GoKawiilCustom firmware for the Xteink X4 e-paper device. Turns a $70 e-ink reader into a smart device with wireless tools, security features, communication, games, and utilities — while keeping full e-reader functionality.
Forked from CrossPoint Reader. All core reading functionality comes from CrossPoint. Biscuit builds on top of it.
What is this
Biscuit treats the Xteink X4 as a general-purpose smart device, not just an e-reader. The home screen is a tile-based dashboard with live system info (battery, heap, uptime, WiFi status). Reading is one of eight categories, not the main focus.
The 4.26" e-ink display is readable in direct sunlight, retains its image without power, and gives the device days of battery life. Seven physical buttons provide navigation without a touchscreen. WiFi and BLE 5.0 enable wireless tools. A MicroSD card stores everything.
Hardware
Spec Value SoC ESP32-C3 (RISC-V, 160MHz) RAM 380KB SRAM (no PSRAM) Flash 16MB Display 4.26" 800×480 e-ink, 1-bit mono Input 7 buttons (4 front, 3 side) WiFi 2.4GHz 802.11 b/g/n BLE 5.0 (shared radio with WiFi) Storage MicroSD (FAT32) Port USB-C (serial + power)
Apps
The home screen is a dashboard of eight tiles. Everything lives under one of them.
Tile Purpose Recon Passive scanning and monitoring — no transmission Offense Active wireless testing, grouped into Scan → Profile → Attack → Capture Defense Stealth, detection, and device hardening Comms Communication and exchange Tools Crypto, network, productivity, and creative utilities Games Entertainment Reader Ebooks, OPDS, reading stats Settings Preferences, file transfer, system management
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