The numbers you asked will help but I just wanted to add that in my opinion a per-character putchar interface is not suitable for production due to the reasons you mentioned. I would compile it out in

Yeah, I think you are right that it is not a must-have feature but a nice-to-have feature.

That is because it is useful to have debug console output when porting a hypervisor or baremetal code to a new board. Of course, if a hypervisor is already available for the board, then it would be ju

This could be done. As an example Xen provides the hypercall HYPERVISOR_console_io. The first parameter is the operation: CONSOLEIO_write or CONSOLEIO_read. The interface in RISC-V spec language would