Re: [PATCH v2 2/4] docs/system/arm/fby35: document execute-in-place property

[Pierrick Bouvier]

On 12/5/24 09:29, Cédric Le Goater wrote:
> On 12/5/24 18:09, Pierrick Bouvier wrote:
> > On 12/5/24 00:18, Cédric Le Goater wrote:
> > > Hello Pierrick,
> > >
> > > Thanks for improving the documentation !
> > >
> > > On 12/4/24 21:39, Pierrick Bouvier wrote:
> > > > Signed-off-by: Pierrick Bouvier <pierrick.bouvier@linaro.org>
> > > > ---
> > > >     docs/system/arm/fby35.rst | 3 +++
> > > >     1 file changed, 3 insertions(+)
> > > >
> > > > diff --git a/docs/system/arm/fby35.rst b/docs/system/arm/fby35.rst
> > > > index bf6da6baa2a..ed9faef363c 100644
> > > > --- a/docs/system/arm/fby35.rst
> > > > +++ b/docs/system/arm/fby35.rst
> > > > @@ -45,3 +45,6 @@ process starts.
> > > >         $ screen /dev/tty0 # In a separate TMUX pane, terminal window, etc.
> > > >         $ screen /dev/tty1
> > > >         $ (qemu) c           # Start the boot process once screen is setup.
> > > > +
> > > > +This machine model supports emulation of the boot from the CEO flash device by
> > > > +setting option ``execute-in-place``.
> > >
> > > Could we add a link to the "Boot options" section of the
> > > "Aspeed family boards" document instead ?
> >
> > The problem is that the aspeed board has other options (fmc-model, spi-model), 
> > so it would be confusing for the reader.
>
> ok. Just to clarify, the Aspeed machines always boot from CE0 (if you
> exclude rainier).

Ok, I was not aware of that.
I'm not familiar with those machine models, and just have been a 
documentation updater here, so my knowledge is limited.

> With the "execute-in-place" option, the CPU fetches instructions to
> execute by reading CE0 and not from a preloaded ROM initialized at
> machine init time. I think it is good to mention the difference and
> the impact on performance : It is more accurate modeling but slower.

I'll add this.

This machine model supports emulation of the boot from the CE0 flash 
device by setting option ``execute-in-place``. When using this option, 
the CPU fetches instructions to execute by reading CE0 and not from a 
preloaded ROM initialized at machine init time. As a result, execution 
will be slower.

Is that ok for you?

> > It's worth repeating what the option means IMHO.
>
> sure. np.
>
> Thanks,
>
> C.