Ubuntu 25.10 Raises RISC-V Profile Requirements

原始链接: https://www.omgubuntu.co.uk/2025/06/ubuntu-riscv-rva23-support

Canonical's Ubuntu is raising the bar for RISC-V hardware support, impacting future compatibility. Ubuntu 25.10 will require the RVA23 RISC-V profile, a significant leap from RVA20, which includes mandatory Vector and Hypervisor extensions crucial for AI/ML, cryptography, and enterprise workloads. This means most existing RISC-V devices won't be able to run Ubuntu 25.10 due to lacking the necessary extensions. While Ubuntu 24.04 LTS remains supported on older hardware until 2029, this shift signals a strategic move. By targeting more capable RISC-V profiles, Ubuntu aims to solidify its position as the leading OS on the platform as RISC-V hardware evolves and demands increase. RVA23 achieves feature parity with ARMv9 and x86-64v4. Although current RVA23 hardware is scarce, this pre-emptive move prepares Ubuntu to fully leverage advanced RISC-V capabilities by the time Ubuntu 26.04 LTS arrives.

The Hacker News discussion revolves around Ubuntu 25.10's decision to require RVA23, a more advanced RISC-V profile, raising concerns about potentially excluding existing hardware. Some argue this prioritizes future-proofing, while others worry about missing out if less powerful RISC-V devices gain popularity, referencing Debian's ARM experience. Commenters debate whether RVA23 is truly ready, noting the current lack of commercially available hardware that fully implements it. There's speculation that Ubuntu may have insider knowledge of upcoming hardware releases. Some view it as a positive move to avoid future compatibility issues and fragmentation, likening it to the USB-C charging standard. Concerns are also raised about the timeline for competitive RVA23 chips, with projections of Zen5-level performance potentially arriving in early 2026, but those claims are considered speculative given the vendors are promoting their own hardware.

原文

Canonical is bullish in promoting Ubuntu for RISC-V devices, be it enthusiast-orientated hardware like DeepComputing’s RISC-V tablet, single-board computers, or embedded equipment.

But with a new long-term support (LTS) release looming, it’s rethinking the kind of RISC-V hardware it wants to support going forward.

A recent bug report filed against Ubuntu’s upgrading tool confirmed a major change with regards to the RISC-V requirements for the upcoming Ubuntu 25.10 release — most existing RISC-V devices will not be able to run Ubuntu 25.10.

How come?

A New Baseline for RISC-V

Ubuntu 25.10 plans to bumps its baseline RISC-V profile (RVA) from RVA20 to RVA23. It may sound like a small jump but it has a big impact since the bulk of RISC-V devices currently sold don’t support it.

An RVA (RISC-V Application) profile is a specification that outlines the vector processing capabilities a RISC-V system must have, so “software can rely on the existence of a certain set of […] features in a particular generation of RISC-V implementations”.

That’s according to RISC-V International, the main collaborative group steering and overseeing development of this open source and royalty free processor architecture.

“RISC-V was designed to provide a highly modular and extensible instruction set (ISA) and includes a large and growing set of standard extensions, where each standard extension is a bundle of instruction-set features,” RISC-V International explains.

The RVA23 profile makes a number of ‘extensions’ mandatory, notably Vector and Hypervisor extensions to power “math-intensive workloads including AI/ML & cryptography, and enterprise hardware, operating systems and software workloads.”

Per Samsung, the RISC-V ‘V’ Vector extension “allows CPUs to perform many operations simultaneously, making them faster and more efficient”. With RVA23 RISC-V reaches a clear feature parity level with ARMv9 and x86-64v4.

It is (naturally) more involved than that. Plenty of deep-dives on RISC-V Vector extensions are available online if you find yourself curious about the computational underpinnings and future opportunities they stand to provide.

Impact on Existing Hardware

According to an open issue on Launchpad, the “ubuntu-release-upgrader should stop upgrades beyond Ubuntu 24.04 on hardware that does not support the RVA23U64 profile”, noting that “RVA23U64 is the profile relevant for user space”.

Support for earlier versions of Ubuntu on existing RISC-V hadn’t isn’t impacted, but this change does mean that Ubuntu 25.10 (and later) will not run on most existing RISC-V hardware (like the Orange Pi RV2) since they lack the extensions the RVA23 profile requires.

Will that really be an issue long-term?

Ubuntu 24.04 LTS is supported until 2029 at the earliest and will continue to work on existing hardware, so that’s covered. RISC-V usage remains niche so the impact from Ubuntu ‘raising the bar’ on baseline profile requirements won’t be huge.

What could be huge is the benefit to Ubuntu going forward.

Focusing future Ubuntu support to devices that have more capable RISC-V profile sets will further position the distro as the de-facto OS on the platform. As workload demands increase, and RISC-V hardware becomes more capable and affordable, the opportunities are obvious.

Admittedly there is one big rub: the range of RISC-V devices with RVA23 support is, at the time or writing this, near non-existent. That will change in the coming year, and by the release of Ubuntu 26.04 LTS, the distro will be primed to take full advantage.