EASYLIFE OS · for the XTEINK X4
Your e-reader can do more than the vendor allowed.
EASYLIFE OS replaces the firmware on the XTEINK X4. Fifteen apps, a reader that sets justified type, weather and maps that work with the radio off, and a snake game. Written from scratch, because the vendor documented nothing.
Your original firmware is never overwritten. It sits untouched in the other flash bank, and one command puts it back.
$2.99, once. A perpetual licence for one person, on every device you own.
Reverse engineered from nothing
No datasheet. No source. No recovery image anywhere online.
The X4 ships as a locked reader. It uploads books through a captive hotspot and reports to a vendor endpoint over unencrypted HTTP, sending the name and signal strength of your Wi-Fi network among other fields. The printed manual says the USB port is for charging only. That is false.
Underneath is an ESP32-C3 with 16MB of flash, a large e-paper panel, two button ladders on ADC pins, Bluetooth, and a MicroSD slot. None of it is documented. The pin map was recovered by halting the processor over JTAG in the middle of a screen refresh and reading the GPIO matrix out of memory — e-ink holds its image with no power, so every pin is released between redraws and there is nothing to observe unless you catch one in flight.
The detail that decided the project: four pins float low at boot and one of them holds the panel controller in reset forever. Three bring-ups failed before they were pulled high. A full refresh takes 1.7 seconds and a partial one takes about 400 milliseconds, and every screen in this operating system is designed around that number.
Device
XTEINK X4 · 4.26" 800×480 mono e-paper
Silicon
ESP32-C3 · RISC-V · 160MHz · 16MB flash
Input
Six buttons. No keyboard, no touch.
Radios
Wi-Fi 2.4GHz · BLE 5 · MicroSD
Interface
480×800 portrait · Ubuntu Mono · 1-bit
Licence
$2.99 once · perpetual · one person
Read
A page, set properly, that holds itself without power.
The reader justifies. Not the ragged right that most small devices settle for — the line is measured, the shortfall is divided among the spaces, and the last line of a paragraph is left flush. On a 1-bit panel with no anti-aliasing, a monospace face lands every stem on a whole pixel, which is why the whole system is set in Ubuntu Mono.
Books live on the MicroSD card. EPUB and PDF are converted on your computer by a small host tool and copied over Wi-Fi through Drive; the device reads plain text so that a page turn is a page turn and not a parse. Your place in each book is kept in flash and survives a power cut, which on a screen that needs no power to hold an image is the entire point.
Weather · Atlas
Both of these are useful with the radio switched off.
Weather pulls a seven-day forecast from the National Weather Service and keeps the last one. Out of range, the dashboard still draws — with the age of the data printed under it.
Atlas renders roads, water and place names from vector tiles on the card. No tiles are downloaded, no position is reported, and nothing needs a network. It is a map you carry, not a map that watches.
And the rest of it
Fifteen apps. One of them is Snake.
- QR
- Turns a line of text or a URL into a code on the panel. Paper that never runs out.
- Le-Hue
- Reads a document off the card and holds it open. Built for the things that are not books.
- Drive
- The device raises a Wi-Fi network and a web page. Drag books and maps onto it from a browser.
- Vitals
- Battery, voltage, free heap, uptime, SD state. What the machine knows about itself.
- Wi-Fi
- Scan, join, remember.
- Bluetooth
- Scans for what is nearby, including HID keyboards.
- Keys
- Prints the raw value of every button you press. This is how the button ladders were mapped.
- Invert
- White ink on black. One tap.
- Refresh
- A full waveform pass to clear ghosting.
- About
- Version, licence state, and the device MAC.
Reverting
Your original firmware is never overwritten.
The flash has two application banks. The stock firmware occupies the first one and is left exactly as it was; EASYLIFE OS is written to the second. A small table decides which of the two boots.
Going back rewrites that table and nothing else. It takes one command and a few seconds, and the device comes up as the reader it was in the shop.
tools/revert_to_stock.shInstalling replaces the software on hardware you own, and that is never risk-free. Take the verified backup the installer offers before you start.
The licence
$2.99. Once. Yours.
Buying sends a licence key to your email. Open Drive on the device, join the network it raises, and paste the key into the page it serves. The device checks it offline and never asks again.
One person, every device you own, no expiry and no subscription. Read, Drive, Wi-Fi, Bluetooth, Vitals and About work without a key at all.
The check happens on the device with no network, which means the secret it checks against lives in the firmware and can be extracted by anyone determined enough to dump the flash. This is stated plainly rather than dressed up. The price assumes you would rather pay than bother.
Before you buy
- You need an XTEINK X4. This is firmware, not a device.
- Installing is a command line, a USB cable, and about five minutes.
- This is young software written by one person. It is sold as it is.
- Support is a real person answering the form below.
Support
Something not working?
Lost key, a screen that will not draw, a book that will not open. Tell me what happened and what the device did.
On the pictures
Every screen on this page is a drawing, not a photograph. Each one is redrawn in the browser at the panel’s real 480×800 from the layout constants in the firmware source — the same margins, row heights and baselines the device uses. The icons are traced equivalents of the Material Symbols it draws, and the type is the same Ubuntu Mono. Nothing here is a render of a physical object, and no photograph of the device is presented as one.