Ferrocene 25.05.0

Ferrocene 25.05.0 is the sixth major release of Ferrocene.

The highlights of this release are the inclusion of Rust 1.86.0, as well as two new qualified targets.

New features

  • Two new targets are now supported and qualified for safety critical use:

    • Armv7E-M bare-metal (soft-float) (thumbv7em-none-eabi)

    • Armv7E-M bare-metal (hard-float) (thumbv7em-none-eabihf)

Fixed known problems

A list of fixed known problems in this release can be found on the Ferrocene 25.05 Known Problems page.

Rust changes

This release includes the following changes introduced by the upstream Rust project. Note that this changelog is maintained by upstream. The target support changes described here describe Rust’s support levels, and have no correlation to the targets and platforms supported by Ferrocene.

Rust 1.84.0

Language

Compiler

Libraries

Stabilized APIs

These APIs are now stable in const contexts

Cargo

Rustdoc

Compatibility Notes

Rust 1.84.1

Rust 1.85.0

Language

Compiler

Platform Support

Refer to Rust’s platform support page for more information on Rust’s tiered platform support.

Libraries

Stabilized APIs

These APIs are now stable in const contexts:

Cargo

Rustdoc

Compatibility Notes

Internal Changes

These changes do not affect any public interfaces of Rust, but they represent significant improvements to the performance or internals of rustc and related tools.

Rust 1.85.1

Rust 1.86.0

Language

Compiler

Platform Support

Refer to Rust’s platform support page for more information on Rust’s tiered platform support.

Libraries

Stabilized APIs

These APIs are now stable in const contexts:

Cargo

Rustdoc

Compatibility Notes

Internal Changes

These changes do not affect any public interfaces of Rust, but they represent significant improvements to the performance or internals of rustc and related tools.

  • Build the rustc on AArch64 Linux with ThinLTO + PGO. The ARM 64-bit compiler (AArch64) on Linux is now optimized with ThinLTO and PGO, similar to the optimizations we have already performed for the x86-64 compiler on Linux. This should make it up to 30% faster.