1 /* ScummVM - Graphic Adventure Engine 2 * 3 * ScummVM is the legal property of its developers, whose names 4 * are too numerous to list here. Please refer to the COPYRIGHT 5 * file distributed with this source distribution. 6 * 7 * This program is free software; you can redistribute it and/or 8 * modify it under the terms of the GNU General Public License 9 * as published by the Free Software Foundation; either version 2 10 * of the License, or (at your option) any later version. 11 * 12 * This program is distributed in the hope that it will be useful, 13 * but WITHOUT ANY WARRANTY; without even the implied warranty of 14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 15 * GNU General Public License for more details. 16 * 17 * You should have received a copy of the GNU General Public License 18 * along with this program; if not, write to the Free Software 19 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. 20 * 21 */ 22 23 #ifndef BACKENDS_PLUGINS_ELF_LOADER_H 24 #define BACKENDS_PLUGINS_ELF_LOADER_H 25 26 #include "common/scummsys.h" 27 28 #if defined(DYNAMIC_MODULES) && defined(USE_ELF_LOADER) 29 30 #include <stddef.h> 31 32 #include "backends/plugins/elf/elf32.h" 33 #include "backends/plugins/dynamic-plugin.h" 34 35 #include "common/stream.h" 36 37 /** 38 * DLObject 39 * 40 * Class that most directly handles operations on a plugin file 41 * (opening it for reading, loading/unloading it in memory, finding a specific symbol in the file, etc.) 42 * Subclasses have the same functionality, but implementations specific to different processors/platforms. 43 */ 44 class DLObject { 45 protected: 46 Common::SeekableReadStream *_file; 47 48 byte *_segment; 49 Elf32_Sym *_symtab; 50 char *_strtab; 51 52 uint32 _segmentSize; 53 ptrdiff_t _segmentOffset; 54 uint32 _segmentVMA; 55 56 uint32 _symbol_cnt; 57 int32 _symtab_sect; 58 void *_dtors_start, *_dtors_end; 59 60 virtual void unload(); 61 bool load(); 62 63 bool readElfHeader(Elf32_Ehdr *ehdr); 64 bool readProgramHeaders(Elf32_Ehdr *ehdr, Elf32_Phdr *phdr, Elf32_Half num); 65 virtual bool loadSegment(Elf32_Phdr *phdr); 66 Elf32_Shdr *loadSectionHeaders(Elf32_Ehdr *ehdr); 67 int findSymbolTableSection(Elf32_Ehdr *ehdr, Elf32_Shdr *shdr); 68 int loadSymbolTable(Elf32_Ehdr *ehdr, Elf32_Shdr *shdr); 69 bool loadStringTable(Elf32_Shdr *shdr); 70 virtual void relocateSymbols(ptrdiff_t offset); 71 void discardSegment(); 72 73 // architecture specific 74 75 /** 76 * Follow the instruction of a relocation section. 77 * 78 * @param fileOffset Offset into the File 79 * @param size Size of relocation section 80 * @param relSegment Base address of relocated segment in memory (memory offset) 81 */ 82 virtual bool relocate(Elf32_Off offset, Elf32_Word size, byte *relSegment) = 0; 83 virtual bool relocateRels(Elf32_Ehdr *ehdr, Elf32_Shdr *shdr) = 0; 84 85 // platform specific 86 virtual void flushDataCache(void *ptr, uint32 len) const = 0; 87 virtual void *allocateMemory(uint32 align, uint32 size); 88 virtual void deallocateMemory(void *ptr, uint32 size); protectMemory(void * ptr,uint32 len,int prot)89 virtual void protectMemory(void *ptr, uint32 len, int prot) const {}; 90 91 public: 92 DLObject(); 93 virtual ~DLObject(); 94 95 /** 96 * Test the size of the plugin in memory using the memory manager. 97 * @param path Path of file 98 */ 99 void trackSize(const char *path); 100 bool open(const char *path); 101 bool close(); 102 void *symbol(const char *name); 103 void discardSymtab(); 104 }; 105 106 #endif /* defined(DYNAMIC_MODULES) && defined(USE_ELF_LOADER) */ 107 108 #endif /* BACKENDS_PLUGINS_ELF_LOADER_H */ 109