The GNU project takes a bold step toward architectural diversity, as GCC 16 adds early support for building binaries targeting RISC-V on GNU/Hurd.
After years of limited hardware support and ongoing challenges in achieving full x86_64 compatibility, GNU/Hurd is now expanding its scope. A recent update to the GNU Compiler Collection (GCC) marks the beginning of what could be a new chapter: support for the RISC-V instruction set architecture (ISA), an increasingly influential player in the open hardware ecosystem.
GCC 16 Enables RISC-V Support for GNU/Hurd
In a patch merged on 18 April 2025 by Jeff Law, with initial work by developer Hakan Candar, GCC now recognizes riscv*-*-gnu* targets. This change enables the creation of toolchains capable of building binaries specifically for running on GNU/Hurd with a RISC-V backend.
The patch introduces a new configuration file (gnu.h) under the riscv directory, setting up the necessary runtime and linker options, including support for .init_array—critical for correct program initialization. The update also includes the definition of the dynamic linker (ld-riscv) and handling for endianness and ABI-specific behavior.
A Notable Shift for Hurd
GNU/Hurd has long been an experimental project within the GNU ecosystem, envisioned as a pure microkernel-based replacement for Linux. However, its development has been slow and heavily tied to x86 hardware, with limited support for modern devices and drivers.
As recently as 2023, the idea of porting Hurd to RISC-V was met with hesitation by the developer community, which had shown more interest in AArch64. The shift toward RISC-V now reflects growing confidence in the maturity of the open ISA and a broader push to decouple from proprietary processor architectures.
What This Means for the Future
While this is only an early-stage development, it lays the groundwork for future RISC-V-based GNU/Hurd systems. Having a functional compiler toolchain is the essential first step for porting a kernel to a new platform. The path ahead will require porting the Hurd kernel and its associated userland to RISC-V, a task that could take years—but the momentum is building.
The move underscores a growing interest in architectural diversity, especially within free and open-source software communities. It also highlights RISC-V’s increasing relevance as a credible alternative to traditional ISAs like x86 and ARM, particularly in academia, research, and embedded systems.
Looking Ahead
The GCC 16 development cycle has just begun, following the recent branching of GCC 15. More refinements to the RISC-V GNU/Hurd support are expected over time, along with experimentation by Hurd developers to bring up the kernel on this new architecture.
Though a stable, production-ready GNU/Hurd system running on RISC-V remains a distant goal, this compiler support is a significant milestone. It opens the door to experimentation, collaboration, and potentially a revitalized future for a long-standing but often overlooked part of the GNU operating system vision.
Source: GCC GNU
