runtime: openbsd amd64 runtime support

Add support for the go runtime on openbsd/amd64. This is based on
the existing freebsd runtime.

Threads are implemented using OpenBSD's rthreads, which are currently
disabled by default, however can be enabled via the kern.rthreads
sysctl.

For now, cgo is disabled.

R=rsc
CC=golang-dev
https://golang.org/cl/4815067

10 files changed, 977 insertions, 0 deletions

diff --git a/src/pkg/runtime/cgo/Makefile b/src/pkg/runtime/cgo/Makefile
index 7e752f127f..e7a2fa7c64 100644
--- a/src/pkg/runtime/cgo/Makefile
+++ b/src/pkg/runtime/cgo/Makefile
@@ -13,6 +13,9 @@ endif
 ifeq ($(GOOS),plan9)
 ENABLED:=0
 endif
+ifeq ($(GOOS),openbsd)
+ENABLED:=0
+endif
 
 ifeq ($(DISABLE_CGO),1)
 ENABLED:=0
diff --git a/src/pkg/runtime/openbsd/amd64/defs.h b/src/pkg/runtime/openbsd/amd64/defs.h
new file mode 100644
index 0000000000..4eb5cd2056
--- /dev/null
+++ b/src/pkg/runtime/openbsd/amd64/defs.h
@@ -0,0 +1,149 @@
+// 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,
+	SA_SIGINFO = 0x40,
+	SA_RESTART = 0x2,
+	SA_ONSTACK = 0x1,
+	EINTR = 0x4,
+	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 = 0x1,
+	FPE_INTOVF = 0x2,
+	FPE_FLTDIV = 0x3,
+	FPE_FLTOVF = 0x4,
+	FPE_FLTUND = 0x5,
+	FPE_FLTRES = 0x6,
+	FPE_FLTINV = 0x7,
+	FPE_FLTSUB = 0x8,
+	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 Sigaltstack Sigaltstack;
+struct Sigaltstack {
+	void *ss_sp;
+	uint64 ss_size;
+	int32 ss_flags;
+	byte pad_godefs_0[4];
+};
+
+typedef uint32 Sigset;
+
+typedef struct Siginfo Siginfo;
+struct Siginfo {
+	int32 si_signo;
+	int32 si_code;
+	int32 si_errno;
+	byte pad_godefs_0[4];
+	byte _data[120];
+};
+
+typedef union Sigval Sigval;
+union Sigval {
+	int32 sival_int;
+	void *sival_ptr;
+};
+
+typedef struct StackT StackT;
+struct StackT {
+	void *ss_sp;
+	uint64 ss_size;
+	int32 ss_flags;
+	byte pad_godefs_0[4];
+};
+
+typedef struct Timeval Timeval;
+struct Timeval {
+	int64 tv_sec;
+	int64 tv_usec;
+};
+
+typedef struct Itimerval Itimerval;
+struct Itimerval {
+	Timeval it_interval;
+	Timeval it_value;
+};
+
+typedef void sfxsave64;
+
+typedef struct Sigcontext Sigcontext;
+struct Sigcontext {
+	int64 sc_rdi;
+	int64 sc_rsi;
+	int64 sc_rdx;
+	int64 sc_rcx;
+	int64 sc_r8;
+	int64 sc_r9;
+	int64 sc_r10;
+	int64 sc_r11;
+	int64 sc_r12;
+	int64 sc_r13;
+	int64 sc_r14;
+	int64 sc_r15;
+	int64 sc_rbp;
+	int64 sc_rbx;
+	int64 sc_rax;
+	int64 sc_gs;
+	int64 sc_fs;
+	int64 sc_es;
+	int64 sc_ds;
+	int64 sc_trapno;
+	int64 sc_err;
+	int64 sc_rip;
+	int64 sc_cs;
+	int64 sc_rflags;
+	int64 sc_rsp;
+	int64 sc_ss;
+	sfxsave64 *sc_fpstate;
+	int32 sc_onstack;
+	int32 sc_mask;
+};
+#pragma pack off
diff --git a/src/pkg/runtime/openbsd/amd64/rt0.s b/src/pkg/runtime/openbsd/amd64/rt0.s
new file mode 100644
index 0000000000..e7fce59696
--- /dev/null
+++ b/src/pkg/runtime/openbsd/amd64/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.
+
+TEXT _rt0_amd64_openbsd(SB),7,$-8
+	MOVQ	$_rt0_amd64(SB), DX
+	MOVQ	SP, DI
+	JMP	DX
diff --git a/src/pkg/runtime/openbsd/amd64/signal.c b/src/pkg/runtime/openbsd/amd64/signal.c
new file mode 100644
index 0000000000..01bc76d207
--- /dev/null
+++ b/src/pkg/runtime/openbsd/amd64/signal.c
@@ -0,0 +1,199 @@
+// 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 "signals.h"
+#include "os.h"
+
+extern void runtime·sigtramp(void);
+
+typedef struct sigaction {
+	union {
+		void    (*__sa_handler)(int32);
+		void    (*__sa_sigaction)(int32, Siginfo*, void *);
+	} __sigaction_u;		/* signal handler */
+	uint32	sa_mask;		/* signal mask to apply */
+	int32	sa_flags;		/* see signal options below */
+} Sigaction;
+
+void
+runtime·dumpregs(Sigcontext *r)
+{
+	runtime·printf("rax     %X\n", r->sc_rax);
+	runtime·printf("rbx     %X\n", r->sc_rbx);
+	runtime·printf("rcx     %X\n", r->sc_rcx);
+	runtime·printf("rdx     %X\n", r->sc_rdx);
+	runtime·printf("rdi     %X\n", r->sc_rdi);
+	runtime·printf("rsi     %X\n", r->sc_rsi);
+	runtime·printf("rbp     %X\n", r->sc_rbp);
+	runtime·printf("rsp     %X\n", r->sc_rsp);
+	runtime·printf("r8      %X\n", r->sc_r8);
+	runtime·printf("r9      %X\n", r->sc_r9);
+	runtime·printf("r10     %X\n", r->sc_r10);
+	runtime·printf("r11     %X\n", r->sc_r11);
+	runtime·printf("r12     %X\n", r->sc_r12);
+	runtime·printf("r13     %X\n", r->sc_r13);
+	runtime·printf("r14     %X\n", r->sc_r14);
+	runtime·printf("r15     %X\n", r->sc_r15);
+	runtime·printf("rip     %X\n", r->sc_rip);
+	runtime·printf("rflags  %X\n", r->sc_rflags);
+	runtime·printf("cs      %X\n", r->sc_cs);
+	runtime·printf("fs      %X\n", r->sc_fs);
+	runtime·printf("gs      %X\n", r->sc_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)
+{
+	Sigcontext *r = context;
+	uintptr *sp;
+
+	if(sig == SIGPROF) {
+		runtime·sigprof((uint8*)r->sc_rip,
+			(uint8*)r->sc_rsp, nil, gp);
+		return;
+	}
+
+	if(gp != nil && (runtime·sigtab[sig].flags & SigPanic)) {
+		// 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*)((byte*)info + 16); /* si_addr */
+		gp->sigpc = r->sc_rip;
+
+		// Only push runtime·sigpanic if r->mc_rip != 0.
+		// If r->mc_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->sc_rip != 0) {
+			sp = (uintptr*)r->sc_rsp;
+			*--sp = r->sc_rip;
+			r->sc_rsp = (uintptr)sp;
+		}
+		r->sc_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->sc_rip);
+	runtime·printf("\n");
+
+	if(runtime·gotraceback()){
+		runtime·traceback((void*)r->sc_rip, (void*)r->sc_rsp, 0, gp);
+		runtime·tracebackothers(gp);
+		runtime·dumpregs(r);
+	}
+
+	runtime·exit(2);
+}
+
+// Called from kernel on signal stack, so no stack split.
+#pragma textflag 7
+void
+runtime·sigignore(void)
+{
+}
+
+void
+runtime·signalstack(byte *p, int32 n)
+{
+	Sigaltstack st;
+
+	st.ss_sp = (int8*)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;
+	if (fn == runtime·sighandler)
+		fn = (void*)runtime·sigtramp;
+	sa.__sigaction_u.__sa_sigaction = (void*)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/openbsd/amd64/sys.s b/src/pkg/runtime/openbsd/amd64/sys.s
new file mode 100644
index 0000000000..2a238dffb4
--- /dev/null
+++ b/src/pkg/runtime/openbsd/amd64/sys.s
@@ -0,0 +1,221 @@
+// 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, OpenBSD
+// /usr/src/sys/kern/syscalls.master for syscall numbers.
+//
+
+#include "amd64/asm.h"
+
+// int64 rfork_thread(int32 flags, void *stack, M *m, G *g, void (*fn)(void));
+TEXT runtime·rfork_thread(SB),7,$0
+	MOVL	flags+8(SP), DI
+	MOVQ	stack+16(SP), SI
+
+	// Copy m, g, fn off parent stack for use by child.
+	MOVQ	mm+24(SP), R8
+	MOVQ	gg+32(SP), R9
+	MOVQ	fn+40(SP), R12
+
+	MOVL	$251, AX		// sys_rfork
+	SYSCALL
+
+	// Return if rfork syscall failed
+	JCC	3(PC)
+	NEGL	AX
+	RET
+
+	// In parent, return.
+	CMPL	AX, $0
+	JEQ	2(PC)
+	RET
+
+	// In child, on new stack.
+	MOVQ	SI, SP
+
+	// Initialize m->procid to thread ID
+	MOVL	$299, AX		// sys_getthrid
+	SYSCALL
+	MOVQ	AX, m_procid(R8)
+
+	// Set FS to point at m->tls.
+	LEAQ	m_tls(R8), DI
+	CALL	runtime·settls(SB)
+
+	// In child, set up new stack
+	get_tls(CX)
+	MOVQ	R8, m(CX)
+	MOVQ	R9, g(CX)
+	CALL	runtime·stackcheck(SB)
+
+	// Call fn
+	CALL	R12
+
+	// It shouldn't return.  If it does, exit
+	MOVL	$302, AX		// sys_threxit
+	SYSCALL
+	JMP	-3(PC)  // keep exiting
+
+TEXT runtime·sys_sched_yield(SB),7,$0
+	MOVL $298, AX
+	SYSCALL
+	RET
+
+TEXT runtime·sys_thrsleep(SB),7,$0
+	MOVQ 8(SP), DI
+	MOVL 16(SP), SI
+	MOVQ 24(SP), DX
+	MOVQ 32(SP), R10
+	MOVL $300, AX
+	SYSCALL
+	RET
+
+TEXT runtime·sys_thrwakeup(SB),7,$0
+	MOVQ 8(SP), DI
+	MOVL 16(SP), SI
+	MOVL $301, AX
+	SYSCALL
+	RET
+
+// Exit the entire program (like C exit)
+TEXT runtime·exit(SB),7,$-8
+	MOVL	8(SP), DI		// arg 1 - exit status
+	MOVL	$1, AX			// sys_exit
+	SYSCALL
+	CALL	runtime·notok(SB)
+	RET
+
+TEXT runtime·exit1(SB),7,$-8
+	MOVL	$302, AX		// sys_threxit
+	SYSCALL
+	CALL	runtime·notok(SB)
+	RET
+
+TEXT runtime·write(SB),7,$-8
+	MOVL	8(SP), DI		// arg 1 - fd
+	MOVQ	16(SP), SI		// arg 2 - buf
+	MOVL	24(SP), DX		// arg 3 - nbyte
+	MOVL	$4, AX			// sys_write
+	SYSCALL
+	RET
+
+TEXT runtime·raisesigpipe(SB),7,$16
+	MOVL	$299, AX		// sys_getthrid
+	SYSCALL
+	MOVQ	AX, DI			// arg 1 - pid
+	MOVQ	$13, SI			// arg 2 - signum == SIGPIPE
+	MOVL	$37, AX			// sys_kill
+	SYSCALL
+	RET
+
+TEXT runtime·setitimer(SB),7,$-8
+	MOVL	8(SP), DI		// arg 1 - which
+	MOVQ	16(SP), SI		// arg 2 - itv
+	MOVQ	24(SP), DX		// arg 3 - oitv
+	MOVL	$83, AX			// sys_setitimer
+	SYSCALL
+	RET
+
+TEXT runtime·gettime(SB),7,$32
+	LEAQ	8(SP), DI		// arg 1 - tp
+	MOVQ	$0, SI			// arg 2 - tzp
+	MOVL	$116, AX		// sys_gettimeofday
+	SYSCALL
+
+	MOVQ	8(SP), BX	// sec
+	MOVQ	sec+0(FP), DI
+	MOVQ	BX, (DI)
+
+	MOVL	16(SP), BX	// usec
+	MOVQ	usec+8(FP), DI
+	MOVL	BX, (DI)
+	RET
+
+TEXT runtime·sigaction(SB),7,$-8
+	MOVL	8(SP), DI		// arg 1 - signum
+	MOVQ	16(SP), SI		// arg 2 - nsa
+	MOVQ	24(SP), DX		// arg 3 - osa
+	MOVL	$46, AX
+	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, 40(SP)
+	
+	// g = m->signal
+	MOVQ	m(BX), BP
+	MOVQ	m_gsignal(BP), BP
+	MOVQ	BP, g(BX)
+	
+	MOVQ	DI, 0(SP)
+	MOVQ	SI, 8(SP)
+	MOVQ	DX, 16(SP)
+	MOVQ	R10, 24(SP)
+	
+	CALL	runtime·sighandler(SB)
+
+	// restore g
+	get_tls(BX)
+	MOVQ	40(SP), R10
+	MOVQ	R10, g(BX)
+	RET
+
+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 - fd
+	MOVQ	36(SP), R9
+	SUBQ	$16, SP
+	MOVQ	R9, 8(SP)		// arg 7 - offset (passed on stack)
+	MOVQ	$0, R9			// arg 6 - pad
+	MOVL	$197, AX
+	SYSCALL
+	JCC	2(PC)
+	NEGL	AX
+	ADDQ	$16, SP
+	RET
+
+TEXT runtime·munmap(SB),7,$0
+	MOVQ	8(SP), DI		// arg 1 - addr
+	MOVQ	16(SP), SI		// arg 2 - len
+	MOVL	$73, AX			// sys_munmap
+	SYSCALL
+	JCC	2(PC)
+	CALL	runtime·notok(SB)
+	RET
+
+TEXT runtime·notok(SB),7,$-8
+	MOVL	$0xf1, BP
+	MOVQ	BP, (BP)
+	RET
+
+TEXT runtime·sigaltstack(SB),7,$-8
+	MOVQ	new+8(SP), DI		// arg 1 - nss
+	MOVQ	old+16(SP), SI		// arg 2 - oss
+	MOVQ	$288, AX		// sys_sigaltstack
+	SYSCALL
+	JCC	2(PC)
+	CALL	runtime·notok(SB)
+	RET
+
+// set tls base to DI
+TEXT runtime·settls(SB),7,$8
+	// adjust for ELF: wants to use -16(FS) and -8(FS) for g and m
+	ADDQ	$16, DI
+	MOVQ	DI, 0(SP)
+	MOVQ	SP, SI
+	MOVQ	$12, DI			// AMD64_SET_FSBASE (machine/sysarch.h)
+	MOVQ	$165, AX		// sys_sysarch
+	SYSCALL
+	JCC	2(PC)
+	CALL	runtime·notok(SB)
+	RET
diff --git a/src/pkg/runtime/openbsd/defs.c b/src/pkg/runtime/openbsd/defs.c
new file mode 100644
index 0000000000..d8adec9810
--- /dev/null
+++ b/src/pkg/runtime/openbsd/defs.c
@@ -0,0 +1,103 @@
+// 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
+ */
+
+#include <sys/types.h>
+#include <sys/mman.h>
+#include <sys/time.h>
+#include <sys/unistd.h>
+#include <sys/signal.h>
+#include <machine/mcontext.h>
+#include <errno.h>
+#include <signal.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,
+
+	$SA_SIGINFO = SA_SIGINFO,
+	$SA_RESTART = SA_RESTART,
+	$SA_ONSTACK = SA_ONSTACK,
+
+	$EINTR = EINTR,
+	
+	$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 struct sigaltstack $Sigaltstack;
+typedef sigset_t $Sigset;
+typedef siginfo_t $Siginfo;
+typedef union sigval $Sigval;
+
+typedef stack_t $StackT;
+
+typedef struct timeval $Timeval;
+typedef struct itimerval $Itimerval;
+
+// This is a hack to avoid pulling in machine/fpu.h and struct fxsave64.
+typedef void $sfxsave64;
+
+typedef struct sigcontext $Sigcontext;
diff --git a/src/pkg/runtime/openbsd/mem.c b/src/pkg/runtime/openbsd/mem.c
new file mode 100644
index 0000000000..07abf2cfe0
--- /dev/null
+++ b/src/pkg/runtime/openbsd/mem.c
@@ -0,0 +1,74 @@
+#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)
+{
+	// On 64-bit, people with ulimit -v set complain if we reserve too
+	// much address space.  Instead, assume that the reservation is okay
+	// and check the assumption in SysMap.
+	if(sizeof(void*) == 8)
+		return v;
+	
+	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;
+
+	// On 64-bit, we don't actually have v reserved, so tread carefully.
+	if(sizeof(void*) == 8) {
+		p = runtime·mmap(v, n, PROT_READ|PROT_WRITE|PROT_EXEC, MAP_ANON|MAP_PRIVATE, -1, 0);
+		if(p == (void*)-ENOMEM)
+			runtime·throw("runtime: out of memory");
+		if(p != v) {
+			runtime·printf("runtime: address space conflict: map(%p) = %p\n", v, p);
+			runtime·throw("runtime: address space conflict");
+		}
+		return;
+	}
+
+	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/openbsd/os.h b/src/pkg/runtime/openbsd/os.h
new file mode 100644
index 0000000000..eba53b7cc2
--- /dev/null
+++ b/src/pkg/runtime/openbsd/os.h
@@ -0,0 +1,12 @@
+#define SIG_DFL ((void*)0)
+#define SIG_IGN ((void*)1)
+
+struct sigaction;
+
+void	runtime·sigpanic(void);
+void	runtime·sigaltstack(Sigaltstack*, Sigaltstack*);
+void	runtime·sigaction(int32, struct sigaction*, struct sigaction*);
+void	runtime·setitimerval(int32, Itimerval*, Itimerval*);
+void	runtime·setitimer(int32, Itimerval*, Itimerval*);
+
+void	runtime·raisesigpipe(void);
diff --git a/src/pkg/runtime/openbsd/signals.h b/src/pkg/runtime/openbsd/signals.h
new file mode 100644
index 0000000000..63a84671d9
--- /dev/null
+++ b/src/pkg/runtime/openbsd/signals.h
@@ -0,0 +1,52 @@
+// 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",
+	/* 6 */		C, "SIGABRT: abort",
+	/* 7 */		C, "SIGEMT: EMT instruction",
+	/* 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, unblockable",
+	/* 18 */	Q+I+R, "SIGTSTP: stop from tty",
+	/* 19 */	0, "SIGCONT: continue",
+	/* 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: information request",
+	/* 30 */	Q+I+R, "SIGUSR1: user-defined signal 1",
+	/* 31 */	Q+I+R, "SIGUSR2: user-defined signal 2",
+	/* 32 */	Q+I+R, "SIGTHR: reserved",
+};
+#undef C
+#undef I
+#undef R
+#undef Q
+#undef P
+
+#define	NSIG 33
diff --git a/src/pkg/runtime/openbsd/thread.c b/src/pkg/runtime/openbsd/thread.c
new file mode 100644
index 0000000000..7e9ba5d67e
--- /dev/null
+++ b/src/pkg/runtime/openbsd/thread.c
@@ -0,0 +1,156 @@
+// Use of this source file 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[];
+
+extern int64 runtime·rfork_thread(int32 flags, void *stack, M *m, G *g, void (*fn)(void));
+extern void runtime·sys_sched_yield(void);
+
+// Basic spinlocks using CAS. We can improve on these later.
+static void
+lock(Lock *l)
+{
+	uint32 v;
+	int32 ret;
+
+	for(;;) {
+		if(runtime·cas(&l->key, 0, 1))
+			return;
+		runtime·sys_sched_yield();
+	}
+}
+
+static void
+unlock(Lock *l)
+{
+	uint32 v;
+	int32 ret;
+
+	for (;;) {
+		v = l->key;
+		if((v&1) == 0)
+			runtime·throw("unlock of unlocked lock");
+		if(runtime·cas(&l->key, v, 0))
+			break;
+	}
+}
+
+void
+runtime·lock(Lock *l)
+{
+	if(m->locks < 0)
+		runtime·throw("lock count");
+	m->locks++;
+	lock(l);
+}
+
+void 
+runtime·unlock(Lock *l)
+{
+	m->locks--;
+	if(m->locks < 0)
+		runtime·throw("lock count");
+	unlock(l);
+}
+
+// Event notifications.
+void
+runtime·noteclear(Note *n)
+{
+	n->lock.key = 0;
+	lock(&n->lock);
+}
+
+void
+runtime·notesleep(Note *n)
+{
+	lock(&n->lock);
+	unlock(&n->lock);
+}
+
+void
+runtime·notewakeup(Note *n)
+{
+	unlock(&n->lock);
+}
+
+// From OpenBSD's sys/param.h
+#define RFPROC		(1<<4)  /* change child (else changes curproc) */
+#define RFMEM		(1<<5)  /* share `address space' */
+#define RFNOWAIT	(1<<6)  /* parent need not wait() on child */
+#define RFTHREAD	(1<<13) /* create a thread, not a process */
+
+void
+runtime·newosproc(M *m, G *g, void *stk, void (*fn)(void))
+{
+	int32 flags;
+	int32 ret;
+
+	flags = RFPROC | RFTHREAD | RFMEM | RFNOWAIT;
+
+	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);
+	}
+
+	m->tls[0] = m->id;	// so 386 asm can find it
+
+	if((ret = runtime·rfork_thread(flags, stk, m, g, fn)) < 0) {
+		runtime·printf("runtime: failed to create new OS thread (have %d already; errno=%d)\n", runtime·mcount() - 1, -ret);
+		runtime·printf("runtime: is kern.rthreads disabled?\n");
+
+		runtime·throw("runtime.newosproc");
+	}
+}
+
+void
+runtime·osinit(void)
+{
+}
+
+void
+runtime·goenvs(void)
+{
+	runtime·goenvs_unix();
+}
+
+// Called to initialize a new m (including the bootstrap m).
+void
+runtime·minit(void)
+{
+	// Initialize signal handling
+	m->gsignal = runtime·malg(32*1024);
+	runtime·signalstack(m->gsignal->stackguard - StackGuard, 32*1024);
+}
+
+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);
+}