On 17 June 2015 at 01:22, Stephen Boyd [off-list ref] wrote:

On 06/16/2015 02:51 PM, Stefan Agner wrote:

quoted

Add early fixmap support, initially to support permanent, fixed
mapping support for early console. A temporary, early pte is
created which is migrated to a permanent mapping in paging_init.
This is also needed since the attributes may change as the memory
types are initialized. The 3MiB range of fixmap spans two pte
tables, but currently only one pte is created for early fixmap
support.

Re-add FIX_KMAP_BEGIN to the index calculation in highmem.c since
the index for kmap does not start at zero anymore. This reverts
4221e2e6b316 ("ARM: 8031/1: fixmap: remove FIX_KMAP_BEGIN and
FIX_KMAP_END") to some extent.

Cc: Mark Salter <redacted>
Cc: Russell King <redacted>
Cc: Kees Cook <redacted>
Cc: Laura Abbott <redacted>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Ard Biesheuvel <redacted>
Signed-off-by: Rob Herring <robh@kernel.org>
Signed-off-by: Stefan Agner <stefan@agner.ch>

Works on msm_serial.

Tested-by: Stephen Boyd <redacted>

I gave this a spin as well, on Arndale, with /chosen/stdout-path set
to &serial_2  and just 'earlycon' (without value) passed on the
command line, and it works fine.

Tested-by: Ard Biesheuvel <redacted>