zmodem2 provides a ZMODEM file transmission protocol implementation driven by the caller, who owns all I/O. It is based on prior work of Aleksei Arbuzov in the zmodem crate.

This crate is fully no_std compatible and heapless.

Create a Sender or Receiver, then loop on poll() and act on the returned Action:

1. Action::WriteWire(bytes) — write the bytes to the transport, then call wire_written(n) with the number of bytes accepted.
2. Action::ReadFile { offset, max_len } (sender) — read the requested file bytes and provide them with submit_file(data).
3. Action::WriteFile(bytes) (receiver) — persist the bytes, then call file_written(n).
4. Action::Event(event) — handle a protocol Event (file/session lifecycle).
5. Action::Idle — feed incoming transport bytes with submit_wire(bytes), or call timeout() if none arrive.

The sender offers files with start_file(FileInfo) and ends the session with finish(). Either side can abort().

• Git: https://codeberg.org/jarkko/zmodem2.git
• Commits follow the Conventional Commits specification.
• New commits must include a Signed-off-by trailer.
• Versioning scheme uses Semantic Versioning.