tunex

Web-based ECU firmware editor following TunerPro conventions. Load a binary, edit it as raw hex, or use a TunerPro .xdf definition to edit named constants, flags, patches and tables in a structured tree. Save the modified binary back to disk.

Everything runs in the browser. No server, no upload — firmware bytes stay on your machine.

Live: https://tunex.bimmerz.app

What it does

RAW editor

• Virtualised hex view (16 bytes / row) that handles multi-MB firmware without jank.
• Cursor via click + arrow keys + Home / End / PageUp / PageDown.
• g jumps focus to the go-to-offset input; type decimal or 0x… hex.
• "At cursor" interpretation panel — paired LE/BE columns for every multi-byte type (u16, i16, u32, i32, f32, f64) plus u8/i8, ASCII, and UTF-8. Collapsible to a single header row when you don't need it.
• Edit-as-type input auto-populates with the cursor's current value; flip the input base between decimal and hex; submit to write back.
• Double-click any byte to start an inline hex-pair edit (type FF AA CC…, Enter commits, Esc cancels).
• Right-column contents view toggleable to ASCII / u8 / u16 / i16 / u32 / i32 with an optional bars-mode visualisation. Click any element to jump the cursor to its byte range — a u16 click highlights two bytes, a u32 four.
• Bookmarks: named offsets with descriptions, organised into one level of user-defined folders, persisted to localStorage.
• Resizable divider between the hex view and the right sidebar (drag, or focus and use Left/Right with Shift for larger steps).

Structured editor

• Open a TunerPro .xdf definition file (independent of the firmware — the same .xdf usually covers multiple binary versions of one ECU). Encrypted files are detected and surfaced with a clear error.
• Left rail: categories with item counts, collapsible, with a search-as-you-type filter. Tree state resets when you replace the .xdf.
• Per-kind editors:
  • XDFCONSTANT — read engineering value via the MATH equation, write back through the inverse for linear forms (aX+b). Non-linear MATH falls back to raw-value entry. Author-declared outputtype="3" pre-selects hex display.
  • XDFFLAG — checkbox toggling the masked bit.
  • XDFPATCH — per-entry applied / virgin / neither state badges; Apply or Revert per entry, plus whole-patch Apply / Revert-to-virgin (the "virginise" workflow). Destructive patches without basedata (e.g. "Clear ISN Data") apply but can't be reverted.
  • XDFTABLE — row/column grid with axis labels resolved through <embedinfo> (shared RPM / load axes resolve automatically), inline cell editing, dec/hex toggle, heatmap colouring by value (on by default), and support for non-contiguous sub-views via the stride formula.
• Selecting an item highlights its byte range in the hex view, and the "Jump 0x… →" button switches to the RAW tab with the cursor seated at the item's start.

Project layout

tunex/
├── apps/web/                       # Svelte 5 + Vite + Tailwind SPA
│   ├── src/
│   │   ├── App.svelte
│   │   ├── components/             # FilePicker, HexView, BookmarksPanel, XdfTreePanel, …
│   │   └── lib/
│   │       ├── state.svelte.ts     # Top-level $state, view + binary + xdf
│   │       ├── bookmarks.svelte.ts # Bookmarks store + localStorage persistence
│   │       ├── ui-prefs.svelte.ts  # Sidebar width etc.
│   │       ├── interpret.ts        # Numeric read/encode + ASCII / UTF-8 helpers
│   │       └── format.ts           # hex / offset parsing helpers
│   ├── tailwind.config.ts          # @emdzej/bimmerz-theme preset + blue accent
│   └── vite.config.ts
├── packages/xdf-parser/            # Pure TS, no Svelte/DOM deps
│   └── src/
│       ├── index.ts                # parseXdf → XdfDefinition, types
│       ├── math.ts                 # MATH parser + evaluator + linear inverter
│       ├── embedded.ts             # readScalar / encodeScalar / patchEntryState …
│       └── *.test.ts               # Vitest, runs against MS42/MS43 fixtures
└── .github/workflows/
    ├── ci.yml                      # typecheck / lint / test / build on push + PR
    └── deploy-web.yml              # Manual Pages deploy with CNAME

Getting started

Prerequisites: Node 22+, pnpm 10.33+.

pnpm install
pnpm web        # dev server at http://localhost:5176/

Other workspace scripts:

pnpm typecheck  # tsc + svelte-check across both packages
pnpm test       # vitest in @tunex/xdf-parser
pnpm lint       # svelte-check (lint = static analysis at v0)
pnpm build      # production build (apps/web + packages/xdf-parser)

pnpm dev is an alias of pnpm web.

Deployment

The deploy workflow is manual-trigger only — open the Actions tab on GitHub and click Deploy web to GitHub Pages → Run workflow. The job builds apps/web, writes CNAME for tunex.bimmerz.app, and uploads the dist as the Pages artifact.

One-time setup in the repo: Settings → Pages → Source = GitHub Actions.

XDF support — scope and caveats

• The two community patchlists (Siemens_MS42_*.xdf and Siemens_MS43_*.xdf) parse end-to-end and exercise constant, flag, patch and table paths.
• 1D and 2D tables render — including sub-views described by non-zero mmedmajorstridebits / mmedminorstridebits (e.g. the MS43 user-information-field VIN / DATE / SOFT cells).
• BASEOFFSET is applied uniformly to embed addresses and patch-entry addresses. Both fixtures use offset="0", so non-zero base offsets are unverified.
• 3D tables (Z axis as data, with separate X and Y axes for indexing) aren't rendered yet — the parser captures the axes; the grid renderer is the missing piece.

Tech notes

• Svelte 5 (runes — $state, $derived, $effect).
• Tailwind via the shared @emdzej/bimmerz-theme preset; per-app accent is blue (#3b82f6).
• XML parsed with @xmldom/xmldom for deterministic behaviour across Node tests and the browser.
• PWA via vite-plugin-pwa — installable; runs offline after the first visit.
• Firmware lives in a single Uint8Array in memory. Edits mutate that array directly; "Save" downloads a fresh blob.

Related projects

tunex is a sister project to the bimmerz family — same shared theme, similar workspace shape:

• ncsx-web — BMW NCS Expert coding in the browser.
• inpax-web — INPA / EDIABAS over Web Serial.

Support

If you find this project useful, consider buying me a coffee or sponsoring on GitHub or if it's your thing: via PayPal

License

PolyForm Noncommercial 1.0.0 — free for noncommercial use (personal projects, research, education, hobby tuning on your own car). Commercial use requires a separate licence — open an issue if you need one.

This repository contains no proprietary firmware, vendor data, or TunerPro source. All firmware binaries and .xdf definition files the tool consumes must come from sources the user has the right to use.

Disclaimer

This project is for educational and research purposes only. It is not affiliated with TunerPro.