STATIC mp_obj_t set_intersect_int(mp_obj_t self_in, mp_obj_t other, bool update) {
    if (update) {
        check_set(self_in);
    } else {
        check_set_or_frozenset(self_in);
    }

    if (self_in == other) {
        return update ? mp_const_none : set_copy(self_in);
    }

    mp_obj_set_t *self = MP_OBJ_TO_PTR(self_in);
    mp_obj_set_t *out = MP_OBJ_TO_PTR(mp_obj_new_set(0, NULL));

    mp_obj_t iter = mp_getiter(other, NULL);
    mp_obj_t next;
    while ((next = mp_iternext(iter)) != MP_OBJ_STOP_ITERATION) {
        if (mp_set_lookup(&self->set, next, MP_MAP_LOOKUP)) {
            set_add(MP_OBJ_FROM_PTR(out), next);
        }
    }

    if (update) {
        m_del(mp_obj_t, self->set.table, self->set.alloc);
        self->set.alloc = out->set.alloc;
        self->set.used = out->set.used;
        self->set.table = out->set.table;
    }

    return update ? mp_const_none : MP_OBJ_FROM_PTR(out);
}

STATIC void *thread_entry(void *args_in) {
    // Execution begins here for a new thread.  We do not have the GIL.

    thread_entry_args_t *args = (thread_entry_args_t*)args_in;

    mp_state_thread_t ts;
    mp_thread_set_state(&ts);

    mp_stack_set_top(&ts + 1); // need to include ts in root-pointer scan
    mp_stack_set_limit(args->stack_size);

    #if MICROPY_ENABLE_PYSTACK
    // TODO threading and pystack is not fully supported, for now just make a small stack
    mp_obj_t mini_pystack[128];
    mp_pystack_init(mini_pystack, &mini_pystack[128]);
    #endif

    // set locals and globals from the calling context
    mp_locals_set(args->dict_locals);
    mp_globals_set(args->dict_globals);

    MP_THREAD_GIL_ENTER();

    // signal that we are set up and running
    mp_thread_start();

    // TODO set more thread-specific state here:
    //  mp_pending_exception? (root pointer)
    //  cur_exception (root pointer)

    DEBUG_printf("[thread] start ts=%p args=%p stack=%p\n", &ts, &args, MP_STATE_THREAD(stack_top));

    nlr_buf_t nlr;
    if (nlr_push(&nlr) == 0) {
        mp_call_function_n_kw(args->fun, args->n_args, args->n_kw, args->args);
        nlr_pop();
    } else {
        // uncaught exception
        // check for SystemExit
        mp_obj_base_t *exc = (mp_obj_base_t*)nlr.ret_val;
        if (mp_obj_is_subclass_fast(MP_OBJ_FROM_PTR(exc->type), MP_OBJ_FROM_PTR(&mp_type_SystemExit))) {
            // swallow exception silently
        } else {
            // print exception out
            mp_printf(MICROPY_ERROR_PRINTER, "Unhandled exception in thread started by ");
            mp_obj_print_helper(MICROPY_ERROR_PRINTER, args->fun, PRINT_REPR);
            mp_printf(MICROPY_ERROR_PRINTER, "\n");
            mp_obj_print_exception(MICROPY_ERROR_PRINTER, MP_OBJ_FROM_PTR(exc));
        }
    }

    DEBUG_printf("[thread] finish ts=%p\n", &ts);

    // signal that we are finished
    mp_thread_finish();

    MP_THREAD_GIL_EXIT();

    return NULL;
}

STATIC mp_obj_t gen_resume_and_raise(mp_obj_t self_in, mp_obj_t send_value, mp_obj_t throw_value) {
    mp_obj_t ret;
    switch (mp_obj_gen_resume(self_in, send_value, throw_value, &ret)) {
        case MP_VM_RETURN_NORMAL:
        default:
            // Optimize return w/o value in case generator is used in for loop
            if (ret == mp_const_none || ret == MP_OBJ_STOP_ITERATION) {
                return MP_OBJ_STOP_ITERATION;
            } else {
                nlr_raise(mp_obj_new_exception_args(&mp_type_StopIteration, 1, &ret));
            }

        case MP_VM_RETURN_YIELD:
            return ret;

        case MP_VM_RETURN_EXCEPTION:
            // TODO: Optimization of returning MP_OBJ_STOP_ITERATION is really part
            // of mp_iternext() protocol, but this function is called by other methods
            // too, which may not handled MP_OBJ_STOP_ITERATION.
            if (mp_obj_is_subclass_fast(MP_OBJ_FROM_PTR(mp_obj_get_type(ret)), MP_OBJ_FROM_PTR(&mp_type_StopIteration))) {
                mp_obj_t val = mp_obj_exception_get_value(ret);
                if (val == mp_const_none) {
                    return MP_OBJ_STOP_ITERATION;
                }
            }
            nlr_raise(ret);
    }
}

STATIC mp_obj_t mod_termios_tcgetattr(mp_obj_t fd_in) {
    struct termios term;
    int fd = mp_obj_get_int(fd_in);

    int res = tcgetattr(fd, &term);
    RAISE_ERRNO(res, errno);

    mp_obj_list_t *r = MP_OBJ_TO_PTR(mp_obj_new_list(7, NULL));
    r->items[0] = MP_OBJ_NEW_SMALL_INT(term.c_iflag);
    r->items[1] = MP_OBJ_NEW_SMALL_INT(term.c_oflag);
    r->items[2] = MP_OBJ_NEW_SMALL_INT(term.c_cflag);
    r->items[3] = MP_OBJ_NEW_SMALL_INT(term.c_lflag);
    r->items[4] = MP_OBJ_NEW_SMALL_INT(cfgetispeed(&term));
    r->items[5] = MP_OBJ_NEW_SMALL_INT(cfgetospeed(&term));

    mp_obj_list_t *cc = MP_OBJ_TO_PTR(mp_obj_new_list(NCCS, NULL));
    r->items[6] = MP_OBJ_FROM_PTR(cc);
    for (int i = 0; i < NCCS; i++) {
        if (i == VMIN || i == VTIME) {
            cc->items[i] = MP_OBJ_NEW_SMALL_INT(term.c_cc[i]);
        } else {
            // https://docs.python.org/3/library/termios.html says value is *string*,
            // but no way unicode chars could be there, if c_cc is defined to be a
            // a "char". But it's type is actually cc_t, which can be anything.
            // TODO: For now, we still deal with it like that.
            cc->items[i] = mp_obj_new_bytes((byte*)&term.c_cc[i], 1);
        }
    }
    return MP_OBJ_FROM_PTR(r);
}

STATIC bool mp_native_yield_from(mp_obj_t gen, mp_obj_t send_value, mp_obj_t *ret_value) {
    mp_vm_return_kind_t ret_kind;
    nlr_buf_t nlr_buf;
    mp_obj_t throw_value = *ret_value;
    if (nlr_push(&nlr_buf) == 0) {
        if (throw_value != MP_OBJ_NULL) {
            send_value = MP_OBJ_NULL;
        }
        ret_kind = mp_resume(gen, send_value, throw_value, ret_value);
        nlr_pop();
    } else {
        ret_kind = MP_VM_RETURN_EXCEPTION;
        *ret_value = nlr_buf.ret_val;
    }

    if (ret_kind == MP_VM_RETURN_YIELD) {
        return true;
    } else if (ret_kind == MP_VM_RETURN_NORMAL) {
        if (*ret_value == MP_OBJ_STOP_ITERATION) {
            *ret_value = mp_const_none;
        }
    } else {
        assert(ret_kind == MP_VM_RETURN_EXCEPTION);
        if (!mp_obj_exception_match(*ret_value, MP_OBJ_FROM_PTR(&mp_type_StopIteration))) {
            nlr_raise(*ret_value);
        }
        *ret_value = mp_obj_exception_get_value(*ret_value);
    }

    if (throw_value != MP_OBJ_NULL && mp_obj_exception_match(throw_value, MP_OBJ_FROM_PTR(&mp_type_GeneratorExit))) {
        nlr_raise(mp_make_raise_obj(throw_value));
    }

    return false;
}

STATIC mp_obj_t mod_socket_sockaddr(mp_obj_t sockaddr_in) {
    mp_buffer_info_t bufinfo;
    mp_get_buffer_raise(sockaddr_in, &bufinfo, MP_BUFFER_READ);
    switch (((struct sockaddr*)bufinfo.buf)->sa_family) {
        case AF_INET: {
            struct sockaddr_in *sa = (struct sockaddr_in*)bufinfo.buf;
            mp_obj_tuple_t *t = MP_OBJ_TO_PTR(mp_obj_new_tuple(3, NULL));
            t->items[0] = MP_OBJ_NEW_SMALL_INT(AF_INET);
            t->items[1] = mp_obj_new_bytes((byte*)&sa->sin_addr, sizeof(sa->sin_addr));
            t->items[2] = MP_OBJ_NEW_SMALL_INT(ntohs(sa->sin_port));
            return MP_OBJ_FROM_PTR(t);
        }
        case AF_INET6: {
            struct sockaddr_in6 *sa = (struct sockaddr_in6*)bufinfo.buf;
            mp_obj_tuple_t *t = MP_OBJ_TO_PTR(mp_obj_new_tuple(5, NULL));
            t->items[0] = MP_OBJ_NEW_SMALL_INT(AF_INET6);
            t->items[1] = mp_obj_new_bytes((byte*)&sa->sin6_addr, sizeof(sa->sin6_addr));
            t->items[2] = MP_OBJ_NEW_SMALL_INT(ntohs(sa->sin6_port));
            t->items[3] = MP_OBJ_NEW_SMALL_INT(ntohl(sa->sin6_flowinfo));
            t->items[4] = MP_OBJ_NEW_SMALL_INT(ntohl(sa->sin6_scope_id));
            return MP_OBJ_FROM_PTR(t);
        }
        default: {
            struct sockaddr *sa = (struct sockaddr*)bufinfo.buf;
            mp_obj_tuple_t *t = MP_OBJ_TO_PTR(mp_obj_new_tuple(2, NULL));
            t->items[0] = MP_OBJ_NEW_SMALL_INT(sa->sa_family);
            t->items[1] = mp_obj_new_bytes((byte*)sa->sa_data, bufinfo.len - offsetof(struct sockaddr, sa_data));
            return MP_OBJ_FROM_PTR(t);
        }
    }
    return mp_const_none;
}

mp_obj_t mp_obj_new_attrtuple(const qstr *fields, mp_uint_t n, const mp_obj_t *items) {
    mp_obj_tuple_t *o = m_new_obj_var(mp_obj_tuple_t, mp_obj_t, n + 1);
    o->base.type = &mp_type_attrtuple;
    o->len = n;
    for (mp_uint_t i = 0; i < n; i++) {
        o->items[i] = items[i];
    }
    o->items[n] = MP_OBJ_FROM_PTR(fields);
    return MP_OBJ_FROM_PTR(o);
}

/// \method callback(fun)
/// Register the given function to be called when the switch is pressed down.
/// If `fun` is `None`, then it disables the callback.
mp_obj_t pyb_switch_callback(mp_obj_t self_in, mp_obj_t callback) {
    MP_STATE_PORT(pyb_switch_callback) = callback;
    // Init the EXTI each time this function is called, since the EXTI
    // may have been disabled by an exception in the interrupt, or the
    // user disabling the line explicitly.
    extint_register(MP_OBJ_FROM_PTR(MICROPY_HW_USRSW_PIN),
                    MICROPY_HW_USRSW_EXTI_MODE,
                    MICROPY_HW_USRSW_PULL,
                    callback == mp_const_none ? mp_const_none : MP_OBJ_FROM_PTR(&switch_callback_obj),
                    true);
    return mp_const_none;
}

STATIC mp_obj_t stringio_make_new(const mp_obj_type_t *type_in, size_t n_args, size_t n_kw, const mp_obj_t *args) {
    (void)n_kw; // TODO check n_kw==0
    mp_obj_stringio_t *o = stringio_new(type_in);

    if (n_args > 0) {
        mp_buffer_info_t bufinfo;
        mp_get_buffer_raise(args[0], &bufinfo, MP_BUFFER_READ);
        stringio_write(MP_OBJ_FROM_PTR(o), bufinfo.buf, bufinfo.len, NULL);
        // Cur ptr is always at the beginning of buffer at the construction
        o->pos = 0;
    }
    return MP_OBJ_FROM_PTR(o);
}

STATIC void *thread_entry(void *args_in) {
    // Execution begins here for a new thread.  We do not have the GIL.

    thread_entry_args_t *args = (thread_entry_args_t*)args_in;

    mp_state_thread_t ts;
    mp_thread_set_state(&ts);

    mp_stack_set_top(&ts + 1); // need to include ts in root-pointer scan
    mp_stack_set_limit(args->stack_size);

    MP_THREAD_GIL_ENTER();

    // signal that we are set up and running
    mp_thread_start();

    // TODO set more thread-specific state here:
    //  mp_pending_exception? (root pointer)
    //  cur_exception (root pointer)
    //  dict_locals? (root pointer) uPy doesn't make a new locals dict for functions, just for classes, so it's different to CPy

    DEBUG_printf("[thread] start ts=%p args=%p stack=%p\n", &ts, &args, MP_STATE_THREAD(stack_top));

    nlr_buf_t nlr;
    if (nlr_push(&nlr) == 0) {
        mp_call_function_n_kw(args->fun, args->n_args, args->n_kw, args->args);
        nlr_pop();
    } else {
        // uncaught exception
        // check for SystemExit
        mp_obj_base_t *exc = (mp_obj_base_t*)nlr.ret_val;
        if (mp_obj_is_subclass_fast(MP_OBJ_FROM_PTR(exc->type), MP_OBJ_FROM_PTR(&mp_type_SystemExit))) {
            // swallow exception silently
        } else {
            // print exception out
            mp_printf(&mp_plat_print, "Unhandled exception in thread started by ");
            mp_obj_print_helper(&mp_plat_print, args->fun, PRINT_REPR);
            mp_printf(&mp_plat_print, "\n");
            mp_obj_print_exception(&mp_plat_print, MP_OBJ_FROM_PTR(exc));
        }
    }

    DEBUG_printf("[thread] finish ts=%p\n", &ts);

    // signal that we are finished
    mp_thread_finish();

    MP_THREAD_GIL_EXIT();

    return NULL;
}

STATIC mp_obj_t fdfile_open(const mp_obj_type_t *type, mp_arg_val_t *args) {
    mp_obj_fdfile_t *o = m_new_obj(mp_obj_fdfile_t);
    const char *mode_s = mp_obj_str_get_str(args[1].u_obj);

    int mode_rw = 0, mode_x = 0;
    while (*mode_s) {
        switch (*mode_s++) {
            case 'r':
                mode_rw = O_RDONLY;
                break;
            case 'w':
                mode_rw = O_WRONLY;
                mode_x = O_CREAT | O_TRUNC;
                break;
            case 'a':
                mode_rw = O_WRONLY;
                mode_x = O_CREAT | O_APPEND;
                break;
            case '+':
                mode_rw = O_RDWR;
                break;
            #if MICROPY_PY_IO_FILEIO
            // If we don't have io.FileIO, then files are in text mode implicitly
            case 'b':
                type = &mp_type_fileio;
                break;
            case 't':
                type = &mp_type_textio;
                break;
            #endif
        }
    }

    o->base.type = type;

    mp_obj_t fid = args[0].u_obj;

    if (MP_OBJ_IS_SMALL_INT(fid)) {
        o->fd = MP_OBJ_SMALL_INT_VALUE(fid);
        return MP_OBJ_FROM_PTR(o);
    }

    const char *fname = mp_obj_str_get_str(fid);
    int fd = open(fname, mode_x | mode_rw, 0644);
    if (fd == -1) {
        nlr_raise(mp_obj_new_exception_arg1(&mp_type_OSError, MP_OBJ_NEW_SMALL_INT(errno)));
    }
    o->fd = fd;
    return MP_OBJ_FROM_PTR(o);
}

STATIC mp_obj_t list_binary_op(mp_binary_op_t op, mp_obj_t lhs, mp_obj_t rhs) {
    mp_obj_list_t *o = MP_OBJ_TO_PTR(lhs);
    switch (op) {
        case MP_BINARY_OP_ADD: {
            if (!MP_OBJ_IS_TYPE(rhs, &mp_type_list)) {
                return MP_OBJ_NULL; // op not supported
            }
            mp_obj_list_t *p = MP_OBJ_TO_PTR(rhs);
            mp_obj_list_t *s = list_new(o->len + p->len);
            mp_seq_cat(s->items, o->items, o->len, p->items, p->len, mp_obj_t);
            return MP_OBJ_FROM_PTR(s);
        }
        case MP_BINARY_OP_INPLACE_ADD: {
            list_extend(lhs, rhs);
            return lhs;
        }
        case MP_BINARY_OP_MULTIPLY: {
            mp_int_t n;
            if (!mp_obj_get_int_maybe(rhs, &n)) {
                return MP_OBJ_NULL; // op not supported
            }
            if (n < 0) {
                n = 0;
            }
            mp_obj_list_t *s = list_new(o->len * n);
            mp_seq_multiply(o->items, sizeof(*o->items), o->len, n, s->items);
            return MP_OBJ_FROM_PTR(s);
        }
        case MP_BINARY_OP_EQUAL:
        case MP_BINARY_OP_LESS:
        case MP_BINARY_OP_LESS_EQUAL:
        case MP_BINARY_OP_MORE:
        case MP_BINARY_OP_MORE_EQUAL: {
            if (!MP_OBJ_IS_TYPE(rhs, &mp_type_list)) {
                if (op == MP_BINARY_OP_EQUAL) {
                    return mp_const_false;
                }
                return MP_OBJ_NULL; // op not supported
            }

            mp_obj_list_t *another = MP_OBJ_TO_PTR(rhs);
            bool res = mp_seq_cmp_objs(op, o->items, o->len, another->items, another->len);
            return mp_obj_new_bool(res);
        }

        default:
            return MP_OBJ_NULL; // op not supported
    }
}

STATIC mp_obj_t socket_accept(mp_obj_t self_in) {
    mp_obj_socket_t *self = MP_OBJ_TO_PTR(self_in);
    // sockaddr_storage isn't stack-friendly (129 bytes or so)
    //struct sockaddr_storage addr;
    byte addr[32];
    socklen_t addr_len = sizeof(addr);
    int fd = accept(self->fd, (struct sockaddr*)&addr, &addr_len);
    RAISE_ERRNO(fd, errno);

    mp_obj_tuple_t *t = MP_OBJ_TO_PTR(mp_obj_new_tuple(2, NULL));
    t->items[0] = MP_OBJ_FROM_PTR(socket_new(fd));
    t->items[1] = mp_obj_new_bytearray(addr_len, &addr);

    return MP_OBJ_FROM_PTR(t);
}

STATIC mp_obj_t listdir_next(mp_obj_t self_in) {
    mp_obj_listdir_t *self = MP_OBJ_TO_PTR(self_in);

    if (self->dir == NULL) {
        goto done;
    }
    struct dirent *dirent = readdir(self->dir);
    if (dirent == NULL) {
        closedir(self->dir);
        self->dir = NULL;
    done:
        return MP_OBJ_STOP_ITERATION;
    }

    mp_obj_tuple_t *t = MP_OBJ_TO_PTR(mp_obj_new_tuple(3, NULL));
    t->items[0] = mp_obj_new_str(dirent->d_name, strlen(dirent->d_name), false);
    #ifdef _DIRENT_HAVE_D_TYPE
    t->items[1] = MP_OBJ_NEW_SMALL_INT(dirent->d_type);
    #else
    // DT_UNKNOWN should have 0 value on any reasonable system
    t->items[1] = MP_OBJ_NEW_SMALL_INT(0);
    #endif
    #ifdef _DIRENT_HAVE_D_INO
    t->items[2] = MP_OBJ_NEW_SMALL_INT(dirent->d_ino);
    #else
    t->items[2] = MP_OBJ_NEW_SMALL_INT(0);
    #endif
    return MP_OBJ_FROM_PTR(t);
}

mp_obj_t mp_obj_new_complex(mp_float_t real, mp_float_t imag) {
    mp_obj_complex_t *o = m_new_obj(mp_obj_complex_t);
    o->base.type = &mp_type_complex;
    o->real = real;
    o->imag = imag;
    return MP_OBJ_FROM_PTR(o);
}

STATIC mp_obj_t get_wlan(size_t n_args, const mp_obj_t *args) {
    int idx = 0;
    if (n_args > 0) {
        idx = mp_obj_get_int(args[0]);
    }
    return MP_OBJ_FROM_PTR(&wlan_objs[idx]);
}

STATIC mp_obj_t deque_make_new(const mp_obj_type_t *type, size_t n_args, size_t n_kw, const mp_obj_t *args) {
    mp_arg_check_num(n_args, n_kw, 2, 3, false);

    /* Initialization from existing sequence is not supported, so an empty
       tuple must be passed as such. */
    if (args[0] != mp_const_empty_tuple) {
        mp_raise_ValueError(NULL);
    }

    // Protect against -1 leading to zero-length allocation and bad array access
    mp_int_t maxlen = mp_obj_get_int(args[1]);
    if (maxlen < 0) {
        mp_raise_ValueError(NULL);
    }

    mp_obj_deque_t *o = m_new_obj(mp_obj_deque_t);
    o->base.type = type;
    o->alloc = maxlen + 1;
    o->i_get = o->i_put = 0;
    o->items = m_new0(mp_obj_t, o->alloc);

    if (n_args > 2) {
        o->flags = mp_obj_get_int(args[2]);
    }

    return MP_OBJ_FROM_PTR(o);
}

// Return true if exception (type or instance) is a subclass of given
// exception type.  Assumes exc_type is a subclass of BaseException, as
// defined by mp_obj_is_exception_type(exc_type).
bool mp_obj_exception_match(mp_obj_t exc, mp_const_obj_t exc_type) {
    // if exc is an instance of an exception, then extract and use its type
    if (mp_obj_is_exception_instance(exc)) {
        exc = MP_OBJ_FROM_PTR(mp_obj_get_type(exc));
    }
    return mp_obj_is_subclass_fast(exc, exc_type);
}

// If exc is SystemExit, return value where FORCED_EXIT bit set,
// and lower 8 bits are SystemExit value. For all other exceptions,
// return 1.
STATIC int handle_uncaught_exception(mp_obj_base_t *exc) {
    // check for SystemExit
    if (mp_obj_is_subclass_fast(MP_OBJ_FROM_PTR(exc->type), MP_OBJ_FROM_PTR(&mp_type_SystemExit))) {
        // None is an exit value of 0; an int is its value; anything else is 1
        mp_obj_t exit_val = mp_obj_exception_get_value(MP_OBJ_FROM_PTR(exc));
        mp_int_t val = 0;
        if (exit_val != mp_const_none && !mp_obj_get_int_maybe(exit_val, &val)) {
            val = 1;
        }
        return FORCED_EXIT | (val & 255);
    }

    // Report all other exceptions
    mp_obj_print_exception(&mp_stderr_print, MP_OBJ_FROM_PTR(exc));
    return 1;
}

STATIC mp_obj_t range_subscr(mp_obj_t self_in, mp_obj_t index, mp_obj_t value) {
    if (value == MP_OBJ_SENTINEL) {
        // load
        mp_obj_range_t *self = MP_OBJ_TO_PTR(self_in);
        mp_int_t len = range_len(self);
#if MICROPY_PY_BUILTINS_SLICE
        if (MP_OBJ_IS_TYPE(index, &mp_type_slice)) {
            mp_bound_slice_t slice;
            mp_seq_get_fast_slice_indexes(len, index, &slice);
            mp_obj_range_t *o = m_new_obj(mp_obj_range_t);
            o->base.type = &mp_type_range;
            o->start = self->start + slice.start * self->step;
            o->stop = self->start + slice.stop * self->step;
            o->step = slice.step * self->step;
            if (slice.step < 0) {
                // Negative slice steps have inclusive stop, so adjust for exclusive
                o->stop -= self->step;
            }
            return MP_OBJ_FROM_PTR(o);
        }
#endif
        size_t index_val = mp_get_index(self->base.type, len, index, false);
        return MP_OBJ_NEW_SMALL_INT(self->start + index_val * self->step);
    } else {
        return MP_OBJ_NULL; // op not supported
    }
}