# FlashKraft ⚡
[](https://crates.io/crates/flashkraft)
[](https://docs.rs/flashkraft)
[](https://opensource.org/licenses/MIT)
[](https://github.com/sorinirimies/flashkraft/actions/workflows/release.yml)
[](https://github.com/sorinirimies/flashkraft/actions/workflows/ci.yml)
A lightning-fast, lightweight OS image writer built entirely in Rust. Choose your interface:
| Framework | [Iced](https://github.com/iced-rs/iced) 0.13 | [Ratatui](https://github.com/ratatui-org/ratatui) 0.30 |
| Input | Mouse + keyboard | Keyboard only |
| Themes | 21 built-in Iced themes | Multiple themes via `tui-file-explorer` |
| Best for | Desktop users | SSH / headless / minimal setups |
No Electron, no shell scripts, no external tooling — pure Rust from UI to block device.
## Preview
### GUI (Iced desktop)
### TUI (Ratatui terminal)
#### Full workflow
#### Flash progress (tui-slider)
#### File explorer & theme switcher
> **Note:** Demo GIFs are stored with [Git LFS](https://git-lfs.github.com/).
> Run `git lfs install && git lfs pull` after cloning if the images appear broken.
## Features
### Shared (both interfaces)
- ⚡ **Pure-Rust flash engine** — no `dd`, no bash scripts; writes directly to the block device using `std::fs`, `nix` ioctls, and `sha2` verification
- 🔒 **Write verification** — SHA-256 of the source image is compared against a read-back of the device after every flash
- 🔄 **Partition table refresh** — `BLKRRPART` ioctl ensures the kernel picks up the new partition layout immediately, so the USB boots first time
- 🧲 **Lazy unmount** — all partitions are cleanly detached via `umount2(MNT_DETACH)` before writing
- 📁 **Multiple image formats** — ISO, IMG, DMG, ZIP, and more
- 💾 **Automatic drive detection** — removable drives refreshed on demand
- 🛡️ **Safe drive selection** — system drives flagged, oversized drives warned, read-only drives blocked
- 🎯 **Real-time progress** — stage-aware progress bar with live MB/s speed display
- 🪶 **Tiny footprint** — Rust-compiled binary, C-like memory usage, no Electron runtime
### GUI extras
- 🎨 **21 beautiful Iced themes** to choose from, persisted across sessions via `sled`
- 🖱️ **Native file picker** — powered by `rfd` for OS-native open dialogs
### TUI extras
- ⌨️ **Fully keyboard-driven** — vim-style `j/k` navigation, `b`/`Esc` to go back
- 📂 **Built-in file explorer** — browse and pick ISO files without leaving the terminal (`Tab` / `Ctrl+F`)
- 📊 **Pie-chart drive overview** — storage breakdown rendered inline using `tui-piechart`
- ✅ **Checkbox confirmation screen** — safety checklist before every flash via `tui-checkbox`
- 🎚️ **Slider progress bar** — smooth flash-progress widget via [`tui-slider`](https://crates.io/crates/tui-slider)
- 🎨 **Multiple file-explorer themes** — switchable live with `t` / `[`, panel toggled with `T`, powered by [`tui-file-explorer`](https://crates.io/crates/tui-file-explorer)
- 🖥️ **Works over SSH** — no display server required
## How flashing works
FlashKraft uses a **self-elevating pure-Rust helper** pattern. When you click/confirm Flash:
```
Main process (GUI or TUI)
└─ pkexec /path/to/flashkraft[−tui] --flash-helper <image> <device>
└─ Runs as root, pure Rust, no shell
1. UNMOUNTING — reads /proc/mounts, calls umount2(MNT_DETACH) per partition
2. WRITING — streams image → block device in 4 MiB chunks, emits PROGRESS lines
3. SYNCING — fsync(fd) + sync() to flush all kernel write-back caches
4. REREADING — BLKRRPART ioctl so the kernel sees the new partition table
5. VERIFYING — SHA-256(image) == SHA-256(device[0..image_size])
6. DONE — UI shows success
```
The same binary is re-executed with elevated privileges via `pkexec` — no separate helper binary needs to be installed. All output (progress, logs, errors) is written to stdout as structured lines that the UI reads in real time.
### Why not `dd`?
| Shell dependency | ✗ requires bash, coreutils | ✓ pure Rust |
| Progress format | `\r`-terminated, locale-dependent | ✓ structured `PROGRESS:bytes:speed` |
| Speed unit handling | ✗ kB/s / MB/s / GB/s mixed | ✓ always normalised to MB/s |
| Write verification | ✗ none | ✓ SHA-256 read-back |
| Partition table refresh | ✗ not done | ✓ `BLKRRPART` ioctl |
| Error reporting | ✗ exit code only | ✓ `ERROR:<message>` on every failure path |
## The Elm Architecture (GUI)
The GUI crate is built using **The Elm Architecture (TEA)**, which Iced embraces as its natural pattern for interactive applications.
### Core Concepts
#### 1. Model (State)
```rust
struct FlashKraft {
selected_image: Option<ImageInfo>, // Currently selected image file
selected_target: Option<DriveInfo>, // Currently selected target drive
available_drives: Vec<DriveInfo>, // Detected drives
flash_progress: Option<f32>, // Progress 0.0–1.0
flash_bytes_written: u64, // Bytes written so far
flash_speed_mb_s: f32, // Current transfer speed
error_message: Option<String>, // Error message if any
flashing_active: bool, // Subscription guard
flash_cancel_token: Arc<AtomicBool>, // Cancellation signal
}
```
#### 2. Messages
```rust
enum Message {
SelectImageClicked,
TargetDriveClicked(DriveInfo),
FlashClicked,
CancelFlash,
ResetClicked,
ImageSelected(Option<PathBuf>),
DrivesRefreshed(Vec<DriveInfo>),
FlashProgressUpdate(f32, u64, f32),
FlashCompleted(Result<(), String>),
ThemeChanged(Theme),
}
```
#### 3. Data Flow
```
User Action → Message → Update → State
↓
Task/Subscription
↓
Async Result → Message → Update → State
↓
View → UI
```
## TUI Screen Flow
The TUI is a multi-screen application driven entirely by keyboard input:
```
SelectImage ──(Enter/confirm)──► SelectDrive ──(Enter)──► DriveInfo
▲ ▲ │
│ (Esc/b) │ (Esc/b) (f/Enter)
│ │ ▼
│ SelectDrive ConfirmFlash
│ │
│ (y — flash)
│ ▼
│ Flashing
│ (c — cancel)
│ │
└──────────────────(r — reset)────────── Complete / Error
```
### TUI Key Bindings
| SelectImage | `i` / `Enter` | Enter editing mode |
| SelectImage | `Tab` / `Ctrl+F` | Open built-in file browser |
| SelectImage | `Esc` / `q` | Quit |
| BrowseImage | `j` / `↓` | Move cursor down |
| BrowseImage | `k` / `↑` | Move cursor up |
| BrowseImage | `Enter` | Descend into directory / select file |
| BrowseImage | `Backspace` | Ascend to parent directory |
| BrowseImage | `Esc` / `q` | Dismiss without selecting |
| SelectDrive | `j` / `↓` | Scroll drive list down |
| SelectDrive | `k` / `↑` | Scroll drive list up |
| SelectDrive | `Enter` / `Space` | Confirm selected drive |
| SelectDrive | `r` / `F5` | Refresh drive list |
| SelectDrive | `Esc` / `b` | Go back |
| DriveInfo | `f` / `Enter` | Advance to ConfirmFlash |
| DriveInfo | `Esc` / `b` | Go back |
| ConfirmFlash | `y` / `Y` | Begin flashing |
| ConfirmFlash | `n` / `Esc` / `b` | Go back |
| Flashing | `c` / `Esc` | Cancel flash |
| Complete | `r` / `R` | Reset to start |
| Complete | `q` / `Esc` | Quit |
| Error | `r` / `Enter` | Reset to start |
| Error | `q` / `Esc` | Quit |
| Any | `Ctrl+C` / `Ctrl+Q` | Force quit |
## Building and Running
### Prerequisites
- Rust 1.70 or later
- `pkexec` (part of `polkit`, available on all major Linux distributions)
- For GUI: a running display server (X11 or Wayland)
- For TUI: any terminal emulator (works over SSH)
### Build
```bash
git clone https://github.com/sorinirimies/flashkraft.git
cd flashkraft
# Build everything
cargo build --release
# Build only the GUI
cargo build --release --bin flashkraft
# Build only the TUI
cargo build --release --bin flashkraft-tui
```
### Run
```bash
# Launch the GUI
cargo run --bin flashkraft
# Launch the TUI
cargo run --bin flashkraft-tui
```
### Development
```bash
# Debug builds (faster compilation)
cargo run --bin flashkraft
cargo run --bin flashkraft-tui
# Run all tests across the workspace
cargo test
# Check without building
cargo check --workspace
# Lint
cargo clippy --workspace
# With backtraces
RUST_BACKTRACE=1 cargo run --bin flashkraft-tui
```
## Usage
### GUI
1. **Select Image** — click the `+` button and choose an ISO, IMG, or DMG file
2. **Select Drive** — pick the target USB or SD card from the detected drives list
3. **Flash** — click **Flash!**; authenticate with `pkexec` when prompted
4. **Wait** — the progress bar shows live stage, bytes written, and MB/s
5. **Done** — verification passes automatically; safely remove the drive
### TUI
1. **Select Image** — press `i` to start typing a path, or `Tab`/`Ctrl+F` to open the file browser
2. **Select Drive** — use `j`/`k` to scroll, `r` to refresh, `Enter` to confirm
3. **Review Drive Info** — inspect the storage pie-chart, then press `f` to proceed
4. **Confirm** — read the safety checklist and press `y` to flash, or `b` to go back
5. **Wait** — the slider progress bar shows live stage, bytes written, and MB/s
6. **Done** — press `r` to reset or `q` to quit
## Project Structure
This is a [Cargo workspace](https://doc.rust-lang.org/cargo/reference/workspaces.html) with three crates:
```
flashkraft/ ← workspace root
├── Cargo.toml ← workspace manifest (shared dep versions)
│
├── crates/
│ │
│ ├── flashkraft-core/ ★ shared logic — no GUI/TUI deps
│ │ └── src/
│ │ ├── lib.rs
│ │ ├── flash_helper.rs ★ privileged flash pipeline (pkexec)
│ │ ├── flash_writer.rs ★ wire-protocol parser & speed normaliser
│ │ ├── domain/
│ │ │ ├── drive_info.rs
│ │ │ ├── image_info.rs
│ │ │ └── constraints.rs drive/image compatibility checks
│ │ ├── commands/
│ │ │ └── drive_detection.rs async /sys/block enumeration
│ │ └── utils/
│ │ └── logger.rs debug_log!, flash_debug!, status_log! macros
│ │
│ ├── flashkraft-gui/ Iced desktop application
│ │ ├── examples/
│ │ │ ├── basic_usage.rs
│ │ │ ├── custom_theme.rs
│ │ └── vhs/ GUI VHS tapes
│ │ ├── demo-basic.tape
│ │ ├── demo-build.tape
│ │ ├── demo-quick.tape
│ │ └── generated/ output GIFs (Git LFS)
│ │ └── src/
│ │ ├── main.rs entry point + --flash-helper dispatch
│ │ ├── lib.rs
│ │ ├── view.rs view orchestration
│ │ ├── core/ Elm Architecture
│ │ │ ├── state.rs Model + TEA methods
│ │ │ ├── message.rs all Message variants
│ │ │ ├── update.rs state transition logic
│ │ │ ├── storage.rs sled-backed theme persistence
│ │ │ ├── flash_subscription.rs Iced Subscription — streams FlashProgress
│ │ │ └── commands/
│ │ │ └── file_selection.rs async rfd file dialog
│ │ └── components/ UI widgets
│ │ ├── animated_progress.rs
│ │ ├── device_selector.rs
│ │ ├── header.rs
│ │ ├── progress_line.rs
│ │ ├── selection_panels.rs
│ │ ├── status_views.rs
│ │ ├── step_indicators.rs
│ │ └── theme_selector.rs
│ │
│ └── flashkraft-tui/ Ratatui terminal application
│ ├── examples/
│ │ ├── headless_demo.rs
│ │ ├── tui_demo.rs
│ │ ├── flash_progress_demo.rs ← tui-slider progress showcase
│ │ └── theme_demo.rs ← file-explorer theme switcher showcase
│ └── vhs/ TUI VHS tapes
│ ├── tui-demo.tape
│ ├── tui-headless.tape
│ ├── flash-progress.tape
│ ├── theme-switcher.tape
│ └── generated/ output GIFs (Git LFS)
│ └── src/
│ ├── main.rs entry point + --flash-helper dispatch
│ ├── lib.rs
│ ├── tui/
│ │ ├── app.rs App state + all screen transitions
│ │ ├── ui.rs ratatui Frame rendering (all screens)
│ │ ├── events.rs keyboard event handler per screen
│ │ ├── flash_runner.rs async pkexec supervisor + line parser
│ │ └── mod.rs
│ └── file_explorer/
│ └── mod.rs built-in keyboard-driven file browser
│
├── scripts/
│ ├── bump_version.sh
│ └── check_publish.sh
│
└── .github/workflows/
├── ci.yml
└── release.yml
```
Items marked ★ form the flash pipeline and are described in detail above.
## Dependencies
### `flashkraft-core`
| `sysinfo` | 0.30 | Drive enumeration |
| `nix` | 0.29 | `umount2`, `BLKRRPART` ioctl, `fsync` |
| `sha2` | 0.10 | SHA-256 write verification |
| `tokio` | 1 | Async runtime |
| `futures` / `futures-timer` | 0.3 / 3.0 | Async channel primitives |
| `sled` | 0.34 | Embedded key-value store |
| `dirs` | 5.0 | XDG data directory resolution |
| `anyhow` | 1 | Error handling |
### `flashkraft-gui`
| `iced` | 0.13 | Cross-platform GUI framework (Elm Architecture) |
| `iced_aw` | 0.12 | Additional Iced widgets |
| `iced_fonts` | 0.1 | Bootstrap icon font |
| `rfd` | 0.15 | Native file/folder dialogs |
### `flashkraft-tui`
| `ratatui` | 0.30 | Terminal UI framework |
| `crossterm` | 0.29 | Cross-platform terminal control |
| `tui-slider` | git | Flash-progress slider widget |
| `tui-piechart` | git | Drive storage pie-chart widget |
| `tui-checkbox` | git | Drive-list and confirm-screen checkboxes |
## Architecture Highlights
- **Shared core crate** — `flashkraft-core` contains all flash logic; both UIs are thin frontends over the same engine
- **Pure-Rust flash engine** — zero shell scripts or external binaries
- **Self-elevating helper** — single binary per UI, no install-time setup beyond `polkit`
- **Elm Architecture (GUI)** — unidirectional data flow, pure `update`/`view` functions
- **Screen-based state machine (TUI)** — each `AppScreen` variant owns its event handler and render function
- **0 warnings** — clean `cargo build --workspace` and `cargo test --workspace`
## Demo GIFs & Git LFS
All generated GIFs under `examples/vhs/generated/` are tracked by [Git LFS](https://git-lfs.github.com/) (see `.gitattributes`).
```bash
# One-time setup after cloning
git lfs install && git lfs pull # or: just lfs-pull
# Regenerate all demos (requires vhs installed)
just vhs-all
# Regenerate TUI demos only (output: crates/flashkraft-tui/examples/vhs/generated/)
just vhs-tui
# Regenerate GUI demos only (output: crates/flashkraft-gui/examples/vhs/generated/)
just vhs-gui
# Render a single tape by name
just vhs-tape tui-demo
just vhs-tape flash-progress
just vhs-tape theme-switcher
just vhs-tape demo-basic
# List all available tapes and generated GIFs
just vhs-list
```
| `tui-demo` | Full keyboard-driven wizard: image → drive → flash → complete |
| `tui-headless` | Headless state-machine demo (no TTY required) |
| `flash-progress` | Animated `tui-slider` progress bar during a simulated write |
| `theme-switcher` | Live file-explorer theme cycling (`t` / `[`) and theme panel (`T`) |
| `demo-basic` | GUI basic usage |
| `demo-build` | GUI build walkthrough |
| `demo-quick` | GUI quick-start |
Install VHS:
```bash
brew install vhs # macOS
go install github.com/charmbracelet/vhs@latest # any platform
```
To run Rust examples from the workspace root:
```bash
# Core examples
cargo run -p flashkraft-core --example detect_drives
cargo run -p flashkraft-core --example constraints_demo
cargo run -p flashkraft-core --example flash_writer_demo
# GUI examples (crates/flashkraft-gui/examples/)
cargo run -p flashkraft-gui --example basic_usage
cargo run -p flashkraft-gui --example custom_theme
# TUI examples (crates/flashkraft-tui/examples/)
cargo run -p flashkraft-tui --example headless_demo
cargo run -p flashkraft-tui --example flash_progress_demo # animated tui-slider demo
cargo run -p flashkraft-tui --example theme_demo # file-explorer theme switcher
```
## Contributing
Contributions are welcome! Please:
1. Keep all flash logic in `flashkraft-core` — neither the GUI nor the TUI crate should contain flash pipeline code
2. Follow the Elm Architecture pattern in the GUI — all state changes via `update`
3. Follow the screen-state-machine pattern in the TUI — screen transitions via `App` methods
4. Keep functions pure where possible
5. Add unit tests for any new logic, especially in `flash_helper.rs`, `flash_writer.rs`, `app.rs`, and `events.rs`
6. Run `cargo test --workspace` and `cargo clippy --workspace` before opening a PR
## Learning Resources
- [Iced Documentation](https://docs.rs/iced/)
- [Ratatui Documentation](https://docs.rs/ratatui/)
- [The Elm Architecture Guide](https://guide.elm-lang.org/architecture/)
- [Iced Examples](https://github.com/iced-rs/iced/tree/master/examples)
- [Ratatui Examples](https://github.com/ratatui-org/ratatui/tree/main/examples)
- [The Rust Book](https://doc.rust-lang.org/book/)
- [nix crate](https://docs.rs/nix/) — POSIX ioctls and syscalls from Rust
## License
MIT — see [LICENSE](LICENSE) for details.
## Acknowledgments
- GUI built with [Iced](https://github.com/iced-rs/iced)
- TUI built with [Ratatui](https://github.com/ratatui-org/ratatui)
- Follows [The Elm Architecture](https://guide.elm-lang.org/architecture/)
- Flash pipeline design inspired by [Balena Etcher](https://github.com/balena-io/etcher)
- Terminal widgets: [tui-slider](https://github.com/sorinirimies/tui-slider), [tui-piechart](https://github.com/sorinirimies/tui-piechart), [tui-checkbox](https://github.com/sorinirimies/tui-checkbox)