Move the Boston board flattened image tree source into its own file
which is concatenated into the final image tree source used to build the
flattened image tree. Separating boards into different files will help
us to avoid conflicts as boards are added.
Signed-off-by: NPaul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/16939/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

In preparation for splitting arch/mips/generic/vmlinux.its.S into
multiple files such that it doesn't become a conflict magnet as boards
are added, allow platforms to specify a list of image tree source files
which will be concatenated to form the final source used to build the
image tree.
Signed-off-by: NPaul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/16938/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

Introduce a "generic" platform, which aims to be board-agnostic by
making use of device trees passed by the boot protocol defined in the
MIPS UHI (Universal Hosting Interface) specification. Provision is made
for supporting boards which use a legacy boot protocol that can't be
changed, but adding support for such boards or any others is left to
followon patches.

Right now the built kernels expect to be loaded to 0x80100000, ie. in
kseg0. This is fine for the vast majority of MIPS platforms, but
nevertheless it would be good to remove this limitation in the future by
mapping the kernel via the TLB such that it can be loaded anywhere & map
itself appropriately.

Configuration is handled by dynamically generating configs using
scripts/kconfig/merge_config.sh, somewhat similar to the way powerpc
makes use of it. This allows for variations upon the configuration, eg.
differing architecture revisions or subsets of driver support for
differing boards, to be handled without having a large number of
defconfig files.
Signed-off-by: NPaul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/14353/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>