Copy stable/10@r272459 to releng/10.1 as part of
the 10.1-RELEASE process.

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

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

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

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.

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.

Start each of the license/copyright comments with /*-

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

Use __FBSDID rather than rcsid[].

Renamed the loader's zipfs to gzipfs. zipfs.c was repo-copied to gzipfs.c.

Disable loader ufs support. It causes the loader to crash on the Itanium2
box that I have. We have no EFI disk drivers yet anyway (maybe that is the
problem).

Boot from efifs first.

Add EFI network support.

Plug in ELF backend.

Hook up the native EFI filesystem reader.

style(9) and remove a left over Alpha comment

First approximation of an ia64 EFI loader. Not functional.