Do not disable tick interrupt

dont_disable_tick.diff

diff --git a/hw/mcu/stm/stm32f3xx/include/mcu/stm32f3xx_mynewt_hal.h b/hw/mcu/stm/stm32f3xx/include/mcu/stm32f3xx_mynewt_hal.h
index 0b24798dc..7c0f41287 100644
index 0b24798dc..7c0f41287 100644
--- a/hw/mcu/stm/stm32f3xx/include/mcu/stm32f3xx_mynewt_hal.h
+++ b/hw/mcu/stm/stm32f3xx/include/mcu/stm32f3xx_mynewt_hal.h
@@ -27,21 +27,23 @@
 extern "C" {
 #endif
 
+/* PendSV has the highest prio, followed by SysTick */
+#define OS_TICK_PRIO    ((1 << __NVIC_PRIO_BITS) - 2)
+
 /* Helper functions to enable/disable interrupts. */
 #define __HAL_DISABLE_INTERRUPTS(x)                     \
     do {                                                \
-        x = __get_PRIMASK();                            \
-        __disable_irq();                                \
+        x = __get_BASEPRI();                            \
+        __set_BASEPRI(OS_TICK_PRIO + 1);                \
     } while(0);
 
 #define __HAL_ENABLE_INTERRUPTS(x)                      \
     do {                                                \
         if (!x) {                                       \
-            __enable_irq();                             \
+            __set_BASEPRI(0);                           \
         }                                               \
     } while(0);
 
-
 int hal_gpio_init_stm(int pin, GPIO_InitTypeDef *cfg);
 int hal_gpio_deinit_stm(int pin, GPIO_InitTypeDef *cfg);