Tools

Most of what a distribution ships is upstream software it packaged. This page is the other part — the programs that exist because Nerv exists, and that a general-purpose distribution has no way to provide.

On the running system

axon

The accelerator boundary.

axond owns the device and hands out pre-authenticated sockets; every process is a client. Because local and remote are the same path, a CUDA program can execute on a GPU in another machine without being rebuilt. axon top answers where a given piece of work actually ran, which is the part a profiler normally cannot tell you.

atfield

Provenance, and a short queue of questions.

Measures every byte against the image it was composed from and the packages that own it, then asks about the remainder. Answering is what produces the declaration; there is no manifest to maintain. The output is a patch to the repository, never a mutation of a live slot.

cage

Slot transactions.

install, seal, boot, promote, rollback. An update composes into the subvolume you are not running and the bootloader default moves only after the new slot has booted.

S2

Inference, in the image.

One artifact per model, compiled ahead of time into replayable CUDA graphs and an arena layout. The runtime replays them. Residency and speculation depth are the only decisions left to run time, and both query the same ledger.

Building the distribution

These are how Nerv is made. They are in the tree because building a musl-first system correctly turned out to need them.

Tool	What it does
`geofront`	Composes a pure-musl chroot from the local repository and builds in it. Building a musl target inside a glibc buildroot bakes glibc-shaped answers into musl binaries; this is the tool that prevents it.
`nerv-repo`	Publishes packages and image generations to the artifact host. The signing key stays on the builder and never reaches the host.
`nerv-mkimage`	Composes a rootfs image for a target.
`nerv-qemu`	Boots an image under QEMU/KVM and runs the smoke test.
`nerv-ab-install`	Installs into a second btrfs subvolume, non-destructively, leaving the existing system bootable.
`nerv-native-buildroot`	Composes a zero-Fedora chroot and builds the packaging stack inside it. This is what produced rpm and dnf5 running pure-musl.

Source: tools/ · axon/