how to mapping device memory in head.S

[Russell King - ARM Linux]

On Sun, Apr 12, 2015 at 08:23:59PM +0800, yoma sophian wrote:
> hi all:
> I need to map peripheral address in head.S for early usage.

Basically, you do not.

Please explain in detail what you're trying to do.

> 1. CONFIG_DEBUG_LL is  using short-descriptor 1st-level section
> descriptor formats. Is it possible to use short-descriptor 2nd-level
> small page descriptor in head.S?

Definitely not, there is no memory management at that stage to allocate
a 2nd level descriptor table.

> 2. The peripheral mapping virtual address created in head.S is need to
> access even after paging_init. Is it possible to put the mapping in
> the persistent mapping in head.S?

No, we don't support that.

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