csr: fix mseccfg for rv32

Signed-off-by: Chih-Min Chao <chihmin.chao@sifive.com>

riscv/csr_init.cc

@@ -281,7 +281,14 @@ void state_t::csr_init(processor_t* const proc, reg_t max_isa)
   auto hcontext = std::make_shared<masked_csr_t>(proc, CSR_HCONTEXT, (reg_t(1) << hcontext_length) - 1, 0);
   add_hypervisor_csr(CSR_HCONTEXT, hcontext);
   add_csr(CSR_MCONTEXT, mcontext = std::make_shared<proxy_csr_t>(proc, CSR_MCONTEXT, hcontext));
-  add_csr(CSR_MSECCFG, mseccfg = std::make_shared<mseccfg_csr_t>(proc, CSR_MSECCFG));
+
+  mseccfg = std::make_shared<mseccfg_csr_t>(proc, CSR_MSECCFG);
+  if (xlen == 32) {
+    add_csr(CSR_MSECCFG, std::make_shared<rv32_low_csr_t>(proc, CSR_MSECCFG, mseccfg));
+    add_csr(CSR_MSECCFGH, mseccfgh = std::make_shared<rv32_high_csr_t>(proc, CSR_MSECCFGH, mseccfg));
+  } else {
+    add_csr(CSR_MSECCFG, mseccfg);
+  }
 
   for (int i = 0; i < max_pmp; ++i) {
     add_csr(CSR_PMPADDR0 + i, pmpaddr[i] = std::make_shared<pmpaddr_csr_t>(proc, CSR_PMPADDR0 + i));

riscv/processor.h

@@ -152,6 +152,7 @@ struct state_t
   bool debug_mode;
 
   mseccfg_csr_t_p mseccfg;
+  csr_t_p mseccfgh;
 
   static const int max_pmp = 64;
   pmpaddr_csr_t_p pmpaddr[max_pmp];