- Import zstd-1.3.6 from upstream
- Add zstd's module.c file
- Add the zstd module to Makefile.core.def
Import zstd-1.3.6 from upstream [1]. Only the files need for decompression
are imported. I used the latest zstd release, which includes patches [2] to
build cleanly in GRUB.
I included the script used to import zstd-1.3.6 below at the bottom of the
commit message.
Upstream zstd commit hash: 4fa456d7f12f8b27bd3b2f5dfd4f46898cb31c24
Upstream zstd commit name: Merge pull request #1354 from facebook/dev
Zstd requires some posix headers, which it gets from posix_wrap.
This can be checked by inspecting the .Po files generated by automake,
which contain the header dependencies. After building run the command
`cat grub-core/lib/zstd/.deps-core/*.Po` to see the dependencies [3].
The only OS dependencies are:
- stddef.h, which is already a dependency in posix_wrap, and used for size_t
by lzo and xz.
- stdarg.h, which comes from the grub/misc.h header, and we don't use in zstd.
All the types like uint64_t are typedefed to grub_uint64_t under the hood.
The only exception is size_t, which comes from stddef.h. This is already the
case for lzo and xz. I don't think there are any cross-compilation concerns,
because cross-compilers provide their own system headers (and it would already
be broken).
[1] https://github.com/facebook/zstd/releases/tag/v1.3.6
[2] https://github.com/facebook/zstd/pull/1344
[3] https://gist.github.com/terrelln/7a16b92f5a1b3aecf980f944b4a966c4
```
curl -L -O https://github.com/facebook/zstd/releases/download/v1.3.6/zstd-1.3.6.tar.gz
curl -L -O https://github.com/facebook/zstd/releases/download/v1.3.6/zstd-1.3.6.tar.gz.sha256
sha256sum --check zstd-1.3.6.tar.gz.sha256
tar xzf zstd-1.3.6.tar.gz
SRC_LIB="zstd-1.3.6/lib"
DST_LIB="grub-core/lib/zstd"
rm -rf $DST_LIB
mkdir -p $DST_LIB
cp $SRC_LIB/zstd.h $DST_LIB/
cp $SRC_LIB/common/*.[hc] $DST_LIB/
cp $SRC_LIB/decompress/*.[hc] $DST_LIB/
rm $DST_LIB/{pool.[hc],threading.[hc]}
rm -rf zstd-1.3.6*
echo SUCCESS!
```
Signed-off-by: Nick Terrell <terrelln@fb.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
