EXC_EXI
mtspr(SPR_IVOR4, EXC_EXI); /* external input */
memcpy((void *)EXC_EXI, &extint, (size_t)&extsize);
__syncicache((void *)EXC_EXI, (int)&extsize);
case EXC_EXI:
oea_install_extint_vec(handler, EXC_EXI);
case EXC_EXI: trapstr = "EXI"; break;
case EXC_EXI: /* External interrupt */