Hi Palmer, On Fri, Jul 10, 2020 at 8:45 AM Palmer Dabbelt <palmerdabb...@google.com> wrote: > > On Thu, 09 Jul 2020 15:09:18 PDT (-0700), alistai...@gmail.com wrote: > > On Thu, Jul 9, 2020 at 3:07 AM Bin Meng <bmeng...@gmail.com> wrote: > >> > >> From: Bin Meng <bin.m...@windriver.com> > >> > >> The reset vector codes are subject to change, e.g.: with recent > >> fw_dynamic type image support, it breaks oreboot again. > > > > This is a recurring problem, I have another patch for Oreboot to fix > > the latest breakage. > > > >> > >> Add a subregion in the MROM, with the size of machine RAM stored, > >> so that we can provide a reliable way for bootloader to detect > >> whether it is running in QEMU. > > > > I don't really like this though. I would prefer that we don't > > encourage guest software to behave differently on QEMU. I don't think > > other upstream boards do this. > > I agree. If you want an explicitly virtual board, use the virt board. Users > of sifive_u are presumably trying to do their best to test against what the > hardware does without actually using the hardware. Otherwise there should be > no reason to use the sifive_u board, as it's just sticking a layer of > complexity in the middle of everything.
Understood. Then let's drop this patch. > > > Besides Oreboot setting up the clocks are there any other users of this? > > IIRC we have a scheme for handling the clock setup in QEMU where we accept > pretty much any control write and then just return reads that say the PLLs > have > locked. I'd be in favor of improving the scheme to improve compatibility with > the actual hardware, but adding some way for programs to skip the clocks > because they know they're in QEMU seems like the wrong way to go. > Yep, that's my question to Oreboot too. U-Boot SPL can boot with QEMU and no problem was seen with clock settings in PRCI model in QEMU. Regards, Bin
