gem5/dev/disk_image.hh
Ron Dreslinski 1044b29a1d Serialization support for cow images
dev/disk_image.cc:
dev/disk_image.hh:
    Serialization of cow images

--HG--
extra : convert_revision : 144179b8cad00b32df8c448a8556a465e24737aa
2003-10-30 16:48:23 -05:00

133 lines
4.1 KiB
C++

/*
* Copyright (c) 2003 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 __DISK_IMAGE_HH__
#define __DISK_IMAGE_HH__
#include <fstream>
#include "base/hashmap.hh"
#include "sim/sim_object.hh"
#define SectorSize (512)
/*
* Basic interface for accessing a disk image.
*/
class DiskImage : public SimObject
{
protected:
bool initialized;
public:
DiskImage(const std::string &name) : SimObject(name), initialized(false) {}
virtual ~DiskImage() {}
virtual off_t size() const = 0;
virtual off_t read(uint8_t *data, off_t offset) const = 0;
virtual off_t write(const uint8_t *data, off_t offset) = 0;
};
/*
* Specialization for accessing a raw disk image
*/
class RawDiskImage : public DiskImage
{
protected:
mutable std::fstream stream;
std::string file;
bool readonly;
mutable off_t disk_size;
public:
RawDiskImage(const std::string &name, const std::string &filename,
bool rd_only);
~RawDiskImage();
void close();
void open(const std::string &filename, bool rd_only = false);
virtual off_t size() const;
virtual off_t read(uint8_t *data, off_t offset) const;
virtual off_t write(const uint8_t *data, off_t offset);
};
/*
* 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 int VersionMajor;
static const int VersionMinor;
protected:
struct Sector {
uint8_t data[SectorSize];
};
typedef m5::hash_map<uint64_t, Sector *> SectorTable;
protected:
std::string filename;
DiskImage *child;
SectorTable *table;
public:
CowDiskImage(const std::string &name, DiskImage *kid, int hash_size);
CowDiskImage(const std::string &name, DiskImage *kid, int hash_size,
const std::string &filename, bool read_only);
~CowDiskImage();
void init(int hash_size);
bool open(const std::string &file);
void save();
void save(const std::string &file);
void writeback();
void serialize(std::ostream &os);
void unserialize(Checkpoint *cp, const std::string &section);
virtual off_t size() const;
virtual off_t read(uint8_t *data, off_t offset) const;
virtual off_t write(const uint8_t *data, off_t offset);
};
#endif // __DISK_IMAGE_HH__