Christoph Müllner
Chair Of The RISC-V Toolchain SIG at VRULL GmbH
Vienna, Austria
Summary
🤩
Rockstar🎓
Top SchoolChristoph Müllner is a seasoned embedded systems and toolchain engineer with 12 years of experience, based in Vienna, Austria, and currently chairs the RISC-V Toolchain SIG at RISC-V International. He combines hands-on low-level development—optimizing OpenSSL RISC‑V assembly for AES/GCM and hardening Trusted Firmware-A for Rockchip SoCs—with leadership in standards and tooling for the RISC‑V ecosystem. As Lead Developer at VRULL and former Compiler Engineer at SBA Research, he bridges compiler, runtime and firmware concerns to deliver secure, performant platforms. His open-source contributions reveal deep expertise with RISC‑V ISA extensions and practical hardware integration, improving cryptographic performance and system security. Colleagues know him for turning complex assembly- and firmware-level challenges into reusable, standards-aligned solutions that advance the broader RISC‑V community.
12 years of coding experience
14 years of employment as a software developer
Vienna University of Technology
Stackoverflow
1reputation
0reached
0answers
0questions
Github Skills (38)
assembly10
bit-manipulation10
qemu10
architecture10
risc-v10
gcc-compiler10
rockchip10
c-programming10
c1110
device-emulation10
c1710
compiler-design10
soc10
sys10
assemble10
Programming languages (16)
Github contributions (5)
ARM-software/arm-trusted-firmware
Apr 2019 - Nov 2020
Read-only mirror of Trusted Firmware-A
Role in this project:
Embedded Systems Engineer / IoT Developer
Embedded Systems Engineer / IoT DeveloperContributions:7 commits in 1 year 7 months
Contributions summary:Christoph focused on modifying the Trusted Firmware-A (TF-A) codebase for Rockchip platforms. Their primary contributions involved addressing compiler warnings, streamlining UART base address definitions, and enhancing console device configuration through the use of device tree blobs (DTB). Furthermore, the user implemented stack protector support to enhance system security. These changes suggest a deep understanding of embedded systems and hardware integration, specifically related to Rockchip SoCs.
trustedread-onlyfirmwareembedded
openssl/openssl
Jan 2023 - Jan 2023
TLS/SSL and crypto library
Role in this project:Back-end Developer & Assembly/Low-Level Programmer
Back-end Developer & Assembly/Low-Level ProgrammerContributions:36 reviews, 4 commits, 3 PRs in 1 day
Contributions summary:Christoph primarily contributes to the RISC-V assembly code for the OpenSSL library, focusing on optimizations and new features related to cryptography. Their contributions involve implementing and optimizing assembly routines for the GCM (Galois/Counter Mode) and AES (Advanced Encryption Standard) ciphers, leveraging specific RISC-V instruction set extensions (Zbb, Zbc, Zvbb, Zvbc, Zvkg, Zvksed, Zvkned). They also refactor existing assembly code, improve error messages, and enhance code reusability within the library. Their work leads to performance improvements and enhanced cryptographic capabilities within the OpenSSL project.
crypto-librarycryptographyssltlscrypto
Find and Hire Top DevelopersWe’ve analyzed the programming source code of over 60 million software developers on GitHub and scored them by 50,000 skills. Sign-up on Prog,AI to search for software developers.