diff --git a/docs/firmware-design.rst b/docs/firmware-design.rst
index 997d29b..aeb883a 100644
--- a/docs/firmware-design.rst
+++ b/docs/firmware-design.rst
@@ -1161,6 +1161,56 @@
 already been performed and act as appropriate. Possible courses of actions are,
 e.g. skip the action the second time, or undo/redo it.
 
+Configuring secure interrupts
+-----------------------------
+
+The GIC driver is responsible for performing initial configuration of secure
+interrupts on the platform. To this end, the platform is expected to provide the
+GIC driver (either GICv2 or GICv3, as selected by the platform) with the
+interrupt configuration during the driver initialisation.
+
+There are two ways to specify secure interrupt configuration:
+
+#. Array of secure interrupt properties: In this scheme, in both GICv2 and GICv3
+   driver data structures, the ``interrupt_props`` member points to an array of
+   interrupt properties. Each element of the array specifies the interrupt
+   number and its configuration, viz. priority, group, configuration. Each
+   element of the array shall be populated by the macro ``INTR_PROP_DESC()``.
+   The macro takes the following arguments:
+
+   -  10-bit interrupt number,
+
+   -  8-bit interrupt priority,
+
+   -  Interrupt type (one of ``INTR_TYPE_EL3``, ``INTR_TYPE_S_EL1``,
+      ``INTR_TYPE_NS``),
+
+   -  Interrupt configuration (either ``GIC_INTR_CFG_LEVEL`` or
+      ``GIC_INTR_CFG_EDGE``).
+
+#. Array of secure interrupts: In this scheme, the GIC driver is provided an
+   array of secure interrupt numbers. The GIC driver, at the time of
+   initialisation, iterates through the array and assigns each interrupt
+   the appropriate group.
+
+   -  For the GICv2 driver, in ``gicv2_driver_data`` structure, the
+      ``g0_interrupt_array`` member of the should point to the array of
+      interrupts to be assigned to *Group 0*, and the ``g0_interrupt_num``
+      member of the should be set to the number of interrupts in the array.
+
+   -  For the GICv3 driver, in ``gicv3_driver_data`` structure:
+
+      -  The ``g0_interrupt_array`` member of the should point to the array of
+         interrupts to be assigned to *Group 0*, and the ``g0_interrupt_num``
+         member of the should be set to the number of interrupts in the array.
+
+      -  The ``g1s_interrupt_array`` member of the should point to the array of
+         interrupts to be assigned to *Group 1 Secure*, and the
+         ``g1s_interrupt_num`` member of the should be set to the number of
+         interrupts in the array.
+
+   **Note that this scheme is deprecated.**
+
 CPU specific operations framework
 ---------------------------------