Re: [PATCH 20/23] ARM: i.MX8M: Add support to extract OP-TEE provided informations

[Marco Felsch <m.felsch@pengutronix.de>]

Hi Ahmad,

On 26-01-15, Ahmad Fatoum wrote:
> Hello,
> 
> On 1/15/26 4:19 PM, Marco Felsch wrote:
> > On 26-01-15, Ahmad Fatoum wrote:
> >>>> +		pr_warn("Failed to extract OP-TEE FDTO, continue without FDTO\n");
> >>>> +		/*
> >>>> +		 * Don't BUG() because the system may have compile-time config
> >>>> +		 * support
> >>>> +		 */
> >>>> +		return;
> >>>> +	}
> >>>> +
> >>>> +	handoff_data_add(HANDOFF_DATA_BL32_DT_OVL, fdto_dst, fdto_size);
> >>>
> >>> The overlay isn't used in barebox itself, but only for the Kernel.
> > 
> > This is not true. This patchset adds to support to use the overlay
> > within barebox too. With the patches Fabian provided, it would eliminate
> > the need for i.MX6(ULL) boards to have this strange initcall which
> > checks a magic memory location for an overlay to apply it.
> > >>>
> >>> You Could just pick up the overlay from the i.MX scratch space in
> >>> barebox proper and pass it to optee_register_overlay().
> >>
> >> Agreed. There seems to be no need to do this in the PBL.
> > 
> > The early barebox code checks for HANDOFF_DATA_BL32_DT_OVL and applies
> > the overlay. Do you suggest that I shall extract the data within barebox
> > common code rather? I'm not sure if this is even possible.
> 
> Isn't this basically what virt_board_driver_init() is doing? Would this
> not work for your purposes?
> 
> I am generally not a friend of putting logic that can equally well be
> located in barebox proper into the PBL. It's slow, it's code duplication
> and if we do it, there should be a strong reason why it needs to be in
> the PBL. There might very well be a reason here that this needs to be
> absolutely done in the PBL (e.g. I can understand fixing up memory size
> in PBL, because firmware needs it that early), but I don't yet see it
> here for application of the overlay.

I see and you're completely right, if something can be done in barebox
proper we should do it there. I have to check the
virt_board_driver_init() and how this approach can be re-used for the
this common abbroach.

Thanks for your input :-)

Regards,
  Marco


> 
> Thanks,
> Ahmad
> 
> > 
> > Regards,
> >   Marco
> > 
> >>
> >> Thanks,
> >> Ahmad
> >>
> >>>
> >>> Sascha
> >>>
> >>>
> >>
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> >>
> >>
> > 
> 
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> 

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