title: How do I enter supervisor mode on the ARM Cortex m4 to disable interrupts?
body: <p>Im trying to find out how I can disable and enable interrupts on the STM32L4x6RG Nucleo?</p>
  
  <p>After a bit of googling I found the macros __disble_irq() and __enable_irq() but I'm not convinced these are disabling interrupts.</p>
  
  <p>After more investigation it seems that the cpsid instruction this macro maps to only has effect when it runs in supervisor context. So the question becomes how do I move to supervisor mode to disable interrupts and back again??</p>