On Tue, 4 Oct 2022 at 11:56, Jason A. Donenfeld <Jason@xxxxxxxxx> wrote: > > On Tue, Oct 4, 2022 at 12:53 PM Peter Maydell <peter.maydell@xxxxxxxxxx> wrote: > > > > On Tue, 4 Oct 2022 at 11:40, Jason A. Donenfeld <Jason@xxxxxxxxx> wrote: > > I think the unusual thing here is that this patch isn't > > "this facility is implemented by u-boot [commit whatever, > > docs whatever], and here is the patch adding it to QEMU's > > handling of the same interface". That is, for boards like > > Malta the general expectation is that we're emulating > > a piece of real hardware and the firmware/bootloader > > that it would be running, so "this is a patch that > > implements an interface that the real bootloader doesn't > > have" is a bit odd. > > Except it's not different from other platforms that get bootloader > seeds as such. A bootloader can easily pass this; QEMU most certainly > should pass this. (I sincerely hope you're not arguing in favor of > holding back progress in this area for yet another decade.) What I'm asking, I guess, is why you're messing with this board model at all if you haven't added this functionality to u-boot. This is just an emulation of an ancient bit of MIPS hardware, which nobody really cares about very much I hope. I'm not saying this is a bad patch -- I'm just saying that QEMU should not be in the business of defining bootloader-to-kernel interfaces if it can avoid it, so usually the expectation is that we are just implementing interfaces that are already defined, documented and implemented by a real bootloader and kernel. [from your other mail] > Also, in case you've missed the actual context of this patch, it > happens for `-kernel ...`. So we're now strictly in the realm of QEMU > things. -kernel generally means "emulate the platform's boot loader": it is exactly because we do not want to be in a realm of QEMU-defined interfaces that we try to follow what the platform boot loader does rather than defining new interfaces. That's not always possible or the right thing, but it's usually the cleaner way to go. thanks -- PMM
