2 files changed, 33 insertions, 17 deletions

diff --git a/src/core/arm/arm_interface.cpp b/src/core/arm/arm_interface.cpp
new file mode 100644
index 000000000..bcc812da4
--- /dev/null
+++ b/src/core/arm/arm_interface.cpp
@@ -0,0 +1,26 @@
+// Copyright 2018 yuzu emulator team
+// Licensed under GPLv2 or any later version
+// Refer to the license.txt file included.
+
+#include "arm_interface.h"
+#include "common/common_types.h"
+#include "common/logging/log.h"
+#include "core/memory.h"
+
+namespace Core {
+void ARM_Interface::LogBacktrace() {
+    VAddr fp = GetReg(29);
+    VAddr lr = GetReg(30);
+    VAddr sp = GetReg(13);
+    VAddr pc = GetPC();
+    LOG_ERROR(Core_ARM, "Backtrace, sp={:016X}, pc={:016X}", sp, pc);
+    for (;;) {
+        LOG_ERROR(Core_ARM, "{:016X}", lr);
+        if (!fp) {
+            break;
+        }
+        lr = Memory::Read64(fp + 8) - 4;
+        fp = Memory::Read64(fp);
+    }
+}
+}; // namespace Core
diff --git a/src/core/arm/arm_interface.h b/src/core/arm/arm_interface.h
index b0472d55d..91d2b0f81 100644
--- a/src/core/arm/arm_interface.h
+++ b/src/core/arm/arm_interface.h
@@ -6,8 +6,6 @@
 
 #include <array>
 #include "common/common_types.h"
-#include "common/logging/log.h"
-#include "core/memory.h"
 
 namespace Kernel {
 enum class VMAPermission : u8;
@@ -144,21 +142,13 @@ public:
     /// Prepare core for thread reschedule (if needed to correctly handle state)
     virtual void PrepareReschedule() = 0;
 
-    void LogBacktrace() {
-        VAddr fp = GetReg(29);
-        VAddr lr = GetReg(30);
-        VAddr sp = GetReg(13);
-        VAddr pc = GetPC();
-        LOG_ERROR(Core_ARM, "Backtrace, sp={:016X}, pc={:016X}", sp, pc);
-        for (;;) {
-            LOG_ERROR(Core_ARM, "{:016X}", lr);
-            if (!fp) {
-                break;
-            }
-            lr = Memory::Read64(fp + 8) - 4;
-            fp = Memory::Read64(fp);
-        }
-    }
+    /// fp (= r29) points to the last frame record.
+    /// Note that this is the frame record for the *previous* frame, not the current one.
+    /// Note we need to subtract 4 from our last read to get the proper address
+    /// Frame records are two words long:
+    /// fp+0 : pointer to previous frame record
+    /// fp+8 : value of lr for frame
+    void LogBacktrace();
 };
 
 } // namespace Core