build: gen_isr_tables.py: fix bad IRQ index computation for L3 interr…

…upts

According to the Zephyr documentation, the multi-level interrupts
are encoded as follows:

`L1_ID | ((L2_ID + 1) << L2_BITS) | ((L3_ID + 1) << (L3_BITS + L2_BITS))`

This means that when L3 interrupts are enabled, the gen_isr_table.py
script will receive the value of L2_ID + 1. Currently, the script
takes this value and directly compares it with the offsets set via
`CONFIG_3RD_LVL_INTR_xx_OFFSET`. This is wrong because the values from
said configurations are the same as L2_ID and because of that the
script will generate an error. To fix this, use the value of L2_ID
instead of L2_ID + 1.

Signed-off-by: Laurentiu Mihalcea <[email protected]>

scripts/build/gen_isr_tables.py

@@ -200,7 +200,7 @@ def get_swt_table_index(self, offset, irq):
         irq1 = irq & self.int_lvl_masks[0]
         # Figure out third level interrupt position
         if irq3:
-            list_index = self.get_irq_index(irq2, 3)
+            list_index = self.get_irq_index(irq2 - 1, 3)
             irq3_pos = self.get_irq_baseoffset(3) + self.__max_irq_per * list_index + irq3 - 1
             self.__log.debug('IRQ_level = 3')
             self.__log.debug('IRQ_Indx = ' + str(irq3))