Installing and interrupt handler (sa1100.c)

unsigned vec, oldvec;

vec = ( (routine - (unsigned)vector - 0x8) >> 2 );

if (vec & 0xff000000) {

return 0;

}

vec = 0xea000000 | vec;

oldvec = *vector;

*vector = vec;

CleanAllCaches();

return oldvec;

}