Imported Upstream version 60upstream/60

13 files changed, 2396 insertions, 0 deletions

diff --git a/src/pkg/runtime/darwin/386/defs.h b/src/pkg/runtime/darwin/386/defs.h
new file mode 100644
index 000000000..bb70207fd
--- /dev/null
+++ b/src/pkg/runtime/darwin/386/defs.h
@@ -0,0 +1,289 @@
+// godefs -f -m32 defs.c
+
+// MACHINE GENERATED - DO NOT EDIT.
+
+// Constants
+enum {
+	PROT_NONE = 0,
+	PROT_READ = 0x1,
+	PROT_WRITE = 0x2,
+	PROT_EXEC = 0x4,
+	MAP_ANON = 0x1000,
+	MAP_PRIVATE = 0x2,
+	MAP_FIXED = 0x10,
+	MACH_MSG_TYPE_MOVE_RECEIVE = 0x10,
+	MACH_MSG_TYPE_MOVE_SEND = 0x11,
+	MACH_MSG_TYPE_MOVE_SEND_ONCE = 0x12,
+	MACH_MSG_TYPE_COPY_SEND = 0x13,
+	MACH_MSG_TYPE_MAKE_SEND = 0x14,
+	MACH_MSG_TYPE_MAKE_SEND_ONCE = 0x15,
+	MACH_MSG_TYPE_COPY_RECEIVE = 0x16,
+	MACH_MSG_PORT_DESCRIPTOR = 0,
+	MACH_MSG_OOL_DESCRIPTOR = 0x1,
+	MACH_MSG_OOL_PORTS_DESCRIPTOR = 0x2,
+	MACH_MSG_OOL_VOLATILE_DESCRIPTOR = 0x3,
+	MACH_MSGH_BITS_COMPLEX = 0x80000000,
+	MACH_SEND_MSG = 0x1,
+	MACH_RCV_MSG = 0x2,
+	MACH_RCV_LARGE = 0x4,
+	MACH_SEND_TIMEOUT = 0x10,
+	MACH_SEND_INTERRUPT = 0x40,
+	MACH_SEND_CANCEL = 0x80,
+	MACH_SEND_ALWAYS = 0x10000,
+	MACH_SEND_TRAILER = 0x20000,
+	MACH_RCV_TIMEOUT = 0x100,
+	MACH_RCV_NOTIFY = 0x200,
+	MACH_RCV_INTERRUPT = 0x400,
+	MACH_RCV_OVERWRITE = 0x1000,
+	NDR_PROTOCOL_2_0 = 0,
+	NDR_INT_BIG_ENDIAN = 0,
+	NDR_INT_LITTLE_ENDIAN = 0x1,
+	NDR_FLOAT_IEEE = 0,
+	NDR_CHAR_ASCII = 0,
+	SA_SIGINFO = 0x40,
+	SA_RESTART = 0x2,
+	SA_ONSTACK = 0x1,
+	SA_USERTRAMP = 0x100,
+	SA_64REGSET = 0x200,
+	SIGHUP = 0x1,
+	SIGINT = 0x2,
+	SIGQUIT = 0x3,
+	SIGILL = 0x4,
+	SIGTRAP = 0x5,
+	SIGABRT = 0x6,
+	SIGEMT = 0x7,
+	SIGFPE = 0x8,
+	SIGKILL = 0x9,
+	SIGBUS = 0xa,
+	SIGSEGV = 0xb,
+	SIGSYS = 0xc,
+	SIGPIPE = 0xd,
+	SIGALRM = 0xe,
+	SIGTERM = 0xf,
+	SIGURG = 0x10,
+	SIGSTOP = 0x11,
+	SIGTSTP = 0x12,
+	SIGCONT = 0x13,
+	SIGCHLD = 0x14,
+	SIGTTIN = 0x15,
+	SIGTTOU = 0x16,
+	SIGIO = 0x17,
+	SIGXCPU = 0x18,
+	SIGXFSZ = 0x19,
+	SIGVTALRM = 0x1a,
+	SIGPROF = 0x1b,
+	SIGWINCH = 0x1c,
+	SIGINFO = 0x1d,
+	SIGUSR1 = 0x1e,
+	SIGUSR2 = 0x1f,
+	FPE_INTDIV = 0x7,
+	FPE_INTOVF = 0x8,
+	FPE_FLTDIV = 0x1,
+	FPE_FLTOVF = 0x2,
+	FPE_FLTUND = 0x3,
+	FPE_FLTRES = 0x4,
+	FPE_FLTINV = 0x5,
+	FPE_FLTSUB = 0x6,
+	BUS_ADRALN = 0x1,
+	BUS_ADRERR = 0x2,
+	BUS_OBJERR = 0x3,
+	SEGV_MAPERR = 0x1,
+	SEGV_ACCERR = 0x2,
+	ITIMER_REAL = 0,
+	ITIMER_VIRTUAL = 0x1,
+	ITIMER_PROF = 0x2,
+};
+
+// Types
+#pragma pack on
+
+typedef struct MachBody MachBody;
+struct MachBody {
+	uint32 msgh_descriptor_count;
+};
+
+typedef struct MachHeader MachHeader;
+struct MachHeader {
+	uint32 msgh_bits;
+	uint32 msgh_size;
+	uint32 msgh_remote_port;
+	uint32 msgh_local_port;
+	uint32 msgh_reserved;
+	int32 msgh_id;
+};
+
+typedef struct MachNDR MachNDR;
+struct MachNDR {
+	uint8 mig_vers;
+	uint8 if_vers;
+	uint8 reserved1;
+	uint8 mig_encoding;
+	uint8 int_rep;
+	uint8 char_rep;
+	uint8 float_rep;
+	uint8 reserved2;
+};
+
+typedef struct MachPort MachPort;
+struct MachPort {
+	uint32 name;
+	uint32 pad1;
+	uint16 pad2;
+	uint8 disposition;
+	uint8 type;
+};
+
+typedef struct StackT StackT;
+struct StackT {
+	void *ss_sp;
+	uint32 ss_size;
+	int32 ss_flags;
+};
+
+typedef union Sighandler Sighandler;
+union Sighandler {
+	uint32 __sa_handler;
+	uint32 __sa_sigaction;
+};
+
+typedef struct Sigaction Sigaction;
+struct Sigaction {
+	Sighandler __sigaction_u;
+	uint32 sa_tramp;
+	uint32 sa_mask;
+	int32 sa_flags;
+};
+
+typedef union Sigval Sigval;
+union Sigval {
+	int32 sival_int;
+	void *sival_ptr;
+};
+
+typedef struct Siginfo Siginfo;
+struct Siginfo {
+	int32 si_signo;
+	int32 si_errno;
+	int32 si_code;
+	int32 si_pid;
+	uint32 si_uid;
+	int32 si_status;
+	void *si_addr;
+	Sigval si_value;
+	int32 si_band;
+	uint32 __pad[7];
+};
+
+typedef struct Timeval Timeval;
+struct Timeval {
+	int32 tv_sec;
+	int32 tv_usec;
+};
+
+typedef struct Itimerval Itimerval;
+struct Itimerval {
+	Timeval it_interval;
+	Timeval it_value;
+};
+
+typedef struct FPControl FPControl;
+struct FPControl {
+	byte pad_godefs_0[2];
+};
+
+typedef struct FPStatus FPStatus;
+struct FPStatus {
+	byte pad_godefs_0[2];
+};
+
+typedef struct RegMMST RegMMST;
+struct RegMMST {
+	int8 mmst_reg[10];
+	int8 mmst_rsrv[6];
+};
+
+typedef struct RegXMM RegXMM;
+struct RegXMM {
+	int8 xmm_reg[16];
+};
+
+typedef struct Regs Regs;
+struct Regs {
+	uint32 eax;
+	uint32 ebx;
+	uint32 ecx;
+	uint32 edx;
+	uint32 edi;
+	uint32 esi;
+	uint32 ebp;
+	uint32 esp;
+	uint32 ss;
+	uint32 eflags;
+	uint32 eip;
+	uint32 cs;
+	uint32 ds;
+	uint32 es;
+	uint32 fs;
+	uint32 gs;
+};
+
+typedef struct FloatState FloatState;
+struct FloatState {
+	uint64 fpu_reserved;
+	FPControl fpu_fcw;
+	FPStatus fpu_fsw;
+	uint8 fpu_ftw;
+	uint8 fpu_rsrv1;
+	uint16 fpu_fop;
+	uint32 fpu_ip;
+	uint16 fpu_cs;
+	uint16 fpu_rsrv2;
+	uint32 fpu_dp;
+	uint16 fpu_ds;
+	uint16 fpu_rsrv3;
+	uint32 fpu_mxcsr;
+	uint32 fpu_mxcsrmask;
+	RegMMST fpu_stmm0;
+	RegMMST fpu_stmm1;
+	RegMMST fpu_stmm2;
+	RegMMST fpu_stmm3;
+	RegMMST fpu_stmm4;
+	RegMMST fpu_stmm5;
+	RegMMST fpu_stmm6;
+	RegMMST fpu_stmm7;
+	RegXMM fpu_xmm0;
+	RegXMM fpu_xmm1;
+	RegXMM fpu_xmm2;
+	RegXMM fpu_xmm3;
+	RegXMM fpu_xmm4;
+	RegXMM fpu_xmm5;
+	RegXMM fpu_xmm6;
+	RegXMM fpu_xmm7;
+	int8 fpu_rsrv4[224];
+	int32 fpu_reserved1;
+};
+
+typedef struct ExceptionState ExceptionState;
+struct ExceptionState {
+	uint32 trapno;
+	uint32 err;
+	uint32 faultvaddr;
+};
+
+typedef struct Mcontext Mcontext;
+struct Mcontext {
+	ExceptionState es;
+	Regs ss;
+	FloatState fs;
+};
+
+typedef struct Ucontext Ucontext;
+struct Ucontext {
+	int32 uc_onstack;
+	uint32 uc_sigmask;
+	StackT uc_stack;
+	uint32 uc_link;
+	uint32 uc_mcsize;
+	Mcontext *uc_mcontext;
+};
+#pragma pack off
diff --git a/src/pkg/runtime/darwin/386/rt0.s b/src/pkg/runtime/darwin/386/rt0.s
new file mode 100644
index 000000000..30b497f5e
--- /dev/null
+++ b/src/pkg/runtime/darwin/386/rt0.s
@@ -0,0 +1,8 @@
+// Copyright 2009 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Darwin and Linux use the same linkage to main
+
+TEXT _rt0_386_darwin(SB),7,$0
+	JMP	_rt0_386(SB)
diff --git a/src/pkg/runtime/darwin/386/signal.c b/src/pkg/runtime/darwin/386/signal.c
new file mode 100644
index 000000000..29170b669
--- /dev/null
+++ b/src/pkg/runtime/darwin/386/signal.c
@@ -0,0 +1,194 @@
+// Copyright 2009 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+#include "runtime.h"
+#include "defs.h"
+#include "os.h"
+#include "signals.h"
+
+void
+runtime·dumpregs(Regs *r)
+{
+	runtime·printf("eax     %x\n", r->eax);
+	runtime·printf("ebx     %x\n", r->ebx);
+	runtime·printf("ecx     %x\n", r->ecx);
+	runtime·printf("edx     %x\n", r->edx);
+	runtime·printf("edi     %x\n", r->edi);
+	runtime·printf("esi     %x\n", r->esi);
+	runtime·printf("ebp     %x\n", r->ebp);
+	runtime·printf("esp     %x\n", r->esp);
+	runtime·printf("eip     %x\n", r->eip);
+	runtime·printf("eflags  %x\n", r->eflags);
+	runtime·printf("cs      %x\n", r->cs);
+	runtime·printf("fs      %x\n", r->fs);
+	runtime·printf("gs      %x\n", r->gs);
+}
+
+String
+runtime·signame(int32 sig)
+{
+	if(sig < 0 || sig >= NSIG)
+		return runtime·emptystring;
+	return runtime·gostringnocopy((byte*)runtime·sigtab[sig].name);
+}
+
+void
+runtime·sighandler(int32 sig, Siginfo *info, void *context, G *gp)
+{
+	Ucontext *uc;
+	Mcontext *mc;
+	Regs *r;
+	uintptr *sp;
+	byte *pc;
+
+	uc = context;
+	mc = uc->uc_mcontext;
+	r = &mc->ss;
+
+	if(sig == SIGPROF) {
+		runtime·sigprof((uint8*)r->eip, (uint8*)r->esp, nil, gp);
+		return;
+	}
+
+	if(gp != nil && (runtime·sigtab[sig].flags & SigPanic)) {
+		// Work around Leopard bug that doesn't set FPE_INTDIV.
+		// Look at instruction to see if it is a divide.
+		// Not necessary in Snow Leopard (si_code will be != 0).
+		if(sig == SIGFPE && info->si_code == 0) {
+			pc = (byte*)r->eip;
+			if(pc[0] == 0x66)	// 16-bit instruction prefix
+				pc++;
+			if(pc[0] == 0xF6 || pc[0] == 0xF7)
+				info->si_code = FPE_INTDIV;
+		}
+		
+		// Make it look like a call to the signal func.
+		// Have to pass arguments out of band since
+		// augmenting the stack frame would break
+		// the unwinding code.
+		gp->sig = sig;
+		gp->sigcode0 = info->si_code;
+		gp->sigcode1 = (uintptr)info->si_addr;
+		gp->sigpc = r->eip;
+
+		// Only push runtime·sigpanic if r->eip != 0.
+		// If r->eip == 0, probably panicked because of a
+		// call to a nil func.  Not pushing that onto sp will
+		// make the trace look like a call to runtime·sigpanic instead.
+		// (Otherwise the trace will end at runtime·sigpanic and we
+		// won't get to see who faulted.)
+		if(r->eip != 0) {
+			sp = (uintptr*)r->esp;
+			*--sp = r->eip;
+			r->esp = (uintptr)sp;
+		}
+		r->eip = (uintptr)runtime·sigpanic;
+		return;
+	}
+
+	if(runtime·sigtab[sig].flags & SigQueue) {
+		if(runtime·sigsend(sig) || (runtime·sigtab[sig].flags & SigIgnore))
+			return;
+		runtime·exit(2);	// SIGINT, SIGTERM, etc
+	}
+
+	if(runtime·panicking)	// traceback already printed
+		runtime·exit(2);
+	runtime·panicking = 1;
+
+	if(sig < 0 || sig >= NSIG){
+		runtime·printf("Signal %d\n", sig);
+	}else{
+		runtime·printf("%s\n", runtime·sigtab[sig].name);
+	}
+
+	runtime·printf("pc: %x\n", r->eip);
+	runtime·printf("\n");
+
+	if(runtime·gotraceback()){
+		runtime·traceback((void*)r->eip, (void*)r->esp, 0, gp);
+		runtime·tracebackothers(gp);
+		runtime·dumpregs(r);
+	}
+
+	runtime·exit(2);
+}
+
+void
+runtime·sigignore(int32, Siginfo*, void*)
+{
+}
+
+void
+runtime·signalstack(byte *p, int32 n)
+{
+	StackT st;
+
+	st.ss_sp = p;
+	st.ss_size = n;
+	st.ss_flags = 0;
+	runtime·sigaltstack(&st, nil);
+}
+
+static void
+sigaction(int32 i, void (*fn)(int32, Siginfo*, void*, G*), bool restart)
+{
+	Sigaction sa;
+
+	runtime·memclr((byte*)&sa, sizeof sa);
+	sa.sa_flags = SA_SIGINFO|SA_ONSTACK;
+	if(restart)
+		sa.sa_flags |= SA_RESTART;
+	sa.sa_mask = ~0U;
+	sa.sa_tramp = (uintptr)runtime·sigtramp;	// runtime·sigtramp's job is to call into real handler
+	sa.__sigaction_u.__sa_sigaction = (uintptr)fn;
+	runtime·sigaction(i, &sa, nil);
+}
+
+void
+runtime·initsig(int32 queue)
+{
+	int32 i;
+	void *fn;
+
+	runtime·siginit();
+
+	for(i = 0; i<NSIG; i++) {
+		if(runtime·sigtab[i].flags) {
+			if((runtime·sigtab[i].flags & SigQueue) != queue)
+				continue;
+			if(runtime·sigtab[i].flags & (SigCatch | SigQueue))
+				fn = runtime·sighandler;
+			else
+				fn = runtime·sigignore;
+			sigaction(i, fn, (runtime·sigtab[i].flags & SigRestart) != 0);
+		}
+	}
+}
+
+void
+runtime·resetcpuprofiler(int32 hz)
+{
+	Itimerval it;
+	
+	runtime·memclr((byte*)&it, sizeof it);
+	if(hz == 0) {
+		runtime·setitimer(ITIMER_PROF, &it, nil);
+		sigaction(SIGPROF, SIG_IGN, true);
+	} else {
+		sigaction(SIGPROF, runtime·sighandler, true);
+		it.it_interval.tv_sec = 0;
+		it.it_interval.tv_usec = 1000000 / hz;
+		it.it_value = it.it_interval;
+		runtime·setitimer(ITIMER_PROF, &it, nil);
+	}
+	m->profilehz = hz;
+}
+
+void
+os·sigpipe(void)
+{
+	sigaction(SIGPIPE, SIG_DFL, false);
+	runtime·raisesigpipe();
+}
diff --git a/src/pkg/runtime/darwin/386/sys.s b/src/pkg/runtime/darwin/386/sys.s
new file mode 100644
index 000000000..87fbdbb79
--- /dev/null
+++ b/src/pkg/runtime/darwin/386/sys.s
@@ -0,0 +1,311 @@
+// Copyright 2009 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// System calls and other sys.stuff for 386, Darwin
+// See http://fxr.watson.org/fxr/source/bsd/kern/syscalls.c?v=xnu-1228
+// or /usr/include/sys/syscall.h (on a Mac) for system call numbers.
+
+#include "386/asm.h"
+
+TEXT runtime·notok(SB),7,$0
+	MOVL	$0xf1, 0xf1
+	RET
+
+// Exit the entire program (like C exit)
+TEXT runtime·exit(SB),7,$0
+	MOVL	$1, AX
+	INT	$0x80
+	CALL	runtime·notok(SB)
+	RET
+
+// Exit this OS thread (like pthread_exit, which eventually
+// calls __bsdthread_terminate).
+TEXT runtime·exit1(SB),7,$0
+	MOVL	$361, AX
+	INT	$0x80
+	JAE 2(PC)
+	CALL	runtime·notok(SB)
+	RET
+
+TEXT runtime·write(SB),7,$0
+	MOVL	$4, AX
+	INT	$0x80
+	RET
+
+TEXT runtime·raisesigpipe(SB),7,$8
+	get_tls(CX)
+	MOVL	m(CX), DX
+	MOVL	m_procid(DX), DX
+	MOVL	DX, 0(SP)	// thread_port
+	MOVL	$13, 4(SP)	// signal: SIGPIPE
+	MOVL	$328, AX	// __pthread_kill
+	INT	$0x80
+	RET
+
+TEXT runtime·mmap(SB),7,$0
+	MOVL	$197, AX
+	INT	$0x80
+	RET
+
+TEXT runtime·munmap(SB),7,$0
+	MOVL	$73, AX
+	INT	$0x80
+	JAE	2(PC)
+	CALL	runtime·notok(SB)
+	RET
+
+TEXT runtime·setitimer(SB),7,$0
+	MOVL	$83, AX
+	INT	$0x80
+	RET
+
+// void gettime(int64 *sec, int32 *usec)
+TEXT runtime·gettime(SB), 7, $32
+	LEAL	12(SP), AX	// must be non-nil, unused
+	MOVL	AX, 4(SP)
+	MOVL	$0, 8(SP)	// time zone pointer
+	MOVL	$116, AX
+	INT	$0x80
+
+	MOVL	sec+0(FP), DI
+	MOVL	AX, (DI)
+	MOVL	$0, 4(DI)	// zero extend 32 -> 64
+
+	MOVL	usec+4(FP), DI
+	MOVL	DX, (DI)
+	RET
+
+TEXT runtime·sigaction(SB),7,$0
+	MOVL	$46, AX
+	INT	$0x80
+	JAE	2(PC)
+	CALL	runtime·notok(SB)
+	RET
+
+// Sigtramp's job is to call the actual signal handler.
+// It is called with the following arguments on the stack:
+//	0(FP)	"return address" - ignored
+//	4(FP)	actual handler
+//	8(FP)	siginfo style - ignored
+//	12(FP)	signal number
+//	16(FP)	siginfo
+//	20(FP)	context
+TEXT runtime·sigtramp(SB),7,$40
+	get_tls(CX)
+
+	// save g
+	MOVL	g(CX), DI
+	MOVL	DI, 20(SP)
+	
+	// g = m->gsignal
+	MOVL	m(CX), BP
+	MOVL	m_gsignal(BP), BP
+	MOVL	BP, g(CX)
+
+	// copy arguments to sighandler
+	MOVL	sig+8(FP), BX
+	MOVL	BX, 0(SP)
+	MOVL	info+12(FP), BX
+	MOVL	BX, 4(SP)
+	MOVL	context+16(FP), BX
+	MOVL	BX, 8(SP)
+	MOVL	DI, 12(SP)
+	
+	MOVL	handler+0(FP), BX
+	CALL	BX
+
+	// restore g
+	get_tls(CX)
+	MOVL	20(SP), DI
+	MOVL	DI, g(CX)
+
+	// call sigreturn
+	MOVL	context+16(FP), CX
+	MOVL	style+4(FP), BX
+	MOVL	$0, 0(SP)	// "caller PC" - ignored
+	MOVL	CX, 4(SP)
+	MOVL	BX, 8(SP)
+	MOVL	$184, AX	// sigreturn(ucontext, infostyle)
+	INT	$0x80
+	CALL	runtime·notok(SB)
+	RET
+
+TEXT runtime·sigaltstack(SB),7,$0
+	MOVL	$53, AX
+	INT	$0x80
+	JAE	2(PC)
+	CALL	runtime·notok(SB)
+	RET
+
+// void bsdthread_create(void *stk, M *m, G *g, void (*fn)(void))
+// System call args are: func arg stack pthread flags.
+TEXT runtime·bsdthread_create(SB),7,$32
+	MOVL	$360, AX
+	// 0(SP) is where the caller PC would be; kernel skips it
+	MOVL	func+12(FP), BX
+	MOVL	BX, 4(SP)	// func
+	MOVL	mm+4(FP), BX
+	MOVL	BX, 8(SP)	// arg
+	MOVL	stk+0(FP), BX
+	MOVL	BX, 12(SP)	// stack
+	MOVL	gg+8(FP), BX
+	MOVL	BX, 16(SP)	// pthread
+	MOVL	$0x1000000, 20(SP)	// flags = PTHREAD_START_CUSTOM
+	INT	$0x80
+	JAE	3(PC)
+	NEGL	AX
+	RET
+	MOVL	$0, AX
+	RET
+
+// The thread that bsdthread_create creates starts executing here,
+// because we registered this function using bsdthread_register
+// at startup.
+//	AX = "pthread" (= g)
+//	BX = mach thread port
+//	CX = "func" (= fn)
+//	DX = "arg" (= m)
+//	DI = stack top
+//	SI = flags (= 0x1000000)
+//	SP = stack - C_32_STK_ALIGN
+TEXT runtime·bsdthread_start(SB),7,$0
+	// set up ldt 7+id to point at m->tls.
+	// m->tls is at m+40.  newosproc left
+	// the m->id in tls[0].
+	LEAL	m_tls(DX), BP
+	MOVL	0(BP), DI
+	ADDL	$7, DI	// m0 is LDT#7. count up.
+	// setldt(tls#, &tls, sizeof tls)
+	PUSHAL	// save registers
+	PUSHL	$32	// sizeof tls
+	PUSHL	BP	// &tls
+	PUSHL	DI	// tls #
+	CALL	runtime·setldt(SB)
+	POPL	AX
+	POPL	AX
+	POPL	AX
+	POPAL
+
+	// Now segment is established.  Initialize m, g.
+	get_tls(BP)
+	MOVL	AX, g(BP)
+	MOVL	DX, m(BP)
+	MOVL	BX, m_procid(DX)	// m->procid = thread port (for debuggers)
+	CALL	runtime·stackcheck(SB)		// smashes AX
+	CALL	CX	// fn()
+	CALL	runtime·exit1(SB)
+	RET
+
+// void bsdthread_register(void)
+// registers callbacks for threadstart (see bsdthread_create above
+// and wqthread and pthsize (not used).  returns 0 on success.
+TEXT runtime·bsdthread_register(SB),7,$40
+	MOVL	$366, AX
+	// 0(SP) is where kernel expects caller PC; ignored
+	MOVL	$runtime·bsdthread_start(SB), 4(SP)	// threadstart
+	MOVL	$0, 8(SP)	// wqthread, not used by us
+	MOVL	$0, 12(SP)	// pthsize, not used by us
+	MOVL	$0, 16(SP)	// dummy_value [sic]
+	MOVL	$0, 20(SP)	// targetconc_ptr
+	MOVL	$0, 24(SP)	// dispatchqueue_offset
+	INT	$0x80
+	JAE	2(PC)
+	CALL	runtime·notok(SB)
+	RET
+
+// Invoke Mach system call.
+// Assumes system call number in AX,
+// caller PC on stack, caller's caller PC next,
+// and then the system call arguments.
+//
+// Can be used for BSD too, but we don't,
+// because if you use this interface the BSD
+// system call numbers need an extra field
+// in the high 16 bits that seems to be the
+// argument count in bytes but is not always.
+// INT $0x80 works fine for those.
+TEXT runtime·sysenter(SB),7,$0
+	POPL	DX
+	MOVL	SP, CX
+	BYTE $0x0F; BYTE $0x34;  // SYSENTER
+	// returns to DX with SP set to CX
+
+TEXT runtime·mach_msg_trap(SB),7,$0
+	MOVL	$-31, AX
+	CALL	runtime·sysenter(SB)
+	RET
+
+TEXT runtime·mach_reply_port(SB),7,$0
+	MOVL	$-26, AX
+	CALL	runtime·sysenter(SB)
+	RET
+
+TEXT runtime·mach_task_self(SB),7,$0
+	MOVL	$-28, AX
+	CALL	runtime·sysenter(SB)
+	RET
+
+// Mach provides trap versions of the semaphore ops,
+// instead of requiring the use of RPC.
+
+// uint32 mach_semaphore_wait(uint32)
+TEXT runtime·mach_semaphore_wait(SB),7,$0
+	MOVL	$-36, AX
+	CALL	runtime·sysenter(SB)
+	RET
+
+// uint32 mach_semaphore_timedwait(uint32, uint32, uint32)
+TEXT runtime·mach_semaphore_timedwait(SB),7,$0
+	MOVL	$-38, AX
+	CALL	runtime·sysenter(SB)
+	RET
+
+// uint32 mach_semaphore_signal(uint32)
+TEXT runtime·mach_semaphore_signal(SB),7,$0
+	MOVL	$-33, AX
+	CALL	runtime·sysenter(SB)
+	RET
+
+// uint32 mach_semaphore_signal_all(uint32)
+TEXT runtime·mach_semaphore_signal_all(SB),7,$0
+	MOVL	$-34, AX
+	CALL	runtime·sysenter(SB)
+	RET
+
+// setldt(int entry, int address, int limit)
+// entry and limit are ignored.
+TEXT runtime·setldt(SB),7,$32
+	MOVL	address+4(FP), BX	// aka base
+
+	/*
+	 * When linking against the system libraries,
+	 * we use its pthread_create and let it set up %gs
+	 * for us.  When we do that, the private storage
+	 * we get is not at 0(GS) but at 0x468(GS).
+	 * To insulate the rest of the tool chain from this ugliness,
+	 * 8l rewrites 0(GS) into 0x468(GS) for us.
+	 * To accommodate that rewrite, we translate the
+	 * address and limit here so that 0x468(GS) maps to 0(address).
+	 *
+	 * See ../../../../libcgo/darwin_386.c for the derivation
+	 * of the constant.
+	 */
+	SUBL	$0x468, BX
+
+	/*
+	 * Must set up as USER_CTHREAD segment because
+	 * Darwin forces that value into %gs for signal handlers,
+	 * and if we don't set one up, we'll get a recursive
+	 * fault trying to get into the signal handler.
+	 * Since we have to set one up anyway, it might as
+	 * well be the value we want.  So don't bother with
+	 * i386_set_ldt.
+	 */
+	MOVL	BX, 4(SP)
+	MOVL	$3, AX	// thread_fast_set_cthread_self - machdep call #3
+	INT	$0x82	// sic: 0x82, not 0x80, for machdep call
+
+	XORL	AX, AX
+	MOVW	GS, AX
+	RET
diff --git a/src/pkg/runtime/darwin/amd64/defs.h b/src/pkg/runtime/darwin/amd64/defs.h
new file mode 100644
index 000000000..90f798e8a
--- /dev/null
+++ b/src/pkg/runtime/darwin/amd64/defs.h
@@ -0,0 +1,305 @@
+// godefs -f -m64 defs.c
+
+// MACHINE GENERATED - DO NOT EDIT.
+
+// Constants
+enum {
+	PROT_NONE = 0,
+	PROT_READ = 0x1,
+	PROT_WRITE = 0x2,
+	PROT_EXEC = 0x4,
+	MAP_ANON = 0x1000,
+	MAP_PRIVATE = 0x2,
+	MAP_FIXED = 0x10,
+	MACH_MSG_TYPE_MOVE_RECEIVE = 0x10,
+	MACH_MSG_TYPE_MOVE_SEND = 0x11,
+	MACH_MSG_TYPE_MOVE_SEND_ONCE = 0x12,
+	MACH_MSG_TYPE_COPY_SEND = 0x13,
+	MACH_MSG_TYPE_MAKE_SEND = 0x14,
+	MACH_MSG_TYPE_MAKE_SEND_ONCE = 0x15,
+	MACH_MSG_TYPE_COPY_RECEIVE = 0x16,
+	MACH_MSG_PORT_DESCRIPTOR = 0,
+	MACH_MSG_OOL_DESCRIPTOR = 0x1,
+	MACH_MSG_OOL_PORTS_DESCRIPTOR = 0x2,
+	MACH_MSG_OOL_VOLATILE_DESCRIPTOR = 0x3,
+	MACH_MSGH_BITS_COMPLEX = 0x80000000,
+	MACH_SEND_MSG = 0x1,
+	MACH_RCV_MSG = 0x2,
+	MACH_RCV_LARGE = 0x4,
+	MACH_SEND_TIMEOUT = 0x10,
+	MACH_SEND_INTERRUPT = 0x40,
+	MACH_SEND_CANCEL = 0x80,
+	MACH_SEND_ALWAYS = 0x10000,
+	MACH_SEND_TRAILER = 0x20000,
+	MACH_RCV_TIMEOUT = 0x100,
+	MACH_RCV_NOTIFY = 0x200,
+	MACH_RCV_INTERRUPT = 0x400,
+	MACH_RCV_OVERWRITE = 0x1000,
+	NDR_PROTOCOL_2_0 = 0,
+	NDR_INT_BIG_ENDIAN = 0,
+	NDR_INT_LITTLE_ENDIAN = 0x1,
+	NDR_FLOAT_IEEE = 0,
+	NDR_CHAR_ASCII = 0,
+	SA_SIGINFO = 0x40,
+	SA_RESTART = 0x2,
+	SA_ONSTACK = 0x1,
+	SA_USERTRAMP = 0x100,
+	SA_64REGSET = 0x200,
+	SIGHUP = 0x1,
+	SIGINT = 0x2,
+	SIGQUIT = 0x3,
+	SIGILL = 0x4,
+	SIGTRAP = 0x5,
+	SIGABRT = 0x6,
+	SIGEMT = 0x7,
+	SIGFPE = 0x8,
+	SIGKILL = 0x9,
+	SIGBUS = 0xa,
+	SIGSEGV = 0xb,
+	SIGSYS = 0xc,
+	SIGPIPE = 0xd,
+	SIGALRM = 0xe,
+	SIGTERM = 0xf,
+	SIGURG = 0x10,
+	SIGSTOP = 0x11,
+	SIGTSTP = 0x12,
+	SIGCONT = 0x13,
+	SIGCHLD = 0x14,
+	SIGTTIN = 0x15,
+	SIGTTOU = 0x16,
+	SIGIO = 0x17,
+	SIGXCPU = 0x18,
+	SIGXFSZ = 0x19,
+	SIGVTALRM = 0x1a,
+	SIGPROF = 0x1b,
+	SIGWINCH = 0x1c,
+	SIGINFO = 0x1d,
+	SIGUSR1 = 0x1e,
+	SIGUSR2 = 0x1f,
+	FPE_INTDIV = 0x7,
+	FPE_INTOVF = 0x8,
+	FPE_FLTDIV = 0x1,
+	FPE_FLTOVF = 0x2,
+	FPE_FLTUND = 0x3,
+	FPE_FLTRES = 0x4,
+	FPE_FLTINV = 0x5,
+	FPE_FLTSUB = 0x6,
+	BUS_ADRALN = 0x1,
+	BUS_ADRERR = 0x2,
+	BUS_OBJERR = 0x3,
+	SEGV_MAPERR = 0x1,
+	SEGV_ACCERR = 0x2,
+	ITIMER_REAL = 0,
+	ITIMER_VIRTUAL = 0x1,
+	ITIMER_PROF = 0x2,
+};
+
+// Types
+#pragma pack on
+
+typedef struct MachBody MachBody;
+struct MachBody {
+	uint32 msgh_descriptor_count;
+};
+
+typedef struct MachHeader MachHeader;
+struct MachHeader {
+	uint32 msgh_bits;
+	uint32 msgh_size;
+	uint32 msgh_remote_port;
+	uint32 msgh_local_port;
+	uint32 msgh_reserved;
+	int32 msgh_id;
+};
+
+typedef struct MachNDR MachNDR;
+struct MachNDR {
+	uint8 mig_vers;
+	uint8 if_vers;
+	uint8 reserved1;
+	uint8 mig_encoding;
+	uint8 int_rep;
+	uint8 char_rep;
+	uint8 float_rep;
+	uint8 reserved2;
+};
+
+typedef struct MachPort MachPort;
+struct MachPort {
+	uint32 name;
+	uint32 pad1;
+	uint16 pad2;
+	uint8 disposition;
+	uint8 type;
+};
+
+typedef struct StackT StackT;
+struct StackT {
+	void *ss_sp;
+	uint64 ss_size;
+	int32 ss_flags;
+	byte pad_godefs_0[4];
+};
+
+typedef union Sighandler Sighandler;
+union Sighandler {
+	uint64 __sa_handler;
+	uint64 __sa_sigaction;
+};
+
+typedef struct Sigaction Sigaction;
+struct Sigaction {
+	Sighandler __sigaction_u;
+	uint64 sa_tramp;
+	uint32 sa_mask;
+	int32 sa_flags;
+};
+
+typedef union Sigval Sigval;
+union Sigval {
+	int32 sival_int;
+	void *sival_ptr;
+};
+
+typedef struct Siginfo Siginfo;
+struct Siginfo {
+	int32 si_signo;
+	int32 si_errno;
+	int32 si_code;
+	int32 si_pid;
+	uint32 si_uid;
+	int32 si_status;
+	void *si_addr;
+	Sigval si_value;
+	int64 si_band;
+	uint64 __pad[7];
+};
+
+typedef struct Timeval Timeval;
+struct Timeval {
+	int64 tv_sec;
+	int32 tv_usec;
+	byte pad_godefs_0[4];
+};
+
+typedef struct Itimerval Itimerval;
+struct Itimerval {
+	Timeval it_interval;
+	Timeval it_value;
+};
+
+typedef struct FPControl FPControl;
+struct FPControl {
+	byte pad_godefs_0[2];
+};
+
+typedef struct FPStatus FPStatus;
+struct FPStatus {
+	byte pad_godefs_0[2];
+};
+
+typedef struct RegMMST RegMMST;
+struct RegMMST {
+	int8 mmst_reg[10];
+	int8 mmst_rsrv[6];
+};
+
+typedef struct RegXMM RegXMM;
+struct RegXMM {
+	int8 xmm_reg[16];
+};
+
+typedef struct Regs Regs;
+struct Regs {
+	uint64 rax;
+	uint64 rbx;
+	uint64 rcx;
+	uint64 rdx;
+	uint64 rdi;
+	uint64 rsi;
+	uint64 rbp;
+	uint64 rsp;
+	uint64 r8;
+	uint64 r9;
+	uint64 r10;
+	uint64 r11;
+	uint64 r12;
+	uint64 r13;
+	uint64 r14;
+	uint64 r15;
+	uint64 rip;
+	uint64 rflags;
+	uint64 cs;
+	uint64 fs;
+	uint64 gs;
+};
+
+typedef struct FloatState FloatState;
+struct FloatState {
+	uint64 fpu_reserved;
+	FPControl fpu_fcw;
+	FPStatus fpu_fsw;
+	uint8 fpu_ftw;
+	uint8 fpu_rsrv1;
+	uint16 fpu_fop;
+	uint32 fpu_ip;
+	uint16 fpu_cs;
+	uint16 fpu_rsrv2;
+	uint32 fpu_dp;
+	uint16 fpu_ds;
+	uint16 fpu_rsrv3;
+	uint32 fpu_mxcsr;
+	uint32 fpu_mxcsrmask;
+	RegMMST fpu_stmm0;
+	RegMMST fpu_stmm1;
+	RegMMST fpu_stmm2;
+	RegMMST fpu_stmm3;
+	RegMMST fpu_stmm4;
+	RegMMST fpu_stmm5;
+	RegMMST fpu_stmm6;
+	RegMMST fpu_stmm7;
+	RegXMM fpu_xmm0;
+	RegXMM fpu_xmm1;
+	RegXMM fpu_xmm2;
+	RegXMM fpu_xmm3;
+	RegXMM fpu_xmm4;
+	RegXMM fpu_xmm5;
+	RegXMM fpu_xmm6;
+	RegXMM fpu_xmm7;
+	RegXMM fpu_xmm8;
+	RegXMM fpu_xmm9;
+	RegXMM fpu_xmm10;
+	RegXMM fpu_xmm11;
+	RegXMM fpu_xmm12;
+	RegXMM fpu_xmm13;
+	RegXMM fpu_xmm14;
+	RegXMM fpu_xmm15;
+	int8 fpu_rsrv4[96];
+	int32 fpu_reserved1;
+};
+
+typedef struct ExceptionState ExceptionState;
+struct ExceptionState {
+	uint32 trapno;
+	uint32 err;
+	uint64 faultvaddr;
+};
+
+typedef struct Mcontext Mcontext;
+struct Mcontext {
+	ExceptionState es;
+	Regs ss;
+	FloatState fs;
+	byte pad_godefs_0[4];
+};
+
+typedef struct Ucontext Ucontext;
+struct Ucontext {
+	int32 uc_onstack;
+	uint32 uc_sigmask;
+	StackT uc_stack;
+	uint64 uc_link;
+	uint64 uc_mcsize;
+	Mcontext *uc_mcontext;
+};
+#pragma pack off
diff --git a/src/pkg/runtime/darwin/amd64/rt0.s b/src/pkg/runtime/darwin/amd64/rt0.s
new file mode 100644
index 000000000..4cfab5876
--- /dev/null
+++ b/src/pkg/runtime/darwin/amd64/rt0.s
@@ -0,0 +1,10 @@
+// Copyright 2009 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Darwin and Linux use the same linkage to main
+
+TEXT _rt0_amd64_darwin(SB),7,$-8
+	MOVQ	$_rt0_amd64(SB), AX
+	MOVQ	SP, DI
+	JMP	AX
diff --git a/src/pkg/runtime/darwin/amd64/signal.c b/src/pkg/runtime/darwin/amd64/signal.c
new file mode 100644
index 000000000..036a3aca7
--- /dev/null
+++ b/src/pkg/runtime/darwin/amd64/signal.c
@@ -0,0 +1,204 @@
+// Copyright 2009 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+#include "runtime.h"
+#include "defs.h"
+#include "os.h"
+#include "signals.h"
+
+void
+runtime·dumpregs(Regs *r)
+{
+	runtime·printf("rax     %X\n", r->rax);
+	runtime·printf("rbx     %X\n", r->rbx);
+	runtime·printf("rcx     %X\n", r->rcx);
+	runtime·printf("rdx     %X\n", r->rdx);
+	runtime·printf("rdi     %X\n", r->rdi);
+	runtime·printf("rsi     %X\n", r->rsi);
+	runtime·printf("rbp     %X\n", r->rbp);
+	runtime·printf("rsp     %X\n", r->rsp);
+	runtime·printf("r8      %X\n", r->r8 );
+	runtime·printf("r9      %X\n", r->r9 );
+	runtime·printf("r10     %X\n", r->r10);
+	runtime·printf("r11     %X\n", r->r11);
+	runtime·printf("r12     %X\n", r->r12);
+	runtime·printf("r13     %X\n", r->r13);
+	runtime·printf("r14     %X\n", r->r14);
+	runtime·printf("r15     %X\n", r->r15);
+	runtime·printf("rip     %X\n", r->rip);
+	runtime·printf("rflags  %X\n", r->rflags);
+	runtime·printf("cs      %X\n", r->cs);
+	runtime·printf("fs      %X\n", r->fs);
+	runtime·printf("gs      %X\n", r->gs);
+}
+
+String
+runtime·signame(int32 sig)
+{
+	if(sig < 0 || sig >= NSIG)
+		return runtime·emptystring;
+	return runtime·gostringnocopy((byte*)runtime·sigtab[sig].name);
+}
+
+void
+runtime·sighandler(int32 sig, Siginfo *info, void *context, G *gp)
+{
+	Ucontext *uc;
+	Mcontext *mc;
+	Regs *r;
+	uintptr *sp;
+	byte *pc;
+
+	uc = context;
+	mc = uc->uc_mcontext;
+	r = &mc->ss;
+
+	if(sig == SIGPROF) {
+		runtime·sigprof((uint8*)r->rip, (uint8*)r->rsp, nil, gp);
+		return;
+	}
+
+	if(gp != nil && (runtime·sigtab[sig].flags & SigPanic)) {
+		// Work around Leopard bug that doesn't set FPE_INTDIV.
+		// Look at instruction to see if it is a divide.
+		// Not necessary in Snow Leopard (si_code will be != 0).
+		if(sig == SIGFPE && info->si_code == 0) {
+			pc = (byte*)r->rip;
+			if((pc[0]&0xF0) == 0x40)	// 64-bit REX prefix
+				pc++;
+			else if(pc[0] == 0x66)	// 16-bit instruction prefix
+				pc++;
+			if(pc[0] == 0xF6 || pc[0] == 0xF7)
+				info->si_code = FPE_INTDIV;
+		}
+		
+		// Make it look like a call to the signal func.
+		// Have to pass arguments out of band since
+		// augmenting the stack frame would break
+		// the unwinding code.
+		gp->sig = sig;
+		gp->sigcode0 = info->si_code;
+		gp->sigcode1 = (uintptr)info->si_addr;
+		gp->sigpc = r->rip;
+		
+		// Only push runtime·sigpanic if r->rip != 0.
+		// If r->rip == 0, probably panicked because of a
+		// call to a nil func.  Not pushing that onto sp will
+		// make the trace look like a call to runtime·sigpanic instead.
+		// (Otherwise the trace will end at runtime·sigpanic and we
+		// won't get to see who faulted.)
+		if(r->rip != 0) {
+			sp = (uintptr*)r->rsp;
+			*--sp = r->rip;
+			r->rsp = (uintptr)sp;
+		}
+		r->rip = (uintptr)runtime·sigpanic;
+		return;
+	}
+
+	if(runtime·sigtab[sig].flags & SigQueue) {
+		if(runtime·sigsend(sig) || (runtime·sigtab[sig].flags & SigIgnore))
+			return;
+		runtime·exit(2);	// SIGINT, SIGTERM, etc
+	}
+
+	if(runtime·panicking)	// traceback already printed
+		runtime·exit(2);
+	runtime·panicking = 1;
+
+	if(sig < 0 || sig >= NSIG){
+		runtime·printf("Signal %d\n", sig);
+	}else{
+		runtime·printf("%s\n", runtime·sigtab[sig].name);
+	}
+
+	runtime·printf("pc: %X\n", r->rip);
+	runtime·printf("\n");
+
+	if(runtime·gotraceback()){
+		runtime·traceback((void*)r->rip, (void*)r->rsp, 0, gp);
+		runtime·tracebackothers(gp);
+		runtime·dumpregs(r);
+	}
+
+	runtime·exit(2);
+}
+
+void
+runtime·sigignore(int32, Siginfo*, void*)
+{
+}
+
+void
+runtime·signalstack(byte *p, int32 n)
+{
+	StackT st;
+
+	st.ss_sp = p;
+	st.ss_size = n;
+	st.ss_flags = 0;
+	runtime·sigaltstack(&st, nil);
+}
+
+static void
+sigaction(int32 i, void (*fn)(int32, Siginfo*, void*, G*), bool restart)
+{
+	Sigaction sa;
+
+	runtime·memclr((byte*)&sa, sizeof sa);
+	sa.sa_flags = SA_SIGINFO|SA_ONSTACK;
+	if(restart)
+		sa.sa_flags |= SA_RESTART;
+	sa.sa_mask = ~0ULL;
+	sa.sa_tramp = (uintptr)runtime·sigtramp;	// runtime·sigtramp's job is to call into real handler
+	sa.__sigaction_u.__sa_sigaction = (uintptr)fn;
+	runtime·sigaction(i, &sa, nil);
+}
+
+void
+runtime·initsig(int32 queue)
+{
+	int32 i;
+	void *fn;
+
+	runtime·siginit();
+
+	for(i = 0; i<NSIG; i++) {
+		if(runtime·sigtab[i].flags) {
+			if((runtime·sigtab[i].flags & SigQueue) != queue)
+				continue;
+			if(runtime·sigtab[i].flags & (SigCatch | SigQueue))
+				fn = runtime·sighandler;
+			else
+				fn = runtime·sigignore;
+			sigaction(i, fn, (runtime·sigtab[i].flags & SigRestart) != 0);
+		}
+	}
+}
+
+void
+runtime·resetcpuprofiler(int32 hz)
+{
+	Itimerval it;
+	
+	runtime·memclr((byte*)&it, sizeof it);
+	if(hz == 0) {
+		runtime·setitimer(ITIMER_PROF, &it, nil);
+		sigaction(SIGPROF, SIG_IGN, true);
+	} else {
+		sigaction(SIGPROF, runtime·sighandler, true);
+		it.it_interval.tv_sec = 0;
+		it.it_interval.tv_usec = 1000000 / hz;
+		it.it_value = it.it_interval;
+		runtime·setitimer(ITIMER_PROF, &it, nil);
+	}
+	m->profilehz = hz;
+}
+
+void
+os·sigpipe(void)
+{
+	sigaction(SIGPIPE, SIG_DFL, false);
+	runtime·raisesigpipe();
+}
diff --git a/src/pkg/runtime/darwin/amd64/sys.s b/src/pkg/runtime/darwin/amd64/sys.s
new file mode 100644
index 000000000..8d1b20f11
--- /dev/null
+++ b/src/pkg/runtime/darwin/amd64/sys.s
@@ -0,0 +1,295 @@
+// Copyright 2009 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+//
+// System calls and other sys.stuff for AMD64, Darwin
+// See http://fxr.watson.org/fxr/source/bsd/kern/syscalls.c?v=xnu-1228
+// or /usr/include/sys/syscall.h (on a Mac) for system call numbers.
+//
+// The low 24 bits are the system call number.
+// The high 8 bits specify the kind of system call: 1=Mach, 2=BSD, 3=Machine-Dependent.
+//
+
+#include "amd64/asm.h"
+
+// Exit the entire program (like C exit)
+TEXT runtime·exit(SB),7,$0
+	MOVL	8(SP), DI		// arg 1 exit status
+	MOVL	$(0x2000000+1), AX	// syscall entry
+	SYSCALL
+	CALL	runtime·notok(SB)
+	RET
+
+// Exit this OS thread (like pthread_exit, which eventually
+// calls __bsdthread_terminate).
+TEXT runtime·exit1(SB),7,$0
+	MOVL	8(SP), DI		// arg 1 exit status
+	MOVL	$(0x2000000+361), AX	// syscall entry
+	SYSCALL
+	CALL	runtime·notok(SB)
+	RET
+
+TEXT runtime·write(SB),7,$0
+	MOVL	8(SP), DI		// arg 1 fd
+	MOVQ	16(SP), SI		// arg 2 buf
+	MOVL	24(SP), DX		// arg 3 count
+	MOVL	$(0x2000000+4), AX	// syscall entry
+	SYSCALL
+	RET
+
+TEXT runtime·raisesigpipe(SB),7,$24
+	get_tls(CX)
+	MOVQ	m(CX), DX
+	MOVL	$13, DI	// arg 1 SIGPIPE
+	MOVQ	m_procid(DX), SI	// arg 2 thread_port
+	MOVL	$(0x2000000+328), AX	// syscall entry __pthread_kill
+	SYSCALL
+	RET
+
+TEXT runtime·setitimer(SB), 7, $0
+	MOVL	8(SP), DI
+	MOVQ	16(SP), SI
+	MOVQ	24(SP), DX
+	MOVL	$(0x2000000+83), AX	// syscall entry
+	SYSCALL
+	RET
+
+// void gettime(int64 *sec, int32 *usec)
+TEXT runtime·gettime(SB), 7, $32
+	MOVQ	SP, DI	// must be non-nil, unused
+	MOVQ	$0, SI
+	MOVL	$(0x2000000+116), AX
+	SYSCALL
+	MOVQ	sec+0(FP), DI
+	MOVQ	AX, (DI)
+	MOVQ	usec+8(FP), DI
+	MOVL	DX, (DI)
+	RET
+
+TEXT runtime·sigaction(SB),7,$0
+	MOVL	8(SP), DI		// arg 1 sig
+	MOVQ	16(SP), SI		// arg 2 act
+	MOVQ	24(SP), DX		// arg 3 oact
+	MOVQ	24(SP), CX		// arg 3 oact
+	MOVQ	24(SP), R10		// arg 3 oact
+	MOVL	$(0x2000000+46), AX	// syscall entry
+	SYSCALL
+	JCC	2(PC)
+	CALL	runtime·notok(SB)
+	RET
+
+TEXT runtime·sigtramp(SB),7,$64
+	get_tls(BX)
+	
+	// save g
+	MOVQ	g(BX), R10
+	MOVQ	R10, 48(SP)
+	
+	// g = m->gsignal
+	MOVQ	m(BX), BP
+	MOVQ	m_gsignal(BP), BP
+	MOVQ	BP, g(BX)
+
+	MOVL	DX, 0(SP)
+	MOVQ	CX, 8(SP)
+	MOVQ	R8, 16(SP)
+	MOVQ	R10, 24(SP)
+
+	MOVQ	R8, 32(SP)	// save ucontext
+	MOVQ	SI, 40(SP)	// save infostyle
+	CALL	DI
+
+	// restore g
+	get_tls(BX)
+	MOVQ	48(SP), R10
+	MOVQ	R10, g(BX)
+
+	// call sigreturn
+	MOVL	$(0x2000000+184), AX	// sigreturn(ucontext, infostyle)
+	MOVQ	32(SP), DI	// saved ucontext
+	MOVQ	40(SP), SI	// saved infostyle
+	SYSCALL
+	INT $3	// not reached
+
+TEXT runtime·mmap(SB),7,$0
+	MOVQ	8(SP), DI		// arg 1 addr
+	MOVQ	16(SP), SI		// arg 2 len
+	MOVL	24(SP), DX		// arg 3 prot
+	MOVL	28(SP), R10		// arg 4 flags
+	MOVL	32(SP), R8		// arg 5 fid
+	MOVL	36(SP), R9		// arg 6 offset
+	MOVL	$(0x2000000+197), AX	// syscall entry
+	SYSCALL
+	RET
+
+TEXT runtime·munmap(SB),7,$0
+	MOVQ	8(SP), DI		// arg 1 addr
+	MOVQ	16(SP), SI		// arg 2 len
+	MOVL	$(0x2000000+73), AX	// syscall entry
+	SYSCALL
+	JCC	2(PC)
+	CALL	runtime·notok(SB)
+	RET
+
+TEXT runtime·notok(SB),7,$0
+	MOVL	$0xf1, BP
+	MOVQ	BP, (BP)
+	RET
+
+TEXT runtime·sigaltstack(SB),7,$0
+	MOVQ	new+8(SP), DI
+	MOVQ	old+16(SP), SI
+	MOVQ	$(0x2000000+53), AX
+	SYSCALL
+	JCC	2(PC)
+	CALL	runtime·notok(SB)
+	RET
+
+// void bsdthread_create(void *stk, M *m, G *g, void (*fn)(void))
+TEXT runtime·bsdthread_create(SB),7,$0
+	// Set up arguments to bsdthread_create system call.
+	// The ones in quotes pass through to the thread callback
+	// uninterpreted, so we can put whatever we want there.
+	MOVQ	fn+32(SP), DI	// "func"
+	MOVQ	mm+16(SP), SI	// "arg"
+	MOVQ	stk+8(SP), DX	// stack
+	MOVQ	gg+24(SP), R10	// "pthread"
+	MOVQ	$0x01000000, R8	// flags = PTHREAD_START_CUSTOM
+	MOVQ	$0, R9	// paranoia
+	MOVQ	$(0x2000000+360), AX	// bsdthread_create
+	SYSCALL
+	JCC 3(PC)
+	NEGL	AX
+	RET
+	MOVL	$0, AX
+	RET
+
+// The thread that bsdthread_create creates starts executing here,
+// because we registered this function using bsdthread_register
+// at startup.
+//	DI = "pthread"
+//	SI = mach thread port
+//	DX = "func" (= fn)
+//	CX = "arg" (= m)
+//	R8 = stack
+//	R9 = flags (= 0)
+//	SP = stack - C_64_REDZONE_LEN (= stack - 128)
+TEXT runtime·bsdthread_start(SB),7,$0
+	MOVQ	R8, SP		// empirically, SP is very wrong but R8 is right
+
+	PUSHQ	DX
+	PUSHQ	CX
+	PUSHQ	SI
+
+	// set up thread local storage pointing at m->tls.
+	LEAQ	m_tls(CX), DI
+	CALL	runtime·settls(SB)
+
+	POPQ	SI
+	POPQ	CX
+	POPQ	DX
+	
+	get_tls(BX)
+	MOVQ	CX, m(BX)
+	MOVQ	SI, m_procid(CX)	// thread port is m->procid
+	MOVQ	m_g0(CX), AX
+	MOVQ	AX, g(BX)
+	CALL	runtime·stackcheck(SB)	// smashes AX, CX
+	CALL	DX	// fn
+	CALL	runtime·exit1(SB)
+	RET
+
+// void bsdthread_register(void)
+// registers callbacks for threadstart (see bsdthread_create above
+// and wqthread and pthsize (not used).  returns 0 on success.
+TEXT runtime·bsdthread_register(SB),7,$0
+	MOVQ	$runtime·bsdthread_start(SB), DI	// threadstart
+	MOVQ	$0, SI	// wqthread, not used by us
+	MOVQ	$0, DX	// pthsize, not used by us
+	MOVQ	$0, R10	// dummy_value [sic]
+	MOVQ	$0, R8	// targetconc_ptr
+	MOVQ	$0, R9	// dispatchqueue_offset
+	MOVQ	$(0x2000000+366), AX	// bsdthread_register
+	SYSCALL
+	JCC 2(PC)
+	CALL	runtime·notok(SB)
+	RET
+
+// Mach system calls use 0x1000000 instead of the BSD's 0x2000000.
+
+// uint32 mach_msg_trap(void*, uint32, uint32, uint32, uint32, uint32, uint32)
+TEXT runtime·mach_msg_trap(SB),7,$0
+	MOVQ	8(SP), DI
+	MOVL	16(SP), SI
+	MOVL	20(SP), DX
+	MOVL	24(SP), R10
+	MOVL	28(SP), R8
+	MOVL	32(SP), R9
+	MOVL	36(SP), R11
+	PUSHQ	R11	// seventh arg, on stack
+	MOVL	$(0x1000000+31), AX	// mach_msg_trap
+	SYSCALL
+	POPQ	R11
+	RET
+
+TEXT runtime·mach_task_self(SB),7,$0
+	MOVL	$(0x1000000+28), AX	// task_self_trap
+	SYSCALL
+	RET
+
+TEXT runtime·mach_thread_self(SB),7,$0
+	MOVL	$(0x1000000+27), AX	// thread_self_trap
+	SYSCALL
+	RET
+
+TEXT runtime·mach_reply_port(SB),7,$0
+	MOVL	$(0x1000000+26), AX	// mach_reply_port
+	SYSCALL
+	RET
+
+// Mach provides trap versions of the semaphore ops,
+// instead of requiring the use of RPC.
+
+// uint32 mach_semaphore_wait(uint32)
+TEXT runtime·mach_semaphore_wait(SB),7,$0
+	MOVL	8(SP), DI
+	MOVL	$(0x1000000+36), AX	// semaphore_wait_trap
+	SYSCALL
+	RET
+
+// uint32 mach_semaphore_timedwait(uint32, uint32, uint32)
+TEXT runtime·mach_semaphore_timedwait(SB),7,$0
+	MOVL	8(SP), DI
+	MOVL	12(SP), SI
+	MOVL	16(SP), DX
+	MOVL	$(0x1000000+38), AX	// semaphore_timedwait_trap
+	SYSCALL
+	RET
+
+// uint32 mach_semaphore_signal(uint32)
+TEXT runtime·mach_semaphore_signal(SB),7,$0
+	MOVL	8(SP), DI
+	MOVL	$(0x1000000+33), AX	// semaphore_signal_trap
+	SYSCALL
+	RET
+
+// uint32 mach_semaphore_signal_all(uint32)
+TEXT runtime·mach_semaphore_signal_all(SB),7,$0
+	MOVL	8(SP), DI
+	MOVL	$(0x1000000+34), AX	// semaphore_signal_all_trap
+	SYSCALL
+	RET
+
+// set tls base to DI
+TEXT runtime·settls(SB),7,$32
+	/*
+	* Same as in ../386/sys.s:/ugliness, different constant.
+	* See ../../../../libcgo/darwin_amd64.c for the derivation
+	* of the constant.
+	*/
+	SUBQ $0x8a0, DI
+
+	MOVL	$(0x3000000+3), AX	// thread_fast_set_cthread_self - machdep call #3
+	SYSCALL
+	RET
diff --git a/src/pkg/runtime/darwin/defs.c b/src/pkg/runtime/darwin/defs.c
new file mode 100644
index 000000000..032a6bcbb
--- /dev/null
+++ b/src/pkg/runtime/darwin/defs.c
@@ -0,0 +1,159 @@
+// Copyright 2009 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+/*
+ * Input to godefs.
+ *
+	godefs -f -m64 defs.c >amd64/defs.h
+	godefs -f -m32 defs.c >386/defs.h
+ */
+
+#define __DARWIN_UNIX03 0
+
+#include <mach/mach.h>
+#include <mach/message.h>
+#include <sys/types.h>
+#include <sys/time.h>
+#include <signal.h>
+#include <sys/mman.h>
+
+enum {
+	$PROT_NONE = PROT_NONE,
+	$PROT_READ = PROT_READ,
+	$PROT_WRITE = PROT_WRITE,
+	$PROT_EXEC = PROT_EXEC,
+
+	$MAP_ANON = MAP_ANON,
+	$MAP_PRIVATE = MAP_PRIVATE,
+	$MAP_FIXED = MAP_FIXED,
+
+	$MACH_MSG_TYPE_MOVE_RECEIVE = MACH_MSG_TYPE_MOVE_RECEIVE,
+	$MACH_MSG_TYPE_MOVE_SEND = MACH_MSG_TYPE_MOVE_SEND,
+	$MACH_MSG_TYPE_MOVE_SEND_ONCE = MACH_MSG_TYPE_MOVE_SEND_ONCE,
+	$MACH_MSG_TYPE_COPY_SEND = MACH_MSG_TYPE_COPY_SEND,
+	$MACH_MSG_TYPE_MAKE_SEND = MACH_MSG_TYPE_MAKE_SEND,
+	$MACH_MSG_TYPE_MAKE_SEND_ONCE = MACH_MSG_TYPE_MAKE_SEND_ONCE,
+	$MACH_MSG_TYPE_COPY_RECEIVE = MACH_MSG_TYPE_COPY_RECEIVE,
+
+	$MACH_MSG_PORT_DESCRIPTOR = MACH_MSG_PORT_DESCRIPTOR,
+	$MACH_MSG_OOL_DESCRIPTOR = MACH_MSG_OOL_DESCRIPTOR,
+	$MACH_MSG_OOL_PORTS_DESCRIPTOR = MACH_MSG_OOL_PORTS_DESCRIPTOR,
+	$MACH_MSG_OOL_VOLATILE_DESCRIPTOR = MACH_MSG_OOL_VOLATILE_DESCRIPTOR,
+
+	$MACH_MSGH_BITS_COMPLEX = MACH_MSGH_BITS_COMPLEX,
+
+	$MACH_SEND_MSG = MACH_SEND_MSG,
+	$MACH_RCV_MSG = MACH_RCV_MSG,
+	$MACH_RCV_LARGE = MACH_RCV_LARGE,
+
+	$MACH_SEND_TIMEOUT = MACH_SEND_TIMEOUT,
+	$MACH_SEND_INTERRUPT = MACH_SEND_INTERRUPT,
+	$MACH_SEND_CANCEL = MACH_SEND_CANCEL,
+	$MACH_SEND_ALWAYS = MACH_SEND_ALWAYS,
+	$MACH_SEND_TRAILER = MACH_SEND_TRAILER,
+	$MACH_RCV_TIMEOUT = MACH_RCV_TIMEOUT,
+	$MACH_RCV_NOTIFY = MACH_RCV_NOTIFY,
+	$MACH_RCV_INTERRUPT = MACH_RCV_INTERRUPT,
+	$MACH_RCV_OVERWRITE = MACH_RCV_OVERWRITE,
+
+	$NDR_PROTOCOL_2_0 = NDR_PROTOCOL_2_0,
+	$NDR_INT_BIG_ENDIAN = NDR_INT_BIG_ENDIAN,
+	$NDR_INT_LITTLE_ENDIAN = NDR_INT_LITTLE_ENDIAN,
+	$NDR_FLOAT_IEEE = NDR_FLOAT_IEEE,
+	$NDR_CHAR_ASCII = NDR_CHAR_ASCII,
+
+	$SA_SIGINFO = SA_SIGINFO,
+	$SA_RESTART = SA_RESTART,
+	$SA_ONSTACK = SA_ONSTACK,
+	$SA_USERTRAMP = SA_USERTRAMP,
+	$SA_64REGSET = SA_64REGSET,
+	
+	$SIGHUP = SIGHUP,
+	$SIGINT = SIGINT,
+	$SIGQUIT = SIGQUIT,
+	$SIGILL = SIGILL,
+	$SIGTRAP = SIGTRAP,
+	$SIGABRT = SIGABRT,
+	$SIGEMT = SIGEMT,
+	$SIGFPE = SIGFPE,
+	$SIGKILL = SIGKILL,
+	$SIGBUS = SIGBUS,
+	$SIGSEGV = SIGSEGV,
+	$SIGSYS = SIGSYS,
+	$SIGPIPE = SIGPIPE,
+	$SIGALRM = SIGALRM,
+	$SIGTERM = SIGTERM,
+	$SIGURG = SIGURG,
+	$SIGSTOP = SIGSTOP,
+	$SIGTSTP = SIGTSTP,
+	$SIGCONT = SIGCONT,
+	$SIGCHLD = SIGCHLD,
+	$SIGTTIN = SIGTTIN,
+	$SIGTTOU = SIGTTOU,
+	$SIGIO = SIGIO,
+	$SIGXCPU = SIGXCPU,
+	$SIGXFSZ = SIGXFSZ,
+	$SIGVTALRM = SIGVTALRM,
+	$SIGPROF = SIGPROF,
+	$SIGWINCH = SIGWINCH,
+	$SIGINFO = SIGINFO,
+	$SIGUSR1 = SIGUSR1,
+	$SIGUSR2 = SIGUSR2,
+	
+	$FPE_INTDIV = FPE_INTDIV,
+	$FPE_INTOVF = FPE_INTOVF,
+	$FPE_FLTDIV = FPE_FLTDIV,
+	$FPE_FLTOVF = FPE_FLTOVF,
+	$FPE_FLTUND = FPE_FLTUND,
+	$FPE_FLTRES = FPE_FLTRES,
+	$FPE_FLTINV = FPE_FLTINV,
+	$FPE_FLTSUB = FPE_FLTSUB,
+	
+	$BUS_ADRALN = BUS_ADRALN,
+	$BUS_ADRERR = BUS_ADRERR,
+	$BUS_OBJERR = BUS_OBJERR,
+	
+	$SEGV_MAPERR = SEGV_MAPERR,
+	$SEGV_ACCERR = SEGV_ACCERR,
+	
+	$ITIMER_REAL = ITIMER_REAL,
+	$ITIMER_VIRTUAL = ITIMER_VIRTUAL,
+	$ITIMER_PROF = ITIMER_PROF,
+};
+
+typedef mach_msg_body_t	$MachBody;
+typedef mach_msg_header_t	$MachHeader;
+typedef NDR_record_t		$MachNDR;
+typedef mach_msg_port_descriptor_t	$MachPort;
+
+typedef stack_t	$StackT;
+typedef union __sigaction_u	$Sighandler;
+
+typedef struct __sigaction	$Sigaction;	// used in syscalls
+// typedef struct sigaction	$Sigaction;	// used by the C library
+typedef union sigval $Sigval;
+typedef siginfo_t $Siginfo;
+typedef struct timeval	$Timeval;
+typedef struct itimerval	$Itimerval;
+
+typedef struct fp_control $FPControl;
+typedef struct fp_status $FPStatus;
+typedef struct mmst_reg $RegMMST;
+typedef struct xmm_reg $RegXMM;
+
+#ifdef __LP64__
+// amd64
+typedef x86_thread_state64_t	$Regs;
+typedef x86_float_state64_t $FloatState;
+typedef x86_exception_state64_t $ExceptionState;
+typedef struct mcontext64 $Mcontext;
+#else
+// 386
+typedef x86_thread_state32_t	$Regs;
+typedef x86_float_state32_t $FloatState;
+typedef x86_exception_state32_t $ExceptionState;
+typedef struct mcontext32 $Mcontext;
+#endif
+
+typedef ucontext_t	$Ucontext;
diff --git a/src/pkg/runtime/darwin/mem.c b/src/pkg/runtime/darwin/mem.c
new file mode 100644
index 000000000..935c032bc
--- /dev/null
+++ b/src/pkg/runtime/darwin/mem.c
@@ -0,0 +1,55 @@
+#include "runtime.h"
+#include "defs.h"
+#include "os.h"
+#include "malloc.h"
+
+void*
+runtime·SysAlloc(uintptr n)
+{
+	void *v;
+
+	mstats.sys += n;
+	v = runtime·mmap(nil, n, PROT_READ|PROT_WRITE|PROT_EXEC, MAP_ANON|MAP_PRIVATE, -1, 0);
+	if(v < (void*)4096)
+		return nil;
+	return v;
+}
+
+void
+runtime·SysUnused(void *v, uintptr n)
+{
+	USED(v);
+	USED(n);
+	// TODO(rsc): call madvise MADV_DONTNEED
+}
+
+void
+runtime·SysFree(void *v, uintptr n)
+{
+	mstats.sys -= n;
+	runtime·munmap(v, n);
+}
+
+void*
+runtime·SysReserve(void *v, uintptr n)
+{
+	return runtime·mmap(v, n, PROT_NONE, MAP_ANON|MAP_PRIVATE, -1, 0);
+}
+
+enum
+{
+	ENOMEM = 12,
+};
+
+void
+runtime·SysMap(void *v, uintptr n)
+{
+	void *p;
+	
+	mstats.sys += n;
+	p = runtime·mmap(v, n, PROT_READ|PROT_WRITE|PROT_EXEC, MAP_ANON|MAP_FIXED|MAP_PRIVATE, -1, 0);
+	if(p == (void*)-ENOMEM)
+		runtime·throw("runtime: out of memory");
+	if(p != v)
+		runtime·throw("runtime: cannot map pages in arena address space");
+}
diff --git a/src/pkg/runtime/darwin/os.h b/src/pkg/runtime/darwin/os.h
new file mode 100644
index 000000000..db3c2e8a7
--- /dev/null
+++ b/src/pkg/runtime/darwin/os.h
@@ -0,0 +1,31 @@
+// Copyright 2009 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+#define SIG_DFL ((void*)0)
+#define SIG_IGN ((void*)1)
+
+int32	runtime·bsdthread_create(void*, M*, G*, void(*)(void));
+void	runtime·bsdthread_register(void);
+int32	runtime·mach_msg_trap(MachHeader*, int32, uint32, uint32, uint32, uint32, uint32);
+uint32	runtime·mach_reply_port(void);
+void	runtime·mach_semacquire(uint32);
+uint32	runtime·mach_semcreate(void);
+void	runtime·mach_semdestroy(uint32);
+void	runtime·mach_semrelease(uint32);
+void	runtime·mach_semreset(uint32);
+uint32	runtime·mach_task_self(void);
+uint32	runtime·mach_task_self(void);
+uint32	runtime·mach_thread_self(void);
+uint32	runtime·mach_thread_self(void);
+
+struct Sigaction;
+void	runtime·sigaction(uintptr, struct Sigaction*, struct Sigaction*);
+
+struct StackT;
+void	runtime·sigaltstack(struct StackT*, struct StackT*);
+void	runtime·sigtramp(void);
+void	runtime·sigpanic(void);
+void	runtime·setitimer(int32, Itimerval*, Itimerval*);
+
+void	runtime·raisesigpipe(void);
diff --git a/src/pkg/runtime/darwin/signals.h b/src/pkg/runtime/darwin/signals.h
new file mode 100644
index 000000000..035027fad
--- /dev/null
+++ b/src/pkg/runtime/darwin/signals.h
@@ -0,0 +1,51 @@
+// Copyright 2009 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+#define C SigCatch
+#define I SigIgnore
+#define R SigRestart
+#define Q SigQueue
+#define P SigPanic
+
+SigTab runtime·sigtab[] = {
+	/* 0 */	0, "SIGNONE: no trap",
+	/* 1 */	Q+R, "SIGHUP: terminal line hangup",
+	/* 2 */	Q+R, "SIGINT: interrupt",
+	/* 3 */	C, "SIGQUIT: quit",
+	/* 4 */	C, "SIGILL: illegal instruction",
+	/* 5 */	C, "SIGTRAP: trace trap",	/* used by panic and array out of bounds, etc. */
+	/* 6 */	C, "SIGABRT: abort",
+	/* 7 */	C, "SIGEMT: emulate instruction executed",
+	/* 8 */	C+P, "SIGFPE: floating-point exception",
+	/* 9 */	0, "SIGKILL: kill",
+	/* 10 */	C+P, "SIGBUS: bus error",
+	/* 11 */	C+P, "SIGSEGV: segmentation violation",
+	/* 12 */	C, "SIGSYS: bad system call",
+	/* 13 */	I, "SIGPIPE: write to broken pipe",
+	/* 14 */	Q+I+R, "SIGALRM: alarm clock",
+	/* 15 */	Q+R, "SIGTERM: termination",
+	/* 16 */	Q+I+R, "SIGURG: urgent condition on socket",
+	/* 17 */	0, "SIGSTOP: stop",
+	/* 18 */	Q+I+R, "SIGTSTP: keyboard stop",
+	/* 19 */	0, "SIGCONT: continue after stop",
+	/* 20 */	Q+I+R, "SIGCHLD: child status has changed",
+	/* 21 */	Q+I+R, "SIGTTIN: background read from tty",
+	/* 22 */	Q+I+R, "SIGTTOU: background write to tty",
+	/* 23 */	Q+I+R, "SIGIO: i/o now possible",
+	/* 24 */	Q+I+R, "SIGXCPU: cpu limit exceeded",
+	/* 25 */	Q+I+R, "SIGXFSZ: file size limit exceeded",
+	/* 26 */	Q+I+R, "SIGVTALRM: virtual alarm clock",
+	/* 27 */	Q+I+R, "SIGPROF: profiling alarm clock",
+	/* 28 */	Q+I+R, "SIGWINCH: window size change",
+	/* 29 */	Q+I+R, "SIGINFO: status request from keyboard",
+	/* 30 */	Q+I+R, "SIGUSR1: user-defined signal 1",
+	/* 31 */	Q+I+R, "SIGUSR2: user-defined signal 2",
+};
+#undef C
+#undef I
+#undef R
+#undef Q
+#undef P
+
+#define	NSIG 32
diff --git a/src/pkg/runtime/darwin/thread.c b/src/pkg/runtime/darwin/thread.c
new file mode 100644
index 000000000..6733e815e
--- /dev/null
+++ b/src/pkg/runtime/darwin/thread.c
@@ -0,0 +1,484 @@
+// Copyright 2009 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+#include "runtime.h"
+#include "defs.h"
+#include "os.h"
+#include "stack.h"
+
+extern SigTab runtime·sigtab[];
+
+static void
+unimplemented(int8 *name)
+{
+	runtime·prints(name);
+	runtime·prints(" not implemented\n");
+	*(int32*)1231 = 1231;
+}
+
+// Thread-safe allocation of a semaphore.
+// Psema points at a kernel semaphore key.
+// It starts out zero, meaning no semaphore.
+// Fill it in, being careful of others calling initsema
+// simultaneously.
+static void
+initsema(uint32 *psema)
+{
+	uint32 sema;
+
+	if(*psema != 0)	// already have one
+		return;
+
+	sema = runtime·mach_semcreate();
+	if(!runtime·cas(psema, 0, sema)){
+		// Someone else filled it in.  Use theirs.
+		runtime·mach_semdestroy(sema);
+		return;
+	}
+}
+
+
+// Blocking locks.
+
+// Implement Locks, using semaphores.
+// l->key is the number of threads who want the lock.
+// In a race, one thread increments l->key from 0 to 1
+// and the others increment it from >0 to >1.  The thread
+// who does the 0->1 increment gets the lock, and the
+// others wait on the semaphore.  When the 0->1 thread
+// releases the lock by decrementing l->key, l->key will
+// be >0, so it will increment the semaphore to wake up
+// one of the others.  This is the same algorithm used
+// in Plan 9's user-level locks.
+
+void
+runtime·lock(Lock *l)
+{
+	if(m->locks < 0)
+		runtime·throw("lock count");
+	m->locks++;
+
+	if(runtime·xadd(&l->key, 1) > 1) {	// someone else has it; wait
+		// Allocate semaphore if needed.
+		if(l->sema == 0)
+			initsema(&l->sema);
+		runtime·mach_semacquire(l->sema);
+	}
+}
+
+void
+runtime·unlock(Lock *l)
+{
+	m->locks--;
+	if(m->locks < 0)
+		runtime·throw("lock count");
+
+	if(runtime·xadd(&l->key, -1) > 0) {	// someone else is waiting
+		// Allocate semaphore if needed.
+		if(l->sema == 0)
+			initsema(&l->sema);
+		runtime·mach_semrelease(l->sema);
+	}
+}
+
+static void
+destroylock(Lock *l)
+{
+	if(l->sema != 0) {
+		runtime·mach_semdestroy(l->sema);
+		l->sema = 0;
+	}
+}
+
+// User-level semaphore implementation:
+// try to do the operations in user space on u,
+// but when it's time to block, fall back on the kernel semaphore k.
+// This is the same algorithm used in Plan 9.
+void
+runtime·usemacquire(Usema *s)
+{
+	if((int32)runtime·xadd(&s->u, -1) < 0) {
+		if(s->k == 0)
+			initsema(&s->k);
+		runtime·mach_semacquire(s->k);
+	}
+}
+
+void
+runtime·usemrelease(Usema *s)
+{
+	if((int32)runtime·xadd(&s->u, 1) <= 0) {
+		if(s->k == 0)
+			initsema(&s->k);
+		runtime·mach_semrelease(s->k);
+	}
+}
+
+
+// Event notifications.
+void
+runtime·noteclear(Note *n)
+{
+	n->wakeup = 0;
+}
+
+void
+runtime·notesleep(Note *n)
+{
+	while(!n->wakeup)
+		runtime·usemacquire(&n->sema);
+}
+
+void
+runtime·notewakeup(Note *n)
+{
+	n->wakeup = 1;
+	runtime·usemrelease(&n->sema);
+}
+
+
+// BSD interface for threading.
+void
+runtime·osinit(void)
+{
+	// Register our thread-creation callback (see {amd64,386}/sys.s)
+	// but only if we're not using cgo.  If we are using cgo we need
+	// to let the C pthread libary install its own thread-creation callback.
+	if(!runtime·iscgo)
+		runtime·bsdthread_register();
+	runtime·destroylock = destroylock;
+}
+
+void
+runtime·goenvs(void)
+{
+	runtime·goenvs_unix();
+}
+
+void
+runtime·newosproc(M *m, G *g, void *stk, void (*fn)(void))
+{
+	int32 errno;
+
+	m->tls[0] = m->id;	// so 386 asm can find it
+	if(0){
+		runtime·printf("newosproc stk=%p m=%p g=%p fn=%p id=%d/%d ostk=%p\n",
+			stk, m, g, fn, m->id, m->tls[0], &m);
+	}
+	if((errno = runtime·bsdthread_create(stk, m, g, fn)) < 0) {
+		runtime·printf("runtime: failed to create new OS thread (have %d already; errno=%d)\n", runtime·mcount(), -errno);
+		runtime·throw("runtime.newosproc");
+	}
+}
+
+// Called to initialize a new m (including the bootstrap m).
+void
+runtime·minit(void)
+{
+	// Initialize signal handling.
+	m->gsignal = runtime·malg(32*1024);	// OS X wants >=8K, Linux >=2K
+	runtime·signalstack(m->gsignal->stackguard - StackGuard, 32*1024);
+}
+
+// Mach IPC, to get at semaphores
+// Definitions are in /usr/include/mach on a Mac.
+
+static void
+macherror(int32 r, int8 *fn)
+{
+	runtime·printf("mach error %s: %d\n", fn, r);
+	runtime·throw("mach error");
+}
+
+enum
+{
+	DebugMach = 0
+};
+
+static MachNDR zerondr;
+
+#define MACH_MSGH_BITS(a, b) ((a) | ((b)<<8))
+
+static int32
+mach_msg(MachHeader *h,
+	int32 op,
+	uint32 send_size,
+	uint32 rcv_size,
+	uint32 rcv_name,
+	uint32 timeout,
+	uint32 notify)
+{
+	// TODO: Loop on interrupt.
+	return runtime·mach_msg_trap(h, op, send_size, rcv_size, rcv_name, timeout, notify);
+}
+
+// Mach RPC (MIG)
+
+enum
+{
+	MinMachMsg = 48,
+	Reply = 100,
+};
+
+#pragma pack on
+typedef struct CodeMsg CodeMsg;
+struct CodeMsg
+{
+	MachHeader h;
+	MachNDR NDR;
+	int32 code;
+};
+#pragma pack off
+
+static int32
+machcall(MachHeader *h, int32 maxsize, int32 rxsize)
+{
+	uint32 *p;
+	int32 i, ret, id;
+	uint32 port;
+	CodeMsg *c;
+
+	if((port = m->machport) == 0){
+		port = runtime·mach_reply_port();
+		m->machport = port;
+	}
+
+	h->msgh_bits |= MACH_MSGH_BITS(MACH_MSG_TYPE_COPY_SEND, MACH_MSG_TYPE_MAKE_SEND_ONCE);
+	h->msgh_local_port = port;
+	h->msgh_reserved = 0;
+	id = h->msgh_id;
+
+	if(DebugMach){
+		p = (uint32*)h;
+		runtime·prints("send:\t");
+		for(i=0; i<h->msgh_size/sizeof(p[0]); i++){
+			runtime·prints(" ");
+			runtime·printpointer((void*)p[i]);
+			if(i%8 == 7)
+				runtime·prints("\n\t");
+		}
+		if(i%8)
+			runtime·prints("\n");
+	}
+
+	ret = mach_msg(h, MACH_SEND_MSG|MACH_RCV_MSG,
+		h->msgh_size, maxsize, port, 0, 0);
+	if(ret != 0){
+		if(DebugMach){
+			runtime·prints("mach_msg error ");
+			runtime·printint(ret);
+			runtime·prints("\n");
+		}
+		return ret;
+	}
+
+	if(DebugMach){
+		p = (uint32*)h;
+		runtime·prints("recv:\t");
+		for(i=0; i<h->msgh_size/sizeof(p[0]); i++){
+			runtime·prints(" ");
+			runtime·printpointer((void*)p[i]);
+			if(i%8 == 7)
+				runtime·prints("\n\t");
+		}
+		if(i%8)
+			runtime·prints("\n");
+	}
+
+	if(h->msgh_id != id+Reply){
+		if(DebugMach){
+			runtime·prints("mach_msg reply id mismatch ");
+			runtime·printint(h->msgh_id);
+			runtime·prints(" != ");
+			runtime·printint(id+Reply);
+			runtime·prints("\n");
+		}
+		return -303;	// MIG_REPLY_MISMATCH
+	}
+
+	// Look for a response giving the return value.
+	// Any call can send this back with an error,
+	// and some calls only have return values so they
+	// send it back on success too.  I don't quite see how
+	// you know it's one of these and not the full response
+	// format, so just look if the message is right.
+	c = (CodeMsg*)h;
+	if(h->msgh_size == sizeof(CodeMsg)
+	&& !(h->msgh_bits & MACH_MSGH_BITS_COMPLEX)){
+		if(DebugMach){
+			runtime·prints("mig result ");
+			runtime·printint(c->code);
+			runtime·prints("\n");
+		}
+		return c->code;
+	}
+
+	if(h->msgh_size != rxsize){
+		if(DebugMach){
+			runtime·prints("mach_msg reply size mismatch ");
+			runtime·printint(h->msgh_size);
+			runtime·prints(" != ");
+			runtime·printint(rxsize);
+			runtime·prints("\n");
+		}
+		return -307;	// MIG_ARRAY_TOO_LARGE
+	}
+
+	return 0;
+}
+
+
+// Semaphores!
+
+enum
+{
+	Tmach_semcreate = 3418,
+	Rmach_semcreate = Tmach_semcreate + Reply,
+
+	Tmach_semdestroy = 3419,
+	Rmach_semdestroy = Tmach_semdestroy + Reply,
+
+	// Mach calls that get interrupted by Unix signals
+	// return this error code.  We retry them.
+	KERN_ABORTED = 14,
+};
+
+typedef struct Tmach_semcreateMsg Tmach_semcreateMsg;
+typedef struct Rmach_semcreateMsg Rmach_semcreateMsg;
+typedef struct Tmach_semdestroyMsg Tmach_semdestroyMsg;
+// Rmach_semdestroyMsg = CodeMsg
+
+#pragma pack on
+struct Tmach_semcreateMsg
+{
+	MachHeader h;
+	MachNDR ndr;
+	int32 policy;
+	int32 value;
+};
+
+struct Rmach_semcreateMsg
+{
+	MachHeader h;
+	MachBody body;
+	MachPort semaphore;
+};
+
+struct Tmach_semdestroyMsg
+{
+	MachHeader h;
+	MachBody body;
+	MachPort semaphore;
+};
+#pragma pack off
+
+uint32
+runtime·mach_semcreate(void)
+{
+	union {
+		Tmach_semcreateMsg tx;
+		Rmach_semcreateMsg rx;
+		uint8 pad[MinMachMsg];
+	} m;
+	int32 r;
+
+	m.tx.h.msgh_bits = 0;
+	m.tx.h.msgh_size = sizeof(m.tx);
+	m.tx.h.msgh_remote_port = runtime·mach_task_self();
+	m.tx.h.msgh_id = Tmach_semcreate;
+	m.tx.ndr = zerondr;
+
+	m.tx.policy = 0;	// 0 = SYNC_POLICY_FIFO
+	m.tx.value = 0;
+
+	while((r = machcall(&m.tx.h, sizeof m, sizeof(m.rx))) != 0){
+		if(r == KERN_ABORTED)	// interrupted
+			continue;
+		macherror(r, "semaphore_create");
+	}
+	if(m.rx.body.msgh_descriptor_count != 1)
+		unimplemented("mach_semcreate desc count");
+	return m.rx.semaphore.name;
+}
+
+void
+runtime·mach_semdestroy(uint32 sem)
+{
+	union {
+		Tmach_semdestroyMsg tx;
+		uint8 pad[MinMachMsg];
+	} m;
+	int32 r;
+
+	m.tx.h.msgh_bits = MACH_MSGH_BITS_COMPLEX;
+	m.tx.h.msgh_size = sizeof(m.tx);
+	m.tx.h.msgh_remote_port = runtime·mach_task_self();
+	m.tx.h.msgh_id = Tmach_semdestroy;
+	m.tx.body.msgh_descriptor_count = 1;
+	m.tx.semaphore.name = sem;
+	m.tx.semaphore.disposition = MACH_MSG_TYPE_MOVE_SEND;
+	m.tx.semaphore.type = 0;
+
+	while((r = machcall(&m.tx.h, sizeof m, 0)) != 0){
+		if(r == KERN_ABORTED)	// interrupted
+			continue;
+		macherror(r, "semaphore_destroy");
+	}
+}
+
+// The other calls have simple system call traps in sys.s
+int32 runtime·mach_semaphore_wait(uint32 sema);
+int32 runtime·mach_semaphore_timedwait(uint32 sema, uint32 sec, uint32 nsec);
+int32 runtime·mach_semaphore_signal(uint32 sema);
+int32 runtime·mach_semaphore_signal_all(uint32 sema);
+
+void
+runtime·mach_semacquire(uint32 sem)
+{
+	int32 r;
+
+	while((r = runtime·mach_semaphore_wait(sem)) != 0) {
+		if(r == KERN_ABORTED)	// interrupted
+			continue;
+		macherror(r, "semaphore_wait");
+	}
+}
+
+void
+runtime·mach_semrelease(uint32 sem)
+{
+	int32 r;
+
+	while((r = runtime·mach_semaphore_signal(sem)) != 0) {
+		if(r == KERN_ABORTED)	// interrupted
+			continue;
+		macherror(r, "semaphore_signal");
+	}
+}
+
+void
+runtime·sigpanic(void)
+{
+	switch(g->sig) {
+	case SIGBUS:
+		if(g->sigcode0 == BUS_ADRERR && g->sigcode1 < 0x1000)
+			runtime·panicstring("invalid memory address or nil pointer dereference");
+		runtime·printf("unexpected fault address %p\n", g->sigcode1);
+		runtime·throw("fault");
+	case SIGSEGV:
+		if((g->sigcode0 == 0 || g->sigcode0 == SEGV_MAPERR || g->sigcode0 == SEGV_ACCERR) && g->sigcode1 < 0x1000)
+			runtime·panicstring("invalid memory address or nil pointer dereference");
+		runtime·printf("unexpected fault address %p\n", g->sigcode1);
+		runtime·throw("fault");
+	case SIGFPE:
+		switch(g->sigcode0) {
+		case FPE_INTDIV:
+			runtime·panicstring("integer divide by zero");
+		case FPE_INTOVF:
+			runtime·panicstring("integer overflow");
+		}
+		runtime·panicstring("floating point error");
+	}
+	runtime·panicstring(runtime·sigtab[g->sig].name);
+}