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

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

sparc64/zfs boot: take advantage of new libzfsboot capabilities

Also drop the now unneeded compatibility shims.

Tested by: marius
MFC after: 1 month

Provide support in loader for booting 64-bit PowerPC kernels. Like amd64,
64-bit PowerPC kernels are loaded by a 32-bit loader, since nearly all
powerpc64 firmwares execute in 32-bit mode.

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.

Use an ihandle_t to store the instance handle of an opened device
instead of a phandle_t (package handle). Since both are typedefed
to unsigned int, this is more or less cosmetic.

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

G5 support: handle the case where the OpenFirmware memory array uses
64 bits for the phys address, but only 32 for the virtual address.

- Add ':' as a separator between the OpenFirmware device space and
the file path. Commonly used on Macs e.g. "hd:9".
- Update the ofw_setcurrdev routine to match libstand setenv prototype

Not objected to by: sparc64

Change the device path representation in libofw to use the full firmware
path, instead of an internal i386 specific one. Don't try to interpret
a disklabel in ofw_disk.c, open the partition's device node directly and
let the firmware do it. This fixes booting from a partition other than 'a'
on sparc64, which is needed to support more installation methods.

No objection: ppc

Change the disk probing so that it will actually find disks other
than the first one on a controller, and work for secondary
controllers.
Due to the prom not having nodes for each disk, but a catch-all one,
we have to iterate over each device, trying to open it to determine
whether it is actually present.
Since probing this way takese some time (and spews some spurious
warnings), it should maybe be short-circuited if we use the
device we were booted from.
Implement lazy device probing, and correct slice/partiniton
handling in the ofwd_open() code. With this, I can now actually boot
a kernel from disk, and the loader does not create unnecessary
delays.

Submitted by: tmm

Make the ofw_reg structure and ofw_alloc_heap 64-bit save.

- Include openfirm.h for phandle_t.
- Add some necessary members to the ofwdisk structure.
- Add a prototype for ofw_parseofwdev.

Mega-patch for OpenFirmware loader support.

- Flesh out ofw_readin routine.
- Add OpenFirmware load and exec routines.
- Make sure memory allocation for the kernel is done correctly.
- Change the way the heap is allocated so as to make it easier to deallocate
when we hand over.
- Add a command to print memory maps similar to the one for ia64.

With this patch, I can now load and hand over to a kernel on my iMac. There
are some problems with OpenFirmware routines failing after the hand over that
still need to be addressed.

OpenFirmware/PowerPC loader, part 2.

As of this patchset, the loader builds (under NetBSD/macppc), boots, interacts
and talks to BOOTP/NFS servers.

(main.c was moved from boot/ofw/libofw to boot/ofw/common but has no revision
history)

Reviewed by: obrien

"Ok, my loader's now up to putting up a prompt. It probes disks partially
but can't boot from them yet."

Thanks to Stephane Potvin for the some of the code in this set.

Submitted by: Benno Rice <benno@jeamland.net>