lowRISC/opentitan
Mar 2023 – Mar 2026
12 Months active
Languages Used
LDCAssemblyPythonRustC++Starlark
Technical Skills
embedded systemsfirmware developmentlinker script developmentC programminglow-level programminglinker script management
Luís Marques
PROFILE
Luís Marques
Luís Marques contributed to the lowRISC/opentitan repository by developing and refining embedded firmware and build systems, focusing on reliability, portability, and code safety. He engineered linker script enhancements for memory layout stability, ported power-management features to new hardware platforms, and improved test automation using C, Rust, and Python. His work addressed compiler warnings, undefined behavior, and toolchain dependencies, resulting in cleaner builds and safer runtime behavior. By fixing critical bugs in logging, clock management, and cryptographic drivers, Luís ensured robust cross-platform validation and maintainability. His technical depth is evident in low-level programming, toolchain management, and embedded systems development.
Overall Statistics
Feature vs Bugs
35%Features
Repository Contributions
35Total
Bugs
11
Commits
35
Features
6
Lines of code
1,033
Activity Months12
Your Network
124 peopleWork History
March 2026
9 Commits • 1 Features
Mar 1, 2026March 2026 — lowRISC/opentitan: Delivered the primary feature for GPIO test coverage, hardened code safety across the stack, and fixed a critical alert-handling bug. The work emphasizes test coverage, reliability, and maintainability with clang-oriented warnings mitigation and cross-module consistency.
9 Commits • 1 Features
Mar 1, 2026March 2026 — lowRISC/opentitan: Delivered the primary feature for GPIO test coverage, hardened code safety across the stack, and fixed a critical alert-handling bug. The work emphasizes test coverage, reliability, and maintainability with clang-oriented warnings mitigation and cross-module consistency.
March 2026
February 2026
1 Commits
Feb 1, 2026February 2026 monthly summary for lowRISC/opentitan: This period focused on improving compiler warning hygiene and code safety by addressing sign-conversion warnings flagged under Clang. The work ensures explicit type conversions to satisfy -Wsign-conversion while -Wconversion is enabled, thereby reducing potential runtime and correctness issues due to implicit sign handling. The changes are isolated to the OpenTitan software stack and contribute to long-term code quality, maintainability, and safer hardware-software interfaces.
February 2026
1 Commits
Feb 1, 2026February 2026 monthly summary for lowRISC/opentitan: This period focused on improving compiler warning hygiene and code safety by addressing sign-conversion warnings flagged under Clang. The work ensures explicit type conversions to satisfy -Wsign-conversion while -Wconversion is enabled, thereby reducing potential runtime and correctness issues due to implicit sign handling. The changes are isolated to the OpenTitan software stack and contribute to long-term code quality, maintainability, and safer hardware-software interfaces.
October 2025
1 Commits
Oct 1, 20252025-10 Monthly Summary for lowRISC/opentitan focusing on test reliability improvements for OTP descrambling and cross-environment validation. The primary deliverable was an OTP descrambling test reliability fix with corrected prints and expanded supported execution environments, resulting in more stable CI results and better multi-target coverage.
1 Commits
Oct 1, 20252025-10 Monthly Summary for lowRISC/opentitan focusing on test reliability improvements for OTP descrambling and cross-environment validation. The primary deliverable was an OTP descrambling test reliability fix with corrected prints and expanded supported execution environments, resulting in more stable CI results and better multi-target coverage.
October 2025
August 2025
6 Commits • 1 Features
Aug 1, 2025Month: 2025-08 — Developer monthly summary focusing on key accomplishments, business impact, and technical achievements for the opentitan repository (lowRISC/opentitan).
August 2025
6 Commits • 1 Features
Aug 1, 2025Month: 2025-08 — Developer monthly summary focusing on key accomplishments, business impact, and technical achievements for the opentitan repository (lowRISC/opentitan).
July 2025
8 Commits • 2 Features
Jul 1, 2025July 2025 monthly summary for lowRISC/opentitan: Key features delivered: - Freestanding Build and Dependency Reduction: Transitioned the toolchain to a freestanding environment, removing dependencies on Newlib and GCC headers; introduced a freestanding directory with essential C library routines and trimmed include usage to reduce toolchain dependencies and simplify the build. Commits: d6be5b8f14d24e4728a4163980d06cd4fda5441d; 0043974c97d95b2237320c319ba1578ff90ce75e; 6f041a8e477fd983fb9fe58b22fae1e70cdc6012; 6a30d0d4337f702aa4037ef20e8c543247ac51ec. - Compiler Safety and Correctness Improvements: Added nonstring attribute support (OT_NONSTRING), improved warning handling, addressed alignment concerns in RISC-V core tests, added a wrapper to correctly cast return types for ujson_putbuf when used as a sink, and preemptively initializing variables to avoid warnings. Commits: 2df6501c63beb1f2bd11e5e5d315e3a903fbebd3; f0a09fbd849fd9bd13710035de206597451b123a; 5e10315d184fc92d2f499b404d7fa85a7d2bfa45; f74a3031ebc31443c98b1539b6e570bf39a046e4. Major bugs fixed: - Reduced and fixed warning surface by ensuring variables are initialized to avoid potential clang false positives, and by aligning string handling to prevent misalignment in code sections. - Removed unused/irrelevant includes (e.g., ctype.h in usb_logging, and unnecessary cvt.c in coremark), contributing to leaner builds and fewer path-dependent issues. (Related commits: 6f041a8e...; 6a30d0d4...; 0043974c...) Overall impact and accomplishments: - Business value: Lower build-time and CI resource usage due to a leaner freestanding toolchain and fewer dependencies; easier onboarding and safer release cycles with improved runtime correctness and fewer build-time errors. - Technical impact: Cleaner build environment, stronger type and warning safety, and improved maintainability through targeted fixes and attribute-driven correctness. - The month culminated in a more robust opentitan baseline with preserved feature delivery velocity and clearer paths for future hardening. Technologies/skills demonstrated: - C safety attributes (OT_NONSTRING), pointer casting wrappers, and careful type handling. - Build system refactoring and toolchain simplification. - clang warning mitigation and proactive initialization for stability. - Cross-repo hygiene: removal of dead includes and unused modules to reduce surface area for regressions.
8 Commits • 2 Features
Jul 1, 2025July 2025 monthly summary for lowRISC/opentitan: Key features delivered: - Freestanding Build and Dependency Reduction: Transitioned the toolchain to a freestanding environment, removing dependencies on Newlib and GCC headers; introduced a freestanding directory with essential C library routines and trimmed include usage to reduce toolchain dependencies and simplify the build. Commits: d6be5b8f14d24e4728a4163980d06cd4fda5441d; 0043974c97d95b2237320c319ba1578ff90ce75e; 6f041a8e477fd983fb9fe58b22fae1e70cdc6012; 6a30d0d4337f702aa4037ef20e8c543247ac51ec. - Compiler Safety and Correctness Improvements: Added nonstring attribute support (OT_NONSTRING), improved warning handling, addressed alignment concerns in RISC-V core tests, added a wrapper to correctly cast return types for ujson_putbuf when used as a sink, and preemptively initializing variables to avoid warnings. Commits: 2df6501c63beb1f2bd11e5e5d315e3a903fbebd3; f0a09fbd849fd9bd13710035de206597451b123a; 5e10315d184fc92d2f499b404d7fa85a7d2bfa45; f74a3031ebc31443c98b1539b6e570bf39a046e4. Major bugs fixed: - Reduced and fixed warning surface by ensuring variables are initialized to avoid potential clang false positives, and by aligning string handling to prevent misalignment in code sections. - Removed unused/irrelevant includes (e.g., ctype.h in usb_logging, and unnecessary cvt.c in coremark), contributing to leaner builds and fewer path-dependent issues. (Related commits: 6f041a8e...; 6a30d0d4...; 0043974c...) Overall impact and accomplishments: - Business value: Lower build-time and CI resource usage due to a leaner freestanding toolchain and fewer dependencies; easier onboarding and safer release cycles with improved runtime correctness and fewer build-time errors. - Technical impact: Cleaner build environment, stronger type and warning safety, and improved maintainability through targeted fixes and attribute-driven correctness. - The month culminated in a more robust opentitan baseline with preserved feature delivery velocity and clearer paths for future hardening. Technologies/skills demonstrated: - C safety attributes (OT_NONSTRING), pointer casting wrappers, and careful type handling. - Build system refactoring and toolchain simplification. - clang warning mitigation and proactive initialization for stability. - Cross-repo hygiene: removal of dead includes and unused modules to reduce surface area for regressions.
July 2025
February 2025
3 Commits
Feb 1, 2025February 2025 focused on stabilizing OpenTitan clock management tests and hardening ROM extension retention. These changes reduce flaky CI failures, improve test reliability, and reinforce ROM integrity, delivering direct business value through faster, more reliable releases.
February 2025
3 Commits
Feb 1, 2025February 2025 focused on stabilizing OpenTitan clock management tests and hardening ROM extension retention. These changes reduce flaky CI failures, improve test reliability, and reinforce ROM integrity, delivering direct business value through faster, more reliable releases.
November 2024
1 Commits
Nov 1, 2024November 2024: Delivered a targeted fix to enable FPGA execution of the pwrmgr_all_reset_reqs_test in OpenTitan by removing the 'broken' tag and updating the BUILD configuration. This work also addresses sival ROM_EXT handling on FPGA, restoring test reliability. The changes improve FPGA validation coverage, reduce hardware bring-up risk, and strengthen confidence in the FPGA path.
1 Commits
Nov 1, 2024November 2024: Delivered a targeted fix to enable FPGA execution of the pwrmgr_all_reset_reqs_test in OpenTitan by removing the 'broken' tag and updating the BUILD configuration. This work also addresses sival ROM_EXT handling on FPGA, restoring test reliability. The changes improve FPGA validation coverage, reduce hardware bring-up risk, and strengthen confidence in the FPGA path.
November 2024
June 2024
1 Commits • 1 Features
Jun 1, 2024June 2024: Delivered port of sleep_pin_wake functionality to the SiVal platform within lowRISC/opentitan, including updating test configurations and introducing a new Rust-based test to validate sleep/wake behavior on SiVal. This work extends platform portability and strengthens power-management validation for a diversified hardware portfolio.
June 2024
1 Commits • 1 Features
Jun 1, 2024June 2024: Delivered port of sleep_pin_wake functionality to the SiVal platform within lowRISC/opentitan, including updating test configurations and introducing a new Rust-based test to validate sleep/wake behavior on SiVal. This work extends platform portability and strengthens power-management validation for a diversified hardware portfolio.
March 2024
1 Commits
Mar 1, 2024March 2024 monthly summary for lowRISC/opentitan focused on reliability of the logging subsystem and robustness of log parsing across base address configurations.
1 Commits
Mar 1, 2024March 2024 monthly summary for lowRISC/opentitan focused on reliability of the logging subsystem and robustness of log parsing across base address configurations.
March 2024
February 2024
2 Commits • 1 Features
Feb 1, 2024February 2024 — opentitan: Focused on stability and memory-management improvements through linker script consolidation. Implemented memory layout enhancements: reordering sections by ascending address, reorganizing non-volatile counter sections and scratch area, and introducing PHDRS to delineate segments (static data, manifest, data, FreeRTOS, scratch) for improved memory management in embedded firmware. Results: reduced linker-related failures, improved memory predictability, easier maintenance, enabling safer firmware updates. Technologies demonstrated: linker scripts, PHDRS, memory layout optimization, embedded firmware (FreeRTOS).
February 2024
2 Commits • 1 Features
Feb 1, 2024February 2024 — opentitan: Focused on stability and memory-management improvements through linker script consolidation. Implemented memory layout enhancements: reordering sections by ascending address, reorganizing non-volatile counter sections and scratch area, and introducing PHDRS to delineate segments (static data, manifest, data, FreeRTOS, scratch) for improved memory management in embedded firmware. Results: reduced linker-related failures, improved memory predictability, easier maintenance, enabling safer firmware updates. Technologies demonstrated: linker scripts, PHDRS, memory layout optimization, embedded firmware (FreeRTOS).
May 2023
1 Commits
May 1, 2023Monthly summary for 2023-05 focusing on a targeted bug fix in the OpenTitan project to strengthen boot integrity under Link Time Optimization (LTO). Implemented a robust solution by using OT_USED on unreferenced global declarations to preserve crucial boot measurements and state variables, preventing data loss during optimization and ensuring a reliable boot sequence across builds.
1 Commits
May 1, 2023Monthly summary for 2023-05 focusing on a targeted bug fix in the OpenTitan project to strengthen boot integrity under Link Time Optimization (LTO). Implemented a robust solution by using OT_USED on unreferenced global declarations to preserve crucial boot measurements and state variables, preventing data loss during optimization and ensuring a reliable boot sequence across builds.
May 2023
March 2023
1 Commits
Mar 1, 2023Monthly summary for 2023-03: LLD linker compatibility fix for non-volatile sections in lowRISC/opentitan. Implemented an updated linker script that uses absolute end addresses for non-volatile sections to ensure compatibility with the LLD linker, fixing mis-sized memory ranges and improving build reliability. The change reduces memory-layout-related defects and stabilizes firmware builds across toolchains.
March 2023
1 Commits
Mar 1, 2023Monthly summary for 2023-03: LLD linker compatibility fix for non-volatile sections in lowRISC/opentitan. Implemented an updated linker script that uses absolute end addresses for non-volatile sections to ensure compatibility with the LLD linker, fixing mis-sized memory ranges and improving build reliability. The change reduces memory-layout-related defects and stabilizes firmware builds across toolchains.
Activity
Loading activity data...
Quality Metrics
Correctness96.6%
Maintainability93.2%
Architecture92.6%
Performance90.4%
AI Usage20.0%
Skills & Technologies
Programming Languages
AssemblyCC++LDPythonRustStarlark
Technical Skills
Assembly LanguageBenchmarkingBuild System ConfigurationC ProgrammingC programmingC++ developmentCode RefactoringCompiler DirectivesCompiler OptimizationsCompiler Toolchain ManagementCompiler WarningsEmbedded SystemsEmbedded Systems DevelopmentFirmware DevelopmentHardware Testing
Repositories Contributed To
Overview of all repositories you've contributed to across your timeline