MFC r334656, r334665, r334695

r334656:
Add vsnprintf() to libsa. Alpha-sort the printf prototypes in stand.h.

r334665:
Make the v*printf() functions in libsa return int instead of void.
This makes them compatible with the C standard signatures, avoiding
spurious mismatch errors in the places where the oddball requirements
of standalone code end up putting two declarations of the same function
in play.

r334695:
Remove comments and assertions that are no longer valid after r330809.

r330809 replaced duplication of devdesc struct fields with an embedded copy
of the devdesc struct, to avoid fragility. That means all the scattered
comments indicating that structs must match are no longer valid. Likewise
asserts that attempted to mitigate some of the old fragility.

Reviewed by: imp@

MFC r330806-r330815, r330837, r330864, r330883

pc98 changes associated with the named commits are also included in this
commit, despite not having been made with the original commits due to its
removal in head.

r330806:
Minor cosmetic changes.

Make sure { on the same line as struct for all struct *devdesc. Move
some type definitions to next to the dv_type define, since that's what
sets the d_type.

r330807:
We can't use d_opendata for blkio storage.

open_disk uses d_opendata for it's own purpse. We can't store blkio
there. Fortunately, blkio is stored elsewhere and we never actually
retrieve blkio from d_opendata. Eliminate it as a source of confusion.
Eliminate all stores of d_opendata in efi since this layer doesn't own
that field.

r330808:
Make struct libi386_devdesc match the struct devdesc better

Move data to top and call it d_opendata.

r330809:
Use the actual struct devdesc at the start of all *_devdesc structs

The current system is fragile and requires very careful layout of all
*_devdesc structures. It also makes it hard to change the base
devdesc. Take a page from CAM and put the 'header' in all the derived
classes and adjust the code to match.

For OFW, move the iHandle h_handle out of a slot conflicting with
d_opendata. Due to quirks in the alignment rules, this worked.
However changing the code to use d_opendata storage now that it's a
pointer is hard, so just have a separate field for it.

All other cleanups were to make the *_devdesc structures match where
they'd taken some liberties that were none-the-less compatible enough
to work.

r330810:
Remove d_type from devdesc. It's not needed as we can fetch it from
d_dev->dv_type when we need it.

r330811:
GC unused routines.

Sponsored by: Netflix

r330812:
Use the one-line-per-file pattern here, and sort the file names.

Sponsored by: Netflix

r330813:
Move the env convenience routines out of boot1.c.

These routines are more generally useful. Even though boot1 is on its
way out, it's better to make these common during the transition than
copy them.

r330814:
Star BootCurrent entry when booting.

Sponsored by: Netflix

r330815:
Print the load and device path as well as BootCurrent and BootOrder

Sponsored by: Netflix

r330837:
biosdisk.c should not set d_opendata.

Same as 330807, d_opendata is owned by open_disk and we should not
set it.

M stand/i386/libi386/biosdisk.c

r330864:
Prefer uintXX_t to u_intXX_t

A foolish consistency is the hobgoblin of little minds, adored by
little statesmen and philosophers and divines. With consistency a
great soul has simply nothing to do. -- Ralph Waldo Emerson

r330883:
Fix typo that misteriously passes compilation.

MFC r325834,r325997,326502: Move sys/boot to stand/

This is effectively a direct commit to stable/11, due to differences between
stable/11 and head. Changes to DTS in sys/boot/fdt/dts were often
accompanied by kernel changes. Many of these were also risc-v updates that
likely had many more dependencies to MFC.

Because of this, sys/boot/fdt/dts remains as-is while everything else in
sys/boot relocates to stand/.

r325834: Move sys/boot to stand. Fix all references to new location

r325997: Remove empty directories.

r326502: Document the sys/boot -> stand move in hier.7 and the top-level README.

MFC Loader Fixes 2017q1: r311458,r312237,r312314,r312374,r312947,r313042,
r313047,r313166,r313328,r313332,r313333,r313337,r313348,r313349,r313389,
r313442,r313451,r313575,r313645,r313710,r314114,r314213,r314275,r314945,
r314948,r315008,r315408,r315427,r315645,r315646,r315648,r315653,r315850,
r316064,r316078,r316079,r316100,r316104,r316111,r316112,r316171,r316279,
r316280,r316287,r316311,r316343,r316424,r316436

r311458: Use compiler driver to link BERI boot loaders

r312237: loader.efi: find_currdev() can leak memory

r312314: loader: move device path definitions to include/efidevp.h

r312374: loader: efi devpath api usage should be more aware of NULL pointers

r312947: Remove "-Xassembler -G0" from CFLAGS.

r313042: loader.efi environment related cleanups

r313047: loader: disk/part api needs to use uint64_t offsets

r313166: loader: libefi/env.c warnings in arm build

r313328: loader: Implement disk_ioctl() to support DIOCGSECTORSIZE and
DIOCGMEDIASIZE.

r313332: loader: bcache read ahead block count should take account the large
sectors

r313333: loader: Replace EFI part devices.

r313337: loader: 313329 missed ZFS guard in loader/main.c

r313348: loader: biosdisk fix for 2+TB disks

r313349: loader: disk io should not use alloca()

r313389: efipart is also using the '%S' printf format, add -Wno-format for
it.

r313442: loader: possible NULL pointer dereference in efipart.c

r313451: loader: possible NULL pointer dereference in bcache.c

r313575: makefs: make the buffer functions look exactly like the kernel ones

r313645: loader: implement MEDIA_FILEPATH_DP support in efipart

r313710: loader: cstyle fixes and DIOCGMEDIASIZE should use uint64_t

r314114: Use LDFLAGS with CC instead of _LDFLAGS.

r314213: Remove control+r handling from geliboot's pwgets()

r314275: Remove unused macro from common/drv.c.

r314945: Some style(9) fixes. No functional changes.

r314948: Try to extract the RFC1048 data from PXE.

r315008: r314948 seems to be missing a variable or two that will break

r315408: loader: remove open_disk cache

r315427: loader: biosdisk should report IO error from INT13

r315645: loader: disk_cleanup was left in userboot_disk.c

r315646: loader: pxe.h constants have wrong values

r315648: libstand: verify value provided by nfs.read_size

r315653: loader: verify the value from dhcp.interface-mtu and use snprintf
o set mtu

r315850: The original author abused Nd (one-line description, used by
makewhatis)

r316064: Fix build with path names with 'align' or 'nop' in them.

r316078: gpt*boot: Save a bit more memory when LOADER_NO_GELI_SUPPORT is
specified

r316079: Simply retire the sedification of the boot2.s file.

r316100: Remove -fno-guess-branch-probability and -fno-unit-at-a-time.

r316104: Use `NO_WCAST_ALIGN` instead of spelling it out as -Wno-cast-align
in CFLAGS

r316111: loader: move bios getsecs into time.c

r316112: loader: ls command should display file types properly

r316171: xfsread inlined uses more space, so remove the inline tag.

r316279: loader: efipart should check disk size from partition table

r316280: loader: simplify efi_zfs_probe and avoid double probing for zfs.

r316287: Remove OLD_NFSV2 from loader and libstand

r316311: Add explicit_bzero() to libstand, and switch GELIBoot to using it

r316343: Implement boot-time encryption key passing (keybuf)

r316424: Fix sparc64 build broken by r316343 and r316076

r316436: Restore EFI boot environment functionality broken in r313333

PR: 216940 217298 217935

Copy head@r302406 to stable/11 as part of the 11.0-RELEASE cycle.
Prune svn:mergeinfo from the new branch, as nothing has been merged
here.

Additional commits post-branch will follow.

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

Fix several instances where the boot loader ignored pager_output
return value when it could return 1 (indicating we should stop).
Fix a few instances of pager_open() / pager_close() not being called.
Actually use these routines for the environment variable printing code
I just committed.

Implement GELI (AES-XTS and AES-CBC only) in gptboot and gptzfsboot

Allows booting from a GELI encrypted root file system, via UFS or ZFS

Reviewed by: gnn, smh (previous version), delphij (previous version)
Relnotes: yes
Sponsored by: ScaleEngine Inc.
Differential Revision: https://reviews.freebsd.org/D4593

Implement simple ops for umass_disk

The initial IOCTL implementation supports reading disk physical
geometry.
Two additional functions were added. They allow reading/writing raw
data to the disk (default partition).

Submitted by: Wojciech Macek <wma@semihalf.com>
Obtained from: Semihalf
Sponsored by: Juniper Networks Inc.
Differential Revision: https://reviews.freebsd.org/D4143

Fix comment.

MFC after: 1 week

Add the flags parameter to the disk_open() function and DISK_F_NOCACHE
flag, that disables the caching of partition tables metadata.
Use this flag for floppies in the libi386/biosdisk driver.

Almost each time when loader opens a file, this leads to calling
disk_open(). Very often this is called several times for one file.
This leads to reading partition table metadata for each call. To
reduce the number of disk I/O we have a simple block cache, but it
is very dumb and more than half of I/O operations related to reading
metadata, misses this cache.

Introduce new cache layer to resolve this problem. It is independent
and doesn't need initialization like bcache, and will work by default
for all loaders which use the new DISK API. A successful disk_open()
call to each new disk or partition produces new entry in the cache.
Even more, when disk was already open, now opening of any nested
partitions does not require reading top level partition table.
So, if without this cache, partition table metadata was read around
20-50 times during boot, now it reads only once. This affects the booting
from GPT and MBR from the UFS.

Unbreak booting from the true dedicated disks.
When we open the disk, check the type of partition table, that has
been detected. If this is BSD label, then we assume this is DD mode.

Reported by: dim@

Introduce new API to work with disks from the loader's drivers.
It uses new API from the part.c to work with partition tables.

Update userboot's disk driver to use new API. Note that struct
loader_callbacks_v1 has changed.

Add a version of the FreeBSD bootloader which can run in userland, packaged
as a shared library. This is intended to be used by BHyVe to load FreeBSD
kernels into new virtual machines.