🔐 SecureLoader

SecureLoader is a cross-platform tool for uploading encrypted firmware binaries to embedded devices over a serial link. It ships with a scriptable CLI (`sld`) and an optional Qt6 GUI (`sld-gui`).

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🧩 Companion tool — EncryptBIN

Firmware files flashed by SecureLoader are produced by EncryptBIN — a companion tool that takes a raw binary and outputs an AES-128 CBC encrypted .bin with the 48-byte header SecureLoader expects.

flowchart LR
    A[Factory / Initial provisioning] --> SB[SecureBootloader flashing] --> D[(Device)]

    A2[EncryptBIN] -->|produces| B([encrypted .bin])
    B -->|input| C[SecureLoader]
    C -->|flashes| D

    classDef tool fill:#3f51b5,stroke:#1a237e,color:#fff,stroke-width:2px
    classDef file fill:#009688,stroke:#004d40,color:#fff
    classDef device fill:#455a64,stroke:#263238,color:#fff

    class A,A2,C tool
    class B file
    class D,SB device

    click SB "https://github.com/niwciu/SECURE_BOOTLOADER" "SecureBootloader repository"
    click A2 "https://github.com/niwciu/EncryptBIN" "EncryptBIN repository"

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✨ Key Features

• 🔒 Encrypted firmware format — 48-byte little-endian header (protocol version, product ID, app version, previous app version, page count, page size, IV, CRC32) followed by an AES-128 CBC encrypted payload created by EncryptBIN.
• 📡 Custom serial bootloader protocol — byte-stream, XOR-based ACK/NAK handshake, automatic reconnect on timeout, configurable baud rate, parity, and stop-bits.
• 📂 Three firmware sources — local .bin file, HTTP server download (sld fetch / GUI Fetch from server), and a GitHub Releases source (scaffold — not yet wired to CLI or GUI; see Roadmap). The HTTP source supports optional Basic Auth and derives the server URL from the device's Product ID automatically.
• ⚡ Full-featured CLI — every capability available from the terminal and scriptable in CI pipelines.
• 🖥️ Qt6 GUI — graphical frontend covering all CLI features with live compatibility indicators and progress bars.
• 🌍 Cross-platform — Linux, Windows, macOS (Python 3.10+, pyserial, PySide6).
• 🗣️ Runtime i18n — language switch without restart (English, German, French, Spanish, Italian, Polish).

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🏗️ Architecture at a Glance

graph TB
    subgraph Frontends
        CLI["CLI — sld<br/><i>click-based</i>"]
        GUI["GUI — sld-gui<br/><i>PySide6 / Qt6</i>"]
    end

    subgraph Core["Core (pure Python — no UI dependency)"]
        direction LR
        firmware["firmware.py<br/>header parser"]
        protocol["protocol.py<br/>serial state machine"]
        sources["sources/<br/>FirmwareSource ABC"]
        updater["updater.py<br/>compatibility check"]
    end

    CLI --> Core
    GUI --> Core

The strict layering rule — core never imports from CLI or GUI — keeps the protocol and firmware logic independently testable and reusable.

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🚀 Quick Start

# Install CLI + GUI
pip install -e ".[gui]"

# Verify
sld --version
sld-gui &

Flash a firmware file:

sld flash --file firmware.bin --port /dev/ttyUSB0

See the User Guide for full installation options and a step-by-step walkthrough.

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📚 Documentation Map

Page	Contents
User Guide	Installation, CLI reference, GUI walkthrough, configuration
Firmware Format	Binary header layout, field semantics, wire vs. disk format
Serial Protocol	Command set, timing, state machine, bootloader requirements
Architecture	Layer design, module responsibilities, threading model
Contributing	Dev setup, testing, code style, adding sources / languages
Troubleshooting	Common errors and fixes
Roadmap	GitHub Releases migration plan

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📄 License

MIT — see LICENSE.

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