--- nono/vm/sram.h	2026/04/29 17:04:28	1.1.1.1
+++ nono/vm/sram.h	2026/04/29 17:04:45	1.1.1.5
@@ -1,44 +1,51 @@
 //
 // nono
-// Copyright (C) 2017 isaki@NetBSD.org
+// Copyright (C) 2020 nono project
+// Licensed under nono-license.txt
 //
 
 #pragma once
 
 #include "device.h"
+#include "mappedfile.h"
 
 class SRAMDevice
 	: public IODevice
 {
-	typedef IODevice inherited;
+	using inherited = IODevice;
  private:
 	static const uint32 baseaddr = 0xed0000;
 
+	// Pluto-X によるホストファイル起動アドレス
+	static const uint32 plutoaddr = 0xeac000;
+
  public:
 	SRAMDevice();
-	virtual ~SRAMDevice();
+	virtual ~SRAMDevice() override;
 
-	virtual bool Init();
+	bool Init() override;
 
-	virtual uint64 Read8(uint32 addr);
-	virtual uint64 Read16(uint32 addr);
-	virtual uint64 Write8(uint32 addr, uint32 data);
-	virtual uint64 Write16(uint32 addr, uint32 data);
-	virtual uint64 Peek8(uint32 addr);
+	uint64 Read8(uint32 addr) override;
+	uint64 Read16(uint32 addr) override;
+	uint64 Write8(uint32 addr, uint32 data) override;
+	uint64 Write16(uint32 addr, uint32 data) override;
+	uint64 Peek8(uint32 addr) override;
 
 	void write_enable(bool value);
 
  private:
-	std::string filename;
-	int fd = 0;
+	// アドレスデコーダ
+	uint64 Decoder(uint32 addr) const;
 
-	// バイト順はファイルイメージそのまま
-	uint8 *mem = NULL;
+	// ファイル
+	std::string filename {};
+	MappedFile file {};
+	uint8 *mem {};
 
-	// mmap する長さ
-	int memlen = 0;
+	bool writeable {};
 
-	bool writeable = false;
+	// ホストファイル起動用の読み出し値を返す
+	uint32 PeekHostBoot(uint32 offset) const;
 };
 
-extern SRAMDevice *gSRAM;
+extern std::unique_ptr<SRAMDevice> gSRAM;