intercept_table

[barbalace at igi.cnr.it]

I want to modify at run-time the linux interrupt handler, I see in
/arch/ppc/kernel/head.S a very interesting array: intercept_table. I don't
understand why there are only few references, in my kernel 2.6.14 there are:

intercept_table:
	.long 0, 0, i0x200, i0x300, i0x400, 0, i0x600, i0x700
	.long i0x800, 0, 0, 0, 0, i0xd00, 0, 0
	.long 0, 0, 0, i0x1300, 0, 0, 0, 0
	.long 0, 0, 0, 0, 0, 0, 0, 0
	.long 0, 0, 0, 0, 0, 0, 0, 0
	.long 0, 0, 0, 0, 0, 0, 0, 0

why 0x500 is missed? Is considered not safe to make user change it? ...so I say
that I want to change some of this pointers at run time but reading head.S I
see that the address of i0x* are in a .text segment, can I write in this
segment? Before I write must I turn off MMU or mask some traps?

Regards,
Antonio Barbalace