FlashKraft ⚡

A lightning-fast, lightweight OS image writer built entirely in Rust. Choose your interface:

	`flashkraft` (GUI)	`flashkraft-tui` (TUI)
Framework	Iced 0.13	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)

flashkraft_demo

TUI (Ratatui terminal)

Full workflow

tui-demo

Flash progress (tui-slider)

flash-progress

File explorer & theme switcher

theme-switcher

Note: Demo GIFs are stored with Git LFS. 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
🎨 Multiple file-explorer themes — switchable live with t / [, panel toggled with T, powered by 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`?

	`dd` approach	FlashKraft
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)

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

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

Screen	Key	Action
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

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

# Launch the GUI
cargo run --bin flashkraft

# Launch the TUI
cargo run --bin flashkraft-tui

Development

# 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

Select Image — click the + button and choose an ISO, IMG, or DMG file
Select Drive — pick the target USB or SD card from the detected drives list
Flash — click Flash!; authenticate with pkexec when prompted
Wait — the progress bar shows live stage, bytes written, and MB/s
Done — verification passes automatically; safely remove the drive

TUI

Select Image — press i to start typing a path, or Tab/Ctrl+F to open the file browser
Select Drive — use j/k to scroll, r to refresh, Enter to confirm
Review Drive Info — inspect the storage pie-chart, then press f to proceed
Confirm — read the safety checklist and press y to flash, or b to go back
Wait — the slider progress bar shows live stage, bytes written, and MB/s
Done — press r to reset or q to quit

Project Structure

This is a Cargo workspace 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`

Crate	Version	Purpose
`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`

Crate	Version	Purpose
`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`

Crate	Version	Purpose
`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 (see .gitattributes).

# 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

Tape	What it shows
`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:

brew install vhs                                   # macOS
go install github.com/charmbracelet/vhs@latest    # any platform

To run Rust examples from the workspace root:

# 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:

Keep all flash logic in flashkraft-core — neither the GUI nor the TUI crate should contain flash pipeline code
Follow the Elm Architecture pattern in the GUI — all state changes via update
Follow the screen-state-machine pattern in the TUI — screen transitions via App methods
Keep functions pure where possible
Add unit tests for any new logic, especially in flash_helper.rs, flash_writer.rs, app.rs, and events.rs
Run cargo test --workspace and cargo clippy --workspace before opening a PR

Learning Resources

Iced Documentation
Ratatui Documentation
The Elm Architecture Guide
Iced Examples
Ratatui Examples
The Rust Book
nix crate — POSIX ioctls and syscalls from Rust

License

MIT — see LICENSE for details.

Acknowledgments

GUI built with Iced
TUI built with Ratatui
Follows The Elm Architecture
Flash pipeline design inspired by Balena Etcher
Terminal widgets: tui-slider, tui-piechart, tui-checkbox

flashkraft 0.7.2