DiskImage.cc

/*
 * Copyright (c) 2008-2014, Pedigree Developers
 *
 * Please see the CONTRIB file in the root of the source tree for a full
 * list of contributors.
 *
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */

#include "DiskImage.h"
#include "pedigree/kernel/BootstrapInfo.h"
#include "pedigree/kernel/Log.h"

extern BootstrapStruct_t *g_pBootstrapInfo;

bool DiskImage::initialise()
{
    if (g_pBootstrapInfo->getModuleCount() < 3)
    {
        NOTICE("not enough modules to create a DiskImage");
        return false;
    }

    uintptr_t baseAddress = g_pBootstrapInfo->getModuleArray()[2].base;
    uintptr_t endAddress = g_pBootstrapInfo->getModuleArray()[2].end;

    m_pBase = reinterpret_cast<void *>(baseAddress);
    m_nSize = endAddress - baseAddress;
    return true;
}

uintptr_t DiskImage::read(uint64_t location)
{
    if ((location > m_nSize) || !m_pBase)
    {
        ERROR("DiskImage::read() - location " << location << " > " << m_nSize);
        ERROR("  -> or " << m_pBase << " is null");
        return ~0;
    }

    uint64_t offset = location % getBlockSize();
    location &= ~(getBlockSize() - 1);

    uintptr_t buffer = m_Cache.lookup(location);
    if (buffer)
    {
        return buffer + offset;
    }

    buffer = m_Cache.insert(location, getBlockSize());
    MemoryCopy(
        reinterpret_cast<void *>(buffer), adjust_pointer(m_pBase, location),
        getBlockSize());

    m_Cache.markNoLongerEditing(location);

    return buffer + offset;
}

size_t DiskImage::getSize() const
{
    return m_nSize;
}

void DiskImage::pin(uint64_t location)
{
    m_Cache.pin(location);
}

void DiskImage::unpin(uint64_t location)
{
    m_Cache.release(location);
}