1 unstable release

0.6.3 Aug 10, 2023

#742 in Operating systems


24K SLoC

Contains (ELF exe/lib, 105KB) rusty-loader-x86_64

RustyHermit: libhermit-rs

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libhermit-rs is the kernel of the RustyHermit unikernel project.


Building the kernel

Usually the kernel will be linked as static library to your applications.

  • Rust applications: Instructions can be found in the rusty-hermit repository.
  • For C/C++ applications: Instructions can be found in the hermit-playground repository.

Standalone static library build

cargo xtask build --arch x86_64

On completion, the script will print the path of libhermit.a. If you want to build libhermit-rs for aarch64, please replace x86_64 by aarch64.

Control the kernel messages verbosity

libhermit-rs uses the lightweight logging crate log to print kernel messages. The environment variable HERMIT_LOG_LEVEL_FILTER controls the verbosity. You can change it by setting it at compile time to a string matching the name of a LevelFilter. If the variable is not set, or the name doesn't match, then LevelFilter::Info is used by default.

$ HERMIT_LOG_LEVEL_FILTER=Debug cargo xtask build --arch x86_64


libhermit-rs is derived from following tutorials and software distributions:

  1. Philipp Oppermann's excellent series of blog posts.
  2. Erik Kidd's toyos-rs, which is an extension of Philipp Opermann's kernel.
  3. The Rust-based teaching operating system eduOS-rs.

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Licensed under either of

at your option.


Unless you explicitly state otherwise, any contribution intentionally submitted for inclusion in the work by you, as defined in the Apache-2.0 license, shall be dual licensed as above, without any additional terms or conditions.

libhermit-rs is being developed on GitHub. Create your own fork, send us a pull request, and chat with us on Zulip.


~238K SLoC