Catch up with internal API changes for initbarea() and getdatablk()
of fsck_ffs introduced with r247212.

Submitted by:	David Wolfskill <david@catwhisker.org>
libc/opendir: Improve behaviour of union uniquifier:

* Reopen the directory using openat(fd, ".", ...) instead of opening the
  pathname again. This fixes a race condition where the meaning of the
  pathname changes and allows a reopen with fdopendir().
* Always reopen the directory for union stacks, not only when DTF_REWIND
  is passed. Applications should be able to fchdir(dirfd(dir)) and
  *at(dirfd(dir), ...). DTF_REWIND now does nothing.
Fix the bug I introduced in r247045.
After digging through more carefully, it looks like there's
no real need to have the DTB in the module directory.
So we can simplify a lot:  Just copy DTB into local heap
for "fdt addr" and U-Boot integration, drop all the extra
COPYIN() calls.

I've left one final COPYIN() to update the in-kernel DTB
for consistency with how this code used to work, but I'm
no longer convinced it's appropriate here.

I've also remove the mem_load_raw() utility that I added
to boot/common/module.c with r247045 since it's no longer
necessary.
kernacc() expects all KVAs to be covered in the kernel map. With the
introduction of the PBVM, this stopped being the case. Redefine the
VM parameters so that the PBVM is included in the kernel map. In
particular this introduces VM_INIT_KERNEL_ADDRESS to point to the base
of region 5 now that VM_MIN_KERNEL_ADDRESS points to the base of
region 4 to include the PBVM.
While here define KERNBASE to the actual link address of the kernel as
is intended.

PR:		169926
- Fix off-by-one error when returning max pin number
- Fix GPIOGET for output pins. Requesting state for
    output pin is valid operation, get the state from
    TI_GPIO_DATAOUTX register
Add new USB ID.

Submitted by:	Dmitry Luhtionov <dmitryluhtionov@gmail.com>
Fix off-by-one error in sanity checks
Fix init/uninit function type.
Turn off fast posting for the ISP2100- I'd forgotten that it actually
might have been enabled for them- now that we use all 32 bits of handle.
Fast Posting doesn't pass the full 32 bits.

Noticed by: Bugs in NetBSD. Only a NetBSD user might actually still use such old hardware.
MFC after:	1 week
MFV v242732:

Merge the ZFS I/O deadman thread from vendor (illumos).
This feature panics the system on hanging ZFS I/O, helps debugging
and resumes failed service.

The panic behavior can be controlled with the loader-only tunables:
vfs.zfs.deadman_enabled (enable or disable panic on stalled ZFS I/O)
vfs.zfs.deadman_synctime (expiration time for stalled ZFS I/O)

By default, ZFS I/O deadman is enabled by default on amd64 and i386
excluding virtual guest machines.

Illumos ZFS issues:
  3246 ZFS I/O deadman thread

References:
  https://www.illumos.org/issues/3246

MFC after:	2 weeks
Don't try and negotiate sync mode if either period or offset are zero.

PR:		kern/163064
Partially Submitted by:	Peter <pmc@citylink.dinoex.sub.org>
MFC after:	1 month
Several cleanups and fixes to mxge:

- Remove vestigial null pointer tests after malloc(..., M_WAITOK).

- Remove vestigal qualhack union

- Use strlcpy() instead of the error-prone strncpy() when parsing
  EEPROM and copying strings

- Check the MAC address in the EEPROM strings more strictly.

- Expand the macro MXGE_NEXT_STRING() at its only user. Due to a typo,
  the macro was very confusing.

- Remove unnecessary buffer limit check.  The buffer is double-NUL
  terminated per construction.

PR:		kern/176369
Submitted by:	Christoph Mallon <christoph.mallon gmx.de>
Fix ARM build by assigning the computed time here to
a variable of the right type for printf.
- Implement and use usage().
- Document the -C option.
- Allow rtadvd to be invoked without any interfaces on the command line,
  and document that possibility.

MFC after:	1 week
If rtadvd_interfaces is set to "none", start rtadvd without listing
any interfaces on the command line.

MFC after:	1 week
Remove EOL whitespace.
Enhance test(1) by adding provision to compare any combination of the
access, birth, change and modify times of two files, instead of only
being able to compare modify times.  The builtin test in sh(1) will
automagically acquire the same expansion.

Approved by:	grog
MFC after:	2 weeks
Fix typo and update copyright.
The 5300 series ciss(4) board does not work in performant mode with our
currnet initialization sequence.  Set it to simple mode only so that
systems can be updated from stable/7 to newer installations.

At some point, we should figure out why we cannot initialize performant
mode on this board.

PR:		kern/153361
Reviewed by:	scottl
Obtained from:	Yahoo! Inc.
MFC after:	2 weeks
Import media selection/preparation framework (sysinstall inspired). Makes
accessing files from various types of media nice and abstracted away from
the wet-work involved in preparing, validating, and initializing those
types of media. This will be used for the package management system module
and other modules that need access to files and want to allow the user to
decide where those files come from (either in a scripted fashion, prompted
fashion, or any combination thereof).

Heavily inspired by sysinstall and even uses the same reserved words so
that scripts are portable. Coded over months, tested continuously through-
out, and reviewed several times.

Some notes about the changes:
- Move network-setting acquisition/validation routines to media/tcpip.subr
- The options screen from sysinstall has been converted to a dialog menu
- The "UFS" media choice is renamed to "Directory" to reflect how sysinstall
  treats the choice and a new [true] "UFS" media choice has been added that
  acts on real UFS partitions (such as external disks with disklabels).
- Many more help files have been resurrected from sysinstall (I noticed that
  some of the content seems a bit dated; I gave them a once-over but they
  could really use an update).
- A total of 10 media choices are presented (via mediaGetType) including:
  CD/DVD, FTP, FTP Passive, HTTP Proxy, Directory, NFS, DOS, UFS, Floppy, USB
- Novel struct/device management layer for managing the issue of passing
  more information than can comfortably fit in an argument list.