MFC r293053, r293061, r293063, r293064, r293065, r293775, r293792:

Use 64-bit math when finding a block of ram to hold the kernel. This fixes
a problem on 32-bit systems which have ram occupying the end of the physical
address space -- for example, a block of ram at 0x80000000 with a size of
0x80000000 was overflowing 32 bit math and ending up with a calculated size
of zero.

Use 64-bit math when processing the lists of physical and excluded memory
to generate the phys_avail and dump_avail arrays.

Work around problems that happen when there is ram at the end of the
physical address space.

Cast pointer through uintptr_t on the way to uint64_t to squelch a warning.

Reword the comment to better describe what I found while researching the
problem that led to this temporary workaround (and also so I can properly
cite the PR in the commit this time).

Cast using uintfptr_t and eliminate the cast to uint64_t which is uneeded
because rounding down cannot increase the number of bits needed to express
the result.

Go back to using uintptr_t, because code that actually compiles is
infinitely less buggy than code that is theoretically correct in some
alternate universe.

PR: 201614

MFC r279702: Update a comment that had drifted out of date.

MFC r277532, r277533: Add Maxmem global for arm.

MFC r272333: Honor exclusion flags when building the memory lists.

MFC r261643, r261646, r261648, r261649, r261651, r261656, r261657, r261663,
r261676, r261677, r261698, r261778

Consolidate code related to setting up physical memory configuration into
a new physmem.c file.

Replace compile-time constant KERNPHYSADDR with abp_physaddr

Calculate the kernel's load address from the PC in the elf / gzip
trampoline instead of relying on KERNPHYSADDR as a compile-time constant.

It turns out a global variable is the only straightforward way to
communicate the kernel's physical load address from where it's known in
initarm() into cpu_mp_start() which is called from non-arm code and
takes no parameters.

Remove the now unused MMU_INIT macro.

Use vm_paddr_t, not vm_offset_t, when dealing with physical addresses.

No need to set physmem in each initarm() instance anymore, it's handled
in common code now.

Pass the pagetable used from locore.S to initarm to allow it to map data
in as required.

Fix the physmem exclude-region clipping logic for the edge-trim case.

Add some extra debugging output when DEBUG is defined.

Update legacy platforms to use new arm_physmem helper routines.

MFC r279702: Update a comment that had drifted out of date.

MFC r277532, r277533: Add Maxmem global for arm.

MFC r272333: Honor exclusion flags when building the memory lists.

MFC r261643, r261646, r261648, r261649, r261651, r261656, r261657, r261663,
r261676, r261677, r261698, r261778

Consolidate code related to setting up physical memory configuration into
a new physmem.c file.

Replace compile-time constant KERNPHYSADDR with abp_physaddr

Calculate the kernel's load address from the PC in the elf / gzip
trampoline instead of relying on KERNPHYSADDR as a compile-time constant.

It turns out a global variable is the only straightforward way to
communicate the kernel's physical load address from where it's known in
initarm() into cpu_mp_start() which is called from non-arm code and
takes no parameters.

Remove the now unused MMU_INIT macro.

Use vm_paddr_t, not vm_offset_t, when dealing with physical addresses.

No need to set physmem in each initarm() instance anymore, it's handled
in common code now.

Pass the pagetable used from locore.S to initarm to allow it to map data
in as required.

Fix the physmem exclude-region clipping logic for the edge-trim case.

Add some extra debugging output when DEBUG is defined.

Update legacy platforms to use new arm_physmem helper routines.