func Pread(fd int, p []byte, offset int64) (n int, err error) {
	var _p0 unsafe.Pointer
	if len(p) > 0 {
		_p0 = unsafe.Pointer(&p[0])
	} else {
		_p0 = unsafe.Pointer(&_zero)
	}
	r0, _, e1 := Syscall6(SYS_PREAD, uintptr(fd), uintptr(_p0), uintptr(len(p)), uintptr(offset), uintptr(offset>>32), 0)
	n = int(r0)
	if int32(r0) == -1 {
		err = e1
	}
	return
}

//sys   mmap(addr uintptr, length uintptr, prot int, flag int, fd int, pos int64) (ret uintptr, err error)
//sys   munmap(addr uintptr, length uintptr) (err error)
//sys	readlen(fd int, buf *byte, nbuf int) (n int, err error) = SYS_READ
//sys	accept4(fd int, rsa *RawSockaddrAny, addrlen *_Socklen, flags int) (nfd int, err error)
//sys	utimensat(dirfd int, path string, times *[2]Timespec, flag int) (err error)

	MOVW	$-1, R2
	MOVW	R2, ret+8(FP)
	RET

TEXT runtime·read(SB),NOSPLIT|NOFRAME,$0
	MOVW	fd+0(FP), R4		// arg 1 - fd
	MOVV	p+8(FP), R5		// arg 2 - buf
	MOVW	n+16(FP), R6		// arg 3 - nbyte
	MOVV	$3, R2			// sys_read
	SYSCALL
	BEQ	R7, 2(PC)
	SUBVU	R2, R0, R2	// caller expects negative errno
	MOVW	R2, ret+24(FP)
	RET

// func pipe2(flags int32) (r, w int32, errno int32)
TEXT runtime·pipe2(SB),NOSPLIT|NOFRAME,$0-20