pussuw commented on pull request #5782: URL: https://github.com/apache/incubator-nuttx/pull/5782#issuecomment-1080306643
At this point I would like to remind that implementing a support for a generic SBI is not just about implementing the SBI API. The current NuttX implementation is not in any way ready for such an approach. It is designed to run in M-mode and it was already a lot of work to make the kernel run in S-mode. So, what is missing ? The boot procedure for example for mpfs (__mpfs_start) assumes that the code runs in machine mode still. Also mpfs_head.S is not ready for a generic SBI. This same applies to every platform. The system must be prepared by the SBI before NuttX is entered, this infrastructure is not in place yet. In order to support a generic SBI this code must be moved out / modified and this is something I did not plan on doing. The **only reason I implemented S-mode is to gain access to the MMU** (requirement for CONFIG_BUILD_KERNEL), as MMU is not accessible from M-mode. My intent was not to provide NuttX as a part of the canonical RISC-V stack (which would be Figure 1. RISC-V System without H-extension). It is too much work and I don't need it. -- 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
