Class KernelElf

src/include/kernel_elf.hpp:22–152

* @brief ELF 文件相关 */

 * @brief ELF 文件相关
 */
class KernelElf {
 public:
  /// 符号表
  std::span<Elf64_Sym> symtab{};
  /// 字符串表
  uint8_t* strtab{nullptr};

  /**
   * @brief 获取 elf 文件大小
   * @return elf 文件大小
   */
  [[nodiscard]] auto GetElfSize() const -> size_t { return elf_.size(); }

  /// @name 构造/析构函数
  /// @{

  /**
   * @brief 构造函数
   * @param elf_addr elf 地址
   */
  explicit KernelElf(uint64_t elf_addr) {
    assert(elf_addr != 0U && "elf_addr is null");

    elf_ = std::span<uint8_t>(reinterpret_cast<uint8_t*>(elf_addr), EI_NIDENT);

    // 检查 elf 头数据
    CheckElfIdentity().or_else([](Error err) -> Expected<void> {
      klog::Err("KernelElf NOT valid ELF file: {}", err.message());
      while (true) {
        cpu_io::Pause();
      }
      return {};
    });

    ehdr_ = *reinterpret_cast<const Elf64_Ehdr*>(elf_.data());

    // 重新计算 elf 大小
    size_t max_size = EI_NIDENT;
    if (ehdr_.e_phoff != 0) {
      size_t ph_end = ehdr_.e_phoff + ehdr_.e_phnum * ehdr_.e_phentsize;
      if (ph_end > max_size) {
        max_size = ph_end;
      }
    }
    if (ehdr_.e_shoff != 0) {
      size_t sh_end = ehdr_.e_shoff + ehdr_.e_shnum * ehdr_.e_shentsize;
      if (sh_end > max_size) {
        max_size = sh_end;
      }
      const auto* shdrs =
          reinterpret_cast<const Elf64_Shdr*>(elf_.data() + ehdr_.e_shoff);
      for (int i = 0; i < ehdr_.e_shnum; ++i) {
        size_t section_end = shdrs[i].sh_offset + shdrs[i].sh_size;
        if (section_end > max_size) {
          max_size = section_end;
        }
      }
    }