From: Yongbok Kim <yongbok.kim@imgtec.com>

Config3.ISAOnExc is read only in nanoMIPS

Signed-off-by: Yongbok Kim <yongbok.kim@mips.com>
---
 target/mips/op_helper.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/target/mips/op_helper.c b/target/mips/op_helper.c
index 102a039..9946f77 100644
--- a/target/mips/op_helper.c
+++ b/target/mips/op_helper.c
@@ -1734,7 +1734,8 @@ void helper_mtc0_config2(CPUMIPSState *env, target_ulong arg1)
 
 void helper_mtc0_config3(CPUMIPSState *env, target_ulong arg1)
 {
-    if (env->insn_flags & ASE_MICROMIPS) {
+    if ((env->insn_flags & ASE_MICROMIPS) &&
+        !(env->insn_flags & ISA_NANOMIPS32)) {
         env->CP0_Config3 = (env->CP0_Config3 & ~(1 << CP0C3_ISA_ON_EXC)) |
                            (arg1 & (1 << CP0C3_ISA_ON_EXC));
     }
-- 
1.9.1