diff --git a/docs/library/machine.Pin.rst b/docs/library/machine.Pin.rst
index 5254e163c02a3..3055491ebbba8 100644
--- a/docs/library/machine.Pin.rst
+++ b/docs/library/machine.Pin.rst
@@ -216,6 +216,7 @@ Methods
      - ``hard`` if true a hardware interrupt is used. This reduces the delay
        between the pin change and the handler being called. Hard interrupt
        handlers may not allocate memory; see :ref:`isr_rules`.
+       Not all ports support this argument.
 
    This method returns a callback object.
 
diff --git a/ports/esp8266/machine_pin.c b/ports/esp8266/machine_pin.c
index f33f977874a9c..4e74ad652dc4e 100644
--- a/ports/esp8266/machine_pin.c
+++ b/ports/esp8266/machine_pin.c
@@ -37,7 +37,6 @@
 #include "py/gc.h"
 #include "py/mphal.h"
 #include "extmod/virtpin.h"
-#include "ets_alt_task.h"
 #include "modmachine.h"
 
 #define GET_TRIGGER(phys_port) \
@@ -87,15 +86,11 @@ STATIC uint8_t pin_mode[16 + 1];
 // forward declaration
 STATIC const pin_irq_obj_t pin_irq_obj[16];
 
-// whether the irq is hard or soft
-STATIC bool pin_irq_is_hard[16];
-
 void pin_init0(void) {
     ETS_GPIO_INTR_DISABLE();
     ETS_GPIO_INTR_ATTACH(pin_intr_handler_iram, NULL);
     // disable all interrupts
     memset(&MP_STATE_PORT(pin_irq_handler)[0], 0, 16 * sizeof(mp_obj_t));
-    memset(pin_irq_is_hard, 0, sizeof(pin_irq_is_hard));
     for (int p = 0; p < 16; ++p) {
         GPIO_REG_WRITE(GPIO_STATUS_W1TC_ADDRESS, 1 << p);
         SET_TRIGGER(p, 0);
@@ -103,24 +98,13 @@ void pin_init0(void) {
     ETS_GPIO_INTR_ENABLE();
 }
 
-void pin_intr_handler(uint32_t status) {
+void MP_FASTCODE(pin_intr_handler)(uint32_t status) {
     status &= 0xffff;
     for (int p = 0; status; ++p, status >>= 1) {
         if (status & 1) {
             mp_obj_t handler = MP_STATE_PORT(pin_irq_handler)[p];
             if (handler != MP_OBJ_NULL) {
-                if (pin_irq_is_hard[p]) {
-                    int orig_ets_loop_iter_disable = ets_loop_iter_disable;
-                    ets_loop_iter_disable = 1;
-                    mp_sched_lock();
-                    gc_lock();
-                    mp_call_function_1_protected(handler, MP_OBJ_FROM_PTR(&pyb_pin_obj[p]));
-                    gc_unlock();
-                    mp_sched_unlock();
-                    ets_loop_iter_disable = orig_ets_loop_iter_disable;
-                } else {
-                    mp_sched_schedule(handler, MP_OBJ_FROM_PTR(&pyb_pin_obj[p]));
-                }
+                mp_sched_schedule(handler, MP_OBJ_FROM_PTR(&pyb_pin_obj[p]));
             }
         }
     }
@@ -390,6 +374,9 @@ STATIC mp_obj_t pyb_pin_irq(size_t n_args, const mp_obj_t *pos_args, mp_map_t *k
     if (self->phys_port >= 16) {
         mp_raise_msg(&mp_type_OSError, MP_ERROR_TEXT("pin does not have IRQ capabilities"));
     }
+    if (args[ARG_hard].u_bool) {
+        mp_raise_ValueError(MP_ERROR_TEXT("hard IRQ not supported"));
+    }
 
     if (n_args > 1 || kw_args->used != 0) {
         // configure irq
@@ -401,7 +388,6 @@ STATIC mp_obj_t pyb_pin_irq(size_t n_args, const mp_obj_t *pos_args, mp_map_t *k
         }
         ETS_GPIO_INTR_DISABLE();
         MP_STATE_PORT(pin_irq_handler)[self->phys_port] = handler;
-        pin_irq_is_hard[self->phys_port] = args[ARG_hard].u_bool;
         SET_TRIGGER(self->phys_port, trigger);
         GPIO_REG_WRITE(GPIO_STATUS_W1TC_ADDRESS, 1 << self->phys_port);
         ETS_GPIO_INTR_ENABLE();
diff --git a/ports/esp8266/mpconfigport.h b/ports/esp8266/mpconfigport.h
index 71c49cd246a8c..5344a98d6a548 100644
--- a/ports/esp8266/mpconfigport.h
+++ b/ports/esp8266/mpconfigport.h
@@ -114,6 +114,10 @@
 #define MICROPY_VM_HOOK_LOOP MICROPY_VM_HOOK_POLL
 #define MICROPY_VM_HOOK_RETURN MICROPY_VM_HOOK_POLL
 
+#include "xtirq.h"
+#define MICROPY_BEGIN_ATOMIC_SECTION() disable_irq()
+#define MICROPY_END_ATOMIC_SECTION(state) enable_irq(state)
+
 // type definitions for the specific machine
 
 #define MICROPY_MAKE_POINTER_CALLABLE(p) ((void *)((mp_uint_t)(p)))
@@ -192,5 +196,6 @@ extern const struct _mp_obj_module_t mp_module_onewire;
 
 #define MP_FASTCODE(n) __attribute__((section(".iram0.text." #n))) n
 #define MICROPY_WRAP_MP_KEYBOARD_INTERRUPT(f) MP_FASTCODE(f)
+#define MICROPY_WRAP_MP_SCHED_SCHEDULE(f) MP_FASTCODE(f)
 
 #define _assert(expr) ((expr) ? (void)0 : __assert_func(__FILE__, __LINE__, __func__, #expr))
diff --git a/py/mpconfig.h b/py/mpconfig.h
index 1327d8b02753f..f2b3af1f2a314 100644
--- a/py/mpconfig.h
+++ b/py/mpconfig.h
@@ -1449,6 +1449,10 @@ typedef double mp_float_t;
 #define MICROPY_WRAP_MP_KEYBOARD_INTERRUPT(f) f
 #endif
 
+#ifndef MICROPY_WRAP_MP_SCHED_SCHEDULE
+#define MICROPY_WRAP_MP_SCHED_SCHEDULE(f) f
+#endif
+
 /*****************************************************************************/
 /* Miscellaneous settings                                                    */
 
diff --git a/py/scheduler.c b/py/scheduler.c
index b559091b83a4a..06d7b36c2cdc4 100644
--- a/py/scheduler.c
+++ b/py/scheduler.c
@@ -120,7 +120,7 @@ void mp_sched_unlock(void) {
     MICROPY_END_ATOMIC_SECTION(atomic_state);
 }
 
-bool mp_sched_schedule(mp_obj_t function, mp_obj_t arg) {
+bool MICROPY_WRAP_MP_SCHED_SCHEDULE(mp_sched_schedule)(mp_obj_t function, mp_obj_t arg) {
     mp_uint_t atomic_state = MICROPY_BEGIN_ATOMIC_SECTION();
     bool ret;
     if (!mp_sched_full()) {