Some work on CSR

emulator/csr_machine_trap_setup.c

@@ -0,0 +1,19 @@
+#include "emulator/csr.h"
+
+#include "emulator/hart.h"
+
+static uint32_t csr_misa(Hart* hart, uint32_t v, enum CsrAction a)
+{
+    uint32_t misa = 0;
+    misa |= 1 << 30; // 32-bit
+    misa |= 1 << 8;  // Base ISA
+    misa |= 1 << 12; // M extension
+    misa |= 1 << 18; // Supervisor mode
+    misa |= 1 << 20; // User mode
+    return misa;
+}
+
+void csr_init_machine_trap_setup(Hart* hart)
+{
+    hart->csrs[CSR_MISA].action = csr_misa;
+}