MFC Loader Interpreter Coexistance: r337806, r337868, r337914, r337927,
r337989, r338052, r338064, r338407, r338418, r338474

r337806:
Create a loader for each interpreter for x86 BIOS and all EFI

Create loader_{4th,lua,simp}{,.efi}. All of these are installed by
default. Create LOADER_DEFAULT_INTERP to specify the default
interpreter when no other is specified. LOADER_INTERP is the current
interpreter language building. Turn building of lua on by default to
match 4th. simploader is a simplified loader build w/o any interpreter
language (but with a simple loader). This is the historic behavir you
got with WITHOUT_FORTH. Make a hard link to the default loader. This
has to be a hard link rather than the more desirable soft link because
older zfsboot blocks don't support symlinks.

r337868:
stand: Use -Oz/-Os for all loader/stand builds.

While we're not super size constrained, the x86 BIOS /boot/loader has
to be less than about 520k-530k to be reliable. The LUA loader is at
this size today. -Oz saves 15-20% on the size, keeping us safely small
enough (comparable to where we were with the 4th loader). This will
also help with sjg's work on bringing in bearssl, though we may again
be looking for space in the LUA loader.

Size table for clang 6.0.0:
default -O1 -Os -Oz
4th 442368 417792 389120 376832
lua 524288 479232 446464 430080

r337914:
Install links for loader.efi.

r337927:
Add ashldi3 and ashrdi3 to mips.

Now that we're using -Os, mips needs these routines.

r337989:
Copy the boot loader from the new location for the co-existing
loaders.

r338052:
libsa: Add lshrdi3.c for powerpc* and mips

r338064:
Turn back the clock just a little: make userboot.so always be 4th

Turns out there was a hidden dependency we hasn't counted upon. The
host load /boot/userboot.so to boot the VMs it runs. This means that
the change to lua meant suddently that nobody could run their older
VMs because LUA wasn't in 10.0, last month's HardenedBSD, 11.2 or
whatever. Even more than for the /boot/loader* binaries, we need a
good coexistance strategy for this. While that's being designed and
implemented, drop back to always 4th for userboot.so. This will fail
safe in all but the most extreme environments (but lua-only hacks
to .lua files won't be processes in VMs until we fix it).

r338407:
lualoader: Print error messages from command failures at the prompt

Previously lualoader would remain silent, rather than printing
command_errmsg or noting that a command had failed or was not found.

r338418:
userboot: handle guest interpreter mismatches more intelligently

The switch to lualoader creates a problem with userboot: the host is
inclined to build userboot with Lua, but the host userboot's interpreter
must match what's available on the guest. For almost all FreeBSD guests in
the wild, Lua is not yet available and a Lua-based userboot will fail.

This revision updates userboot protocol to version 5, which adds a
swap_interpreter callback to request a different interpreter, and tries to
determine the proper interpreter to be used based on how the guest
/boot/loader is compiled. This is still a bit of a guess, but it's likely
the best possible guess we can make in order to get it right. The
interpreter is now embedded in the resulting executable, so we can open
/boot/loader on the guest and hunt that down to derive the interpreter it
was built with.

Using -l with bhyveload will not allow an intepreter swap, even if the
loader specified happens to be a userboot with the wrong interpreter. We'll
simply complain about the mismatch and bail out.

For legacy guests without the interpreter marker, we assume they're 4th.
For new guests with the interpreter marker, we'll read it and swap over
to the proper interpreter if it doesn't match what the userboot we're using
was compiled with.

Both flavors of userboot are installed by default, userboot_4th.so and
userboot_lua.so. This fixes the build WITHOUT_FORTH as a coincidence, which
was broken by userboot being forced to 4th.

r338474:
Be a little conservative about when to force size optimizations.

Reports have come in that there's issue with powerpc and sparc64 since
we've switched to using -Oz / -Os. We don't strictly need them for
!x86, so be conservative about when we enable them.

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 2017q3: r320547,r320553,r321621,r321844,r321969,r321991,
r322037,r322038,r322039,r322040,r322056,r322074,r322542,r322592,r322593,
r322896,r322923,r323671,r322930,r322931,r322932,r322933,r322934,r322935,
r322936,r322937,r322938,r322939,r322941,r323062,r323063,r323064,r323065,
r323100,r323131,r323174,r323258,r323261,r323272,r323367,r323379,r323389,
r323407,r323428,r323436,r323494,r323496,r323497,r323541,r323554,r323589,
r323707,r323867,r323885,r323886,r323895,r323896,r323897,r323905,r323906,
r323907,r323908,r323909,r323952,r323991,r324099,r324558,r326445,r326609,
r326610

This batch includes a special kludge to fix powerpc loader build; <stdlib.h>
was included after <stand.h> there, causing problems with DEBUG_MALLOC bits.
Include <stdlib.h> a little bit earlier to fix the build with the intention
of removing this when eventually libsa silently replaces stdlib.h with
stand.h.

r320547: Link EFI/uboot loaders with -znotext

r320553: Integer underflow in efipart_realstrategy when I/O starts after end
of disk

r321621: Always set the receive mask in loader.efi.

r321844: Clean up style in print_state(..) and pager_printf(..)

r321969: Fix the return types for printf and putchar to match their libc

r321991: Revert r321969

r322037: Add stpcpy and stpncpy to libstand

r322038: Add definitions and utilities for EFI drivers

r322039: Move EFI ZFS functions to libefi

r322040: Add EFI utility functions to libefi

r322056: Move EFI fmtdev functionality to libefi

r322074: libefi/time.c cstyle cleanup

r322542: loader.efi: repace XXX with real comments in trap.c

r322592: Remove unused defines.

r322593: Define proposed GUID for FreeBSD boot loader variables.

r322896: Make spinconsole platform independent and hook it up into EFI
loader

r322923: Hide length of geli passphrase during boot.

r323671: Fix language used in the r322923.

r322930: Move efi_main into efi/loader

r322931: Cleanup efi_main return type

r322932: Use the loader.efi conventions for the various EFI tables.

r322933: No need for MK_ZFS around these: they are by their nature only
active when MK_ZFS is true.

r322934: _STAND is sometimes defined on the command line. Make the define
here match.

r322935: Fix warnings due to type mismatch.

r322936: Remove useless 'static' for an enum definition.

r322937: Forward declare struct dsk to avoid warnings when building libi386.

r322938: Link in libefi for boot1

r322939: Use efi_devpath_str for debug path info.

r322941: Eliminate redunant device path matching.

r323062: Make efichar.c routines available to libefi.

r323063: boot1.efi: print more info about where boot1.efi is loaded from

r323064: Exit rather than panic for most errors.

r323065: Save where we're booted from

r323100: libstand: nfs_readlink() should return proper return code

r323131: Revert r322941: Eliminate redundant device matching functions

r323174: Fix loader bug causing too many pages allocation when bootloader
is U-Boot

r323258: ucs2len

r323261: Fix armv6 build

r323272: Be consistent and do return (1);

r323367: Mark init_chroot and init_script variables as deprecated.

r323379: It's been pointed out that init_script at least is useful w/o

r323389: loader.efi: chain loader should provide proper device handle

r323407: boot1 generate-fat: generate all templates at once

r323428: r323389 breaks the kernel build when WITHOUT_ZFS is defined in
src.conf

r323436: boot1: remove BOOT1_MAXSIZE default value

r323494: loader should support large_dnode

r323496: libstand: tftp_open() can leak pkt on error

r323497: libefi: efipart_open should check the status from disk_open

r323541: libefi: efipart_realstrategy rsize pointer may be NULL

r323554: Increase EFI boot file size frok 128k to 384k

r323589: loader: biosmem.c cstyle cleanup

r323707: loader: biosmem allocate heap just below 4GB

r323867: libefi: devicename.c cleanups

r323885: libefi: efi_devpath_match() should return bool

r323886: libefi: efipart.c should use calloc()

r323895: libefi: efi_devpath_match local len should be unsigned

r323896: r323885 did miss efilib.h update

r323897: efilib.h: typo in structure member description

r323905: libefi: pdinfo_t pd_unit and pd_open should be unsigned

r323906: libefi: efipart_strategy() should return ENXIO when there is no
media

r323907: libefi: efipart.c cstyle fix for efipart_print_common()

r323908: libefi: efipart_hdinfo_add_filepath should check strtol result

r323909: libefi: define EISA PNP constants

r323952: After the r317886 support for TFTP and NFS can be enable
simultaneously.

r323991: libefi: efipart_floppy() will should not pass acpi pointer if the
HID test fails

r324099: Compile loader as Little-Endian on PPC64/POWER8

r324558: Define prototype for exit and ensure references

r326445: Fix random() and srandom() prototypes to match the standard.

r326609: Make putenv and getenv match the userland definition

r326610: Fix random() prototype to match the system.

PR: 219000 221001 222215
Relnotes: yes ("The length of the geli passphrase is hidden during boot")

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

Add vm_set_register() and vm_set_desc() callbacks. These callbacks
translate directly into calls to their namesake API functions in
libvmmapi.

It is an improvement over the existing setreg(), setmsr(), setcr()
setgdt() and exec() callbacks in that the new additions give full
control and don't assume we're booting FreeBSD, like exec() and
don't assume one only wants to set the value of RSP, like setreg().

Add a callback function to userboot.so to fetch a list of environment
variables and pass them to the kernel.

Reviewed by: dfr

Replace all references to loader_callbacks_v1 with loader_callbacks.

Suggested by: grehan@

Bump USERBOOT_VERSION.

Requested by: dfr

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.