mcounteren does not exist if U-mode is not implemented

6 years ago · 6160ee9a94
1 changed files with 4 additions and 1 deletions
--- a/riscv/processor.cc
+++ b/riscv/processor.cc
@ -1404,7 +1404,10 @@ reg_t processor_t::get_csr(int which)
        return state.minstret >> 32;
      break;
    case CSR_SCOUNTEREN: return state.scounteren;
-    case CSR_MCOUNTEREN: return state.mcounteren;
+    case CSR_MCOUNTEREN:
+      if (!supports_extension('U'))
+        break;
+      return state.mcounteren;
    case CSR_MCOUNTINHIBIT: return 0;
    case CSR_SSTATUS: {
      reg_t mask = SSTATUS_SIE | SSTATUS_SPIE | SSTATUS_SPP | SSTATUS_FS