unix: add darwin/arm64 support

Fixes golang/go#10239.

Change-Id: I3ae657b57ca7bef31207780477c44939c0bdc8b5
Signed-off-by: Shenghou Ma <minux@golang.org>
Reviewed-on: https://go-review.googlesource.com/10185
Reviewed-by: Rob Pike <r@golang.org>

unix/asm_darwin_arm64.s

@@ -0,0 +1,30 @@
+// Copyright 2015 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.
+
+// +build !gccgo
+// +build arm64,darwin
+
+#include "textflag.h"
+
+//
+// System call support for AMD64, Darwin
+//
+
+// Just jump to package syscall's implementation for all these functions.
+// The runtime may know about them.
+
+TEXT	·Syscall(SB),NOSPLIT,$0-56
+	B	syscall·Syscall(SB)
+
+TEXT	·Syscall6(SB),NOSPLIT,$0-80
+	B	syscall·Syscall6(SB)
+
+TEXT	·Syscall9(SB),NOSPLIT,$0-104
+	B	syscall·Syscall9(SB)
+
+TEXT	·RawSyscall(SB),NOSPLIT,$0-56
+	B	syscall·RawSyscall(SB)
+
+TEXT	·RawSyscall6(SB),NOSPLIT,$0-80
+	B	syscall·RawSyscall6(SB)

unix/mkall.sh

@@ -129,6 +129,11 @@ darwin_arm)
 	mksysnum="./mksysnum_darwin.pl /usr/include/sys/syscall.h"
 	mktypes="GOARCH=$GOARCH go tool cgo -godefs"
 	;;
+darwin_arm64)
+	mkerrors="$mkerrors -m64"
+	mksysnum="./mksysnum_darwin.pl /usr/include/sys/syscall.h"
+	mktypes="GOARCH=$GOARCH go tool cgo -godefs"
+	;;
 dragonfly_386)
 	mkerrors="$mkerrors -m32"
 	mksyscall="./mksyscall.pl -l32 -dragonfly"

unix/syscall_darwin_arm64.go

@@ -0,0 +1,75 @@
+// Copyright 2015 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.
+
+// +build arm64,darwin
+
+package unix
+
+import (
+	"syscall"
+	"unsafe"
+)
+
+func Getpagesize() int { return 16384 }
+
+func TimespecToNsec(ts Timespec) int64 { return int64(ts.Sec)*1e9 + int64(ts.Nsec) }
+
+func NsecToTimespec(nsec int64) (ts Timespec) {
+	ts.Sec = nsec / 1e9
+	ts.Nsec = nsec % 1e9
+	return
+}
+
+func TimevalToNsec(tv Timeval) int64 { return int64(tv.Sec)*1e9 + int64(tv.Usec)*1e3 }
+
+func NsecToTimeval(nsec int64) (tv Timeval) {
+	nsec += 999 // round up to microsecond
+	tv.Usec = int32(nsec % 1e9 / 1e3)
+	tv.Sec = int64(nsec / 1e9)
+	return
+}
+
+//sysnb	gettimeofday(tp *Timeval) (sec int64, usec int32, err error)
+func Gettimeofday(tv *Timeval) (err error) {
+	// The tv passed to gettimeofday must be non-nil
+	// but is otherwise unused.  The answers come back
+	// in the two registers.
+	sec, usec, err := gettimeofday(tv)
+	tv.Sec = sec
+	tv.Usec = usec
+	return err
+}
+
+func SetKevent(k *Kevent_t, fd, mode, flags int) {
+	k.Ident = uint64(fd)
+	k.Filter = int16(mode)
+	k.Flags = uint16(flags)
+}
+
+func (iov *Iovec) SetLen(length int) {
+	iov.Len = uint64(length)
+}
+
+func (msghdr *Msghdr) SetControllen(length int) {
+	msghdr.Controllen = uint32(length)
+}
+
+func (cmsg *Cmsghdr) SetLen(length int) {
+	cmsg.Len = uint32(length)
+}
+
+func sendfile(outfd int, infd int, offset *int64, count int) (written int, err error) {
+	var length = uint64(count)
+
+	_, _, e1 := Syscall6(SYS_SENDFILE, uintptr(infd), uintptr(outfd), uintptr(*offset), uintptr(unsafe.Pointer(&length)), 0, 0)
+
+	written = int(length)
+
+	if e1 != 0 {
+		err = e1
+	}
+	return
+}
+
+func Syscall9(num, a1, a2, a3, a4, a5, a6, a7, a8, a9 uintptr) (r1, r2 uintptr, err syscall.Errno) // sic