[U-Boot] [PATCH 2/2] riscv: qemu-riscv.h: define CONFIG_PREBOOT (enables extlinux)

[David Abdurachmanov]

On Thu, Apr 11, 2019 at 2:41 PM Auer, Lukas
<lukas.auer at aisec.fraunhofer.de> wrote:
>
> + Bin
>
> On Tue, 2019-04-09 at 12:42 +0200, David Abdurachmanov wrote:
> > - Set fdt_addr variable, which is needed for extlinux to find FDT.
> >   Otherwise booting kernel using extlinux results in missing FDT.
> >
> > - Also run fdt addr with FDT address so that fdt commands would
> >   work out of the box in U-Boot prompt.
>
> While often useful to have, the fdt command is not used during a normal
> boot. I think we should avoid calling commands, which are not normally
> needed. Can you remove this from your patch?

I borrowed idea from other boards, and I find it useful to have fdt working
out-of-the-box without trying to figure the correct variable which holds
address of FDT.

I can remove it from the patch, but I will probably keep adding it as Fedora
specific patch then.

>
> Thanks,
> Lukas
>
> >
> > This is successfully used by Fedora/RISCV with 5.1-rc3+ kernel using
> > OpenSBI -> U-Boot (S-mode) [extlinux] -> Kernel setup.
> >
> > Signed-off-by: David Abdurachmanov <david.abdurachmanov at gmail.com>
> > ---
> >  include/configs/qemu-riscv.h | 4 ++++
> >  1 file changed, 4 insertions(+)
> >
> > diff --git a/include/configs/qemu-riscv.h b/include/configs/qemu-riscv.h
> > index 22a5cd7365..b7110edebc 100644
> > --- a/include/configs/qemu-riscv.h
> > +++ b/include/configs/qemu-riscv.h
> > @@ -48,4 +48,8 @@
> >       "ramdisk_addr_r=0x88300000\0" \
> >       BOOTENV
> >
> > +#define CONFIG_PREBOOT \
> > +     "setenv fdt_addr ${fdtcontroladdr};" \
> > +     "fdt addr ${fdtcontroladdr};"
> > +
> >  #endif /* __CONFIG_H */