LS1046A PPA firmware

[Sascha Hauer]

Hi Renauld,

On Wed, Nov 15, 2023 at 04:50:54PM +0000, Renaud Barbier wrote:
> For your  information, the ppa firmware loaded for the LS1046A by
> Barebox does not work for the LS1026A.  The build from SDK PPA
> Firmware: Version LSDK-18.06 is needed to work with the dual core.

Good to know, thanks.

On a related note, it seems the PPA firmware loading is broken
in current master and likely the last release. With dba1c26f70
("arm: layerscape: ppa: reserve SDRAM region for PPA") the area
where the PPA is started is mapped uncached and non-executable.
That's silly of course because we jump to that area a few moments
later. We have to map it uncached when the PPA returns, but not
before. I think it was broken already before that patch as we call
barebox_arm_entry() with the PPA area skipped, so I think the PPA
range is uncached/non-executable even without this patch due to
latest MMU changes.

Unfortunately I found that out by bricking my board, so I can only
fix that when the board is recovered.

Sascha

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