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

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

o Bump the EFI loader version to 3.1.
o Add the about, pbvm and reboot commands.
o Trim the banner (suppress maker and date).

MFaltix:
Add support for Pre-Boot Virtual Memory (PBVM) to the loader.

PBVM allows us to link the kernel at a fixed virtual address without
having to make any assumptions about the physical memory layout. On
the SGI Altix 350 for example, there's no usuable physical memory
below 192GB. Also, the PBVM allows us to control better where we're
going to physically load the kernel and its modules so that we can
make sure we load the kernel in memory that's close to the BSP.

The PBVM is managed by a simple page table. The minimum size of the
page table is 4KB (EFI page size) and the maximum is currently set
to 1MB. A page in the PBVM is 64KB, as that's the maximum alignment
one can specify in a linker script. The bottom line is that PBVM is
between 64KB and 8GB in size.

The loader maps the PBVM page table at a fixed virtual address and
using a single translations. The PBVM itself is also mapped using a
single translation for a maximum of 32MB.

While here, increase the heap in the EFI loader from 512KB to 2MB
and set the stage for supporting relocatable modules.

Use the kernel's start address to determine what to map. This allows
us to link the kernel at different addresses without needing to build
a corresponding loader.

Add command-line option -dev to set the default value of the currdev
variable. This is to be used by the EFI boot manager.

While here, re-factor the code a little bit and bump the version to
2.1.

Remove file system support based on the simple file system protocol
as this only allows us to access file systems that EFI knows about.
With a loader that can only use EFI-supported file systems, we're
forced to put /boot on the EFI system partition. This is suboptimal
in the following ways:
1. With /boot a symlink to /efi/boot, mergemaster complains about
the mismatch and there's no quick solution.
2. The EFI loader can only boot a single version of FreeBSD. There's
no way to install multiple versions of FreeBSD and select one
at the loader prompt.
3. ZFS maintains /boot/zfs/zpool.cache and with /boot a symlink we
end up with the file on a MSDOS file system. ZFS does not have
proper handling of file systems that are under Giant.

Implement a disk device based on the block I/O protocol instead and
pull in file system code from libstand. The disk devices are really
the partitions that EFI knows about.

This change is backward compatible.

MFC after: 1 week

Major rework of the ia64 loaders. The two primary objectives are:
1. Make libefi portable by removing ia64 specific code and build
it on i386 and amd64 by default to prevent regressions. These
changes include fixes and improvements over previous code to
establish or improve APIs where none existed or when the amount
of kluging was unacceptably high.
2. Increase the amount of sharing between the efi and ski loaders
to improve maintainability of the loaders and simplify making
changes to the loader-kernel handshaking in the future.

The version of the efi and ski loaders are now both changed to 1.2
as user visible improvements and changes have been made.

This file was repocopied from src/sys/boot/efi/loader.

Pass the HCDP table address to the kernel. If no such table exists,
NULL is passed. The address of the HCDP table can be found by
iterating over the configuration tables in the EFI system table.
To avoid more duplication, a function can be called with the GUID
of interest. The function will do the scanning. Use the function
in all places where we iterate over the configuration tables in
an attempt to find a specific one.

Bump the loader version number as the result of this.

Approved by: re (blanket)

Remove a left-over virtual mapping of uncached I/O port space.
Previous kernels unwantingly depended on this mapping, but as
of version 1.123 of src/sys/ia64/ia64/machdep.c this dependency
has been removed. Consequently, one has to update the kernel
before updating the loader. The documented/recommended upgrade
will suffice in this case.

Due to a visible (from the kernels point of view) change in
behaviour, bump the loader version number from 0.3 to 1.0.

Approved by: re (carte blanc)

Pass the physical address of the bootinfo block to the kernel in
register r8. We continue to write the bootinfo block at the same
hardwired address, because the kernel still expects it there.
It is expected that future kernels use register r8 to get to the
bootinfo block and don't depend on the hardwired address anymore.

Bump the loader version once again due to the interface change.

The EFI loader has been improved a lot since it was first added.
Most significantly (from an interfacing point of view) is the
support for the FPSWA pointer passing. Even though that was added
4 months ago, it's probably not a bad idea to bump the version
number to reflect this.

First approximation of an ia64 EFI loader. Not functional.