logo-bin-tool

A web-based tool for extracting, replacing, and repacking Unisoc / Spreadtrum logo.bin firmware images. All frame processing runs locally in the browser — no file uploads to any server.

Features

• Load logo.bin via drag-and-drop or file picker
• Preview all embedded frames in a responsive grid
• Replace any frame with a custom image (auto-resized to original resolution)
• Download the patched logo.bin ready to flash
• Extract all frames as individual PNG files

Supported Format

Property	Value
Container	GZ-compressed multi-frame BMP
Color depth	24bpp (BGR)
Row order	Bottom-up
Tested device	Unisoc SC9863A / SC7731E series

Binary Format

File Header

Offset	Size	Type	Description
0x00	2B	u8[2]	Magic bytes 47 5A ("GZ")
0x02	4B	uint32 LE	Frame count (typically 2–15)
0x06	18B	—	Reserved, all zeros
0x18	4B × N	uint32 LE	Compressed byte size for each frame
0x18 + (N × 4)	variable	—	Concatenated gzip-compressed BMP payloads

Frame Payload

Each frame is a standard gzip stream containing a raw 24bpp bottom-up BMP. The gzip header includes an embedded filename (1.bmp, 2.bmp, …) set by the firmware packer. The decompressed BMP uses the standard 54-byte header followed by unpadded BGR pixel rows aligned to a 4-byte boundary.

Requirements

• Node.js >= 18.0.0
• npm >= 9.0.0

Installation

git clone https://github.com/lenzarchive/logo-bin-tool
cd logo-bin-tool
npm install

Build

Before starting the server, compile the CSS and copy the icon bundle:

npm run build

This runs two steps:

1. build:css — compiles src/css/input.css through Tailwind CSS into public/css/style.css
2. build:icons — copies the Lucide UMD bundle from node_modules into public/js/vendor/lucide.js

Usage

Development

Watches for CSS changes and restarts the server on file changes:

npm run dev

Production

npm run build
npm start

The server listens on http://localhost:3000 by default. Set the PORT environment variable to change it.

Project Structure

logo-bin-tool/
├── server.js                   # Express entry point
├── package.json
├── tailwind.config.js
├── postcss.config.js
├── README.md
├── scripts/
│   └── copyIcons.js            # Copies Lucide bundle to public
├── src/
│   ├── css/
│   │   └── input.css           # Tailwind directives + component styles
│   ├── routes/
│   │   └── api.js              # REST API endpoints (server-side processing)
│   ├── services/
│   │   └── logoBin.js          # Core parse and repack logic
│   └── utils/
│       └── bmp.js              # BMP header utilities
└── public/
    ├── index.html
    ├── css/
    │   └── style.css           # Compiled Tailwind output (generated)
    └── js/
        ├── vendor/
        │   └── lucide.js       # Lucide UMD bundle (generated)
        ├── app.js              # Application controller
        ├── parser.js           # logo.bin parser (browser, uses pako)
        ├── bmp.js              # BMP writer (browser)
        └── ui.js               # UI helpers and logging

API Endpoints

All endpoints accept multipart/form-data.

POST /api/extract

Parses a logo.bin and returns frame metadata.

Body: bin (file)

Response:

{
  "success": true,
  "frameCount": 5,
  "frames": [
    { "index": 0, "width": 720, "height": 1612, "bpp": 24, "compressedSize": 17997, "decompressedSize": 3481976 }
  ]
}

POST /api/frame/:index

Returns the raw BMP data for a single frame.

Body: bin (file)

Response: image/bmp binary

POST /api/replace

Replaces a frame and returns the patched logo.bin.

Body: bin (file), image (file), frameIndex (integer)

Response: application/octet-stream — logo_new.bin

Notes

• File size of the repacked logo.bin may differ from the original due to gzip compression variance. Verify your device's logo partition is large enough before flashing.
• Always keep a backup of the original logo.bin before flashing.
• Tested against Android 11 Unisoc firmware. Behavior on other versions may vary.

Flowchart

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License

This project is licensed under the MIT License. See LICENSE for the full license text.

Disclaimer

Use at your own risk.

This tool is provided "as is", without warranty of any kind, express or implied, including but not limited to the warranties of merchantability, fitness for a particular purpose, and non-infringement.

The author(s) shall not be held liable for any claim, damages, or other liability — whether arising from contract, tort, or otherwise — including but not limited to:

• Bricked or damaged devices resulting from flashing a patched logo.bin
• Data loss or corruption of firmware partitions
• Incompatibility with specific device models or firmware versions
• Any indirect, incidental, or consequential damages

You are solely responsible for verifying compatibility, keeping a backup of your original logo.bin, and ensuring your device's logo partition is large enough before flashing. Always proceed with caution on production or personal devices.