Tools KUAL Next - native launcher for existing KUAL JSON extensions on jailbroken Kindles

[k0kada]

KUAL Next is a native launcher for existing KUAL JSON extensions on jailbroken Kindles running FW 5.16.3+

Hi folks.

As most people already know, recent Kindle firmwares doesn't support KUAL extensions anymore. This is because recent Kindle firmwares (5.19.3+) removed support for the old Java API that KUAL used to rely.

However, most KUAL extensions still work in recent Kindle firmwares, it is just that without KUAL they can't be run, since KUAL served as a basic UI, driven by declarative config.xml and menu.json files. Reimplementing this part is relatively simple, especially considering projects like https://github.com/NiLuJe/FBInk (to drive the eInk display) already exists.

So I decided to invest sometime today to vibecode this project: https://github.com/thiagokokada/kual-next/. The project is intentionally narrow in scope: the idea here is to bridge the gap between old extensions that rely on KUAL to drive the interface and mostly run their own scripts/programs. Since it is written in C instead of Java, it launches faster than original KUAL, but this is more of a side-effect of the choices (since FBInk is in C, it was easier to write this project in C) than an actual objective of the project.

The following extensions are tested and confirmed working in a Kindle Colorsoft FW 5.19.6 (jailbroken with Véra):

- https://github.com/Satsuoni/DeDRM_tools/
- https://github.com/bfabiszewski/kterm
- https://github.com/koreader/koreader
- https://github.com/mitanshu7/tailscale_kual

Keep in mind that this project focuses kindlehf devices only. For older devices you can still run classic KUAL, so there is no reason to make it work on those.

BTW, I was not aware of KUALA before this project existed. While I did not test it, it also seems an interesting alternative. Mine is in C/FBInk while KUALA is C++/GTK+, so there is that as a difference. The reason I decided to use FBInk was to explicitly not depend on anything that Amazon ships in the FW, avoiding breakages in the future (at least, this is what I hope).

[k0kada]

Some recent updates:
- Ported from C to Zig, mostly because I wanted to know if it was possible (Zig have really good C interop and cross-compiling support, so this means that building is much easier now; if you have just zig 0.16.0+ installed it should work)
- Fixed the issue of partial redrawings
- Introduced the KUAL menu ("Sort menu ABC/123", "Save and reset KUAL log"). This is implemented in native code instead of awk, so it is really fast even without GNU awk


Here is also a screenshot. Kinda boring because this is basically the same as the KUAL UI: