diff --git a/src/boot/libu64/debug.c b/src/boot/libu64/debug.c
index 7398275472..69dec97d7d 100644
--- a/src/boot/libu64/debug.c
+++ b/src/boot/libu64/debug.c
@@ -1,11 +1,33 @@
 #include "global.h"
 #include "fault.h"
 
+#if MM_VERSION < N64_US || DEBUG_FEATURES
+#define DEBUG_PRINTF osSyncPrintf
+#elif IDO_PRINTF_WORKAROUND
+#define DEBUG_PRINTF(args) (void)0
+#else
+#define DEBUG_PRINTF(format, ...) (void)0
+#endif
+
+#if MM_VERSION < N64_US
+f32 LogUtils_CheckFloatRange(const char* exp, int line, const char* valueName, f32 value, const char* minName, f32 min,
+                             const char* maxName, f32 max) {
+    if (value < min || max < value) {
+        osSyncPrintf("%s %d: range error %s(%f) < %s(%f) < %s(%f)\n", exp, line, minName, min, valueName, value,
+                     maxName, max);
+    }
+    return value;
+}
+#endif
+
 NORETURN void _dbg_hungup(const char* file, int lineNum) {
-    osGetThreadId(NULL);
+    OSId threadId = osGetThreadId(NULL);
+
+    DEBUG_PRINTF("*** HungUp in thread %d, [%s:%d] ***\n", threadId, file, lineNum);
     Fault_AddHungupAndCrash(file, lineNum);
 }
 
 NORETURN void Reset(void) {
+    DEBUG_PRINTF("*** Reset ***\n");
     Fault_AddHungupAndCrash("Reset", 0);
 }
diff --git a/tools/disasm/n64-jp-1.1/functions.txt b/tools/disasm/n64-jp-1.1/functions.txt
index 7903d5cefe..aaa8a9578d 100644
--- a/tools/disasm/n64-jp-1.1/functions.txt
+++ b/tools/disasm/n64-jp-1.1/functions.txt
@@ -154,7 +154,7 @@ GfxPrint_VPrintf = 0x8008699C; // type:func size:0x20
 GfxPrint_Printf = 0x800869BC; // type:func size:0x34
 MtxConv_F2L = 0x800869F0; // type:func size:0x148
 MtxConv_L2F = 0x80086B38; // type:func size:0x28
-func_80086B60_unknown = 0x80086B60; // type:func size:0x98
+LogUtils_CheckFloatRange = 0x80086B60; // type:func size:0x98
 _dbg_hungup = 0x80086BF8; // type:func size:0x4C
 Reset = 0x80086C44; // type:func size:0x3C
 SystemHeap_Malloc = 0x80086C80; // type:func size:0x30