On Fri, Sep 27, 2019 at 10:57:45PM +0000, Atish Patra wrote: > On Fri, 2019-09-27 at 15:19 -0700, Christoph Hellwig wrote: > > On Thu, Sep 26, 2019 at 05:09:12PM -0700, Atish Patra wrote: > > > The Supervisor Binary Interface(SBI) specification[1] now defines a > > > base extension that provides extendability to add future extensions > > > while maintaining backward compatibility with previous versions. > > > The new version is defined as 0.2 and older version is marked as > > > 0.1. > > > > > > This series adds support v0.2 and a unified calling convention > > > implementation between 0.1 and 0.2. It also adds minimal SBI > > > functions > > > from 0.2 as well to keep the series lean. > > > > So before we do this game can be please make sure we have a clean 0.2 > > environment that never uses the legacy extensions as discussed > > before? > > Without that all this work is rather futile. > > > > As per our discussion offline, here are things need to be done to > achieve that. > > 1. Replace timer, sfence and ipi with better alternative APIs > - sbi_set_timer will be same but with new calling convention > - send_ipi and sfence_* apis can be modified in such a way that > - we don't have to use unprivileged load anymore > - Make it scalable > > 2. Drop clear_ipi, console, and shutdown in 0.2. > > We will have a new kernel config (LEGACY_SBI) that can be manually > enabled if older firmware need to be used. By default, LEGACY_SBI will > be disabled and kernel with new SBI will be built. We will have to set > a flag day in a year or so when we can remove the LEGACY_SBI > completely. > > Let us know if it is not an acceptable approach to anybody. > I will post a RFC patch with new alternate v0.2 APIs sometime next > week. >
Will this legacy option be compatible will bbl? says, version 1.0.0 or any earlier ones? > > _______________________________________________ > > linux-riscv mailing list > > linux-ri...@lists.infradead.org > > http://lists.infradead.org/mailman/listinfo/linux-riscv > > -- > Regards, > Atish