For misaligned fetch, set mepc = addr of branch/jump

11 years ago · 6c965e11dc
1 changed files with 5 additions and 1 deletions
--- a/riscv/decode.h
+++ b/riscv/decode.h
@ -153,7 +153,11 @@ private:
 #define sext_xlen(x) (((sreg_t)(x) << (64-xlen)) >> (64-xlen))
 #define zext_xlen(x) (((reg_t)(x) << (64-xlen)) >> (64-xlen))

-#define set_pc(x) (npc = sext_xlen(x))
+#define set_pc(x) \
+  do { if ((x) & 3 /* For now... */) \
+         throw trap_instruction_address_misaligned(x); \
+       npc = sext_xlen(x); \
+     } while(0)

 #define validate_csr(which, write) ({ \
  unsigned my_priv = get_field(STATE.mstatus, MSTATUS_PRV); \