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

[Auer, Lukas]

On Thu, 2019-04-11 at 14:51 +0200, David Abdurachmanov wrote:
> 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.
> 

That makes sense. I would still tend towards removing it, but will wait
to see what everybody else thinks.

Other than that, the patch looks good to me.

Reviewed-by: Lukas Auer <lukas.auer at aisec.fraunhofer.de>

> > 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 */