MFC libstand32 clean target fixes

r269029 (sbruno):

  Update so that clean target in sys/boot will delete the symlink
  created for machine

r269036 (sbruno):

  Delete the entire cleandepend/cleanmachine target thing now that its
  been cleared out in r269029
MFC r263005 by royger: howto_names: unify declaration
MFC r269077 (sbruno): libstand qdivrem warning fixes

  libstand's qdivrem.c assumes that sizeof(int) == sizeof(long), this is not
  true on amd64 I'm not quite positive this is the "correct" solution for
  this but it does seem to compile and shut up the spew of warnings when
  compiling libstand for userboot.

  Add two _Static_asserts() so that in the future somebody will get a compile
  failure if an architecture develops that violates the assumptions of this
  code. (strongly suggested by jmg)

  Change commetns to indicate int types instead of long.  (noted by ian in
  phabric review)

  Phabric:    https://phabric.freebsd.org/D443
MFC UEFI loader

This MFC consists of the following SVN revisions:
  258741 261568 261603 261668 263115 263117 263968 264078 264087 264088
  264092 264095 264115 264132 264208 264261 264262 264263 264319 265028
  265057 268974

Detailed commit messages:

r258741: Note that libstand is 32-bit on amd64 and powerpc64

r261568: Build libstand as a 64-bit library on amd64

  The 32-bit bootloaders now link against libstand.a in
  sys/boot/libstand32, so there is no need to force /usr/lib/libstand.a
  to be 32-bit.

r261603: Don't force efi to a 32-bit build on amd64

r261668: Build libstand as a 64-bit library on ppc64

  The 32-bit bootloaders now link against libstand.a in
  sys/boot/libstand32, so there is no need to force /usr/lib/libstand.a
  to be 32-bit.

  This is equivalent to r261568 for amd64.

r263115: Add amd64 EFI headers

r263117: Connect 64-bit boot ficl to the build

  It is not yet used, but this will ensure it doesn't get broken.

r263968: Use EFI types for EFI values (silences warnings).

  EFI UINTN is actually a 64-bit type on 64-bit processors.

r264078: Put each source file on a separate line

  This will simplify rebasing the amd64 UEFI patch set.

r264087: Build boot/ficl as 64-bit library on amd64

  The 32-bit bootloaders on amd64 now use the 32-bit version in ficl32,
  as is done with libstand32.  The native 64-bit ficl will be used by the
  upcoming UEFI loader.

r264088: Merge efilib changes from projects/uefi

  r247216: Add the ability for a device to have an "alias" handle.

  r247379: Fix network device registration.

  r247380: Adjust our load device when we boot from CD under UEFI.

    The process for booting from a CD under UEFI involves adding a FAT
    filesystem containing your loader code as an El Torito boot image.
    When UEFI detects this, it provides a block IO instance that points
    at the FAT filesystem as a child of the device that represents the CD
    itself. The problem being that the CD device is flagged as a "raw
    device" while the boot image is flagged as a "logical partition".
    The existing EFI partition code only looks for logical partitions and
    so the CD filesystem was rendered invisible.

    To fix this, check the type of each block IO device. If it's found to
    be a CD, and thus an El Torito boot image, look up its parent device
    and add that instead so that the loader will then load the kernel from
    the CD filesystem.  This is done by using the handle for the boot
    filesystem as an alias.

    Something similar to this will be required for booting from other media
    as well as the loader will live in the EFI system partition, not on the
    partition containing the kernel.

  r247381: Remove a scatalogical debug printf that crept in.

r264092: Add -fPIC for amd64

r264095: Support UEFI booting on amd64 via loader.efi

  This is largely the work from the projects/uefi branch, with some
  additional refinements.  This is derived from (and replaces) the
  original i386 efi implementation; i386 support will be restored later.

  Specific revisions of note from projects/uefi:

  r247380:

    Adjust our load device when we boot from CD under UEFI.

    The process for booting from a CD under UEFI involves adding a FAT
    filesystem containing your loader code as an El Torito boot image.
    When UEFI detects this, it provides a block IO instance that points at
    the FAT filesystem as a child of the device that represents the CD
    itself. The problem being that the CD device is flagged as a "raw
    device" while the boot image is flagged as a "logical partition". The
    existing EFI partition code only looks for logical partitions and so
    the CD filesystem was rendered invisible.

    To fix this, check the type of each block IO device. If it's found to
    be a CD, and thus an El Torito boot image, look up its parent device
    and add that instead so that the loader will then load the kernel from
    the CD filesystem.  This is done by using the handle for the boot
    filesystem as an alias.

    Something similar to this will be required for booting from other
    media as well as the loader will live in the EFI system partition, not
    on the partition containing the kernel.

  r246231:

    Add necessary code to hand off from loader to an amd64 kernel.

  r246335:

    Grab the EFI memory map and store it as module metadata on the kernel.

    This is the same approach used to provide the BIOS SMAP to the kernel.

  r246336:

    Pass the ACPI table metadata via hints so the kernel ACPI code can
    find them.

  r246608:

    Rework copy routines to ensure we always use memory allocated via EFI.

    The previous code assumed it could copy wherever it liked. This is not
    the case. The approach taken by this code is pretty ham-fisted in that
    it simply allocates a large (32MB) buffer area and stages into that,
    then copies the whole area into place when it's time to execute. A more
    elegant solution could be used but this works for now.

  r247214:

    Fix a number of problems preventing proper handover to the kernel.

    There were two issues at play here. Firstly, there was nothing
    preventing UEFI from placing the loader code above 1GB in RAM. This
    meant that when we switched in the page tables the kernel expects to
    be running on, we are suddenly unmapped and things no longer work. We
    solve this by making our trampoline code not dependent on being at any
    given position and simply copying it to a "safe" location before
    calling it.

    Secondly, UEFI could allocate our stack wherever it wants. As it
    happened on my PC, that was right where I was copying the kernel to.
    This did not cause happiness. The solution to this was to also switch
    to a temporary stack in a safe location before performing the final
    copy of the loaded kernel.

  r246231:

    Add necessary code to hand off from loader to an amd64 kernel.

  r246335:

    Grab the EFI memory map and store it as module metadata on the kernel.

    This is the same approach used to provide the BIOS SMAP to the kernel.

  r246336:

    Pass the ACPI table metadata via hints so the kernel ACPI code can
    find them.

  r246608:

    Rework copy routines to ensure we always use memory allocated via EFI.

    The previous code assumed it could copy wherever it liked. This is not
    the case. The approach taken by this code is pretty ham-fisted in that
    it simply allocates a large (32MB) buffer area and stages into that,
    then copies the whole area into place when it's time to execute. A more
    elegant solution could be used but this works for now.

  r247214:

    Fix a number of problems preventing proper handover to the kernel.

    There were two issues at play here. Firstly, there was nothing
    preventing UEFI from placing the loader code above 1GB in RAM. This
    meant that when we switched in the page tables the kernel expects to
    be running on, we are suddenly unmapped and things no longer work. We
    solve this by making our trampoline code not dependent on being at any
    given position and simply copying it to a "safe" location before
    calling it.

    Secondly, UEFI could allocate our stack wherever it wants. As it
    happened on my PC, that was right where I was copying the kernel to.
    This did not cause happiness. The solution to this was to also switch
    to a temporary stack in a safe location before performing the final
    copy of the loaded kernel.

  r247216:

    Use the UEFI Graphics Output Protocol to get the parameters of the
    framebuffer.

r264115: Fix printf format mismatches

r264132: Connect sys/boot/amd64 to the build

r264208: Do not build the amd64 UEFI loader with GCC

  The UEFI loader causes buildworld to fail when building with (in-tree)
  GCC, due to a typedef redefinition.  As it happens the in-tree GCC
  cannot successfully build the UEFI loader anyhow, as it does not support
  __attribute__((ms_abi)).  Thus, just avoid trying to build it with GCC,
  rather than disconnecting it from the build until the underlying issue
  is fixed.

r264261: Correct a variable's type for 64-bit Ficl

  FICL_INT is long.

r264262: Fix printf args for 64-bit archs

r264263: Add explicit casts to quiet warnings in libefi

r264319: Fix EFI loader object tree creation on 9.x build hosts

  Previously ${COMPILER_TYPE} was checked in sys/boot/amd64, and the efi
  subdirectory was skipped altogether for gcc (since GCC does not support
  a required attribute).  However, during the early buildworld stages
  ${COMPILER_TYPE} is the existing system compiler (i.e., gcc on 9.x build
  hosts), not the compiler that will eventually be used.  This caused
  "make obj" to skip the efi subdirectory.  In later build stages
  ${COMPILER_TYPE} is "clang", and then the efi loader would attempt to
  build in the source directory.

r265028 (dteske): Disable the beastie menu for EFI console ...

  which doesn't support ANSI codes (so things like `at-xy', `clear', and
  other commands don't work making it impossible to generate a living
  menu).

r265057 (nwhitehorn): Turn off various fancy instruction sets...

  as well as deduplicate some options.  This makes the EFI loader build
  work with CPUTYPE=native in make.conf on my Core i5.

r268974 (sbruno): Supress clang warning for FreeBSD printf %b and %D formats

Relnotes:	Yes
Sponsored by:	The FreeBSD Foundation
MFC boot1.efi stub loader

r264391 (nwhitehorn):

  Add a simple EFI stub loader. This is a quick and dirty of boot1.chrp
  from the PowerPC port with all the Open Firmware bits removed and
  replaced by their EFI counterparts. On the whole, I think I prefer
  Open Firmware.

  This code is supposed to be an immutable shim that sits on the EFI
  system partition, loads /boot/loader.efi from UFS and tells the real
  loader what disk/partition to look at. It finds the UFS root partition
  by the somewhat braindead approach of picking the first UFS partition
  it can find. Better approaches are called for, but this works for now.
  This shim loader will also be useful for secure boot in the future,
  which will require some rearchitecture.

r264403 (nwhitehorn):

  Fix buildworld. I had some local bits in my build tree that caused
  this to work by accident.

r264404 (nwhitehorn):

  Add my copyright here. Most of this is unmodified from the original
  sparc64 version, but at least some indication of changes that postdate
  the actual invention of EFI is probably a good idea.

r264414 (nwhitehorn):

  Apparently some of the i386 boot blocks are so close to full that
  adding single lines to ufsread.c spills them over. Duplicate a whole
  bunch of code to get file sizes into boot1.efi/boot1.c rather than
  modifying ufsread.c.

r264975 (nwhitehorn):

  Add generation of an EFI filesystem to hold boot1.efi. This is a near-
  exact copy of the code from boot1.chrp again.

  The resulting image is installed to /boot/boot1.efifat. If dd'ed to an
  800K "efi" partition, it should result in a bootable system.

r268975 (sbruno): Remove boot1.efi during clean target.

Relnotes:	Yes
Sponsored by:	The FreeBSD Foundation
Add UPDATING entry for r271116

Noticed by:	nwhitehorn