:(before "End Includes") const int START = 0x08048000; :(before "End Main") if (is_equal(argv[1], "translate")) { assert(argc > 3); ifstream in(argv[2]); Mem.resize(1024); load_program(in, 1); // since we're not going to run it right now, we can load it anywhere dump_elf(argv[3]); } :(code) // write out the current Memory contents from address 1 to End_of_program to a // bare-bones ELF file with a single section/segment and a hard-coded origin address. void dump_elf(const char* filename) { ofstream out(filename, ios::binary); dump_elf_header(out); for (size_t i = 1; i < End_of_program; ++i) { char c = Mem.at(i); out.write(&c, sizeof(c)); } out.close(); } void dump_elf_header(ostream& out) { char c = '\0'; #define O(X) c = (X); out.write(&c, sizeof(c)) // host is required to be little-endian #define emit(X) out.write(reinterpret_cast(&X), sizeof(X)) //// ehdr // e_ident O(0x7f); O(/*E*/0x45); O(/*L*/0x4c); O(/*F*/0x46); O(0x1); // 32-bit format O(0x1); // little-endian O(0x1); O(0x0); for (size_t i = 0; i < 8; ++i) { O(0x0); } // e_type O(0x02); O(0x00); // e_machine O(0x03); O(0x00); // e_version O(0x01); O(0x00); O(0x00); O(0x00); // e_entry int e_entry = START + /*size of ehdr*/52 + /*size of phdr*/32; emit(e_entry); // e_phoff -- immediately after ELF header int e_phoff = 52; emit(e_phoff); // e_shoff; unused int dummy32 = 0; emit(dummy32); // e_flags; unused emit(dummy32); // e_ehsize uint16_t e_ehsize = 52; emit(e_ehsize); // e_phentsize uint16_t e_phentsize = 0x20; emit(e_phentsize); // e_phnum uint16_t e_phnum = 0x1; emit(e_phnum); // e_shentsize uint16_t dummy16 = 0x0; emit(dummy16); // e_shnum emit(dummy16); // e_shstrndx emit(dummy16); //// phdr // p_type uint32_t p_type = 0x1; emit(p_type); // p_offset emit(dummy32); // p_vaddr emit(START); // p_paddr emit(START); // p_filesz uint32_t size = (End_of_program-1) + /*size of ehdr*/52 + /*size of phdr*/32; emit(size); // p_memsz emit(size); // p_flags uint32_t p_flags = 0x5; emit(p_flags); // p_align uint32_t p_align = 0x1000; emit(p_align); #undef O } :(before "End Includes") using std::ios;