0  iop-constant-folding              [default 0]\
1  iop-unk1 (inaccesible config)     [default 0] \
2  iop-unk2 (inaccesible config)     [default 0]  \
3  iop-evt-check-full                [default 0]   \
4  iop-validate-kernel               [default 0]    |___ set to zero at init
5  iop-pc-coherency                  [default 0]   /
6  iop-inst-marking                  [default 0]  /
7  iop-unk3                          [default 0] /
8  iop-unk4                          [default 0]/