KMSCON 9.3 Brings Default Mouse Support and Atomic Mode-Setting Prep, Paving the Way for Wider VT Replacement

The KMSCON project, a user-space virtual console emulator built on Kernel Mode Setting (KMS) and Direct Rendering Manager (DRM) infrastructure, has released version 9.3. This update represents a significant step forward in making KMSCON a more robust and feature-complete alternative to the traditional in-kernel Virtual Terminal (VT) implementation. The release is notable not just for its technical improvements, but for its growing momentum within the Linux ecosystem, with major distributions like Fedora 44 actively exploring its adoption.

What's New in KMSCON 9.3

KMSCON 9.3 delivers a suite of enhancements that address both user experience and underlying technical foundations. The most user-visible change is the enabling of mouse support by default. This decision follows the successful implementation in version 9.2, where no significant issues were reported. By defaulting to mouse support, KMSCON lowers the barrier to entry for users who expect modern console behavior, especially in environments where graphical applications might be launched from the terminal.

Under the hood, the development team has undertaken a substantial rework of the display and video code. This refactoring is crucial for improving stability and performance, particularly as the project prepares for more advanced graphics features. The rework also includes preparations for atomic mode-setting support. Atomic mode-setting is a modern DRM API that allows for the atomic application of display configuration changes, reducing tearing and improving the reliability of display updates. While not yet fully enabled, this groundwork positions KMSCON to leverage the latest graphics driver capabilities in the future.

Another practical addition is the DPMS (Display Power Management Signaling) screen timeout feature. This allows the console to automatically blank or power down the display after a configurable period of inactivity, saving power—a critical consideration for both mobile devices and energy-conscious homelab setups. To ensure broader hardware compatibility, the release also adds legacy modesetting fallback support, which helps maintain functionality on older graphics hardware that may not support the latest KMS features.

The Broader Context: Replacing the In-Kernel VT

KMSCON's development is driven by a long-standing goal: to replace the aging and monolithic in-kernel VT implementation. The kernel VT code, while functional, is considered complex, difficult to maintain, and limited in its feature set. By moving this functionality to user space, KMSCON offers several advantages:

1. Improved Security: User-space code is generally easier to audit and secure than kernel code.
2. Faster Development Cycles: User-space applications can be updated without requiring kernel rebuilds or module reloads.
3. Enhanced Features: It's easier to add modern features like Unicode support, better font rendering, and, as seen in 9.3, mouse support.
4. Better Integration with Modern Graphics: Direct use of KMS/DRM allows for better handling of multi-monitor setups and high-resolution displays.

The project's progress is being closely watched by the Linux community. Notably, Fedora 44 is considering replacing its kernel console usage with KMSCON. If this adoption proves successful, it could trigger a cascade effect, encouraging other distributions to follow suit. This would mark a major shift in how Linux handles its primary text console, moving a critical system component from the kernel to user space.

Implications for Users and Developers

For homelab builders and system administrators, KMSCON 9.3 offers tangible benefits. The default mouse support makes console navigation more intuitive, especially when managing servers via a direct console connection. The DPMS feature is a welcome addition for power management in always-on systems. The ongoing work on atomic mode-setting suggests that future versions will offer even smoother and more reliable display handling, which is essential for systems that might run a mix of console and graphical applications.

Developers working on low-level system software should note the project's direction. The reworked display code and atomic mode-setting preparations indicate a maturing codebase that is aligning with modern graphics standards. This makes KMSCON a more attractive platform for building new console applications or porting existing ones.

Getting Started with KMSCON 9.3

For those interested in testing or building KMSCON 9.3, the source code is available on GitHub. The project provides instructions for building from source, which is the primary distribution method for this software. As always, testing new system-level software in a non-production environment is recommended.

• Official KMSCON GitHub Repository: https://github.com/Aetf/kmscon
• Release Notes for 9.3: Available in the repository's release section.

Looking Ahead

KMSCON 9.3 is a clear indication of the project's steady progress. The combination of user-facing features like mouse support and foundational work for advanced graphics APIs demonstrates a balanced approach to development. As the project continues to mature and gain adoption, it has the potential to fundamentally change the Linux console landscape. The success of Fedora's potential integration will be a key milestone to watch in the coming months. For now, KMSCON 9.3 stands as a compelling, feature-rich alternative for anyone looking to modernize their system's console experience.