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

Be nice, don't use the f-word.

Revert the last change. Masking only 2 MSBs of the virtual address
to get the physical address doesn't work for all values of KVA_PAGES,
while masking 8 MSBs works for all values of KVA_PAGES that are
multiple of 4 for non-PAE and 8 for PAE. (This leaves us limited
with 12MB for non-PAE kernels and 14MB for PAE kernels.)

To get things right, we'd need to subtract the KERNBASE from the
virtual address (but KERNBASE is not easy to figure out from here),
or have physical addresses set properly in the ELF headers.

Discussed with: jhb

Because the BTX mini-kernel now uses flat memory mode and clients
are no longer limited to a virtual address space of 16 megabytes,
only mask high two bits of a virtual address. This allows to load
larger kernels (up to 1 gigabyte). Not masking addresses at all
was a bad idea on machines with less than >3G of memory -- kernels
are linked at 0xc0xxxxxx, and that would attempt to load a kernel
at above 3G. By masking only two highest bits we stay within the
safe limits while still allowing to boot larger kernels.

(This is a safer reimplmentation of sys/boot/i386/boot2/boot.2.c
rev. 1.71.)

Prodded by: jhb
Tested by: nyan (pc98)

Adopt comments borrowed from aout_freebsd.c.

Add the loader side of support for preloading ELF relocatable object
format modules, which are currently only used on the amd64 platform.
This initial implementation just parses enough of the module to
allow it to extract dependencies and load all the bits into the
right place in memory, so the kernel must still do the full relocation
and linking. The details of the loaded sections are passed to the
kernel by supplying a copy of the ELF section header table as module
metadata with the MODINFOMD_SHDR tag.

Use __FBSDID().
Also some minor copyright style cleanups.

Enable the i386 loader to load and run an amd64 kernel. If this puts
things over floppy size limits, I can exclude it for release builds or
something like that. Most of the changes are to get the load_elf.c file
into a seperate elf32_ or elf64_ namespace so that you can have two
ELF loaders present at once. Note that for 64 bit kernels, it actually
starts up the kernel already in 64 bit mode with paging enabled. This
is really easy because we have a known minimum feature set.

Of note is that for amd64, we have to pass in the bios int 15 0xe821
memory map because once in long mode, you absolutely cannot make VM86
calls. amd64 does not use 'struct bootinfo' at all. It is a pure loader
metadata startup, just like sparc64 and powerpc. Much of the
infrastructure to support this was adapted from sparc64.

Libdisk does not need to include <sys/diskslice.h> any more.

Move the remaining bits of <sys/diskslice.h> to <i386/include/bootinfo.h>

Move i386/pc98 specific bits from <sys/reboot.h> to
<i386/include/bootinfo.h> as well.

Adjust includes in sys/boot accordingly.

Cleanup warnings. Most of these are signed/unsigned warnings, as well as
some added const's.

Delay calling the device cleanup routines until the absolute last
moment. We were cleaning up after PXE too early and the module
dependancy code would not be able to load any files if it needed
too.

Update loader logic to distinguish modules vs. files.
Add support for module metadata. The old way of dependancy
handling will be supported for a while.

Reviewed by: peter

$Id$ -> $FreeBSD$

Turn symbol table info passing back on, although it's probably not
particularly useful in this form. KLD can deal with it much better.
setenv kernelname moved earlier.

Don't include ELF symbol information yet - it causes the ELF DDB to
explode.

biosdisk.c
Allocate space for, and copy, NDOSPART slice entries from the
MBR, not just one. Add some extra debugging while we're at it.

elf_freebsd.c
Initialise the symbol table start/end pointers in case we don't
have them.

Consolidate the bootinfo-loading code, greatly simplifying the _exec
functions.

First shot at loading elf symbols. Things are a bit strange because
of the ..umm.. "wierd" way binutils lays out the file. The section
headers are nearly at the end of the file and this is a problem when
loading from a .gz file which can't seek backwards (or has a limited
reverse seek, ~2K from memory).

This is intended to be compatable with the ddb/db_elf.c code and the
alpha/libalpha/elf_freebsd.c layout. I've studied these (which are NetBSD
derived) but did it a bit differently. Naturally the process is similar
since it's supposed to end up with the same result.

i386 ELF loader startup backend. On an ELF kernel booted with the 3-stage
bootblocks, the kernel shows up as the primary module:

[3:24am]~-100# kldstat
Id Refs Address Size Name
1 1 0xf0100000 ff00000 /kernel
^^^^ oops.. :-)

Based heavily on aout_freebsd.c. Hmm.. There's so much in common that
these could probably be combined and just check the metadata to see which
format it is.