elf-loader.h

/* ScummVM - Graphic Adventure Engine
 *
 * ScummVM is the legal property of its developers, whose names
 * are too numerous to list here. Please refer to the COPYRIGHT
 * file distributed with this source distribution.
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 *
 */

#ifndef BACKENDS_PLUGINS_ELF_LOADER_H
#define BACKENDS_PLUGINS_ELF_LOADER_H

#include "common/scummsys.h"

#if defined(DYNAMIC_MODULES) && defined(USE_ELF_LOADER)

#include <stddef.h>

#include "backends/plugins/elf/elf32.h"
#include "backends/plugins/dynamic-plugin.h"

#include "common/stream.h"

class DLObject {
protected:
    Common::SeekableReadStream *_file;

    byte *_segment;
    Elf32_Sym *_symtab;
    char *_strtab;

    uint32 _segmentSize;
    ptrdiff_t _segmentOffset;
    uint32 _segmentVMA;

    uint32 _symbol_cnt;
    int32 _symtab_sect;
    void *_dtors_start, *_dtors_end;

    virtual void unload();
    bool load();

    bool readElfHeader(Elf32_Ehdr *ehdr);
    bool readProgramHeaders(Elf32_Ehdr *ehdr, Elf32_Phdr *phdr, Elf32_Half num);
    virtual bool loadSegment(Elf32_Phdr *phdr);
    Elf32_Shdr *loadSectionHeaders(Elf32_Ehdr *ehdr);
    int findSymbolTableSection(Elf32_Ehdr *ehdr, Elf32_Shdr *shdr);
    int loadSymbolTable(Elf32_Ehdr *ehdr, Elf32_Shdr *shdr);
    bool loadStringTable(Elf32_Shdr *shdr);
    virtual void relocateSymbols(ptrdiff_t offset);
    void discardSegment();

    // architecture specific

    virtual bool relocate(Elf32_Off offset, Elf32_Word size, byte *relSegment) = 0;
    virtual bool relocateRels(Elf32_Ehdr *ehdr, Elf32_Shdr *shdr) = 0;

    // platform specific
    virtual void flushDataCache(void *ptr, uint32 len) const = 0;
    virtual void *allocateMemory(uint32 align, uint32 size);
    virtual void deallocateMemory(void *ptr, uint32 size);
    virtual void protectMemory(void *ptr, uint32 len, int prot) const {};

public:
    DLObject();
    virtual ~DLObject();

    void trackSize(const Common::Path &path);
    bool open(const Common::Path &path);
    bool close();
    void *symbol(const char *name);
    void discardSymtab();
};

#endif /* defined(DYNAMIC_MODULES) && defined(USE_ELF_LOADER) */

#endif /* BACKENDS_PLUGINS_ELF_LOADER_H */