Hi, Ard, Arnd and Xuerui, On Fri, May 6, 2022 at 7:41 PM Arnd Bergmann <arnd@xxxxxxxx> wrote: > > On Fri, May 6, 2022 at 1:26 PM WANG Xuerui <kernel@xxxxxxxxxx> wrote: > > On 5/6/22 16:14, Ard Biesheuvel wrote: > > > Or is there compatibility at all? > > > > It turns out that this port is already incompatible with shipped > > systems, in other ways, at least since the March revision or so. > > I think we can treat user space compatibility separately from firmware > compatibility. > > > So, in effect, this port is starting from scratch, and taking the chance > > to fix early mistakes and oversights all over; hence my opinion is, > > better do the Right Thing (tm) and give the generic codepath a chance. > > > > For the Loongson devs: at least, declare the struct boot_params flow > > deprecated from day one, then work to eliminate it from future products, > > if you really don't want to delay merging even further (it's already > > unlikely to land in 5.19, given the discussion happening in LKML [3]). > > It's not embarrassing to admit mistakes; we all make mistakes, and > > what's important is to learn from them so we don't collectively repeat > > ourselves. > > Agreed. I think there can be limited compatibility support for old > firmware though, at least to help with the migration: As long as > the interface between grub and linux has a proper definition following > the normal UEFI standard, there can be both a modern grub > that is booted using the same protocol and a backwards-compatible > grub that can be booted from existing firmware and that is able > to boot the kernel. > > The compatibility version of grub can be retired after the firmware > itself is able to speak the normal boot protocol. After an internal discussion, we decide to use the generic stub, and we have a draft version of generic stub now[1]. I hope V10 can solve all problems. :) [1] https://github.com/loongson/linux/tree/loongarch-next-generic-stub Huacai > > Arnd
