The developers of the Illumos project, which continues to develop the OpenSolaris kernel, network stack, file systems, drivers, libraries and a basic set of system utilities, have decided to discontinue support for the 64-bit SPARC architecture. Of the architectures available for Illumos, only x86_64 remains (support for 32-bit x86 systems was discontinued in 2018). If there are enthusiasts, it will be possible to begin implementing more current modern ARM and RISC-V architectures in Illumos. Removing support for legacy SPARC systems will clean up the code base and remove SPARC architecture-specific limitations.
Among the reasons for refusing to support SPARC is the lack of access to equipment for assembly and testing, and the impossibility of providing high-quality assembly support using cross-compilation or emulators. Also mentioned is the desire to use modern technologies in Illumos, such as JIT and the Rust language, the advancement of which is hampered by ties to the SPARC architecture. The end of SPARC support will also provide an opportunity to update the GCC compiler (currently the project is forced to use GCC 4.4.4 to support SPARC) and switch to using a newer standard for the C language.
As for the Rust language, the developers intend to replace some programs in usr/src/tools written in interpreted languages ββwith analogues implemented in the Rust language. In addition, it is planned to use Rust to develop kernel subsystems and libraries. The implementation of Rust in Illumos is currently hampered by the Rust project's limited support for the SPARC architecture.
The end of support for SPARC will not affect the current Illumos distributions of OmniOS and OpenIndiana, which are released only for x86_64 systems. SPARC support was present in the Illumos distributions Dilos, OpenSCXE and Tribblix, of which the first two have not been updated for several years, and Tribblix abandoned updating assemblies for SPARC and switched to the x2018_86 architecture in 64.
Source: opennet.ru