LLVM

LLVM is a collection of modular and reusable compiler and toolchain technologies. These forks integrate CHERI support into LLVM (e.g clang and lld), enabling the creation of memory-safe software for Morello and RISC-V architectures.

Project Home: There are multiple homes, see the Get Involved section for more info.

Downloads & Documentation

Fork VersionBased on Upstream VersionTargetReference SpecDownload
74d200f (master)
2025-10-20		17
2023-07-25		riscv64cUniversity of Cambridge RISC-V ISAv9Source
678272e (codasip-cheri-riscv)
2025-11-19		17
2023-07-25		riscv64cCHERI RISC-V Draft 0.9.3Source
7ca5cdc (codasip-cheri-riscv-18)
2025-12-03		18
2024-01-24		riscv64cCHERI RISC-V Draft 0.9.3Source
a2ac247 (codasip-cheri-riscv-19)
2025-12-03		19
2024-07-23		riscv64cCHERI RISC-V Draft 0.9.3Source
6ec39b3
2026-01-22		21.1.8
2025-12-16		CHERIoTCHERIoT 1.0Source

Fork VersionBased on Upstream VersionTargetReference SpecDownloadDocumentation
morello/dev
2025-05-19		17
2024-10-26		aarch64cARM MorelloSource
morello/linux-release-1.9
2025-01-21		15
2022-07-26		aarch64cARM Morellolinux/aarch64c linux/x86Release Notes Source
morello/linux-release-1.8
2024-02-20		15
2022-07-26		aarch64cmorellolinux/aarch64c linux/x86 baremetal/x86Release Notes Source
morello/linux-release-1.6
2024-02-20		15
2022-07-26		aarch64cmorellolinux/aarch64c linux/x86 baremetal/x86 android/x86Release Notes Source
Please note that the release tarballs for Morello LLVM are based on upstream version 15. Build the morello/dev branch from source (via cheribuild) to get the latest changes and LLVM 17.

Project Status

Historically development for the different reference architectures occurred in parallel. However, all repos descend from work done in the CTSRD-CHERI/llvm-project repo.

Reference ArchitectureDevelopment Repository
University of Cambridge RISC-V ISA v9CTSRD-CHERI/llvm-project
CHERI RISC-V Draft Standard 0.9.3CHERI-Alliance/llvm-project
ARM Morello Prototypemorello/llvm-project
CHERIoT ISA v1.0CHERIoT-Platform/llvm-project

As of 2026, there are currently multiple streams of development for CHERI LLVM. The University of Cambridge CTSRD-CHERI/llvm-project supports the ISAv9 reference spec and contains a lot of the history relating to the development in different branches.

The CHERI Alliance CHERI-Alliance/llvm-project has branches that mirror the work Codasip is doing to increase the LLVM version towards the upstream version (currently what will be LLVM 23). Hence LLVM18 and LLVM19 branches, with LLVM20 due in the near future. This work started originally from the Cambridge LLVM15 CHERI compiler but also supports the draft CHERI-RISC-V standard 0.9.3

There are already shared features and patches between the versions, with an aim to converge these in future (and with the CHERIoT work) to support upstreaming. With CTSRD-CHERI/llvm-project being retained for research.

Building from Source

Instructions for building from source depend on which reference specification you are targeting.

CTSRD and Morello versions are built using the cheribuild.py script. Please refer to the cheribuild repo for usage.

The CHERI Alliance LLVM does not have formal build instructions. Checkout the Building LLVM section in our blog post on Getting started with CHERI Linux on RISC-V, as we cover it there.

Instructions on building CHERIoT LLVM can be found in their Getting Started Guide.

Get Involved

Development for this project happens in the following places:

There is no direct LLVM mailing list.

Support for CHERI LLVM is provided via the CHERI CPU Slack.

  • #cheri-llvm: The main channel for llvm

There are no public meetings for this project

Something missing, incorrect?

This page was last updated on 22nd January 2025. Please let us know of any corrections via support@thecapablehub.org, alternatively raise a GitHub pull request in our repo.