A look at CrossPoint e-reader firmware [LWN.net]

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A look at CrossPoint e-reader firmware

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By Joe Brockmeier<br>August 12, 2026

There are a number of small,<br>inexpensive, low-powered e-reader or e-paper devices that have promise as<br>ebook readers with one minor problem: the firmware they ship with does not<br>realize their full potential. To solve that problem, the CrossPoint Reader project looks to<br>provide replacement firmware that offers necessary features, better performance,<br>and a more pleasant reading experience. On August 7, the project released version<br>1.5.0, which opens large EPUBs more quickly, provides<br>offline dictionary lookups, and has reworked settings for changing layout and<br>font options. The release also improves support for right-to-left text as well<br>as Chinese, Japanese, and<br>Korean (CJK) text rendering.

Tiny e-readers

Mainstream e-readers, such as the Kindle and Kobo<br>devices, have large, high-resolution screens with crisp fonts, lots of<br>features, and are reasonably fast even when reading large ebooks. But<br>they can be somewhat expensive, come tethered to proprietary services,<br>and are too large to comfortably stash in one's pants pocket.

Last year, a Chinese company called Xteink started<br>shipping pocket-sized e-readers globally. The first device was the<br>Xteink 4, which uses an ESP32-based system-on-chip<br>(SoC). It weighs less than three ounces (77g), has a 4.3-inch (114mm) screen<br>with 480x800 resolution (no backlight) at 220PPI, and has physical buttons<br>rather than a touchscreen.

Xteink is not the only vendor shipping tiny e-readers, there are several<br>available with similar specifications, though it did seem to spark the most<br>interest. The big tradeoff for these devices is their resource<br>constraints—they have slow CPUs, only a few hundred kilobytes of RAM, and<br>the display resolution means that fonts are never going to look as good as they<br>do on the larger e-readers. Some of that can be overcome with the right<br>firmware, though. Soon after the Xteink 4 went global, Dave Allie released<br>the first version of CrossPoint to try to get more out of its limited<br>hardware.

Since the first release, CrossPoint has grown well beyond a one-person<br>show. There are more than 200 contributors to the MIT-licensed project, which<br>now supports six tiny e-reader devices, based on the ESP32-C3 or ESP32-S3<br>chipsets, from a variety of vendors. All of the devices supported by CrossPoint<br>are relatively cheap—one is as little as $50, and most are less than<br>$80. The project aims for a monthly release cadence but missed with 1.5, which<br>came out about six weeks after 1.4.0. 1.5.0<br>was also the first release with support for an ESP32-S3 device, the reTerminal Sticky "family notes<br>display" device. Adding a new hardware target probably required a bit more<br>testing than usual.

It is worth noting that CrossPoint does allow use of large-language-model<br>(LLM) tools for contributions, since that's an important consideration for some<br>users. However, the project asks that contributors disclose use of such tools in pull<br>requests. It does not, however, accept features (LLM-assisted or not) outside of<br>the narrow scope of providing a good reading experience.

The project's vision<br>and scope document explains that CrossPoint's goal is to focus on<br>"lightweight, high-performance firmware that maximizes the<br>potential of ESP32-based e-reader hardware, prioritizing legibility,<br>performance, and usability". Features that, for example, improve EPUB<br>rendering, ebook library management, or provide optimizations for rendering on the<br>devices' eInk screens are<br>welcome. On the other hand, the project does<br>not want RSS readers, PDF rendering, writing tools, or other interactive<br>applications because such features are too resource intensive and<br>likely to drain the battery far faster than simply displaying an EPUB.

CrossPoint in a flash

I purchased the Xteink 4 in June, with<br>the plan to use it as shipped, and install CrossPoint if the default firmware<br>was unsatisfactory. The Xteink uses an SD card for storage, rather than built-in<br>storage. Its battery is supposed to last for up to two weeks of reading; I can't<br>verify that, but it's certainly good for several days of heavy use without a<br>charge. The default firmware supports EPUB, Mobipocket, plain-text<br>files, PDFs, as well as PNG and JPEG images.

The default firmware for the Xteink 4 is not terrible, but<br>it does leave a bit to be desired. For example, its rendering of EPUB books was<br>both slow and not very attractive. I found the navigation to be a bit...