1.. SPDX-License-Identifier: GPL-2.0 2 3arch/riscv maintenance guidelines for developers 4================================================ 5 6Overview 7-------- 8The RISC-V instruction set architecture is developed in the open: 9in-progress drafts are available for all to review and to experiment 10with implementations. New module or extension drafts can change 11during the development process - sometimes in ways that are 12incompatible with previous drafts. This flexibility can present a 13challenge for RISC-V Linux maintenance. Linux maintainers disapprove 14of churn, and the Linux development process prefers well-reviewed and 15tested code over experimental code. We wish to extend these same 16principles to the RISC-V-related code that will be accepted for 17inclusion in the kernel. 18 19Submit Checklist Addendum 20------------------------- 21We'll only accept patches for new modules or extensions if the 22specifications for those modules or extensions are listed as being 23"Frozen" or "Ratified" by the RISC-V Foundation. (Developers may, of 24course, maintain their own Linux kernel trees that contain code for 25any draft extensions that they wish.) 26 27Additionally, the RISC-V specification allows implementors to create 28their own custom extensions. These custom extensions aren't required 29to go through any review or ratification process by the RISC-V 30Foundation. To avoid the maintenance complexity and potential 31performance impact of adding kernel code for implementor-specific 32RISC-V extensions, we'll only to accept patches for extensions that 33have been officially frozen or ratified by the RISC-V Foundation. 34(Implementors, may, of course, maintain their own Linux kernel trees 35containing code for any custom extensions that they wish.) 36