struct mach_waiting_proc {
+	TAILQ_ENTRY(mach_waiting_proc) mwp_list;
+	struct proc *mwp_p;
+};
+
+struct mach_semaphore {
+	int ms_value;
+	int ms_policy;
+	LIST_ENTRY(mach_semaphore) ms_list;
+	TAILQ_HEAD(ms_waiting, mach_waiting_proc) ms_waiting;
+	struct lock ms_lock;
+};
+
+/* semaphore_create */
+
+#define MACH_SYNC_POLICY_FIFO 0
+#define MACH_SYNC_POLICY_FIXED_PRIORITY 1
+
+typedef struct {
+	mach_msg_header_t req_msgh;
+	mach_ndr_record_t req_ndr;
+	int req_policy;
+	int req_value;
+} mach_semaphore_create_request_t;
+
+typedef struct {
+	mach_msg_header_t rep_msgh;
+	mach_msg_body_t rep_body;
+	mach_msg_port_descriptor_t rep_sem;
+	mach_msg_trailer_t rep_trailer;
+} mach_semaphore_create_reply_t;
+
+/* semaphore_destroy */
+
+typedef struct {
+	mach_msg_header_t req_msgh;
+	mach_msg_body_t req_body;
+	mach_msg_port_descriptor_t req_sem;
+} mach_semaphore_destroy_request_t;
+
+typedef struct {
+	mach_msg_header_t rep_msgh;
+	mach_ndr_record_t rep_ndr;
+	mach_kern_return_t rep_retval;
+	mach_msg_trailer_t rep_trailer;
+} mach_semaphore_destroy_reply_t;
+
+void mach_semaphore_init(void);
+void mach_semaphore_cleanup(struct proc *);
+int mach_semaphore_create(struct proc *, mach_msg_header_t *, 
+    size_t, mach_msg_header_t *);
+int mach_semaphore_destroy(struct proc *, mach_msg_header_t *, 
+    size_t, mach_msg_header_t *);
+
+#endif /* _MACH_SEMAPHORE_H_ */
+
diff --git a/sys/compat/mach/mach_thread.c b/sys/compat/mach/mach_thread.c
index fefbfd23c471..cb63c6d60637 100644
--- a/sys/compat/mach/mach_thread.c
+++ b/sys/compat/mach/mach_thread.c
@@ -1,4 +1,4 @@
-/*	$NetBSD: mach_thread.c,v 1.4 2002/12/12 00:29:24 manu Exp $ */
+/*	$NetBSD: mach_thread.c,v 1.5 2002/12/12 23:18:22 manu Exp $ */
 
 /*-
  * Copyright (c) 2002 The NetBSD Foundation, Inc.
@@ -37,21 +37,71 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: mach_thread.c,v 1.4 2002/12/12 00:29:24 manu Exp $");
+__KERNEL_RCSID(0, "$NetBSD: mach_thread.c,v 1.5 2002/12/12 23:18:22 manu Exp $");
 
 #include <sys/types.h>
 #include <sys/param.h>
+#include <sys/kernel.h>
 #include <sys/systm.h>
 #include <sys/signal.h>
 #include <sys/proc.h>
 
 #include <compat/mach/mach_types.h>
 #include <compat/mach/mach_message.h>
+#include <compat/mach/mach_exec.h>
 #include <compat/mach/mach_clock.h>
 #include <compat/mach/mach_thread.h>
 #include <compat/mach/mach_errno.h>
 #include <compat/mach/mach_syscallargs.h>
 
+int
+mach_sys_syscall_thread_switch(p, v, retval)
+	struct proc *p;
+	void *v;
+	register_t *retval;
+{
+	struct mach_sys_syscall_thread_switch_args /* {
+		syscallarg(mach_port_name_t) thread_name;
+		syscallarg(int) option;
+		syscallarg(mach_msg_timeout_t) option_time;
+	} */ *uap = v;
+	int timeout;
+	struct mach_emuldata *med;
+		
+	med = (struct mach_emuldata *)p->p_emuldata;
+	timeout = SCARG(uap, option_time) * hz / 1000;
+
+	/*
+	 * The day we will be able to find out the struct proc from 
+	 * the port numeber, try to use preempt() to call the right thread.
+	 */
+	switch(SCARG(uap, option)) {
+	case MACH_SWITCH_OPTION_NONE:
+		yield();
+		break;
+
+	case MACH_SWITCH_OPTION_WAIT:
+		med->med_thpri = 1;
+		while (med->med_thpri != 0)
+			(void)tsleep(&med->med_thpri, PZERO, 
+			    "thread_switch", timeout);
+		break;
+
+	case MACH_SWITCH_OPTION_DEPRESS:
+	case MACH_SWITCH_OPTION_IDLE:
+		/* Use a callout to restore the priority after depression? */
+		med->med_thpri = p->p_priority;
+		p->p_priority = MAXPRI;
+		break;
+
+	default:
+		uprintf("mach_sys_syscall_thread_switch(): unknown option %d\n",		    SCARG(uap, option));
+		break;
+	}
+	return 0;
+}
+
+
 int 
 mach_thread_policy(p, msgh, maxlen, dst)
 	struct proc *p;
diff --git a/sys/compat/mach/mach_thread.h b/sys/compat/mach/mach_thread.h
index 298db081496a..0b3e3a96b89f 100644
--- a/sys/compat/mach/mach_thread.h
+++ b/sys/compat/mach/mach_thread.h
@@ -1,4 +1,4 @@
-/*	$NetBSD: mach_thread.h,v 1.3 2002/12/12 00:29:24 manu Exp $ */
+/*	$NetBSD: mach_thread.h,v 1.4 2002/12/12 23:18:22 manu Exp $ */
 
 /*-
  * Copyright (c) 2002 The NetBSD Foundation, Inc.
@@ -47,6 +47,7 @@
 #include <compat/mach/mach_types.h>
 #include <compat/mach/mach_message.h>
 
+/* For mach_create_thread_child() */
 struct mach_create_thread_child_args {
 	struct proc **mctc_proc;
 	int mctc_flavor;
@@ -54,6 +55,12 @@ struct mach_create_thread_child_args {
 	int mctc_child_done;
 };
 
+/* For mach_sys_syscall_thread_switch() */
+#define MACH_SWITCH_OPTION_NONE	0
+#define MACH_SWITCH_OPTION_DEPRESS	1
+#define MACH_SWITCH_OPTION_WAIT	2
+#define MACH_SWITCH_OPTION_IDLE	3
+
 /* thread_policy */
 typedef int mach_policy_t;