diff --git a/VKernel/Kernel/mm/mm.vp b/VKernel/Kernel/mm/mm.vp
index b46363b..50f56e5 100644
--- a/VKernel/Kernel/mm/mm.vp
+++ b/VKernel/Kernel/mm/mm.vp
@@ -503,6 +503,11 @@ def free_memory_regions() -> t.CStatic | t.CVoid:
 def init(MemmapAddr: t.CUInt64T, MemmapSize: t.CUInt64T, MemmapDescSize: t.CUInt64T, FbAddr: t.CUInt64T = 0, FbSize: t.CUInt64T = 0):
     global BuddySystemObject
     import drivers.serial.uart.serial as serial
+    # [DBG] 无条件打印 memmap 三参数，判定分支未走的根因（用后移除）
+    _dk0: t.CArray[t.CChar, 100]
+    viperlib.snprintf(c.Addr(_dk0), 100, "[mm] raw addr=0x%lx size=%lu desc=%lu\n",
+                      MemmapAddr, MemmapSize, MemmapDescSize)
+    serial.puts(c.Addr(_dk0))
     start_addr: t.CVoid | t.CPtr = None
     size: t.CUInt64T = 0
     if MemmapAddr != 0:
@@ -574,6 +579,14 @@ def init(MemmapAddr: t.CUInt64T, MemmapSize: t.CUInt64T, MemmapDescSize: t.CUInt
                         start_addr = t.CVoid(best_start, t.CPtr)
                         size = max_memory
     if start_addr is None:
+        # [DBG] fallback：打印 detect_memory_size 与 CMOS 原始值（用后移除）
+        _dc0: t.CArray[t.CChar, 100]
+        viperlib.snprintf(c.Addr(_dc0), 100, "[mm] fallback cmos 0x%02x 0x%02x 0x%02x 0x%02x\n",
+                          cmos_read(0x15), cmos_read(0x16), cmos_read(0x17), cmos_read(0x18))
+        serial.puts(c.Addr(_dc0))
+        _dsz: t.CUInt64T = detect_memory_size()
+        viperlib.snprintf(c.Addr(_dc0), 100, "[mm] fallback detect=%lu\n", _dsz)
+        serial.puts(c.Addr(_dc0))
         size = detect_memory_size()
         size = align_4k(size)
         # 起始地址 4MB（内核之后），避免超出物理 RAM