riscv/insns/sret.h

   1 require_privilege(PRV_S);
   2 switch (STATE.prv)
   3 {
   4   case PRV_S: set_pc_and_serialize(p->get_state()->sepc); break;
   5   case PRV_M: set_pc_and_serialize(p->get_state()->mepc); break;
   6   default: abort();
   7 }
   8
   9 reg_t s = STATE.mstatus;
  10 reg_t pie = get_field(s, MSTATUS_UPIE << STATE.prv);
  11 reg_t prev_prv = get_field(s, STATE.prv == PRV_S ? MSTATUS_SPP : MSTATUS_MPP);
  12 s = set_field(s, MSTATUS_UIE << prev_prv, pie); // [[prv]PP]IE = [prv]PIE
  13 s = set_field(s, MSTATUS_UPIE << STATE.prv, 0); // [prv]PIE <- 0
  14 s = set_field(s, STATE.prv == PRV_S ? MSTATUS_SPP : MSTATUS_MPP, PRV_U); // [prv]PP = U
  15 p->set_privilege(prev_prv); // prv <- [prv]PP
  16 p->set_csr(CSR_MSTATUS, s);