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/*
* Copyright (c) 2001-2005 The Regents of The University of Michigan
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are
* met: redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer;
* redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution;
* neither the name of the copyright holders nor the names of its
* contributors may be used to endorse or promote products derived from
* this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
* OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
/** @file
* Disk Image Interfaces
*/
#ifndef __DEV_STORAGE_DISK_IMAGE_HH__
#define __DEV_STORAGE_DISK_IMAGE_HH__
#include <fstream>
#include <unordered_map>
#include "params/CowDiskImage.hh"
#include "params/DiskImage.hh"
#include "params/RawDiskImage.hh"
#include "sim/sim_object.hh"
#define SectorSize (512)
/**
* Basic interface for accessing a disk image.
*/
class DiskImage : public SimObject
{
protected:
bool initialized;
public:
typedef DiskImageParams Params;
DiskImage(const Params *p) : SimObject(p), initialized(false) {}
virtual ~DiskImage() {}
virtual std::streampos size() const = 0;
virtual std::streampos read(uint8_t *data,
std::streampos offset) const = 0;
virtual std::streampos write(const uint8_t *data,
std::streampos offset) = 0;
};
/**
* Specialization for accessing a raw disk image
*/
class RawDiskImage : public DiskImage
{
protected:
mutable std::fstream stream;
std::string file;
bool readonly;
mutable std::streampos disk_size;
public:
typedef RawDiskImageParams Params;
RawDiskImage(const Params *p);
~RawDiskImage();
void notifyFork() override;
void close();
void open(const std::string &filename, bool rd_only = false);
std::streampos size() const override;
std::streampos read(uint8_t *data, std::streampos offset) const override;
std::streampos write(const uint8_t *data, std::streampos offset) override;
};
/**
* Specialization for accessing a copy-on-write disk image layer.
* A copy-on-write(COW) layer must be stacked on top of another disk
* image layer this layer can be another CowDiskImage, or a
* RawDiskImage.
*
* This object is designed to provide a mechanism for persistant
* changes to a main disk image, or to provide a place for temporary
* changes to the image to take place that later may be thrown away.
*/
class CowDiskImage : public DiskImage
{
public:
static const uint32_t VersionMajor;
static const uint32_t VersionMinor;
protected:
struct Sector {
uint8_t data[SectorSize];
};
typedef std::unordered_map<uint64_t, Sector *> SectorTable;
protected:
std::string filename;
DiskImage *child;
SectorTable *table;
public:
typedef CowDiskImageParams Params;
CowDiskImage(const Params *p);
~CowDiskImage();
void notifyFork() override;
void initSectorTable(int hash_size);
bool open(const std::string &file);
void save() const;
void save(const std::string &file) const;
void writeback();
void serialize(CheckpointOut &cp) const override;
void unserialize(CheckpointIn &cp) override;
std::streampos size() const override;
std::streampos read(uint8_t *data, std::streampos offset) const override;
std::streampos write(const uint8_t *data, std::streampos offset) override;
};
void SafeRead(std::ifstream &stream, void *data, int count);
template<class T>
void SafeRead(std::ifstream &stream, T &data);
template<class T>
void SafeReadSwap(std::ifstream &stream, T &data);
void SafeWrite(std::ofstream &stream, const void *data, int count);
template<class T>
void SafeWrite(std::ofstream &stream, const T &data);
template<class T>
void SafeWriteSwap(std::ofstream &stream, const T &data);
#endif // __DEV_STORAGE_DISK_IMAGE_HH__