KSTK_EUEN
KSTK_EUEN(current) |= CSR_EUEN_FPEN;
KSTK_EUEN(tsk) &= ~(CSR_EUEN_FPEN | CSR_EUEN_LSXEN | CSR_EUEN_LASXEN);
KSTK_EUEN(current) |= CSR_EUEN_LBTEN;
KSTK_EUEN(tsk) &= ~(CSR_EUEN_LBTEN);