1 /* 2 * Copyright (C) 2016 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17 #include <elf.h> 18 #include <errno.h> 19 #include <fcntl.h> 20 #include <stdint.h> 21 #include <stdio.h> 22 #include <string.h> 23 #include <sys/stat.h> 24 #include <sys/types.h> 25 #include <unistd.h> 26 27 #include <string> 28 29 #if !defined(EM_AARCH64) 30 #define EM_AARCH64 183 31 #endif 32 33 template <typename Ehdr> 34 void InitEhdr(Ehdr* ehdr, uint32_t elf_class, uint32_t machine) { 35 memset(ehdr, 0, sizeof(Ehdr)); 36 memcpy(&ehdr->e_ident[0], ELFMAG, SELFMAG); 37 ehdr->e_ident[EI_DATA] = ELFDATA2LSB; 38 ehdr->e_ident[EI_VERSION] = EV_CURRENT; 39 ehdr->e_ident[EI_OSABI] = ELFOSABI_SYSV; 40 ehdr->e_ident[EI_CLASS] = elf_class; 41 ehdr->e_type = ET_DYN; 42 ehdr->e_machine = machine; 43 ehdr->e_version = EV_CURRENT; 44 ehdr->e_ehsize = sizeof(Ehdr); 45 } 46 47 template <typename Ehdr, typename Shdr> 48 void GenElf(Ehdr* ehdr, int fd) { 49 uint64_t offset = sizeof(Ehdr); 50 ehdr->e_shoff = offset; 51 ehdr->e_shnum = 3; 52 ehdr->e_shentsize = sizeof(Shdr); 53 ehdr->e_shstrndx = 2; 54 TEMP_FAILURE_RETRY(write(fd, ehdr, sizeof(Ehdr))); 55 56 Shdr shdr; 57 memset(&shdr, 0, sizeof(shdr)); 58 shdr.sh_name = 0; 59 shdr.sh_type = SHT_NULL; 60 TEMP_FAILURE_RETRY(write(fd, &shdr, sizeof(Shdr))); 61 offset += ehdr->e_shentsize; 62 63 memset(&shdr, 0, sizeof(shdr)); 64 shdr.sh_type = SHT_PROGBITS; 65 shdr.sh_name = 11; 66 shdr.sh_addr = 0x5000; 67 shdr.sh_offset = 0x5000; 68 shdr.sh_entsize = 0x100; 69 shdr.sh_size = 0x800; 70 TEMP_FAILURE_RETRY(write(fd, &shdr, sizeof(Shdr))); 71 offset += ehdr->e_shentsize; 72 73 memset(&shdr, 0, sizeof(shdr)); 74 shdr.sh_type = SHT_STRTAB; 75 shdr.sh_name = 1; 76 shdr.sh_offset = 0x200; 77 shdr.sh_size = 24; 78 TEMP_FAILURE_RETRY(write(fd, &shdr, sizeof(Shdr))); 79 80 // Write out the name entries information. 81 lseek(fd, 0x200, SEEK_SET); 82 std::string name; 83 TEMP_FAILURE_RETRY(write(fd, name.data(), name.size() + 1)); 84 name = ".shstrtab"; 85 TEMP_FAILURE_RETRY(write(fd, name.data(), name.size() + 1)); 86 name = ".debug_frame"; 87 TEMP_FAILURE_RETRY(write(fd, name.data(), name.size() + 1)); 88 } 89 90 int main() { 91 int elf32_fd = TEMP_FAILURE_RETRY(open("elf32", O_RDWR | O_CREAT | O_TRUNC | O_CLOEXEC, 0644)); 92 if (elf32_fd == -1) { 93 printf("Failed to create elf32: %s\n", strerror(errno)); 94 return 1; 95 } 96 97 int elf64_fd = TEMP_FAILURE_RETRY(open("elf64", O_RDWR | O_CREAT | O_TRUNC | O_CLOEXEC, 0644)); 98 if (elf64_fd == -1) { 99 printf("Failed to create elf64: %s\n", strerror(errno)); 100 return 1; 101 } 102 103 Elf32_Ehdr ehdr32; 104 InitEhdr<Elf32_Ehdr>(&ehdr32, ELFCLASS32, EM_ARM); 105 GenElf<Elf32_Ehdr, Elf32_Shdr>(&ehdr32, elf32_fd); 106 close(elf32_fd); 107 108 Elf64_Ehdr ehdr64; 109 InitEhdr<Elf64_Ehdr>(&ehdr64, ELFCLASS64, EM_AARCH64); 110 GenElf<Elf64_Ehdr, Elf64_Shdr>(&ehdr64, elf64_fd); 111 close(elf64_fd); 112 } 113
