On Thu, Mar 07, 2024 at 02:26:18PM +0800, Wu, Fei wrote: > On 3/7/2024 8:48 AM, Alistair Francis wrote: > > On Thu, Mar 7, 2024 at 5:13 AM Atish Kumar Patra <ati...@rivosinc.com> > > wrote: > >> > >> On Wed, Mar 6, 2024 at 4:56 AM Wu, Fei <fei2...@intel.com> wrote: > >>> > >>> On 3/6/2024 8:19 AM, Alistair Francis wrote: > >>>> On Mon, Mar 4, 2024 at 8:28 PM Fei Wu <fei2...@intel.com> wrote: ... > >>>>> +config SERVER_PLATFORM_REF > >>>>> + bool > >>>>> + select RISCV_NUMA > >>>>> + select GOLDFISH_RTC > >>>>> + select PCI > >>>>> + select PCI_EXPRESS_GENERIC_BRIDGE > >>>>> + select PFLASH_CFI01 > >>>>> + select SERIAL > >>>>> + select RISCV_ACLINT > >>>>> + select RISCV_APLIC > >>>>> + select RISCV_IMSIC > >>>>> + select SIFIVE_TEST > >>>> > >>>> Do we really need SiFive Test in the server platform? > >>>> > >>> It's used to reset the system, is there any better choice? > > > > If we add this now we are stuck with it forever (or at least a long > > time). So it'd be nice to think about these and decide if these really > > are the best way to do things. We don't have to just copy the existing > > virt machine. > > > We need a solution to poweroff/reboot, and sifive test is one of the > hardware implementations, so in general I think it's okay. But I agree > Sifive test looks a device for testing only. > > > There must be a more standard way to do this then MMIO mapped SiFive > > hardware? > > > The mapped MMIO mechanism leveraged by Sifive test by itself is kinda > generic, the sbsa_ec for sbsa-ref is also an MMIO mapped device. These > two devices look very similar except different encodings of the > shutdown/reboot command. > > Probably we can have a generic shutdown/reboot device in QEMU for both > sifive test and sbsa_ec, and likely more (not in this patch series). In > this way, sifive test device will be replaced by this more generic > device. Any suggestions?
Operating systems shouldn't need to implement odd-ball device drivers to function on a reference of a standard platform. So the reference platform should only be comprised of devices which have specifications and already, or will, have DT bindings. Generic devices would be best, but I don't think it should be a problem to use devices from multiple vendors. The devices just need to allow GPL drivers to be written. With all that in mind, what about adding a generic GPIO controller or using SiFive's GPIO controller. Then, we could add gpio-restart and gpio-poweroff. Thanks, drew
