Re: [Qemu-devel] [PATCH v2] target/xtensa: xtfpga: provide default memory sizes

[Max Filippov]

On Wed, Nov 21, 2018 at 10:34 AM Philippe Mathieu-Daudé
<address@hidden> wrote:
> >   static const TypeInfo xtfpga_lx200_nommu_type = {
> > @@ -632,6 +636,7 @@ static void xtfpga_ml605_class_init(ObjectClass *oc, 
> > void *data)
> >       mc->init = xtfpga_ml605_init;
> >       mc->max_cpus = 4;
> >       mc->default_cpu_type = XTENSA_DEFAULT_CPU_TYPE;
> > +    mc->default_ram_size = 384 * MiB;
>
> Hmm this is now correct but I feel we are hiding information to further
> reviewers/developers. Without reading your v1 comment and looking at the
> new code I'd wonder why 384 and not 512.
>
> What about adding a definition such:
>
> #define XTENSA_CPU_MMU_RESERVED_IO_SIZE (128 * MiB)
>
> Then use:
>
>      mc->default_ram_size = 512 * MiB - XTENSA_CPU_MMU_RESERVED_IO_SIZE;

I'm not sure what's the reason that 128MB are reserved, and I'm sure
it's not a property of the CPU, but rather how it's wired to the board.
I'll call it
XTFPGA_MMU_RESERVED_MEMORY_SIZE
in the v3.

> If this patch goes thru your tree and you agree with the suggested
> changes, then you can directly add:
> Reviewed-by: Philippe Mathieu-Daudé <address@hidden>

-- 
Thanks.
-- Max