diff --git a/tools/copy_bom/src/bom.rs b/tools/copy_bom/src/bom.rs
new file mode 100644
index 00000000..3bc1958f
--- /dev/null
+++ b/tools/copy_bom/src/bom.rs
@@ -0,0 +1,98 @@
+//! This file defines data structures to store contents in bom file
+//! as well as all management on these strcutures.
+//! Structures `Bom`, `Target`, `SymLink`, `Source`, `NormalFile`, `FileWithOption`
+//! are used to parse the bom file.
+//! Structures ending with `management` are used to define managements on different levels.
+//! We will construct a BomManagement for each bom file (the top bom file and all included bom files).
+//! Then do real file operations on each BomManagement
+use crate::error::{FILE_NOT_EXISTS_ERROR, INVALID_BOM_FILE_ERROR};
+use crate::util::{
+    check_file_hash, copy_dir, copy_file, copy_shared_object, create_link, dest_in_root,
+    find_dependent_shared_objects, find_included_bom_file, mkdir, resolve_envs,
+};
+use serde::{Deserialize, Serialize};
+use serde_yaml;
+use std::collections::{HashSet, VecDeque};
+use std::hash::Hash;
+use std::path::PathBuf;
+use std::slice::Iter;
+
+// The whole bom file
+#[derive(Debug, Clone, Serialize, Deserialize)]
+pub struct Bom {
+    pub includes: Option<Vec<String>>,
+    pub excludes: Option<Vec<String>>,
+    targets: Option<Vec<Target>>,
+}
+
+// target in a bom file.
+// Each target represents the same destination.
+#[derive(Debug, Clone, Serialize, Deserialize)]
+pub struct Target {
+    target: String,
+    mkdirs: Option<Vec<String>>,
+    createlinks: Option<Vec<SymLink>>,
+    copy: Option<Vec<Source>>,
+}
+
+#[derive(Debug, Clone, Serialize, Deserialize)]
+pub struct SymLink {
+    src: String,
+    linkname: String,
+}
+
+// source in a target.
+// each Source has the same `from` directory.
+#[derive(Debug, Clone, Serialize, Deserialize)]
+pub struct Source {
+    from: Option<String>,
+    dirs: Option<Vec<String>>,
+    files: Option<Vec<NormalFile>>,
+}
+
+// A file need to be copied
+// It can be only a filename; or file with multiple options to enable checking hash, renaming file, etc.
+#[derive(Debug, Clone, Serialize, Deserialize, PartialEq, Eq)]
+#[serde(untagged)]
+pub enum NormalFile {
+    FileName(String),
+    FileWithOption(FileWithOption),
+}
+
+// A file with multiple optional options
+#[derive(Debug, Clone, Serialize, Deserialize, PartialEq, Eq)]
+pub struct FileWithOption {
+    name: String,
+    hash: Option<String>,
+    autodep: Option<bool>,
+    rename: Option<String>,
+}
+
+/// all operations defined for one bom file
+#[derive(Default)]
+pub struct BomManagement {
+    dirs_to_make: Vec<String>,
+    links_to_create: Vec<(String, String)>,
+    dirs_to_copy: Vec<(String, String)>,
+    files_to_copy: Vec<(String, String)>,
+    shared_objects_to_copy: Vec<(String, String)>,
+}
+
+/// all operations defined for one target
+#[derive(Default)]
+pub struct TargetManagement {
+    dirs_to_make: Vec<String>,
+    links_to_create: Vec<(String, String)>,
+    dirs_to_copy: Vec<(String, String)>,
+    files_to_copy: Vec<(String, String)>,
+    files_autodep: Vec<String>,
+}
+
+/// all operations defined for one source
+#[derive(Default)]
+pub struct SourceManagement {
+    dirs_to_copy: Vec<(String, String)>,
+    files_to_copy: Vec<(String, String)>,
+    files_autodep: Vec<String>,
+}
+