The powerpc kernel always requires an Open Firmware like device tree
to supply device information. On systems without OF, this comes from
a flattened device tree blob. This blob is usually generated by dtc,
a tool which compiles a text description of the device tree into the
flattened format used by the kernel. Sometimes, the bootwrapper makes
small changes to the pre-compiled device tree blob (e.g. filling in
the size of RAM). To do this it uses the libfdt library.
Because these are only used on powerpc, the code for both these tools
is included under arch/powerpc/boot (these were imported and are
periodically updated from the upstream dtc tree).
However, the microblaze architecture, currently being prepared for
merging to mainline also uses dtc to produce device tree blobs. A few
other archs have also mentioned some interest in using dtc.
Therefore, this patch moves dtc and libfdt from arch/powerpc into
scripts, where it can be used by any architecture.
The vast bulk of this patch is a literal move, the rest is adjusting
the various Makefiles to use dtc and libfdt correctly from their new
locations.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Some time ago, a copies of the upstream dtc and libfdt sources were
included in the kernel tree to avoid having these as external
dependencies for building the kernel. Since then development on the
upstream dtc and libfdt has continued. This updates the in-kernel
versions to match the recently released upstream dtc version 1.2.0.
This includes a number of bugfixes, many cleanups and a few new
features.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>
This incorporates a copy of dtc into the kernel source, in
arch/powerpc/boot/dtc-src. This commit only imports the upstream
sources verbatim, a later commit will actually link it into the kernel
Makefiles and use the embedded code during the kernel build.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>
