gdb don't have CSR_MNSTATUS

[quantrpeter]

Hi
In rv64ui-p-addi, it has insturction "csrwi CSR_MNSTATUS, MNSTATUS_NMIE", which is "csrwi 0x744,8". When my qemu-system-riscv64 execute it, it got exception with mcause = 2 (illegal instruction). Is it normal behavior?

thanks
Peter