Hi Robert,

On 03/30/2015 08:05 AM, Robert Jarzmik wrote:

Hi,

I was wondering how the earlyconsole was supposed to work in order to add
support to the pxa architecture. More specifically, I don't understand how the
memory mapping is supposed to be available at the early parameters parsing.

The thing I don't understand is that :
 - in kernel initialization, parse_early_param() is called before
   machine_desc->map_io()
 - as a consequence, the architecture didn't add the vm early mapping for serial
   peripheral (which is added in pxa_map_io())
 - as a consequence, earlycon_map() will fail to map the serial MMIO
   (as in stack showed in [1])

Therefore, are there non-DT earlycon users on the list, and could they tell me
what way they get earlycon support in their arm boards please ?

Fixmap support has not been upstreamed yet, but if you're desperate, here's
the latest patch version:
http://lists.infradead.org/pipermail/linux-arm-kernel/2015-January/318372.html


If you're using /chosen/stdout-path, earlycon gets turned off at dummy
VT console load, so for right now, specify your earlycon and consoles on the
command line.

Regards,
Peter Hurley