diff --git a/sys/mips/include/proc.h b/sys/mips/include/proc.h
index 6a0ce7dc0774..d09620a2d113 100644
--- a/sys/mips/include/proc.h
+++ b/sys/mips/include/proc.h
@@ -54,6 +54,7 @@ struct mdthread {
 	int	md_pc_count;		/* performance counter */
 	int	md_pc_spill;		/* performance counter spill */
 	vm_offset_t	md_realstack;
+	void	*md_tls;
 };
 
 /* md_flags */
diff --git a/sys/mips/include/sysarch.h b/sys/mips/include/sysarch.h
index acb30713a469..350ad9583eec 100644
--- a/sys/mips/include/sysarch.h
+++ b/sys/mips/include/sysarch.h
@@ -35,16 +35,12 @@
 #ifndef _MACHINE_SYSARCH_H_
 #define _MACHINE_SYSARCH_H_
 
+#define	MIPS_SET_TLS	1
+#define	MIPS_GET_TLS	2
+
 #ifndef _KERNEL
 #include <sys/cdefs.h>
 
-#if 0
-/* Something useful for each MIPS platform. */
-#else
-#define	mips_tcb_set(tcb)	do {} while (0)
-#define	mips_tcb_get()		NULL
-#endif /* _MIPS_ARCH_XLR */
-
 __BEGIN_DECLS
 int sysarch(int, void *);
 __END_DECLS
diff --git a/sys/mips/include/ucontext.h b/sys/mips/include/ucontext.h
index d9dfe4ea09f4..c28f08371c7a 100644
--- a/sys/mips/include/ucontext.h
+++ b/sys/mips/include/ucontext.h
@@ -53,6 +53,7 @@ typedef struct	__mcontext {
 	int		mc_fpused;	/* fp has been used */
 	f_register_t	mc_fpregs[33];	/* fp regs 0 to 31 and csr */
 	register_t	mc_fpc_eir;	/* fp exception instruction reg */
+	void		*mc_tls;	/* pointer to TLS area */
 	int	__spare__[8];	/* XXX reserved */ 
 } mcontext_t;
 #endif
diff --git a/sys/mips/mips/genassym.c b/sys/mips/mips/genassym.c
index 90974c7bcff5..2912ab10c626 100644
--- a/sys/mips/mips/genassym.c
+++ b/sys/mips/mips/genassym.c
@@ -69,6 +69,7 @@ ASSYM(TD_REALKSTACK, offsetof(struct thread, td_md.md_realstack));
 ASSYM(TD_FLAGS, offsetof(struct thread, td_flags));
 ASSYM(TD_LOCK, offsetof(struct thread, td_lock));
 ASSYM(TD_FRAME, offsetof(struct thread, td_frame));
+ASSYM(TD_TLS, offsetof(struct thread, td_md.md_tls));
 
 ASSYM(TF_REG_SR, offsetof(struct trapframe, sr));
 
diff --git a/sys/mips/mips/machdep.c b/sys/mips/mips/machdep.c
index 6bd518018e7c..7b2825714aa3 100644
--- a/sys/mips/mips/machdep.c
+++ b/sys/mips/mips/machdep.c
@@ -349,12 +349,6 @@ cpu_pcpu_init(struct pcpu *pcpu, int cpuid, size_t size)
 	pcpu->pc_asid_generation = 1;
 }
 
-int
-sysarch(struct thread *td, register struct sysarch_args *uap)
-{
-	return (ENOSYS);
-}
-
 int
 fill_dbregs(struct thread *td, struct dbreg *dbregs)
 {
diff --git a/sys/mips/mips/pm_machdep.c b/sys/mips/mips/pm_machdep.c
index 3c927521e0a5..097334756f4c 100644
--- a/sys/mips/mips/pm_machdep.c
+++ b/sys/mips/mips/pm_machdep.c
@@ -413,9 +413,16 @@ get_mcontext(struct thread *td, mcontext_t *mcp, int flags)
 		bcopy((void *)&td->td_frame->f0, (void *)&mcp->mc_fpregs,
 		    sizeof(mcp->mc_fpregs));
 	}
+	if (flags & GET_MC_CLEAR_RET) {
+		mcp->mc_regs[V0] = 0;
+		mcp->mc_regs[V1] = 0;
+		mcp->mc_regs[A3] = 0;
+	}
+
 	mcp->mc_pc = td->td_frame->pc;
 	mcp->mullo = td->td_frame->mullo;
 	mcp->mulhi = td->td_frame->mulhi;
+	mcp->mc_tls = td->td_md.md_tls;
 	return (0);
 }
 
@@ -436,6 +443,7 @@ set_mcontext(struct thread *td, const mcontext_t *mcp)
 	td->td_frame->pc = mcp->mc_pc;
 	td->td_frame->mullo = mcp->mullo;
 	td->td_frame->mulhi = mcp->mulhi;
+	td->td_md.md_tls = mcp->mc_tls;
 	/* Dont let user to set any bits in Status and casue registers */
 
 	return (0);
diff --git a/sys/mips/mips/sys_machdep.c b/sys/mips/mips/sys_machdep.c
new file mode 100644
index 000000000000..c316db33a722
--- /dev/null
+++ b/sys/mips/mips/sys_machdep.c
@@ -0,0 +1,77 @@
+/*-
+ * Copyright (c) 1990 The Regents of the University of California.
+ * 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, 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 University of
+ *	California, Berkeley and its contributors.
+ * 4. Neither the name of the University 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 REGENTS 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 REGENTS 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.
+ *
+ *	from: @(#)sys_machdep.c	5.5 (Berkeley) 1/19/91
+ */
+
+#include <sys/cdefs.h>
+__FBSDID("$FreeBSD$");
+
+#include <sys/param.h>
+#include <sys/systm.h>
+#include <sys/proc.h>
+#include <sys/sysproto.h>
+#include <sys/syscall.h>
+#include <sys/sysent.h>
+
+#include <machine/sysarch.h>
+
+#ifndef _SYS_SYSPROTO_H_
+struct sysarch_args {
+	int op;
+	char *parms;
+};
+#endif
+
+int
+sysarch(td, uap)
+	struct thread *td;
+	register struct sysarch_args *uap;
+{
+	int error;
+	void *tlsbase;
+
+	switch (uap->op) {
+	case MIPS_SET_TLS : 
+		td->td_md.md_tls = (void*)uap->parms;
+		error = 0;
+		break;
+
+	case MIPS_GET_TLS : 
+		tlsbase = td->td_md.md_tls;
+		error = copyout(&tlsbase, uap->parms, sizeof(tlsbase));
+		break;
+	default:
+		error = EINVAL;
+	}
+	return (error);
+}
diff --git a/sys/mips/mips/vm_machdep.c b/sys/mips/mips/vm_machdep.c
index 08bb365d8766..9d39401119c3 100644
--- a/sys/mips/mips/vm_machdep.c
+++ b/sys/mips/mips/vm_machdep.c
@@ -156,6 +156,7 @@ cpu_fork(register struct thread *td1,register struct proc *p2,
 	 *  that are needed.
 	 */
 
+	td2->td_md.md_tls = td1->td_md.md_tls;
 	td2->td_md.md_saved_intr = MIPS_SR_INT_IE;
 	td2->td_md.md_spinlock_count = 1;
 #ifdef TARGET_OCTEON
@@ -535,7 +536,7 @@ int
 cpu_set_user_tls(struct thread *td, void *tls_base)
 {
 
-	/* TBD */
+	td->td_md.md_tls = tls_base;
 	return (0);
 }