From b9a7de41face6bde9e6ab20fba9b85b37cd1b8c2 Mon Sep 17 00:00:00 2001
From: Remy van Elst <git@relst.nl>
Date: Tue, 30 Apr 2024 14:07:20 +0200
Subject: [PATCH] Add nullptr check and log. Hit this with icache enabled when
 trying to do ARC stuff from here: https://archive.org/details/es40-1211e8a  /
 https://www.youtube.com/watch?v=V2Nr1O85hss&t=0s

---
 src/AlphaCPU.hpp | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/src/AlphaCPU.hpp b/src/AlphaCPU.hpp
index 720cc19..6d687cf 100644
--- a/src/AlphaCPU.hpp
+++ b/src/AlphaCPU.hpp
@@ -494,8 +494,12 @@ inline int CAlphaCPU::get_icache(u64 address, u32 *data) {
         return result;
     }
 
-    memcpy(state.icache[state.next_icache].data, cSystem->PtrToMem(p_a),
+    char* addr = cSystem->PtrToMem(p_a);
+    if(addr)
+      memcpy(state.icache[state.next_icache].data, addr,
            ICACHE_LINE_SIZE * 4);
+    else
+      printf("PtrToMem(p_a) == nullptr! Address: %lu.\n", p_a);
 
     state.icache[state.next_icache].valid = true;
     state.icache[state.next_icache].asn = state.asn;