lowRISC/opentitan
Nov 2024 – Dec 2025
9 Months active
Languages Used
CBazelMarkdownPythonStarlarkAssemblyC++jinja2
Technical Skills
Embedded Systems DevelopmentFirmware DevelopmentState Machine DesignAPI DesignBuild SystemsControl Flow Integrity
Samuel Ortiz
PROFILE
Samuel Ortiz
Over nine months, Sameo contributed to the lowRISC/opentitan repository by developing and refining embedded systems features, focusing on robust hardware-software integration. Sameo engineered device tree-driven configuration models, scalable ROM state machines, and secure SRAM initialization, using C, C++, and Python to implement dynamic memory management and modular driver architectures. Their work included building extensible APIs, enhancing control flow integrity, and introducing error handling patterns that improved diagnostics and maintainability. By addressing both feature development and bug fixes, Sameo delivered solutions that increased testability, security, and portability across silicon platforms, demonstrating depth in low-level programming and system design throughout the project.
Overall Statistics
Feature vs Bugs
88%Features
Repository Contributions
36Total
Bugs
2
Commits
36
Features
15
Lines of code
3,818
Activity Months9
Your Network
122 peopleSame Organization
@rivosinc.com28
Work History
December 2025
3 Commits • 1 Features
Dec 1, 2025December 2025 monthly summary for lowRISC/opentitan focusing on delivering robust GPIO capabilities and addressing error module conflicts to improve hardware-software integration, stability, and maintainability.
3 Commits • 1 Features
Dec 1, 2025December 2025 monthly summary for lowRISC/opentitan focusing on delivering robust GPIO capabilities and addressing error module conflicts to improve hardware-software integration, stability, and maintainability.
December 2025
October 2025
1 Commits • 1 Features
Oct 1, 2025Concise monthly summary focusing on key accomplishments for 2025-10 in lowRISC/opentitan with emphasis on business value and technical achievements.
October 2025
1 Commits • 1 Features
Oct 1, 2025Concise monthly summary focusing on key accomplishments for 2025-10 in lowRISC/opentitan with emphasis on business value and technical achievements.
September 2025
14 Commits • 4 Features
Sep 1, 2025September 2025 monthly summary for lowRISC/opentitan: Delivered device-tree-based multi-top support across core drivers with dynamic base-address resolution and top-agnostic APIs; extended OTP controller with DT extension; generalized Ibex address remapping slots; and maintenance/build reliability improvements. These changes reduce integration overhead for multi-top hardware and improve testability and deployment readiness.
14 Commits • 4 Features
Sep 1, 2025September 2025 monthly summary for lowRISC/opentitan: Delivered device-tree-based multi-top support across core drivers with dynamic base-address resolution and top-agnostic APIs; extended OTP controller with DT extension; generalized Ibex address remapping slots; and maintenance/build reliability improvements. These changes reduce integration overhead for multi-top hardware and improve testability and deployment readiness.
September 2025
August 2025
6 Commits • 1 Features
Aug 1, 2025Delivery overview for 2025-08: Implemented Device Tree-driven configuration and shutdown across Silicon Creator IPs in lowRISC/opentitan. This included introducing a multi-top shutdown driver, wiring DT-based addresses for OTP, enabling DT lookups for Key Manager, and integrating shutdown routines for flash and driver paths. Achievements also include updating unit tests to multi-top, and ensuring DT API compatibility across components. The work establishes a scalable, DT-driven configuration model across Silicon Creator IPs, reducing shutdown risk and enabling easier maintenance and validation.
August 2025
6 Commits • 1 Features
Aug 1, 2025Delivery overview for 2025-08: Implemented Device Tree-driven configuration and shutdown across Silicon Creator IPs in lowRISC/opentitan. This included introducing a multi-top shutdown driver, wiring DT-based addresses for OTP, enabling DT lookups for Key Manager, and integrating shutdown routines for flash and driver paths. Achievements also include updating unit tests to multi-top, and ensuring DT API compatibility across components. The work establishes a scalable, DT-driven configuration model across Silicon Creator IPs, reducing shutdown risk and enabling easier maintenance and validation.
June 2025
1 Commits • 1 Features
Jun 1, 2025Month: 2025-06 | Repository: lowRISC/opentitan. Focus: Security feature enhancement for SRAM initialization and key renewal during ROM boot.
1 Commits • 1 Features
Jun 1, 2025Month: 2025-06 | Repository: lowRISC/opentitan. Focus: Security feature enhancement for SRAM initialization and key renewal during ROM boot.
June 2025
February 2025
3 Commits • 2 Features
Feb 1, 2025February 2025 monthly summary for lowRISC/opentitan: Delivered scalable hardware configuration via DT-based device definitions for the Ibex core with dynamic memory controller parameter discovery from HJSON, enabling cross-topology integration. Removed hard-coded memory scrambling parameters to support parameterized builds. Added DV simulation support for non-scrambled ROM image generation to reduce test bench run times. Together, these changes enhance design scalability, accelerate validation, and improve testability across top-level designs.
February 2025
3 Commits • 2 Features
Feb 1, 2025February 2025 monthly summary for lowRISC/opentitan: Delivered scalable hardware configuration via DT-based device definitions for the Ibex core with dynamic memory controller parameter discovery from HJSON, enabling cross-topology integration. Removed hard-coded memory scrambling parameters to support parameterized builds. Added DV simulation support for non-scrambled ROM image generation to reduce test bench run times. Together, these changes enhance design scalability, accelerate validation, and improve testability across top-level designs.
January 2025
2 Commits • 1 Features
Jan 1, 2025January 2025 monthly summary for lowRISC/opentitan focusing on cryptographic nonce handling and SRAM scrambler robustness. The period delivered two consolidated changes in scramble_image.py and the Scrambler module, enhancing correctness, scalability, and future-proofing of nonce usage.
2 Commits • 1 Features
Jan 1, 2025January 2025 monthly summary for lowRISC/opentitan focusing on cryptographic nonce handling and SRAM scrambler robustness. The period delivered two consolidated changes in scramble_image.py and the Scrambler module, enhancing correctness, scalability, and future-proofing of nonce usage.
January 2025
December 2024
5 Commits • 3 Features
Dec 1, 2024December 2024 — OpenTitan development (lowRISC). Delivered a cohesive ROM lifecycle platform and strengthening security posture, enabling extensibility for vendor customizations and improved ROM integrity. Key contributions include a ROM state machine with default/no-op hooks, integration of the ROM state API, a vendor customization RFC for mask ROM, and enhanced CFI support integrated into ROM transitions. These changes lay the groundwork for modular ROM initialization, secure boot workflows, and easier collaboration with silicon vendors.
December 2024
5 Commits • 3 Features
Dec 1, 2024December 2024 — OpenTitan development (lowRISC). Delivered a cohesive ROM lifecycle platform and strengthening security posture, enabling extensibility for vendor customizations and improved ROM integrity. Key contributions include a ROM state machine with default/no-op hooks, integration of the ROM state API, a vendor customization RFC for mask ROM, and enhanced CFI support integrated into ROM transitions. These changes lay the groundwork for modular ROM initialization, secure boot workflows, and easier collaboration with silicon vendors.
November 2024
1 Commits • 1 Features
Nov 1, 2024November 2024 (lowRISC/opentitan): Delivered the ROM State API with an FSM and pre/post-run hooks to standardize ROM state management and extend ROM execution flow for silicon creators. This feature introduces a formal ROM state lifecycle with a finite state machine and pre-run/post-run hooks, enabling customizable ROM execution while reducing integration risk for silicon partners. The work establishes a reusable foundation for ROM control and future tooling within the project.
1 Commits • 1 Features
Nov 1, 2024November 2024 (lowRISC/opentitan): Delivered the ROM State API with an FSM and pre/post-run hooks to standardize ROM state management and extend ROM execution flow for silicon creators. This feature introduces a formal ROM state lifecycle with a finite state machine and pre-run/post-run hooks, enabling customizable ROM execution while reducing integration risk for silicon partners. The work establishes a reusable foundation for ROM control and future tooling within the project.
November 2024
Activity
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Quality Metrics
Correctness95.0%
Maintainability93.6%
Architecture94.2%
Performance87.8%
AI Usage20.6%
Skills & Technologies
Programming Languages
AssemblyBazelCC++MarkdownPythonStarlarkjinja2
Technical Skills
API DesignBuild System ConfigurationBuild System DevelopmentBuild SystemsC ProgrammingC programmingC++C++ DevelopmentCode RefactoringConfiguration ManagementControl Flow IntegrityCryptographyDevice DriversDevice TreeDevice Tree Generation
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