[PATCH v6 6/9] ARM: vexpress: Motherboard RS1 memory map support

Pawel Moll pawel.moll at arm.com
Fri Jan 27 09:02:40 EST 2012


On Thu, 2012-01-19 at 16:46 +0000, David Vrabel wrote:
> >>  __create_page_tables has only mapped the single physical
> >> page at 0x1c090000 and thus the test for the UART in the other memory
> >> map faults.

I got to the bottom of the problem... The mapping created by the
DEBUG_LL code in __create_page_tables is actually a section (1MB) so
covers both possible accesses (0xf8009000 and 0xf8090000). The
difference between model and hardware is that "real" RS1 VE has a DAP
ROM located between 0xf8000000 and 0xf800ffff so the 0xf8009000 succeeds
(returning some irrelevant data), while model is "empty" in that space,
so it faults.

Anyway, I have an idea how to solve (or rather work around) the problem
and will get if working on models in the next version of the series.
I'll send you a modified version of the relevant patch before that so
you can test it.

Thanks for your time!

Paweł





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