OEMInterruptHandler (Compact 2013)
This function provides all interrupt service routine (ISR) functionality for ARM-based platforms.
This function is only used by the ARM kernel. You do not need to call HookInterrupt in OEMInit for ARM-based platforms. On all platforms that support a single ISR, the name of the ISR is OEMInterruptHandler.
Before calling this function, the kernel preserves the state of the registers and places the OS in a state in which the OEM can enable nested interrupts.
The OEM must choose a nesting scheme and perform the appropriate masking of the interrupt register in this function before re-enabling interrupts. To do so, call the INTERRUPTS_ON function after the lower priority interrupts have been masked.
This function might call the INTERRUPTS_OFF function again if it requires code that is not re-entrant, but this call is not required because the kernel handles it when returning from this function.