diff --git a/lib/libthr/arch/amd64/Makefile.inc b/lib/libthr/arch/amd64/Makefile.inc
new file mode 100644
index 000000000000..c822c8c8217f
--- /dev/null
+++ b/lib/libthr/arch/amd64/Makefile.inc
@@ -0,0 +1,5 @@
+#$FreeBSD$
+
+.PATH:	 ${.CURDIR}/sys ${.CURDIR}/arch/${MACHINE_ARCH}/${MACHINE_ARCH}
+
+SRCS+=	_setcurthread.c
diff --git a/lib/libthr/arch/amd64/amd64/_setcurthread.c b/lib/libthr/arch/amd64/amd64/_setcurthread.c
new file mode 100644
index 000000000000..51395c147312
--- /dev/null
+++ b/lib/libthr/arch/amd64/amd64/_setcurthread.c
@@ -0,0 +1,101 @@
+/*
+ * Copyright (c) 2004, David Xu <davidxu@freebsd.org>
+ * All rights reserved.
+ *
+ * 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 unmodified, 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 ``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 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.
+ *
+ * $FreeBSD$
+ */
+
+#include <sys/types.h>
+#include <sys/ucontext.h>
+
+#include <pthread.h>
+#include <machine/sysarch.h>
+
+#include "thr_private.h"
+#include "rtld_tls.h"
+
+struct tcb {
+	struct tcb	*tcb_self;      /* required by rtld */
+	void		*tcb_dtv;       /* required by rtld */
+	struct pthread	*tcb_thread;
+};
+
+void
+_retire_thread(void *entry)
+{
+	struct tcb *tcb = (struct tcb *)entry;
+
+	_rtld_free_tls(tcb, sizeof(struct tcb), 16);
+}
+
+void *
+_set_curthread(ucontext_t *uc, struct pthread *thr, int *err)
+{
+	struct tcb *tcb;
+	void *oldtls;
+
+	*err = 0;
+
+	if (thr->arch_id != NULL && uc == NULL) {
+		amd64_set_fsbase(thr->arch_id);
+		return (thr->arch_id);
+	}	
+
+	if (uc == NULL) {
+		__asm __volatile("movq %%fs:0, %0" : "=r" (oldtls));
+        } else {
+		oldtls = NULL;
+        }
+
+	/*
+	 * Allocate and initialise a new TLS block with enough extra
+	 * space for our self pointer.
+	 */
+	tcb = _rtld_allocate_tls(oldtls, sizeof(struct tcb), 16);
+
+	/*
+	 * Cache the address of the thread structure here, after
+	 * rtld's two words of private space.
+ 	 */
+	tcb->tcb_thread = thr;
+
+	if (uc == NULL)
+		amd64_set_fsbase(tcb);
+	return (tcb);
+}
+
+pthread_t
+_get_curthread(void)
+{
+	extern pthread_t _thread_initial;
+	pthread_t td;
+
+	if (_thread_initial == NULL)
+		return (NULL);
+	__asm __volatile("movq %%fs:%1, %0"	\
+		: "=r" (td)         		\
+		: "m" (*(long *)(__offsetof(struct tcb, tcb_thread))));
+
+	return (td);
+}