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Diffstat (limited to 'gold/binary.cc')
| -rw-r--r-- | gold/binary.cc | 356 |
1 files changed, 356 insertions, 0 deletions
diff --git a/gold/binary.cc b/gold/binary.cc new file mode 100644 index 0000000..9909ff4 --- /dev/null +++ b/gold/binary.cc @@ -0,0 +1,356 @@ +// binary.cc -- binary input files for gold + +// Copyright 2008 Free Software Foundation, Inc. +// Written by Ian Lance Taylor <iant@google.com>. + +// This file is part of gold. + +// 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, write to the Free Software +// Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston, +// MA 02110-1301, USA. + +#include "gold.h" + +#include <cerrno> +#include <cstring> +#include "safe-ctype.h" + +#include "elfcpp.h" +#include "stringpool.h" +#include "fileread.h" +#include "output.h" +#include "binary.h" + +// Support for reading binary files as input. These become blobs in +// the final output. These files are treated as though they have a +// single .data section and define three symbols: +// _binary_FILENAME_start, _binary_FILENAME_end, _binary_FILENAME_end. +// The FILENAME is the name of the input file, with any +// non-alphanumeric character changed to an underscore. + +// We implement this by creating an ELF file in memory. + +namespace gold +{ + +// class Binary_to_elf. + +Binary_to_elf::Binary_to_elf(elfcpp::EM machine, int size, bool big_endian, + const std::string& filename) + : elf_machine_(machine), size_(size), big_endian_(big_endian), + filename_(filename), data_(NULL), filesize_(0) +{ +} + +Binary_to_elf::~Binary_to_elf() +{ + if (this->data_ != NULL) + delete[] this->data_; +} + +// Given FILENAME, create a buffer which looks like an ELF file with +// the contents of FILENAME as the contents of the only section. The +// TASK parameters is mainly for debugging, and records who holds +// locks. + +bool +Binary_to_elf::convert(const Task* task) +{ + if (this->size_ == 32) + { + if (!this->big_endian_) + { +#ifdef HAVE_TARGET_32_LITTLE + return this->sized_convert<32, false>(task); +#else + gold_unreachable(); +#endif + } + else + { +#ifdef HAVE_TARGET_32_BIG + return this->sized_convert<32, true>(task); +#else + gold_unreachable(); +#endif + } + } + else if (this->size_ == 64) + { + if (!this->big_endian_) + { +#ifdef HAVE_TARGET_64_LITTLE + return this->sized_convert<64, false>(task); +#else + gold_unreachable(); +#endif + } + else + { +#ifdef HAVE_TARGET_64_BIG + return this->sized_convert<64, true>(task); +#else + gold_unreachable(); +#endif + } + } + else + gold_unreachable(); +} + +// We are going to create: +// * The ELF file header. +// * Five sections: null section, .data, .symtab, .strtab, .shstrtab +// * The contents of the file. +// * Four symbols: null, begin, end, size. +// * Three symbol names. +// * Four section names. + +template<int size, bool big_endian> +bool +Binary_to_elf::sized_convert(const Task* task) +{ + // Read the input file. + + File_read f; + if (!f.open(task, this->filename_)) + { + gold_error(_("cannot open %s: %s:"), this->filename_.c_str(), + strerror(errno)); + return false; + } + + section_size_type filesize = convert_to_section_size_type(f.filesize()); + const unsigned char* fileview = f.get_view(0, filesize, false); + + unsigned int align; + if (size == 32) + align = 4; + else if (size == 64) + align = 8; + else + gold_unreachable(); + section_size_type aligned_filesize = align_address(filesize, align); + + // Build the stringpool for the symbol table. + + std::string mangled_name = this->filename_; + for (std::string::iterator p = mangled_name.begin(); + p != mangled_name.end(); + ++p) + if (!ISALNUM(*p)) + *p = '_'; + mangled_name = "_binary_" + mangled_name; + std::string start_symbol_name = mangled_name + "_start"; + std::string end_symbol_name = mangled_name + "_end"; + std::string size_symbol_name = mangled_name + "_size"; + + Stringpool strtab; + strtab.add(start_symbol_name.c_str(), false, NULL); + strtab.add(end_symbol_name.c_str(), false, NULL); + strtab.add(size_symbol_name.c_str(), false, NULL); + strtab.set_string_offsets(); + + // Build the stringpool for the section name table. + + Stringpool shstrtab; + shstrtab.add(".data", false, NULL); + shstrtab.add(".symtab", false, NULL); + shstrtab.add(".strtab", false, NULL); + shstrtab.add(".shstrtab", false, NULL); + shstrtab.set_string_offsets(); + + // Work out the size of the generated file, and the offsets of the + // various sections, and allocate a buffer. + + const int sym_size = elfcpp::Elf_sizes<size>::sym_size; + + size_t output_size = (elfcpp::Elf_sizes<size>::ehdr_size + + 5 * elfcpp::Elf_sizes<size>::shdr_size); + size_t data_offset = output_size; + output_size += aligned_filesize; + size_t symtab_offset = output_size; + output_size += 4 * sym_size; + size_t strtab_offset = output_size; + output_size += strtab.get_strtab_size(); + size_t shstrtab_offset = output_size; + output_size += shstrtab.get_strtab_size(); + + unsigned char* buffer = new unsigned char[output_size]; + + // Write out the data. + + unsigned char* pout = buffer; + + this->write_file_header<size, big_endian>(&pout); + + this->write_section_header<size, big_endian>("", &shstrtab, elfcpp::SHT_NULL, + 0, 0, 0, 0, 0, + 0, 0, &pout); + // Having the section be named ".data" and having it be writable is + // because th GNU linker does it that way, and existing linker + // script expect it. + this->write_section_header<size, big_endian>(".data", &shstrtab, + elfcpp::SHT_PROGBITS, + (elfcpp::SHF_ALLOC + | elfcpp::SHF_WRITE), + data_offset, + filesize, 0, 0, + align, 0, &pout); + this->write_section_header<size, big_endian>(".symtab", &shstrtab, + elfcpp::SHT_SYMTAB, + 0, symtab_offset, 4 * sym_size, + 3, 1, align, sym_size, &pout); + this->write_section_header<size, big_endian>(".strtab", &shstrtab, + elfcpp::SHT_STRTAB, + 0, strtab_offset, + strtab.get_strtab_size(), + 0, 0, 1, 0, &pout); + this->write_section_header<size, big_endian>(".shstrtab", &shstrtab, + elfcpp::SHT_STRTAB, + 0, shstrtab_offset, + shstrtab.get_strtab_size(), + 0, 0, 1, 0, &pout); + + memcpy(pout, fileview, filesize); + pout += filesize; + memset(pout, 0, aligned_filesize - filesize); + pout += aligned_filesize - filesize; + + this->write_symbol<size, big_endian>("", &strtab, 0, 0, &pout); + this->write_symbol<size, big_endian>(start_symbol_name, &strtab, 0, 1, + &pout); + this->write_symbol<size, big_endian>(end_symbol_name, &strtab, filesize, 1, + &pout); + this->write_symbol<size, big_endian>(size_symbol_name, &strtab, filesize, + elfcpp::SHN_ABS, &pout); + + strtab.write_to_buffer(pout, strtab.get_strtab_size()); + pout += strtab.get_strtab_size(); + + shstrtab.write_to_buffer(pout, shstrtab.get_strtab_size()); + pout += shstrtab.get_strtab_size(); + + gold_assert(static_cast<size_t>(pout - buffer) == output_size); + + this->data_ = buffer; + this->filesize_ = output_size; + + f.unlock(task); + + return true; +} + +// Write out the file header. + +template<int size, bool big_endian> +void +Binary_to_elf::write_file_header(unsigned char** ppout) +{ + elfcpp::Ehdr_write<size, big_endian> oehdr(*ppout); + + unsigned char e_ident[elfcpp::EI_NIDENT]; + memset(e_ident, 0, elfcpp::EI_NIDENT); + e_ident[elfcpp::EI_MAG0] = elfcpp::ELFMAG0; + e_ident[elfcpp::EI_MAG1] = elfcpp::ELFMAG1; + e_ident[elfcpp::EI_MAG2] = elfcpp::ELFMAG2; + e_ident[elfcpp::EI_MAG3] = elfcpp::ELFMAG3; + if (size == 32) + e_ident[elfcpp::EI_CLASS] = elfcpp::ELFCLASS32; + else if (size == 64) + e_ident[elfcpp::EI_CLASS] = elfcpp::ELFCLASS64; + else + gold_unreachable(); + e_ident[elfcpp::EI_DATA] = (big_endian + ? elfcpp::ELFDATA2MSB + : elfcpp::ELFDATA2LSB); + e_ident[elfcpp::EI_VERSION] = elfcpp::EV_CURRENT; + oehdr.put_e_ident(e_ident); + + oehdr.put_e_type(elfcpp::ET_REL); + oehdr.put_e_machine(this->elf_machine_); + oehdr.put_e_version(elfcpp::EV_CURRENT); + oehdr.put_e_entry(0); + oehdr.put_e_phoff(0); + oehdr.put_e_shoff(elfcpp::Elf_sizes<size>::ehdr_size); + oehdr.put_e_flags(0); + oehdr.put_e_ehsize(elfcpp::Elf_sizes<size>::ehdr_size); + oehdr.put_e_phentsize(0); + oehdr.put_e_phnum(0); + oehdr.put_e_shentsize(elfcpp::Elf_sizes<size>::shdr_size); + oehdr.put_e_shnum(5); + oehdr.put_e_shstrndx(4); + + *ppout += elfcpp::Elf_sizes<size>::ehdr_size; +} + +// Write out a section header. + +template<int size, bool big_endian> +void +Binary_to_elf::write_section_header( + const char* name, + const Stringpool* shstrtab, + elfcpp::SHT type, + unsigned int flags, + section_size_type offset, + section_size_type section_size, + unsigned int link, + unsigned int info, + unsigned int addralign, + unsigned int entsize, + unsigned char** ppout) +{ + elfcpp::Shdr_write<size, big_endian> oshdr(*ppout); + + oshdr.put_sh_name(*name == '\0' ? 0 : shstrtab->get_offset(name)); + oshdr.put_sh_type(type); + oshdr.put_sh_flags(flags); + oshdr.put_sh_addr(0); + oshdr.put_sh_offset(offset); + oshdr.put_sh_size(section_size); + oshdr.put_sh_link(link); + oshdr.put_sh_info(info); + oshdr.put_sh_addralign(addralign); + oshdr.put_sh_entsize(entsize); + + *ppout += elfcpp::Elf_sizes<size>::shdr_size; +} + +// Write out a symbol. + +template<int size, bool big_endian> +void +Binary_to_elf::write_symbol( + const std::string& name, + const Stringpool* strtab, + section_size_type value, + unsigned int shndx, + unsigned char** ppout) +{ + unsigned char* pout = *ppout; + + elfcpp::Sym_write<size, big_endian> osym(pout); + osym.put_st_name(name.empty() ? 0 : strtab->get_offset(name.c_str())); + osym.put_st_value(value); + osym.put_st_size(0); + osym.put_st_info(name.empty() ? elfcpp::STB_LOCAL : elfcpp::STB_GLOBAL, + elfcpp::STT_NOTYPE); + osym.put_st_other(elfcpp::STV_DEFAULT, 0); + osym.put_st_shndx(shndx); + + *ppout += elfcpp::Elf_sizes<size>::sym_size; +} + +} // End namespace gold. |