riscv/insns/mret.h

   1 require_privilege(PRV_M);
   2 set_pc_and_serialize(p->get_state()->mepc);
   3 reg_t s = STATE.mstatus;
   4 reg_t prev_prv = get_field(s, MSTATUS_MPP);
   5 s = set_field(s, MSTATUS_UIE << prev_prv, get_field(s, MSTATUS_MPIE));
   6 s = set_field(s, MSTATUS_MPIE, 0);
   7 s = set_field(s, MSTATUS_MPP, PRV_U);
   8 p->set_privilege(prev_prv);
   9 p->set_csr(CSR_MSTATUS, s);