Why do we have ebase located at some high memory address when we use Vectored Interrupts?

["Ardelean, Andrei" <Andrei.Ardelean@idt.com>]

Hi,

Why do we have ebase located at some high memory address when we use
Vectored Interrupts and for Compatible Mode we have the normal location
close to zero?

Thanks,
Andrei
 


.............................. in void __init trap_init(void):
        if (cpu_has_veic || cpu_has_vint) {
                unsigned long size = 0x200 + VECTORSPACING*64;
                ebase = (unsigned long)
                        __alloc_bootmem(size, 1 << fls(size), 0);
        } else {
                ebase = CAC_BASE;
                if (cpu_has_mips_r2)
                        ebase += (read_c0_ebase() & 0x3ffff000);
        }
.........................