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Stefan Kalscheuer

PROFILE

Stefan Kalscheuer

Over a ten-month period, contributed to DragonBluep/openwrt by delivering kernel, bootloader, and device driver enhancements focused on hardware compatibility and build stability. Upgraded U-Boot and Linux kernel versions across multiple targets, aligning device trees with upstream sources and maintaining backward compatibility for smooth transitions. Addressed kernel and driver issues using C and Makefile, implementing structured patch management and configuration updates to reduce maintenance overhead. Fixed critical bugs in both OpenWrt and Apache Tomcat repositories, including Java-based backend improvements. The work emphasized traceability, cross-version support, and robust system programming practices, resulting in more reliable builds and streamlined future upgrades.

Overall Statistics

Feature vs Bugs

82%Features

Repository Contributions

41Total
Bugs
3
Commits
41
Features
14
Lines of code
42,340
Activity Months10

Your Network

456 people

Work History

May 2026

4 Commits • 2 Features

May 1, 2026

May 2026 monthly summary for DragonBluep/openwrt focusing on MVEBU kernel/build stability and U-Boot upgrades. Implemented stability improvements for Marvell MVEBU builds, including disabling WRT1900AC v1 sub-target due to kernel size with Kernel 6.18 to prevent unusable images, upgrading kernel config from 6.12 to 6.18, and restoring Armada 3700/3800 configuration files to maintain compatibility and stability. Upgraded U-Boot MVEBU package to 2026.04 to bring in latest features and fixes while preserving existing patches. These changes increase build reliability, improve platform compatibility (Armada 3700/3800), and position the project for smoother future maintenance and releases. Commits touched include kernel/build stability: 0c97d8707b03ba64f899214ab8ef13b45196cdc6, abbe4140cc9aa17896e51048b23303bf038c5d1a, f42be3be15ae6f392e9e887ebd4b1e1ff59e220f; and U-Boot MVEBU upgrade: decb778ed313e6ffa0240b532bf243850dddfec2.

April 2026

1 Commits

Apr 1, 2026

April 2026 monthly summary for DragonBluep/openwrt focusing on mwlwifi kernel compatibility patch for 6.18+. Implemented a patch series to migrate timer handling and netdev initialization to newer methods with guards to maintain compatibility across kernel versions, addressing compilation errors and preserving mwlwifi functionality.

March 2026

1 Commits

Mar 1, 2026

March 2026: Focused fix in Apache Tomcat's WebSocket DigestAuthenticator to improve Authorization header generation and server interoperability. Resolved a formatting issue that introduced an extra space after the username attribute and standardized all attribute-value pairs to key="value" formats, reducing authentication failures and ensuring compatibility with strict WS servers. Commit reference: 996c5c3b5af2a44b86752e74deab1aab7ddaf075 (BZ69972).

January 2026

3 Commits • 1 Features

Jan 1, 2026

January 2026: Upgraded U-Boot components to 2026.01 across uboot-mvebu, uboot-tools, and mkimage in DragonBluep/openwrt. This delivers improved hardware compatibility, stability, and access to newer features, with three commits providing traceable changes.

November 2025

4 Commits • 2 Features

Nov 1, 2025

November 2025 monthly summary for DragonBluep/openwrt: Focused kernel-level improvements for BCM4908 and BCM53xx to ensure long-term hardware compatibility and maintainability. Delivered 6.12 kernel compatibility patches while preserving backward compatibility for 6.6, addressing driver issues and hardware quirks. Completed structured patching to support Netgear/Linksys devices and reduce upgrade friction. This work directly improves device stability, broadens supported hardware, and accelerates future kernel upgrades.

October 2025

3 Commits • 1 Features

Oct 1, 2025

Month: 2025-10 — DragonBluep/openwrt. Focused on upgrading the U-Boot 2025.10 suite across the bootloader components (u-boot-mvebu, u-boot-tools, mkimage). Delivered cohesive release alignment with version and hash bumps in Makefiles and patches to ensure compatibility and improved system configuration support. This upgrade reduces maintenance friction, stabilizes boot paths for supported hardware, and positions the project for upcoming feature work. No major bugs recorded this month within the scope of the bootloader upgrade; the emphasis was on release engineering, stability, and future-proofing the build.

September 2025

10 Commits • 3 Features

Sep 1, 2025

September 2025 – DragonBluep/openwrt delivered Linux kernel 6.12 support and testing across Zynq, BCM53xx, and BCM4908 targets. Key activities included refreshing/restoring kernel configurations to 6.12, creating 6.12 testing kernels, and updating patches and device-tree specifications to maintain alignment with upstream changes. All changes are committed across the three sub-projects, enabling end-to-end validation for the 6.12 line. Impact: improved hardware compatibility, faster validation for the next OpenWrt release, and reduced upgrade risk. Demonstrated skills include kernel configuration management, patch curation, device-tree updates, cross-architecture testing kernel provisioning, and strong change traceability.

August 2025

8 Commits • 3 Features

Aug 1, 2025

Concise monthly summary for DragonBluep/openwrt — 2025-08 focusing on MVEBU boot/kernel improvements and upstream Device Tree alignment to reduce maintenance burden and improve hardware compatibility across platforms.

May 2025

6 Commits • 1 Features

May 1, 2025

Monthly summary for 2025-05 focusing on feature delivery, bug fixes, and technical impact for DragonBluep/openwrt with emphasis on MVEbu kernel 6.12 support and mwlwifi compatibility.

April 2025

1 Commits • 1 Features

Apr 1, 2025

April 2025 -- DragonBluep/openwrt: Major upstream alignment and hardware support work delivered. Upgraded U-Boot Mvebu to 2025.04, refreshed patches and metadata, updated Makefile with the new version/hash, and added a patch to enable MikroTik RB5009UG-S-IN support. This work enhances build reliability, security posture, and hardware coverage for next OpenWrt releases.

Activity

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Quality Metrics

Correctness95.6%
Maintainability94.2%
Architecture95.2%
Performance94.2%
AI Usage20.0%

Skills & Technologies

Programming Languages

CDTSDevice TreeJavaMakefilePatchShell

Technical Skills

Bootloader DevelopmentBuild SystemBuild SystemsC programmingDevice DriversDevice TreeDevice Tree ConfigurationDriver DevelopmentEmbedded SystemsEmbedded Systems DevelopmentFirmware DevelopmentJavaKernel DevelopmentKernel ManagementLinux

Repositories Contributed To

2 repos

Overview of all repositories you've contributed to across your timeline

DragonBluep/openwrt

Apr 2025 May 2026
9 Months active

Languages Used

MakefileCDTSShellDevice TreePatch

Technical Skills

Build SystemsEmbedded SystemsFirmware DevelopmentDevice DriversDevice TreeDriver Development

apache/tomcat

Mar 2026 Mar 2026
1 Month active

Languages Used

Java

Technical Skills

Javabackend development