diff --git a/src/libthread/Darwin-power-asm.s b/src/libthread/Darwin-power-asm.s
new file mode 100644
index 0000000..0776b1e
--- /dev/null
+++ b/src/libthread/Darwin-power-asm.s
@@ -0,0 +1,83 @@
+/* get FPR and VR use flags with sc 0x7FF3 */
+/* get vsave with mfspr reg, 256 */
+
+.text
+.align 2
+
+.globl	__setlabel
+
+__setlabel:				/* xxx: instruction scheduling */
+	mflr	r0
+	mfcr	r5
+	mfctr	r6
+	mfxer	r7
+	stw	r0, 0*4(r3)
+	stw	r5, 1*4(r3)
+	stw	r6, 2*4(r3)
+	stw	r7, 3*4(r3)
+
+	stw	r1, 4*4(r3)
+	stw	r2, 5*4(r3)
+	li	r5, 1				/* return value for gotolabel */
+	stw	r5, 6*4(r3)
+
+	stw	r13, (0+6)*4(r3)	/* callee-save GPRs */
+	stw	r14, (1+6)*4(r3)	/* xxx: block move */
+	stw	r15, (2+6)*4(r3)
+	stw	r16, (3+6)*4(r3)
+	stw	r17, (4+6)*4(r3)
+	stw	r18, (5+6)*4(r3)
+	stw	r19, (6+6)*4(r3)
+	stw	r20, (7+6)*4(r3)
+	stw	r21, (8+6)*4(r3)
+	stw	r22, (9+6)*4(r3)
+	stw	r23, (10+6)*4(r3)
+	stw	r24, (11+6)*4(r3)
+	stw	r25, (12+6)*4(r3)
+	stw	r26, (13+6)*4(r3)
+	stw	r27, (14+6)*4(r3)
+	stw	r28, (15+6)*4(r3)
+	stw	r29, (16+6)*4(r3)
+	stw	r30, (17+6)*4(r3)
+	stw	r31, (18+6)*4(r3)
+
+	li	r3, 0			/* return */
+	blr
+
+.globl	__gotolabel
+
+__gotolabel:
+	lwz	r13, (0+7)*4(r3)	/* callee-save GPRs */
+	lwz	r14, (1+7)*4(r3)	/* xxx: block move */
+	lwz	r15, (2+7)*4(r3)
+	lwz	r16, (3+7)*4(r3)
+	lwz	r17, (4+7)*4(r3)
+	lwz	r18, (5+7)*4(r3)
+	lwz	r19, (6+7)*4(r3)
+	lwz	r20, (7+7)*4(r3)
+	lwz	r21, (8+7)*4(r3)
+	lwz	r22, (9+7)*4(r3)
+	lwz	r23, (10+7)*4(r3)
+	lwz	r24, (11+7)*4(r3)
+	lwz	r25, (12+7)*4(r3)
+	lwz	r26, (13+7)*4(r3)
+	lwz	r27, (14+7)*4(r3)
+	lwz	r28, (15+7)*4(r3)
+	lwz	r29, (16+7)*4(r3)
+	lwz	r30, (17+7)*4(r3)
+	lwz	r31, (18+7)*4(r3)
+
+	lwz	r1, 4*4(r3)
+	lwz	r2, 5*4(r3)
+
+	lwz	r0, 0*4(r3)
+	mtlr	r0
+	lwz	r0, 1*4(r3)
+	mtcr	r0			/* mtcrf 0xFF, r0 */
+	lwz	r0, 2*4(r3)
+	mtctr	r0
+	lwz	r0, 3*4(r3)
+	mtxer	r0
+
+	lwz	r3,	6*4(r4)
+	blr
diff --git a/src/libthread/Darwin-power.c b/src/libthread/Darwin-power.c
new file mode 100644
index 0000000..373cc62
--- /dev/null
+++ b/src/libthread/Darwin-power.c
@@ -0,0 +1,37 @@
+#include "threadimpl.h"
+
+void
+makecontext(ucontext_t *ucp, void (*func)(void), int argc, ...)
+{
+	ulong *sp, *tos;
+	va_list arg;
+
+	tos = (ulong*)ucp->uc_stack.ss_sp+ucp->uc_stack.ss_size/sizeof(ulong);
+	sp = tos - 16;	
+	ucp->label.pc = (long)func;
+	ucp->label.sp = (long)sp;
+	va_start(arg, argc);
+	ucp->label.r3 = va_arg(arg, long);
+	va_end(arg);
+}
+
+void
+getcontext(ucontext_t *uc)
+{
+	return __setlabel(uc);
+}
+
+int
+setcontext(ucontext_t *uc)
+{
+	return __gotolabel(uc);
+}
+
+int
+swapcontext(ucontext_t *oucp, ucontext_t *ucp)
+{
+	if(getcontext(oucp) == 0)
+		setcontext(ucp);
+	return 0;
+}
+
diff --git a/src/libthread/Darwin-ucontext.h b/src/libthread/Darwin-ucontext.h
new file mode 100644
index 0000000..c7915ff
--- /dev/null
+++ b/src/libthread/Darwin-ucontext.h
@@ -0,0 +1,24 @@
+typedef struct ucontext ucontext_t;
+struct ucontext
+{
+	ulong	pc;		/* lr */
+	ulong	cr;		/* mfcr */
+	ulong	ctr;		/* mfcr */
+	ulong	xer;		/* mfcr */
+	ulong	sp;		/* callee saved: r1 */
+	ulong	toc;		/* callee saved: r2 */
+	ulong	r3;		/* first arg to function, return register: r3 */
+	ulong	gpr[19];	/* callee saved: r13-r31 */
+// XXX: currently do not save vector registers or floating-point state
+//	ulong	pad;
+//	uvlong	fpr[18];	/* callee saved: f14-f31 */
+//	ulong	vr[4*12];	/* callee saved: v20-v31, 256-bits each */
+};
+
+void makecontext(ucontext_t*, void(*)(void), int, ...);
+void getcontext(ucontext_t*);
+int setcontext(ucontext_t*);
+int swapcontext(ucontext_t*, ucontext_t*);
+int __setlabel(ucontext_t*);
+void __gotolabel(ucontext_t*);
+
diff --git a/src/libthread/sysofiles.sh b/src/libthread/sysofiles.sh
index 83b8355..fd22228 100644
--- a/src/libthread/sysofiles.sh
+++ b/src/libthread/sysofiles.sh
@@ -1,6 +1,8 @@
 #!/bin/sh
 
-tag="${OBJTYPE:-`uname -m`}-${SYSNAME:-`uname`}-`uname -r`-${CC9:-cc}"
+OBJTYPE=${OBJTYPE:-`uname -m | sed 's/Power Macintosh/power/;s/i.86/386/'`}
+SYSNAME=${SYSNAME:-`uname`}
+tag="$OBJTYPE-$SYSNAME-`uname -r`-${CC9:-cc}"
 case "$tag" in
 *-Linux-2.6.*)
 	echo pthread.o
@@ -9,11 +11,14 @@
 	echo pthread.o
 	;;
 *-Linux-*)
-	echo `uname`.o `uname`asm.o
+	# will have to fix this for linux power pc
+	echo $SYSNAME.o ${SYSNAME}asm.o
 	;;
 *-FreeBSD-*)
-	echo `uname`.o `uname`asm.o
+	echo $SYSNAME.o ${SYSNAME}asm.o
 	;;
+*-Darwin-*)
+	echo ${SYSNAME}-${OBJTYPE}-asm.o ${SYSNAME}-${OBJTYPE}.o pthread.o
 *)
 	echo pthread.o
 esac
diff --git a/src/libthread/threadimpl.h b/src/libthread/threadimpl.h
index bbf8473..0334fe3 100644
--- a/src/libthread/threadimpl.h
+++ b/src/libthread/threadimpl.h
@@ -16,6 +16,10 @@
 extern	void		makecontext(ucontext_t*, void(*)(), int, ...);
 #endif
 
+#if defined(__APPLE__)
+#	include "Darwin-ucontext.h"
+#endif
+
 typedef struct Context Context;
 typedef struct Execjob Execjob;
 typedef struct Proc Proc;