diff --git a/include/lib9.h b/include/lib9.h
index dd624484..42f6f44b 100644
--- a/include/lib9.h
+++ b/include/lib9.h
@@ -46,6 +46,11 @@ extern "C" {
 #		undef _NEEDUINT
 #	endif
 #endif
+#if defined(__APPLE__)
+#	include <sys/types.h>
+#	undef _NEEDUSHORT
+#	undef _NEEDUINT
+#endif
 
 typedef signed char schar;
 typedef unsigned int u32int;
@@ -213,7 +218,8 @@ extern int		errstr(char*, uint);
 
 /* command line */
 extern char	*argv0;
-#define	ARGBEGIN	for((argv0||(argv0=*argv)),argv++,argc--;\
+extern void __fixargv0(void);
+#define	ARGBEGIN	for((argv0||(argv0=(__fixargv0(),*argv))),argv++,argc--;\
 			    argv[0] && argv[0][0]=='-' && argv[0][1];\
 			    argc--, argv++) {\
 				char *_args, *_argt;\
diff --git a/src/cmd/sam/unix.c b/src/cmd/sam/unix.c
index cc15db44..205af4cd 100644
--- a/src/cmd/sam/unix.c
+++ b/src/cmd/sam/unix.c
@@ -270,3 +270,39 @@ int create(char *name, int omode, int perm)
 
     return fd;                          
 }
+
+/* SHOULD BE ELSEWHERE */
+#ifdef __APPLE__
+#include <lib9.h>
+
+Lock plk;
+
+ulong
+pread(int fd, void *buf, ulong n, ulong off)
+{
+	ulong rv;
+
+	lock(&plk);
+	if (lseek(fd, off, 0) != off)
+		return -1;
+	rv = read(fd, buf, n);
+	unlock(&plk);
+
+	return rv;
+}
+
+ulong
+pwrite(int fd, void *buf, ulong n, ulong off)
+{
+	ulong rv;
+
+	lock(&plk);
+	if (lseek(fd, off, 0) != off)
+		return -1;
+	rv = write(fd, buf, n);
+	unlock(&plk);
+
+	return rv;
+}
+#endif
+
diff --git a/src/lib9/Makefile b/src/lib9/Makefile
index 5f8e5aee..ab694858 100644
--- a/src/lib9/Makefile
+++ b/src/lib9/Makefile
@@ -19,7 +19,7 @@ OFILES=\
 	nrand.$O\
 	qlock.$O\
 	readn.$O\
-	rendez.$O\
+	rendez-$(SYSNAME).$O\
 	strecpy.$O\
 	sysfatal.$O\
 	tas-$(OBJTYPE).$O\
@@ -31,7 +31,7 @@ OFILES=\
 	werrstr.$O\
 
 HFILES=\
-	lib9.h\
+	$(9SRC)/include/lib9.h\
 
 include $(9SRC)/Makesyslib
 
diff --git a/src/lib9/argv0.c b/src/lib9/argv0.c
index 2c846f4d..4c61f444 100644
--- a/src/lib9/argv0.c
+++ b/src/lib9/argv0.c
@@ -2,3 +2,8 @@
 
 char *argv0;
 
+/*
+ * Mac OS can't deal with files that only declare data.
+ * ARGBEGIN mentions this function so that this file gets pulled in.
+ */
+void __fixargv0(void) { }
diff --git a/src/lib9/await.c b/src/lib9/await.c
index 9df7faa5..49160e76 100644
--- a/src/lib9/await.c
+++ b/src/lib9/await.c
@@ -1,5 +1,6 @@
 #include <signal.h>
 #include <sys/types.h>
+#include <sys/time.h>
 #include <sys/resource.h>
 #include <sys/wait.h>
 #include <sys/time.h>
diff --git a/src/lib9/ffork-FreeBSD.c b/src/lib9/ffork-FreeBSD.c
index a7c82e64..3829bb2d 100644
--- a/src/lib9/ffork-FreeBSD.c
+++ b/src/lib9/ffork-FreeBSD.c
@@ -31,3 +31,9 @@ _spinlock(spinlock_t *lk)
 	lock((Lock*)&lk->access_lock);
 }
 
+int
+getfforkid(void)
+{
+	return getpid();
+}
+
diff --git a/src/lib9/ffork-Linux.c b/src/lib9/ffork-Linux.c
index aad80041..3b5c8ee0 100644
--- a/src/lib9/ffork-Linux.c
+++ b/src/lib9/ffork-Linux.c
@@ -37,3 +37,9 @@ ffork(int flags, void (*fn)(void*), void *arg)
 	return pid;
 }
 
+int
+getfforkid(void)
+{
+	return getpid();
+}
+
diff --git a/src/lib9/lock.c b/src/lib9/lock.c
index 2da73626..5d6f2f3e 100644
--- a/src/lib9/lock.c
+++ b/src/lib9/lock.c
@@ -8,12 +8,9 @@ _xtas(void *v)
 {
 	int x;
 
-_ntas++;
+	_ntas++;
 	x = _tas(v);
-	if(x == 0 || x == 0xCAFEBABE)
-		return x;
-	fprint(2, "%d: tas %p got %ux\n", getpid(), v, x);
-	abort();
+	return x;
 }
 
 int
diff --git a/src/lib9/sysfatal.c b/src/lib9/sysfatal.c
index f9ab6985..33a533b8 100644
--- a/src/lib9/sysfatal.c
+++ b/src/lib9/sysfatal.c
@@ -14,6 +14,7 @@ sysfatal(char *fmt, ...)
 	vseprint(buf, buf+sizeof buf, fmt, arg);
 	va_end(arg);
 
+	__fixargv0();
 	fprint(2, "%s; %s\n", argv0 ? argv0 : "<prog>", buf);
 	exits("fatal");
 }
diff --git a/src/libthread/getpid.c b/src/libthread/getpid.c
index da03bd3f..c4d23dad 100644
--- a/src/libthread/getpid.c
+++ b/src/libthread/getpid.c
@@ -1,8 +1,7 @@
 #include "threadimpl.h"
-#include <unistd.h>
-
+extern int getfforkid(void);
 int
 _threadgetpid(void)
 {
-	return getpid();
+	return getfforkid();
 }
diff --git a/src/libthread/label.h b/src/libthread/label.h
index 0c9f3030..a1f6fa5a 100644
--- a/src/libthread/label.h
+++ b/src/libthread/label.h
@@ -17,6 +17,21 @@ struct Label
 	ulong si;
 	ulong di;
 };
+#elif defined(__APPLE__)
+struct Label
+{
+	ulong	pc;		/* lr */
+	ulong	cr;		/* mfcr */
+	ulong	ctr;		/* mfcr */
+	ulong	xer;		/* mfcr */
+	ulong	sp;		/* callee saved: r1 */
+	ulong	toc;		/* callee saved: r2 */
+	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 */
+};
 #else
 #error "Unknown or unsupported architecture"
 #endif
diff --git a/src/libthread/trend.c b/src/libthread/trend.c
index 6f8adcd5..1ccf1a79 100644
--- a/src/libthread/trend.c
+++ b/src/libthread/trend.c
@@ -25,7 +25,7 @@ threadmain(int argc, char **argv)
 	c[1] = chancreate(sizeof(ulong), 1);
 	c[2] = c[0];
 
-	threadcreate(pingpong, c, 16384);
+	proccreate(pingpong, c, 16384);
 	threadcreate(pingpong, c+1, 16384);
 	sendul(c[0], atoi(argv[1]));
 }