[U-Boot] Skipping relocation RAM to RAM, esp. on i.MX6?

[Stefano Babic <sbabic@denx.de>]

On 03/02/2012 11:18, Dirk Behme wrote:

> 
> Ok, understood :) Do you have any pointers or hints how to implement a
> board specific relocation skip? Just in case somebody wants us to
> implement this for a specific i.MX6 board ...

Not really - I think you have to dig into the git history, when we could
skip relocation via a CONFIG_ OPTION. Maybe someone else can give some
more hints. Anyway, nobody nowadays checks if a patch breaks when the
relocation is skipped, as this option is unsupported, and the
possibility that your implementation will be break by next update is
quite high...

>> As your concerns are surely related to speed up the boot process, IMHO
>> we can focus efforts to add cache support for MX5 / MX6.
> 
> Ok, sounds good. Any idea what has to be done for this? Or what would be
> the steps for this?

As armv7 architecture, the MX can profit of the work already done for
other SOCs. Functions for enabling / disabling / invalidate caches are
already provided, in arch/arm/lib and arch/arm/cpu/armv7/cache_v7.c. So
at least for MX5/MX6.

But we should change MXC drivers to be cache-aware. At least the FEC
driver and MMC driver are known to not work when dcache is on.

> Maybe we should open a new thread or at least rename
> the subject of this mail for this discussion?

Not a bad idea.

Best regards,
Stefano Babic

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