Copy stable/9 to releng/9.3 as part of the 9.3-RELEASE cycle.

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

Copy head to stable/9 as part of 9.0-RELEASE release cycle.

Approved by: re (implicit)

Use the new arch_loadaddr I/F to align ELF objects to PBVM page
boundaries. For good measure, align all other objects to cache
lines boundaries.

Use the new arch_loadseg I/F to keep track of kernel text and
data so that we can wire as much of it as is possible. It is
the responsibility of the kernel to link critical (read IVT
related) code and data at the front of the respective segment
so that it's covered by TRs before the kernel has a chance to
add more translations.

Use a better way of determining whether we're loading a legacy
kernel or not. We can't check for the presence of the PBVM page
table, because we may have unloaded that kernel and loaded an
older (legacy) kernel after that. Simply use the latest load
address for it.

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.

Extend struct devdesc with a unit field, called d_unit. Promote the
device (kind) specific unit field to the common field. This change
allows a future version of libefi to work without requiring anything
more than what is defined in struct devdesc and as such makes it
possible to compile said version of libefi for different platforms
without requiring that those platforms have identical derivatives
of struct devdesc.

Don't unconditionally compile-in the bcache code. It's only used on
i386/amd64 and pc98. Remove useless calls to bcache_init() from the
ia64 and sparc64 loaders, as well as from the OFW common code.

Post repocopy build fixes.

Forced commit to note that this file was repocopied from ../skiload.

Repocopy by: peter

Fix the ski loader, broken by the gcc upgrade. Update the linker
script to match the one for the EFI loader and rewrite __start()
in assembly to have gp defined without getting in the way of the
compiler.

Use __FBSDID rather than rcsid[].

At great personal risk, add a __packed and __aligned(x) define that
expand to __attribute__((packed)) and __attribute__((aligned(x)))
respectively. Replace the handful of gcc-ism's that use
__attribute__((aligned(16))) etc around the kernel with __aligned(16).

There are over 400 __attribute__((packed)) to deal with, that can come
later. I just want to use __packed in new code rather than add more
gcc-ism's.

Add a version of the loader which runs under SKI, the HP ia64 simulator.
This loader is quite functional and can load and run kernels. The kernels
don't quite work right after loading but that should be easily fixable.