Getting started on Cortex A5 interrupts

I'm new to Cortex A5 and I'm trying to figure out how the interrupts work.

From my understanding, the Cortex A5 starts in secure mode and I don't change it. Now I set up the "secure interrupt controller" (of course only accessible in secure mode) and let it fire an FIQ interrupt. Now, from within the interrupt, should I be able to talk to the "secure interrupt controller", or does that require changing the SCR first, so the FIQ gets me to "monitor mode" instead? Is there any way to access secure peripherals from within FIQs?