The CactOS 2.0.0 release marks the final version for the x86_32 architecture, shifting the project focus toward a 64-bit future. This release prioritizes system stability, addressing verification debt and correcting architectural flaws before the transition to the 3.0.0 branch.
The kernel ABI has been streamlined from 95 to 15 system calls, moving most functionality to ioctl commands. Security improvements include replacing HMAC-SHA256 with ECDSA P-256 for module signatures and implementing strict memory boundary checks in the ELF loader to prevent unauthorized kernel-space access.
The VFS layer has been rewritten in Rust, introducing a comprehensive data model with support for inodes, dentry caching, and atomic cross-directory renaming. The networking stack, built on smoltcp, now supports TLS 1.3 via rustls, while the userspace environment includes a POSIX-compliant shell and 84 utilities.
Hardware management has been updated with CPUID topology support and a new energy-governor for SMP management. The developer removed the S3 suspend feature due to reliability issues on target hardware, with plans to reintroduce it in the 3.0.0 release.
To ensure consistency, the project now uses a single 'drivers.list' file to manage the 10 included .cctk modules. Testing has been bolstered by 58 host-side unit tests and a new headless CI-compatible verification script that monitors kernel markers via serial output.
