On Sat, Sep 21, 2019 at 6:12 AM Alistair Francis <alistai...@gmail.com> wrote:
>
> On Thu, Sep 19, 2019 at 10:15 PM Bin Meng <bmeng...@gmail.com> wrote:
> >
> > On Fri, Sep 20, 2019 at 6:32 AM Alistair Francis
> > <alistair.fran...@wdc.com> wrote:
> > >
> > > Add a property that when set to true QEMU will jump from the ROM code to
> > > the start of flash memory instead of DRAM which is the default
> > > behaviour.
> > >
> > > Signed-off-by: Alistair Francis <alistair.fran...@wdc.com>
> > > ---
> > > hw/riscv/sifive_u.c | 27 +++++++++++++++++++++++++++
> > > include/hw/riscv/sifive_u.h | 2 ++
> > > 2 files changed, 29 insertions(+)
> > >
> > > diff --git a/hw/riscv/sifive_u.c b/hw/riscv/sifive_u.c
> > > index c3949fb316..b7cd3631cd 100644
> > > --- a/hw/riscv/sifive_u.c
> > > +++ b/hw/riscv/sifive_u.c
> > > @@ -373,6 +373,10 @@ static void riscv_sifive_u_init(MachineState
> > > *machine)
> > > /* dtb: */
> > > };
> > >
> > > + if (s->start_in_flash) {
> > > + reset_vec[6] = memmap[SIFIVE_U_FLASH0].base; /* start: .dword
> > > FLASH0_BASE */
> > > + }
> > > +
> > > /* copy in the reset vector in little_endian byte order */
> > > for (i = 0; i < sizeof(reset_vec) >> 2; i++) {
> > > reset_vec[i] = cpu_to_le32(reset_vec[i]);
> > > @@ -544,8 +548,31 @@ static void riscv_sifive_u_soc_realize(DeviceState
> > > *dev, Error **errp)
> > > memmap[SIFIVE_U_GEM_MGMT].base, memmap[SIFIVE_U_GEM_MGMT].size);
> > > }
> > >
> > > +static bool virt_get_start_in_flash(Object *obj, Error **errp)
> > > +{
> > > + SiFiveUState *s = RISCV_U_MACHINE(obj);
> > > +
> > > + return s->start_in_flash;
> > > +}
> > > +
> > > +static void virt_set_start_in_flash(Object *obj, bool value, Error
> > > **errp)
> > > +{
> > > + SiFiveUState *s = RISCV_U_MACHINE(obj);
> > > +
> > > + s->start_in_flash = value;
> > > +}
> > > +
> > > static void riscv_sifive_u_machine_instance_init(Object *obj)
> > > {
> > > + SiFiveUState *s = RISCV_U_MACHINE(obj);
> > > +
> > > + s->start_in_flash = false;
> > > + object_property_add_bool(obj, "start-in-flash",
> > > virt_get_start_in_flash,
> > > + virt_set_start_in_flash, NULL);
> > > + object_property_set_description(obj, "start-in-flash",
> > > + "Set on to tell QEMU's ROM to jump
> > > to " \
> > > + "flash. Otherwise QEMU will jump to
> > > DRAM",
> > > + NULL);
> > >
> > > }
> > >
> > > diff --git a/include/hw/riscv/sifive_u.h b/include/hw/riscv/sifive_u.h
> > > index a921079fbe..2656b43c58 100644
> > > --- a/include/hw/riscv/sifive_u.h
> > > +++ b/include/hw/riscv/sifive_u.h
> > > @@ -57,6 +57,8 @@ typedef struct SiFiveUState {
> > >
> > > void *fdt;
> > > int fdt_size;
> > > +
> > > + bool start_in_flash;
> > > } SiFiveUState;
> > >
> > > enum {
> >
> > This patch chose a different way from the one used in patch "[v1,6/6]
> > riscv/virt: Jump to pflash if specified":
> >
> > - this patch uses reset_vec[6] while patch [6/6] defines a variable
> > start_addr
> > - this patch adds a "start-in-flash" property to the machine, while
> > patch [6/6] tests against drive IF_PFLASH
>
> Yes, we do it differently for the sifive_u board as the sifive_u board
> doesn't use pflash so there is no way to know if the user has loaded
> anything into the SPI memory.
>
OK.
> >
> > We should be consistent and I would prefer to use the patch [6/6] way.
> > On Unleashed an SPI flash is mounted so we cannot add a PFlash to
> > sifive_u machine like what was done on virt machine, so we should test
> > IF_MTD instead. Thoughts?
>
> How would we test that?
>
> Right now I am loading the binary in SPI with the -device loader
> option. The machine can't really know what is/isn't loaded there.
>
> It's not ideal, but I don't see a nicer way.
I think we need write a SiFive SPI model to support this in a clean
way. Ideally we should simulate the hardware boot workflow as
documented in the FU540 manual chapter 6 "Boot Process".
Regards,
Bin
