Copy stable/10@r272459 to releng/10.1 as part of
the 10.1-RELEASE process.

Approved by: re (implicit)
Sponsored by: The FreeBSD Foundation

MFC 263301

In kernel config files, it is supposed to be 'options<space><tab>' not
'options<tab><tab>', per long standing (but recently not so strictly
enforced) convention.

Copy head (r256279) to stable/10 as part of the 10.0-RELEASE cycle.

Approved by: re (implicit)
Sponsored by: The FreeBSD Foundation

Back out r253779 & r253786.

Decouple yarrow from random(4) device.

* Make Yarrow an optional kernel component -- enabled by "YARROW_RNG" option.
The files sha2.c, hash.c, randomdev_soft.c and yarrow.c comprise yarrow.

* random(4) device doesn't really depend on rijndael-*. Yarrow, however, does.

* Add random_adaptors.[ch] which is basically a store of random_adaptor's.
random_adaptor is basically an adapter that plugs in to random(4).
random_adaptor can only be plugged in to random(4) very early in bootup.
Unplugging random_adaptor from random(4) is not supported, and is probably a
bad idea anyway, due to potential loss of entropy pools.
We currently have 3 random_adaptors:
+ yarrow
+ rdrand (ivy.c)
+ nehemeiah

* Remove platform dependent logic from probe.c, and move it into
corresponding registration routines of each random_adaptor provider.
probe.c doesn't do anything other than picking a specific random_adaptor
from a list of registered ones.

* If the kernel doesn't have any random_adaptor adapters present then the
creation of /dev/random is postponed until next random_adaptor is kldload'ed.

* Fix randomdev_soft.c to refer to its own random_adaptor, instead of a
system wide one.

Submitted by: arthurmesh@gmail.com, obrien
Obtained from: Juniper Networks
Reviewed by: obrien

Migrate the AR71xx UART (an 8250 derivative) to hide behind uart_ar71xx.

The AR9330/AR9331 UART is a totally different thing, so having it included
with 'uart' is not going to work out.

Fix spelling of NFSCL option.

Assume a big-endian default on MIPS and drop the "eb" suffix from MACHINE_ARCH.
This makes our naming scheme more closely match other systems and the
expectations of much third-party software. MIPS builds which are little-endian
should require and exhibit no changes. Big-endian TARGET_ARCHes must be
changed:
From: To:
mipseb mips
mipsn32eb mipsn32
mips64eb mips64

An entry has been added to UPDATING and some foot-shooting protection (complete
with warnings which should become errors in the near future) to the top-level
base system Makefile.

Remove TARGET_BIG_ENDIAN which should have been removed previously.

o) Use ABI, not ISA_* options, to determine whether to compile bits if libkern
required for the ABI the kernel is being built for.
XXX This is implemented in a kind-of nasty way that involves including source
files, but it's still an improvement.
o) Retire ISA_* options since they're unused and were always wrong.

Build some more things (random, bridge/gif/gre, gpio, USB) as modules as well
so some embedded platform builds can use these instead of a fully monolithic
kernel.

Add a couple of missing wlan modules.

Flesh out the RSPRO GPIO config, including the RF LED.

Break out the AR71XX config file into _BASE and board specific
bits.

The ROUERSTATION and RSPRO variants contain:

* the board specific bits (eg the RTC for RSPRO, later on it'll
include the GPIO/LED definitions);
* the boot specific bits (eg, on-board flash, usb flash, etc).

For now the AR71XX_BASE file contains the common board config,
drivers and net80211/ath wireless drivers.

I'll follow this up with config files for the other boards I
have (eg the Ubiquiti LSSR71, as well as some Mikrotik boards
that use the AR71XX and atheros reference boards) which will
be quite easy to do now.