On Fri, Jan 16, 2015 at 03:08:37AM +0000, Jon Masters wrote:

Hi Folks,

We're implementing support for SPCR table parsing shortly[0], since it
will allow to deprecate supplying a "console=" (and eventually, also
"earlycon=") on 64-bit ARM servers, where it's not always the case that
we can assume a 16550 at a specific address. SPCR has been provided on
x86 systems since 2000 but is not (yet) supported by Linux.

For anyone using DT rather than ACPI, the same can be achieved in
mainline with /chosen/stdout-path as of:

7914a7c5651a5161 "of: support passing console options with stdout-path"

Documented in:

2a9d832cc9aae21e "of: Add bindings for chosen node, stdout-path"

e.g.

uart: serial at f00 {
	reg = <0xf00 0x200>;
	compatible = "vendor,some-serial-device";
};

chosen {
	stdout-path = "/serial at f00:115200n8";
};

This will be used for both the console and earlycon. Please make use of
this where possible.

Thanks,
Mark.