What is the meaning of _NTO_INTR_SPARE at the startup_intrin

Hello.



My 32-bit ARM9 RISC SoC has just 1 interrupt controller with 29 interrupt
sources.

If I understood the cascaded vector’s meaning well, I doesn’t need cascaded
vectors.



Is it right ?



const static struct startup_intrinfo intrs[] = {

{ _NTO_INTR_CLASS_EXTERNAL, // vector
base

32, //
number of vectors

_NTO_INTR_SPARE, //
cascade vector

0, //
CPU vector base

0, //
CPU vector stride

0, //
flags

{ INTR_GENFLAG_LOAD_SYSPAGE, 0, &interrupt_id_jaguar2
},

{ INTR_GENFLAG_LOAD_SYSPAGE |
INTR_GENFLAG_LOAD_INTRMASK, 0, &interrupt_eoi_jaguar2 },

&interrupt_mask_jaguar2, // mask callout

&interrupt_unmask_jaguar2, // unmask callout

0, // config
callout

}



The upper source code is my startup_intrinfo but I think its source code has
the problem.

I think that there is some proper value for a cascade vector instead of
_NTO_INTR_SPACE.

Actually, I didn’t understand the meaning of the cascade vector.



Please help me.



Best regards.



Pusik.