xiaoxiang781216 commented on pull request #5782: URL: https://github.com/apache/incubator-nuttx/pull/5782#issuecomment-1076196870
> I think @pussuw has addressed all the comments so far. This looks good to me, can you @xiaoxiang781216 re-check? Yes, I will take a look again. But since the change is huge, I need find the enough free time to finish the review. So, I expect the review will finish in the end of week. The major concern is how to implement the syscall. From "3.3.1 Environment Call and Breakpoint“ at https://github.com/riscv/riscv-isa-manual/releases/tag/draft-20220318-c9a172f: ``` The ECALL instruction is used to make a request to the supporting execution environment. When executed in U-mode, S-mode, or M-mode, it generates an environment-call-from-U-mode exception, environment-call-from-S-mode exception, or environment-call-from-M-mode exception, respectively, and performs no other operation. ECALL generates a different exception for each originating privilege mode so that environment call exceptions can be selectively delegated. A typical use case for Unix-like operating systems is to delegate to S-mode the environment-call-from-U-mode exception but not the others. ``` S-mode can hook ECALL to self, @pussuw could you explain more why we need handle differently in S-mode and M-mode? -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: commits-unsubscr...@nuttx.apache.org For queries about this service, please contact Infrastructure at: us...@infra.apache.org
