[PATCH] riscv/start: Startup sequence update.

[Gedare Bloom]

On Thu, Apr 29, 2021 at 11:53 AM Sebastian Huber
<sebastian.huber at embedded-brains.de> wrote:
>
>
> On 28/04/2021 15:55, Somesh Deshmukh wrote:
> > +/* Clear .bss */
> > +LADDR        a0, bsp_section_bss_begin
> > +li   a1, 0
> > +LADDR        a2, bsp_section_bss_size
> > +call memset
> > +
> >   #ifdef BSP_START_COPY_FDT_FROM_U_BOOT
> >       mv      a0, a1
> >       call    bsp_fdt_copy
> >   #endif
>
> How did you test this? The above memset() sets register a1 to 0 and
> probably uses this register also, the a1 is later used for the
> bsp_fdt_copy(), probably with an invalid value.
>
Good point, that a1 I guess is a parameter passed in by uboot and
needs to be preserved if this code should keep working.

> I would place the device tree in a noinit section.
>
That is probably a better solution.

It should also be documented in this start.S file what are the
assumptions about parameters coming from the bootloader since it is
not obvious.

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