.. SPDX-License-Identifier: GPL-2.0 arch/riscv maintenance guidelines for developers ================================================ Overview -------- The RISC-V instruction set architecture is developed in the open: in-progress drafts are available for all to review and to experiment with implementations. New module or extension drafts can change during the development process - sometimes in ways that are incompatible with previous drafts. This flexibility can present a challenge for RISC-V Linux maintenance. Linux maintainers disapprove of churn, and the Linux development process prefers well-reviewed and tested code over experimental code. We wish to extend these same principles to the RISC-V-related code that will be accepted for inclusion in the kernel. Submit Checklist Addendum ------------------------- We'll only accept patches for new modules or extensions if the specifications for those modules or extensions are listed as being "Frozen" or "Ratified" by the RISC-V Foundation. (Developers may, of course, maintain their own Linux kernel trees that contain code for any draft extensions that they wish.) Additionally, the RISC-V specification allows implementors to create their own custom extensions. These custom extensions aren't required to go through any review or ratification process by the RISC-V Foundation. To avoid the maintenance complexity and potential performance impact of adding kernel code for implementor-specific RISC-V extensions, we'll only to accept patches for extensions that have been officially frozen or ratified by the RISC-V Foundation. (Implementors, may, of course, maintain their own Linux kernel trees containing code for any custom extensions that they wish.)