On Fri, Jan 06, 2023 at 05:16:31PM +0000, Andrew Cooper wrote: > On 20/12/2022 6:23 am, Bobby Eshleman wrote: > > On Fri, Jan 06, 2023 at 03:14:25PM +0200, Oleksii Kurochko wrote: > >> The patch introduce sbi_putchar() SBI call which is necessary > >> to implement initial early_printk > >> > > I think that it might be wise to start off with an alternative to > > sbi_putchar() since it is already planned for deprecation. I realize > > that this will require rework, but it is almost guaranteed that > > early_printk() will break on future SBI implementations if using this > > SBI call. IIRC, Xen/ARM's early printk looked like a reasonable analogy > > for how it could work on RISC-V, IMHO. > > Hmm, we're using it as a stopgap right now in CI so we can break > "upstream RISC-V support" into manageable chunks. > > So perhaps we want to forgo plumbing sbi_putchar() into early_printk() > (to avoid giving the impression that this will stay around in the > future) and use sbi_putchar() directly for the hello world print. > > Next, we focus on getting the real uart driver working along with real > printk (rather than focusing on exceptions which was going to be the > next task), and we can drop sbi_putchar() entirely. > > Thoughts? > > ~Andrew
That sounds like a reasonable approach to me. Best, Bobby
