--- nono/vm/device.cpp	2026/04/29 17:04:44	1.1.1.4
+++ nono/vm/device.cpp	2026/04/29 17:04:50	1.1.1.5
@@ -61,12 +61,6 @@ Device::ResetHard()
 {
 }
 
-// MPU の RESET 命令によるリセット
-void
-Device::ResetSoft()
-{
-}
-
 
 //
 // IODevice
@@ -212,9 +206,12 @@ BusErrDevice::Peek8(uint32 addr)
 // 何もしないデバイス
 //
 
+std::unique_ptr<NullDevice> gNull;
+
 // コンストラクタ
 NullDevice::NullDevice()
 {
+	logname = "null";
 	devname = "(Null)";
 }
 
@@ -225,12 +222,42 @@ NullDevice::~NullDevice()
 uint64
 NullDevice::Read8(uint32 addr)
 {
+	putlog(1, "$%08x.b", addr);
 	return 0xff;
 }
 
 uint64
+NullDevice::Read16(uint32 addr)
+{
+	putlog(1, "$%08x.w", addr);
+	return 0xffff;
+}
+
+uint64
+NullDevice::Read32(uint32 addr)
+{
+	putlog(1, "$%08x.l", addr);
+	return 0xffffffff;
+}
+
+uint64
 NullDevice::Write8(uint32 addr, uint32 data)
 {
+	putlog(1, "$%08x.b <- $%02x", addr, data);
+	return 0;
+}
+
+uint64
+NullDevice::Write16(uint32 addr, uint32 data)
+{
+	putlog(1, "$%08x.w <- $%04x", addr, data);
+	return 0;
+}
+
+uint64
+NullDevice::Write32(uint32 addr, uint32 data)
+{
+	putlog(1, "$%08x.l <- $%08x", addr, data);
 	return 0;
 }