/* $Id: $ */
/** @file
 *
 * kLdr - The Dynamic Loader.
 *
 * Copyright (c) 2006 knut st. osmundsen <bird@anduin.net>
 *
 *
 * This file is part of kLdr.
 *
 * kLdr 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 2 of the License, or
 * (at your option) any later version.
 *
 * kLdr 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 kLdr; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 *
 */

#ifndef __kLdr_h__
#define __kLdr_h__

#ifdef __cplusplus
extern "C" {
#endif

#include <sys/types.h>
#include <stdint.h>

/** A KLDRMOD handle. */
typedef struct KLDRMOD *HKLDRMOD;

/**
 * Loader segment.
 */
typedef struct KLDRSEG
{
    /** The segment load address. */
    void           *pv;
    /** The size of the segment. */
    size_t          cb;
    /** The segment is readable. */
    uint32_t        fRead : 1;
    /** The segment is writable. */
    uint32_t        fWrite : 1;
    /** The segment is executable. */
    uint32_t        fExecute : 1;
    /** Reserved for future use. */
    uint32_t        fReserved : 29;
    /** Reserved for future use. */
    uint32_t        u32Reserved;
} KLDRSEG, *PKLDRSEG;


/**
 * Loader module type.
 */
typedef enum KLDRTYPE
{
    /** The usual invalid 0 type. */
    KLDRTYPE_INVALID = 0,
    /** The native OS loader. */
    KLDRTYPE_NATIVE,
    /** The LX loader. */
    KLDRTYPE_LX,
    /** The end type (not included). */
    KLDRTYPE_END,
    /** Hack to blow the type up to 32-bit. */
    KLDRTYPE_32BIT_HACK = 0x7fffffff
} KLDRTYPE;


/**
 * The state of a module.
 */
typedef enum KLDRSTATE
{
    /** The usual invalid 0 enum. */
    KLDRSTATE_INVALID = 0,
    /** kldrOpen succeeded.
     * Modules in this state will be freed at  */
    KLDRSTATE_OPEN,
    /** Dependencies has been loaded. */
    KLDRSTATE_DEPS,
    /** Fixups has been applied. */
    KLDRSTATE_FIXED,
    /** The module has been initialized. */
    KLDRSTATE_INITED,
    /** The module is loaded successfully. */
    KLDRSTATE_LOADED,
    /** The end of valid states (exclusive) */
    KLDRSTATE_END,
    /** The usual 32-bit blowup. */
    KLDRSTATE_32BIT_HACK = 0x7fffffff
} KLDRSTATE;


/**
 * Loader module.
 */
typedef struct KLDRMOD
{
    /** Pointer to the next module. */
    struct KLDRMOD     *pNext;
    /** Pointer to the previous module. */
    struct KLDRMOD     *pPrev;
    /** Our module handle. */
    HKLDRMOD            hmod;
    /** The module data. */
    void               *pvData;
    /** The type of module this is. */
    KLDRTYPE            enmType;
    /** The module state. */
    KLDRSTATE           enmState;
    /** The number of references. */
    uint32_t            cRefs;
    /** The number of dynamic references. */
    uint32_t            cDynRefs;
    /** Magic number. */
    uint32_t            u32Magic;
    /** Set if this is the executable module. */
    uint32_t            fExecutable : 1;
    /** Global DLL (set) or specific DLL (clear). */
    uint32_t            fGlobal : 1;
    /** Load stage one. */
    uint32_t            fLoadStageOne : 1;
    /** Reserved for future use. */
    uint32_t            fReserved : 29;
    /** The filename length (bytes). */
    uint32_t            cchFilename;
    /** The filename. */
    const char         *pszFilename;
    /** The module name. */
    const char         *pszName;
    /** The module name length (bytes). */
    uint32_t            cchName;
    /** The number of segments in the module. */
    uint32_t            cSegments;
    /** Segments. (variable size, can be zero) */
    KLDRSEG             aSegments[1];
} KLDRMOD, *PKLDRMOD, **PPKLDRMOD;

/** Pointer to the head module (the executable). */
extern PKLDRMOD         kLdrModuleHead;
/** Pointer to the tail module. */
extern PKLDRMOD         kLdrModuleTail;
/** The Library search path. */
extern char             kLdrLibraryPath[4096];

/** @name Process Bootstrapping
 * @{ */

/**
 * Argument package from the stub.
 */
typedef struct KLDREXEARGS
{
    /** Flags. (Currently unused, MBZ.) */
    uint32_t        fFlags;
    /** The executable file that the stub is supposed to load. */
    char            szExecutable[260];
    /** The LD_LIBRARY_PATH prefix for the process.. */
    char            szLibPath[4096 - 260 - sizeof(uint32_t)];
} KLDREXEARGS, *PKLDREXEARGS;

void kLdrLoadExe(PKLDREXEARGS pArgs);
/** @} */

/** @name The Internal APIs
 * @internal
 * @{ */
int kldrOpenExe(const char *pszFilename, PPKLDRMOD ppMod)
int kldrOpen(const char *pszFilename, unsigned fFlags, PPKLDRMOD ppMod);
int kldrClose(PKLDRMOD pMod);

void kldrFailure(const char *pszFilename, ...);
/** @} */

/*
int kLdrLoadDll(const char *pszFilename, unsigned fFlags, unsigned long *pvmod);
*/

#ifndef NULL
# define NULL 0
#endif

#ifdef __cplusplus
}
#endif

#endif