diff --git a/satrs-core/Cargo.toml b/satrs-core/Cargo.toml
index 65ee5e7..2b6d78c 100644
--- a/satrs-core/Cargo.toml
+++ b/satrs-core/Cargo.toml
@@ -76,8 +76,7 @@ optional = true
 # version = "0.7.0-beta.2"
 default-features = false
 git = "https://egit.irs.uni-stuttgart.de/rust/spacepackets.git"
-# rev = "79d26e1a6"
-branch = "writable_pdu_packet"
+rev = "9e74266b768df80fd4118b04c4cc997aba8c85b9"
 
 [dependencies.cobs]
 git = "https://github.com/robamu/cobs.rs.git"
@@ -91,6 +90,7 @@ zerocopy = "0.7"
 once_cell = "1.13"
 serde_json = "1"
 rand = "0.8"
+tempfile = "3"
 
 [dev-dependencies.postcard]
 version = "1"
diff --git a/satrs-core/src/cfdp/dest.rs b/satrs-core/src/cfdp/dest.rs
index f54d22c..5cbc745 100644
--- a/satrs-core/src/cfdp/dest.rs
+++ b/satrs-core/src/cfdp/dest.rs
@@ -771,7 +771,7 @@ mod tests {
     }
 
     #[test]
-    fn test_empty_file_transfer() {
+    fn test_empty_file_transfer_not_acked() {
         let (src_name, dest_name) = init_full_filenames();
         assert!(!Path::exists(&dest_name));
         let mut buf: [u8; 512] = [0; 512];
@@ -810,7 +810,7 @@ mod tests {
     }
 
     #[test]
-    fn test_small_file_transfer() {
+    fn test_small_file_transfer_not_acked() {
         let (src_name, dest_name) = init_full_filenames();
         assert!(!Path::exists(&dest_name));
         let file_data_str = "Hello World!";
@@ -869,7 +869,7 @@ mod tests {
     }
 
     #[test]
-    fn test_segmented_file_transfer() {
+    fn test_segmented_file_transfer_not_acked() {
         let (src_name, dest_name) = init_full_filenames();
         assert!(!Path::exists(&dest_name));
         let mut rng = rand::thread_rng();
diff --git a/satrs-core/src/cfdp/filestore.rs b/satrs-core/src/cfdp/filestore.rs
new file mode 100644
index 0000000..5b03594
--- /dev/null
+++ b/satrs-core/src/cfdp/filestore.rs
@@ -0,0 +1,257 @@
+use alloc::string::{String, ToString};
+use crc::{Crc, CRC_32_CKSUM};
+use spacepackets::cfdp::ChecksumType;
+use spacepackets::ByteConversionError;
+#[cfg(feature = "std")]
+pub use stdmod::*;
+
+pub const CRC_32: Crc<u32> = Crc::<u32>::new(&CRC_32_CKSUM);
+
+pub enum FilestoreError {
+    FileDoesNotExist,
+    FileAlreadyExists,
+    DirDoesNotExist,
+    Permission,
+    IsNotFile,
+    IsNotDirectory,
+    ByteConversion(ByteConversionError),
+    Io {
+        raw_errno: Option<i32>,
+        string: String,
+    },
+    ChecksumTypeNotImplemented(ChecksumType),
+}
+
+impl From<ByteConversionError> for FilestoreError {
+    fn from(value: ByteConversionError) -> Self {
+        Self::ByteConversion(value)
+    }
+}
+
+#[cfg(feature = "std")]
+impl From<std::io::Error> for FilestoreError {
+    fn from(value: std::io::Error) -> Self {
+        Self::Io {
+            raw_errno: value.raw_os_error(),
+            string: value.to_string(),
+        }
+    }
+}
+
+pub trait VirtualFilestore {
+    fn create_file(&self, file_path: &str) -> Result<(), FilestoreError>;
+
+    fn remove_file(&self, file_path: &str) -> Result<(), FilestoreError>;
+
+    /// Truncating a file means deleting all its data so the resulting file is empty.
+    /// This can be more efficient than removing and re-creating a file.
+    fn truncate_file(&self, file_path: &str) -> Result<(), FilestoreError>;
+
+    fn remove_dir(&self, file_path: &str, all: bool) -> Result<(), FilestoreError>;
+
+    fn read_data(
+        &self,
+        file_path: &str,
+        offset: u64,
+        read_len: u64,
+        buf: &mut [u8],
+    ) -> Result<(), FilestoreError>;
+
+    fn write_data(&self, file: &str, offset: u64, buf: &[u8]) -> Result<(), FilestoreError>;
+
+    fn filename_from_full_path<'a>(&self, path: &'a str) -> Option<&'a str>;
+
+    fn is_file(&self, path: &str) -> bool;
+
+    fn is_dir(&self, path: &str) -> bool {
+        !self.is_file(path)
+    }
+
+    fn exists(&self, path: &str) -> bool;
+
+    /// This special function is the CFDP specific abstraction to verify the checksum of a file.
+    /// This allows to keep OS specific details like reading the whole file in the most efficient
+    /// manner inside the file system abstraction.
+    fn checksum_verify(
+        &self,
+        file_path: &str,
+        checksum_type: ChecksumType,
+        expected_checksum: u32,
+        verification_buf: &mut [u8],
+    ) -> Result<bool, FilestoreError>;
+}
+
+#[cfg(feature = "std")]
+pub mod stdmod {
+    use super::*;
+    use std::{
+        fs::{self, File, OpenOptions},
+        io::{BufReader, Read, Seek, SeekFrom, Write},
+        path::Path,
+    };
+
+    pub struct NativeFilestore {}
+
+    impl VirtualFilestore for NativeFilestore {
+        fn create_file(&self, file_path: &str) -> Result<(), FilestoreError> {
+            if self.exists(file_path) {
+                return Err(FilestoreError::FileAlreadyExists);
+            }
+            File::create(file_path)?;
+            Ok(())
+        }
+
+        fn remove_file(&self, file_path: &str) -> Result<(), FilestoreError> {
+            if !self.exists(file_path) {
+                return Ok(());
+            }
+            if !self.is_file(file_path) {
+                return Err(FilestoreError::IsNotFile);
+            }
+            fs::remove_file(file_path)?;
+            Ok(())
+        }
+
+        fn truncate_file(&self, file_path: &str) -> Result<(), FilestoreError> {
+            if !self.exists(file_path) {
+                return Ok(());
+            }
+            if !self.is_file(file_path) {
+                return Err(FilestoreError::IsNotFile);
+            }
+            OpenOptions::new()
+                .write(true)
+                .truncate(true)
+                .open(file_path)?;
+            Ok(())
+        }
+
+        fn remove_dir(&self, dir_path: &str, all: bool) -> Result<(), FilestoreError> {
+            if !self.exists(dir_path) {
+                return Err(FilestoreError::DirDoesNotExist);
+            }
+            if !self.is_dir(dir_path) {
+                return Err(FilestoreError::IsNotDirectory);
+            }
+            if !all {
+                fs::remove_dir(dir_path)?;
+                return Ok(());
+            }
+            fs::remove_dir_all(dir_path)?;
+            Ok(())
+        }
+
+        fn read_data(
+            &self,
+            file_name: &str,
+            offset: u64,
+            read_len: u64,
+            buf: &mut [u8],
+        ) -> Result<(), FilestoreError> {
+            if buf.len() < read_len as usize {
+                return Err(ByteConversionError::ToSliceTooSmall {
+                    found: buf.len(),
+                    expected: read_len as usize,
+                }
+                .into());
+            }
+            if !self.exists(file_name) {
+                return Err(FilestoreError::FileDoesNotExist);
+            }
+            if !self.is_file(file_name) {
+                return Err(FilestoreError::IsNotFile);
+            }
+            let mut file = File::open(file_name)?;
+            file.seek(SeekFrom::Start(offset))?;
+            file.read_exact(&mut buf[0..read_len as usize])?;
+            Ok(())
+        }
+
+        fn write_data(&self, file: &str, offset: u64, buf: &[u8]) -> Result<(), FilestoreError> {
+            if !self.exists(file) {
+                return Err(FilestoreError::FileDoesNotExist);
+            }
+            if !self.is_file(file) {
+                return Err(FilestoreError::IsNotFile);
+            }
+            let mut file = File::open(file)?;
+            file.seek(SeekFrom::Start(offset))?;
+            file.write_all(buf)?;
+            Ok(())
+        }
+
+        fn filename_from_full_path<'a>(&self, path: &'a str) -> Option<&'a str> {
+            // Convert the path string to a Path
+            let path = Path::new(path);
+
+            // Extract the file name using the file_name() method
+            path.file_name().and_then(|name| name.to_str())
+        }
+
+        fn is_file(&self, path: &str) -> bool {
+            let path = Path::new(path);
+            path.is_file()
+        }
+
+        fn is_dir(&self, path: &str) -> bool {
+            let path = Path::new(path);
+            path.is_dir()
+        }
+
+        fn exists(&self, path: &str) -> bool {
+            let path = Path::new(path);
+            if !path.exists() {
+                return false;
+            }
+            true
+        }
+
+        fn checksum_verify(
+            &self,
+            file_path: &str,
+            checksum_type: ChecksumType,
+            expected_checksum: u32,
+            verification_buf: &mut [u8],
+        ) -> Result<bool, FilestoreError> {
+            match checksum_type {
+                ChecksumType::Modular => {
+                    todo!();
+                }
+                ChecksumType::Crc32 => {
+                    let mut digest = CRC_32.digest();
+                    let file_to_check = File::open(file_path)?;
+                    let mut buf_reader = BufReader::new(file_to_check);
+                    loop {
+                        let bytes_read = buf_reader.read(verification_buf)?;
+                        if bytes_read == 0 {
+                            break;
+                        }
+                        digest.update(&verification_buf[0..bytes_read]);
+                    }
+                    if digest.finalize() == expected_checksum {
+                        return Ok(true);
+                    }
+                    Ok(false)
+                }
+                ChecksumType::NullChecksum => Ok(true),
+                _ => Err(FilestoreError::ChecksumTypeNotImplemented(checksum_type)),
+            }
+        }
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use tempfile::tempdir;
+
+    #[test]
+    fn test_basic_native_filestore() {
+        let tmpdir = tempdir().expect("creating tmpdir failed");
+        let file_path = tmpdir.path().join("test.txt");
+        let native_filestore = NativeFilestore {};
+        let result =
+            native_filestore.create_file(file_path.to_str().expect("getting str for file failed"));
+        assert!(result.is_ok());
+    }
+}
diff --git a/satrs-core/src/cfdp/mod.rs b/satrs-core/src/cfdp/mod.rs
index 58edbff..f99712e 100644
--- a/satrs-core/src/cfdp/mod.rs
+++ b/satrs-core/src/cfdp/mod.rs
@@ -17,6 +17,7 @@ use serde::{Deserialize, Serialize};
 
 #[cfg(feature = "std")]
 pub mod dest;
+pub mod filestore;
 #[cfg(feature = "std")]
 pub mod source;
 pub mod user;