/* 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 2 * 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, write to the Free Software * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. * * $URL$ * $Id$ * */ #if defined(DYNAMIC_MODULES) && defined(__PSP__) #include #include #include #include #include #include #include #include "backends/platform/psp/psploader.h" #include "backends/platform/psp/powerman.h" //#define __PSP_DEBUG_PLUGINS__ #ifdef __PSP_DEBUG_PLUGINS__ #define DBG(x,...) fprintf(stderr,x, ## __VA_ARGS__) #else #define DBG(x,...) #endif #define seterror(x,...) fprintf(stderr,x, ## __VA_ARGS__) extern char __plugin_hole_start; // Indicates start of hole in program file for shorts extern char __plugin_hole_end; // Indicates end of hole in program file extern char _gp[]; // Value of gp register DECLARE_SINGLETON(ShortSegmentManager); // For singleton // Get rid of symbol table in memory void DLObject::discard_symtab() { free(_symtab); free(_strtab); _symtab = NULL; _strtab = NULL; _symbol_cnt = 0; } // Unload all objects from memory void DLObject::unload() { discard_symtab(); free(_segment); _segment = NULL; if (_shortsSegment) { ShortsMan.deleteSegment(_shortsSegment); _shortsSegment = NULL; } } /** * Follow the instruction of a relocation section. * * @param fd File Descriptor * @param offset Offset into the File * @param size Size of relocation section * @param relSegment Base address of relocated segment in memory (memory offset) * */ bool DLObject::relocate(int fd, unsigned long offset, unsigned long size, void *relSegment) { Elf32_Rel *rel = NULL; // relocation entry // Allocate memory for relocation table if (!(rel = (Elf32_Rel *)malloc(size))) { seterror("Out of memory."); return false; } // Read in our relocation table if (lseek(fd, offset, SEEK_SET) < 0 || read(fd, rel, size) != (ssize_t)size) { seterror("Relocation table load failed."); free(rel); return false; } // Treat each relocation entry. Loop over all of them int cnt = size / sizeof(*rel); DBG("Loaded relocation table. %d entries. base address=%p\n", cnt, relSegment); bool seenHi16 = false; // For treating HI/LO16 commands int firstHi16 = -1; // Mark the point of the first hi16 seen Elf32_Addr ahl = 0; // Calculated addend int a = 0; // Addend: taken from the target unsigned int *lastTarget = 0; // For processing hi16 when lo16 arrives unsigned int relocation = 0; int debugRelocs[10] = {0}; // For debugging int extendedHi16 = 0; // Count extended hi16 treatments #define DEBUG_NUM 2 // Loop over relocation entries for (int i = 0; i < cnt; i++) { // Get the symbol this relocation entry is referring to Elf32_Sym *sym = (Elf32_Sym *)(_symtab) + (REL_INDEX(rel[i].r_info)); // Get the target instruction in the code unsigned int *target = (unsigned int *)((char *)relSegment + rel[i].r_offset); unsigned int origTarget = *target; // Save for debugging // Act differently based on the type of relocation switch (REL_TYPE(rel[i].r_info)) { case R_MIPS_HI16: // Absolute addressing. if (sym->st_shndx < SHN_LOPROC && // Only shift for plugin section (ie. has a real section index) firstHi16 < 0) { // Only process first in block of HI16s firstHi16 = i; // Keep the first Hi16 we saw seenHi16 = true; ahl = (*target & 0xffff) << 16; // Take lower 16 bits shifted up if (debugRelocs[0]++ < DEBUG_NUM) // Print only a set number DBG("R_MIPS_HI16: i=%d, offset=%x, ahl = %x, target = %x\n", i, rel[i].r_offset, ahl, *target); } break; case R_MIPS_LO16: // Absolute addressing. Needs a HI16 to come before it if (sym->st_shndx < SHN_LOPROC) { // Only shift for plugin section. (ie. has a real section index) if (!seenHi16) { // We MUST have seen HI16 first seterror("R_MIPS_LO16 w/o preceding R_MIPS_HI16 at relocation %d!\n", i); free(rel); return false; } ahl &= 0xffff0000; // Clean lower 16 bits for repeated LO16s a = *target & 0xffff; // Take lower 16 bits of the target a = (a << 16) >> 16; // Sign extend them ahl += a; // Add lower 16 bits. AHL is now complete relocation = ahl + (Elf32_Addr)_segment; // Add in the new offset for the segment if (firstHi16 >= 0) { // We haven't treated the HI16s yet so do it now for (int j = firstHi16; j < i; j++) { if (REL_TYPE(rel[j].r_info) != R_MIPS_HI16) continue; // Skip over non-Hi16s lastTarget = (unsigned int *)((char *)relSegment + rel[j].r_offset); // get hi16 target *lastTarget &= 0xffff0000; // Clear the lower 16 bits of the last target *lastTarget |= (relocation >> 16) & 0xffff; // Take the upper 16 bits of the relocation if (relocation & 0x8000)(*lastTarget)++; // Subtle: we need to add 1 to the HI16 in this case } firstHi16 = -1; // Reset so we'll know we treated it } else { extendedHi16++; } *target &= 0xffff0000; // Clear the lower 16 bits of current target *target |= relocation & 0xffff; // Take the lower 16 bits of the relocation if (debugRelocs[1]++ < DEBUG_NUM) DBG("R_MIPS_LO16: i=%d, offset=%x, a=%x, ahl = %x, lastTarget = %x, origt = %x, target = %x\n", i, rel[i].r_offset, a, ahl, *lastTarget, origTarget, *target); if (ahl & 0x8000 && debugRelocs[2]++ < DEBUG_NUM) DBG("R_MIPS_LO16: i=%d, offset=%x, a=%x, ahl = %x, lastTarget = %x, origt = %x, target = %x\n", i, rel[i].r_offset, a, ahl, *lastTarget, origTarget, *target); } break; case R_MIPS_26: // Absolute addressing if (sym->st_shndx < SHN_LOPROC) { // Only relocate for main segment a = *target & 0x03ffffff; // Get 26 bits' worth of the addend a = (a << 6) >> 6; // Sign extend a relocation = ((a << 2) + (Elf32_Addr)_segment) >> 2; // a already points to the target. Subtract our offset *target &= 0xfc000000; // Clean lower 26 target bits *target |= (relocation & 0x03ffffff); if (debugRelocs[3]++ < DEBUG_NUM) DBG("R_MIPS_26: i=%d, offset=%x, symbol=%d, stinfo=%x, a=%x, origTarget=%x, target=%x\n", i, rel[i].r_offset, REL_INDEX(rel[i].r_info), sym->st_info, a, origTarget, *target); } else { if (debugRelocs[4]++ < DEBUG_NUM) DBG("R_MIPS_26: i=%d, offset=%x, symbol=%d, stinfo=%x, a=%x, origTarget=%x, target=%x\n", i, rel[i].r_offset, REL_INDEX(rel[i].r_info), sym->st_info, a, origTarget, *target); } break; case R_MIPS_GPREL16: // GP Relative addressing if (_shortsSegment->getOffset() != 0 && // Only relocate if we shift the shorts section ShortsMan.inGeneralSegment((char *)sym->st_value)) { // Only relocate things in the plugin hole a = *target & 0xffff; // Get 16 bits' worth of the addend a = (a << 16) >> 16; // Sign extend it relocation = a + _shortsSegment->getOffset(); *target &= 0xffff0000; // Clear the lower 16 bits of the target *target |= relocation & 0xffff; if (debugRelocs[5]++ < DEBUG_NUM) DBG("R_MIPS_GPREL16: i=%d, a=%x, gpVal=%x, origTarget=%x, target=%x, offset=%x\n", i, a, _gpVal, origTarget, *target, _shortsSegment->getOffset()); } break; case R_MIPS_32: // Absolute addressing if (sym->st_shndx < SHN_LOPROC) { // Only shift for plugin section. a = *target; // Get full 32 bits of addend relocation = a + (Elf32_Addr)_segment; // Shift *target = relocation; if (debugRelocs[6]++ < DEBUG_NUM) DBG("R_MIPS_32: i=%d, a=%x, origTarget=%x, target=%x\n", i, a, origTarget, *target); } break; default: seterror("Unknown relocation type %x at relocation %d.\n", REL_TYPE(rel[i].r_info), i); free(rel); return false; } } DBG("Done with relocation. extendedHi16=%d\n\n", extendedHi16); free(rel); return true; } bool DLObject::readElfHeader(int fd, Elf32_Ehdr *ehdr) { // Start reading the elf header. Check for errors if (read(fd, ehdr, sizeof(*ehdr)) != sizeof(*ehdr) || memcmp(ehdr->e_ident, ELFMAG, SELFMAG) || // Check MAGIC ehdr->e_type != ET_EXEC || // Check for executable ehdr->e_machine != EM_MIPS || // Check for MIPS machine type ehdr->e_phentsize < sizeof(Elf32_Phdr) || // Check for size of program header ehdr->e_shentsize != sizeof(Elf32_Shdr)) { // Check for size of section header seterror("Invalid file type."); return false; } DBG("phoff = %d, phentsz = %d, phnum = %d\n", ehdr->e_phoff, ehdr->e_phentsize, ehdr->e_phnum); return true; } bool DLObject::readProgramHeaders(int fd, Elf32_Ehdr *ehdr, Elf32_Phdr *phdr, int num) { // Read program header if (lseek(fd, ehdr->e_phoff + sizeof(*phdr)*num, SEEK_SET) < 0 || read(fd, phdr, sizeof(*phdr)) != sizeof(*phdr)) { seterror("Program header load failed."); return false; } // Check program header values if (phdr->p_type != PT_LOAD || phdr->p_filesz > phdr->p_memsz) { seterror("Invalid program header."); return false; } DBG("offs = %x, filesz = %x, memsz = %x, align = %x\n", phdr->p_offset, phdr->p_filesz, phdr->p_memsz, phdr->p_align); return true; } bool DLObject::loadSegment(int fd, Elf32_Phdr *phdr) { char *baseAddress = 0; // We need to take account of non-allocated segment for shorts if (phdr->p_flags & PF_X) { // This is a relocated segment // Attempt to allocate memory for segment int extra = phdr->p_vaddr % phdr->p_align; // Get extra length TODO: check logic here DBG("extra mem is %x\n", extra); if (phdr->p_align < 0x10000) phdr->p_align = 0x10000; // Fix for wrong alignment on e.g. AGI if (!(_segment = (char *)memalign(phdr->p_align, phdr->p_memsz + extra))) { seterror("Out of memory.\n"); return false; } DBG("allocated segment @ %p\n", _segment); // Get offset to load segment into baseAddress = (char *)_segment + phdr->p_vaddr; _segmentSize = phdr->p_memsz + extra; } else { // This is a shorts section. _shortsSegment = ShortsMan.newSegment(phdr->p_memsz, (char *)phdr->p_vaddr); baseAddress = _shortsSegment->getStart(); DBG("shorts segment @ %p to %p. Segment wants to be at %x. Offset=%x\n", _shortsSegment->getStart(), _shortsSegment->getEnd(), phdr->p_vaddr, _shortsSegment->getOffset()); } // Set bss segment to 0 if necessary (assumes bss is at the end) if (phdr->p_memsz > phdr->p_filesz) { DBG("Setting %p to %p to 0 for bss\n", baseAddress + phdr->p_filesz, baseAddress + phdr->p_memsz); memset(baseAddress + phdr->p_filesz, 0, phdr->p_memsz - phdr->p_filesz); } // Read the segment into memory if (lseek(fd, phdr->p_offset, SEEK_SET) < 0 || read(fd, baseAddress, phdr->p_filesz) != (ssize_t)phdr->p_filesz) { seterror("Segment load failed."); return false; } return true; } Elf32_Shdr * DLObject::loadSectionHeaders(int fd, Elf32_Ehdr *ehdr) { Elf32_Shdr *shdr = NULL; // Allocate memory for section headers if (!(shdr = (Elf32_Shdr *)malloc(ehdr->e_shnum * sizeof(*shdr)))) { seterror("Out of memory."); return NULL; } // Read from file into section headers if (lseek(fd, ehdr->e_shoff, SEEK_SET) < 0 || read(fd, shdr, ehdr->e_shnum * sizeof(*shdr)) != (ssize_t)(ehdr->e_shnum * sizeof(*shdr))) { seterror("Section headers load failed."); return NULL; } return shdr; } int DLObject::loadSymbolTable(int fd, Elf32_Ehdr *ehdr, Elf32_Shdr *shdr) { // Loop over sections, looking for symbol table linked to a string table for (int i = 0; i < ehdr->e_shnum; i++) { //DBG("Section %d: type = %x, size = %x, entsize = %x, link = %x\n", // i, shdr[i].sh_type, shdr[i].sh_size, shdr[i].sh_entsize, shdr[i].sh_link); if (shdr[i].sh_type == SHT_SYMTAB && shdr[i].sh_entsize == sizeof(Elf32_Sym) && shdr[i].sh_link < ehdr->e_shnum && shdr[shdr[i].sh_link].sh_type == SHT_STRTAB && _symtab_sect < 0) { _symtab_sect = i; } } // Check for no symbol table if (_symtab_sect < 0) { seterror("No symbol table."); return -1; } DBG("Symbol section at section %d, size %x\n", _symtab_sect, shdr[_symtab_sect].sh_size); // Allocate memory for symbol table if (!(_symtab = malloc(shdr[_symtab_sect].sh_size))) { seterror("Out of memory."); return -1; } // Read symbol table into memory if (lseek(fd, shdr[_symtab_sect].sh_offset, SEEK_SET) < 0 || read(fd, _symtab, shdr[_symtab_sect].sh_size) != (ssize_t)shdr[_symtab_sect].sh_size) { seterror("Symbol table load failed."); return -1; } // Set number of symbols _symbol_cnt = shdr[_symtab_sect].sh_size / sizeof(Elf32_Sym); DBG("Loaded %d symbols.\n", _symbol_cnt); return _symtab_sect; } bool DLObject::loadStringTable(int fd, Elf32_Shdr *shdr) { int string_sect = shdr[_symtab_sect].sh_link; // Allocate memory for string table if (!(_strtab = (char *)malloc(shdr[string_sect].sh_size))) { seterror("Out of memory."); return false; } // Read string table into memory if (lseek(fd, shdr[string_sect].sh_offset, SEEK_SET) < 0 || read(fd, _strtab, shdr[string_sect].sh_size) != (ssize_t)shdr[string_sect].sh_size) { seterror("Symbol table strings load failed."); return false; } return true; } void DLObject::relocateSymbols(Elf32_Addr offset, Elf32_Addr shortsOffset) { int shortsCount = 0, othersCount = 0; DBG("Relocating symbols by %x. Shorts offset=%x\n", offset, shortsOffset); // Loop over symbols, add relocation offset Elf32_Sym *s = (Elf32_Sym *)_symtab; for (int c = _symbol_cnt; c--; s++) { // Make sure we don't relocate special valued symbols if (s->st_shndx < SHN_LOPROC) { if (!ShortsMan.inGeneralSegment((char *)s->st_value)) { othersCount++; s->st_value += offset; if (s->st_value < (Elf32_Addr)_segment || s->st_value > (Elf32_Addr)_segment + _segmentSize) seterror("Symbol out of bounds! st_value = %x\n", s->st_value); } else { // shorts section shortsCount++; s->st_value += shortsOffset; if (!_shortsSegment->inSegment((char *)s->st_value)) seterror("Symbol out of bounds! st_value = %x\n", s->st_value); } } } DBG("Relocated %d short symbols, %d others.\n", shortsCount, othersCount); } bool DLObject::relocateRels(int fd, Elf32_Ehdr *ehdr, Elf32_Shdr *shdr) { // Loop over sections, finding relocation sections for (int i = 0; i < ehdr->e_shnum; i++) { Elf32_Shdr *curShdr = &(shdr[i]); //Elf32_Shdr *linkShdr = &(shdr[curShdr->sh_info]); if (curShdr->sh_type == SHT_REL && // Check for a relocation section curShdr->sh_entsize == sizeof(Elf32_Rel) && // Check for proper relocation size (int)curShdr->sh_link == _symtab_sect && // Check that the sh_link connects to our symbol table curShdr->sh_info < ehdr->e_shnum && // Check that the relocated section exists (shdr[curShdr->sh_info].sh_flags & SHF_ALLOC)) { // Check if relocated section resides in memory if (!ShortsMan.inGeneralSegment((char *)shdr[curShdr->sh_info].sh_addr)) { // regular segment if (!relocate(fd, curShdr->sh_offset, curShdr->sh_size, _segment)) { return false; } } else { // In Shorts segment if (!relocate(fd, curShdr->sh_offset, curShdr->sh_size, (void *)_shortsSegment->getOffset())) { return false; } } } } return true; } bool DLObject::load(int fd) { fprintf(stderr, "In DLObject::load\n"); Elf32_Ehdr ehdr; // ELF header Elf32_Phdr phdr; // Program header Elf32_Shdr *shdr; // Section header bool ret = true; if (readElfHeader(fd, &ehdr) == false) { return false; } for (int i = 0; i < ehdr.e_phnum; i++) { // Load our 2 segments fprintf(stderr, "Loading segment %d\n", i); if (readProgramHeaders(fd, &ehdr, &phdr, i) == false) return false; if (!loadSegment(fd, &phdr)) return false; } if ((shdr = loadSectionHeaders(fd, &ehdr)) == NULL) ret = false; if (ret && ((_symtab_sect = loadSymbolTable(fd, &ehdr, shdr)) < 0)) ret = false; if (ret && (loadStringTable(fd, shdr) == false)) ret = false; if (ret) relocateSymbols((Elf32_Addr)_segment, _shortsSegment->getOffset()); // Offset by our segment allocated address if (ret && (relocateRels(fd, &ehdr, shdr) == false)) ret = false; if (shdr) free(shdr); return ret; } bool DLObject::open(const char *path) { int fd; void *ctors_start, *ctors_end; DBG("open(\"%s\")\n", path); // Get the address of the global pointer _gpVal = (unsigned int) & _gp; DBG("_gpVal is %x\n", _gpVal); PowerMan.beginCriticalSection(); if ((fd = ::open(path, O_RDONLY)) < 0) { seterror("%s not found.", path); return false; } // Try to load and relocate if (!load(fd)) { ::close(fd); unload(); return false; } ::close(fd); PowerMan.endCriticalSection(); // flush data cache sceKernelDcacheWritebackAll(); // Get the symbols for the global constructors and destructors ctors_start = symbol("___plugin_ctors"); ctors_end = symbol("___plugin_ctors_end"); _dtors_start = symbol("___plugin_dtors"); _dtors_end = symbol("___plugin_dtors_end"); if (ctors_start == NULL || ctors_end == NULL || _dtors_start == NULL || _dtors_end == NULL) { seterror("Missing ctors/dtors."); _dtors_start = _dtors_end = NULL; unload(); return false; } DBG("Calling constructors.\n"); for (void (**f)(void) = (void (**)(void))ctors_start; f != ctors_end; f++) (**f)(); DBG("%s opened ok.\n", path); return true; } bool DLObject::close() { if (_dtors_start != NULL && _dtors_end != NULL) for (void (**f)(void) = (void (**)(void))_dtors_start; f != _dtors_end; f++) (**f)(); _dtors_start = _dtors_end = NULL; unload(); return true; } void *DLObject::symbol(const char *name) { DBG("symbol(\"%s\")\n", name); if (_symtab == NULL || _strtab == NULL || _symbol_cnt < 1) { seterror("No symbol table loaded."); return NULL; } Elf32_Sym *s = (Elf32_Sym *)_symtab; for (int c = _symbol_cnt; c--; s++) { // We can only import symbols that are global or weak in the plugin if ((SYM_BIND(s->st_info) == STB_GLOBAL || SYM_BIND(s->st_info) == STB_WEAK) && /*_strtab[s->st_name] == '_' && */ // Try to make this more efficient !strcmp(name, _strtab + s->st_name)) { // We found the symbol DBG("=> %p\n", (void*)s->st_value); return (void*)s->st_value; } } seterror("Symbol \"%s\" not found.", name); return NULL; } ShortSegmentManager::ShortSegmentManager() { _shortsStart = &__plugin_hole_start ; _shortsEnd = &__plugin_hole_end; } ShortSegmentManager::Segment *ShortSegmentManager::newSegment(int size, char *origAddr) { char *lastAddress = origAddr; Common::List::iterator i; // Find a block that fits, starting from the beginning for (i = _list.begin(); i != _list.end(); i++) { char *currAddress = (*i)->getStart(); if ((int)(currAddress - lastAddress) >= size) break; lastAddress = (*i)->getEnd(); } if ((Elf32_Addr)lastAddress & 3) lastAddress += 4 - ((Elf32_Addr)lastAddress & 3); // Round up to multiple of 4 if (lastAddress + size > _shortsEnd) { seterror("Error. No space in shorts segment for %x bytes. Last address is %p, max address is %p.\n", size, lastAddress, _shortsEnd); return NULL; } Segment *seg = new Segment(lastAddress, size, origAddr); // Create a new segment if (lastAddress + size > _highestAddress) _highestAddress = lastAddress + size; // Keep track of maximum _list.insert(i, seg); DBG("Shorts segment size %x allocated. End = %p. Remaining space = %x. Highest so far is %p.\n", size, lastAddress + size, _shortsEnd - _list.back()->getEnd(), _highestAddress); return seg; } void ShortSegmentManager::deleteSegment(ShortSegmentManager::Segment *seg) { DBG("Deleting shorts segment from %p to %p.\n\n", seg->getStart(), seg->getEnd()); _list.remove(seg); delete seg; } static char dlerr[MAXDLERRLEN]; void *dlopen(const char *filename, int flags) { DLObject *obj = new DLObject(dlerr); if (obj->open(filename)) return (void *)obj; delete obj; return NULL; } int dlclose(void *handle) { DLObject *obj = (DLObject *)handle; if (obj == NULL) { strcpy(dlerr, "Handle is NULL."); return -1; } if (obj->close()) { delete obj; return 0; } return -1; } void *dlsym(void *handle, const char *symbol) { if (handle == NULL) { strcpy(dlerr, "Handle is NULL."); return NULL; } return ((DLObject *)handle)->symbol(symbol); } const char *dlerror() { return dlerr; } void dlforgetsyms(void *handle) { if (handle != NULL) ((DLObject *)handle)->discard_symtab(); } #endif /* DYNAMIC_MODULES && __PSP__ */