CTSRD-CHERI/cheribsd
Feb 2025 – Feb 2025
1 Month active
Languages Used
C
Technical Skills
ARM ArchitectureEmbedded SystemsSystem ProgrammingVirtualization
Mark Johnston
PROFILE
Mark Johnston
Worked on the CTSRD-CHERI/cheribsd and CTSRD-CHERI/cheribuild repositories, focusing on reliability and security improvements in system-level tooling. Addressed a critical bug in ARM64 virtualization by refining trap frame ELR derivation during exception injection, ensuring correct handling in Morello-enabled environments and enhancing guest VM stability. In cheribuild, removed obsolete DSA SSH key generation to prevent build errors and align with modern security standards. Applied expertise in ARM architecture, build systems, and system programming, utilizing C and Python to deliver targeted bug fixes. The work demonstrated careful attention to platform-specific details and maintenance of robust, standards-compliant development workflows.
Overall Statistics
Feature vs Bugs
0%Features
Repository Contributions
2Total
Bugs
2
Commits
2
Features
0
Lines of code
24
Activity Months2
Your Network
42 peopleWork History
April 2025
1 Commits
Apr 1, 2025April 2025 monthly summary for CTSRD-CHERI/cheribuild: Removed DSA SSH key generation due to obsolescence, excluding 'dsa' from the key types during generation. This change prevents errors and aligns with modern SSH standards. Commit 2bfa20cd7d10ada9af6cdeb433feafcb668e003c (#414). Impact: reduces build-time SSH key generation failures, improves security posture, and simplifies maintenance. Demonstrated build tooling maintenance and security-conscious development with clear commit messages.
1 Commits
Apr 1, 2025April 2025 monthly summary for CTSRD-CHERI/cheribuild: Removed DSA SSH key generation due to obsolescence, excluding 'dsa' from the key types during generation. This change prevents errors and aligns with modern SSH standards. Commit 2bfa20cd7d10ada9af6cdeb433feafcb668e003c (#414). Impact: reduces build-time SSH key generation failures, improves security posture, and simplifies maintenance. Demonstrated build tooling maintenance and security-conscious development with clear commit messages.
April 2025
February 2025
1 Commits
Feb 1, 2025February 2025 CTSRD-CHERI/cheribsd monthly summary focused on stabilizing ARM64 virtualization by fixing trap frame ELR derivation during exception injection in Morello-enabled environments. No new features delivered this month; major bug fix delivered with downstream improvements to exception handling reliability and virtualization stability. Technologies demonstrated include ARM64 VMM expertise, trap frame management, Morello capability-based trapping configurations, and CPU execution mode awareness applied in patch delivery.
February 2025
1 Commits
Feb 1, 2025February 2025 CTSRD-CHERI/cheribsd monthly summary focused on stabilizing ARM64 virtualization by fixing trap frame ELR derivation during exception injection in Morello-enabled environments. No new features delivered this month; major bug fix delivered with downstream improvements to exception handling reliability and virtualization stability. Technologies demonstrated include ARM64 VMM expertise, trap frame management, Morello capability-based trapping configurations, and CPU execution mode awareness applied in patch delivery.
Activity
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Quality Metrics
Correctness95.0%
Maintainability90.0%
Architecture90.0%
Performance90.0%
AI Usage20.0%
Skills & Technologies
Programming Languages
CPython
Technical Skills
ARM ArchitectureBuild SystemsEmbedded SystemsSystem AdministrationSystem ProgrammingVirtualization
Repositories Contributed To
Overview of all repositories you've contributed to across your timeline
CTSRD-CHERI/cheribuild
Apr 2025 – Apr 2025
1 Month active
Languages Used
Python
Technical Skills
Build SystemsSystem Administration