diff --git a/spim/include/ape/ureg.h b/spim/include/ape/ureg.h
new file mode 100644
index 000000000..4ff2aa4aa
--- /dev/null
+++ b/spim/include/ape/ureg.h
@@ -0,0 +1,50 @@
+#if !defined(_PLAN9_SOURCE)
+    This header file is an extension to ANSI/POSIX
+#endif
+
+struct Ureg
+{
+	unsigned long	status;
+	unsigned long	pc;
+	union{
+		unsigned long	sp;		/* r29 */
+		unsigned long	usp;		/* r29 */
+	};
+	unsigned long	cause;
+	unsigned long	badvaddr;
+	unsigned long	tlbvirt;
+	unsigned long	hi;
+	unsigned long	lo;
+	unsigned long	r31;
+	unsigned long	r30;
+	unsigned long	r28;
+	unsigned long	r27;		/* unused */
+	unsigned long	r26;		/* unused */
+	unsigned long	r25;
+	unsigned long	r24;
+	unsigned long	r23;
+	unsigned long	r22;
+	unsigned long	r21;
+	unsigned long	r20;
+	unsigned long	r19;
+	unsigned long	r18;
+	unsigned long	r17;
+	unsigned long	r16;
+	unsigned long	r15;
+	unsigned long	r14;
+	unsigned long	r13;
+	unsigned long	r12;
+	unsigned long	r11;
+	unsigned long	r10;
+	unsigned long	r9;
+	unsigned long	r8;
+	unsigned long	r7;
+	unsigned long	r6;
+	unsigned long	r5;
+	unsigned long	r4;
+	unsigned long	r3;
+	unsigned long	r2;
+	unsigned long	r1;
+};
+
+#endif