diff options
| -rw-r--r-- | Makefile | 3 | ||||
| -rw-r--r-- | init/Kconfig | 15 | ||||
| -rw-r--r-- | scripts/Makefile.lib | 22 |
3 files changed, 38 insertions, 2 deletions
@@ -464,6 +464,7 @@ KLZOP = lzop LZMA = lzma LZ4 = lz4c XZ = xz +ZSTD = zstd CHECKFLAGS := -D__linux__ -Dlinux -D__STDC__ -Dunix -D__unix__ \ -Wbitwise -Wno-return-void -Wno-unknown-attribute $(CF) @@ -512,7 +513,7 @@ CLANG_FLAGS := export ARCH SRCARCH CONFIG_SHELL BASH HOSTCC KBUILD_HOSTCFLAGS CROSS_COMPILE LD CC export CPP AR NM STRIP OBJCOPY OBJDUMP OBJSIZE READELF PAHOLE LEX YACC AWK INSTALLKERNEL export PERL PYTHON PYTHON3 CHECK CHECKFLAGS MAKE UTS_MACHINE HOSTCXX -export KGZIP KBZIP2 KLZOP LZMA LZ4 XZ +export KGZIP KBZIP2 KLZOP LZMA LZ4 XZ ZSTD export KBUILD_HOSTCXXFLAGS KBUILD_HOSTLDFLAGS KBUILD_HOSTLDLIBS LDFLAGS_MODULE export KBUILD_CPPFLAGS NOSTDINC_FLAGS LINUXINCLUDE OBJCOPYFLAGS KBUILD_LDFLAGS diff --git a/init/Kconfig b/init/Kconfig index 0498af567f70..2b6409fec53f 100644 --- a/init/Kconfig +++ b/init/Kconfig @@ -191,13 +191,16 @@ config HAVE_KERNEL_LZO config HAVE_KERNEL_LZ4 bool +config HAVE_KERNEL_ZSTD + bool + config HAVE_KERNEL_UNCOMPRESSED bool choice prompt "Kernel compression mode" default KERNEL_GZIP - depends on HAVE_KERNEL_GZIP || HAVE_KERNEL_BZIP2 || HAVE_KERNEL_LZMA || HAVE_KERNEL_XZ || HAVE_KERNEL_LZO || HAVE_KERNEL_LZ4 || HAVE_KERNEL_UNCOMPRESSED + depends on HAVE_KERNEL_GZIP || HAVE_KERNEL_BZIP2 || HAVE_KERNEL_LZMA || HAVE_KERNEL_XZ || HAVE_KERNEL_LZO || HAVE_KERNEL_LZ4 || HAVE_KERNEL_ZSTD || HAVE_KERNEL_UNCOMPRESSED help The linux kernel is a kind of self-extracting executable. Several compression algorithms are available, which differ @@ -276,6 +279,16 @@ config KERNEL_LZ4 is about 8% bigger than LZO. But the decompression speed is faster than LZO. +config KERNEL_ZSTD + bool "ZSTD" + depends on HAVE_KERNEL_ZSTD + help + ZSTD is a compression algorithm targeting intermediate compression + with fast decompression speed. It will compress better than GZIP and + decompress around the same speed as LZO, but slower than LZ4. You + will need at least 192 KB RAM or more for booting. The zstd command + line tool is required for compression. + config KERNEL_UNCOMPRESSED bool "None" depends on HAVE_KERNEL_UNCOMPRESSED diff --git a/scripts/Makefile.lib b/scripts/Makefile.lib index 916b2f7f7098..54f7b7eb580b 100644 --- a/scripts/Makefile.lib +++ b/scripts/Makefile.lib @@ -413,6 +413,28 @@ quiet_cmd_xzkern = XZKERN $@ quiet_cmd_xzmisc = XZMISC $@ cmd_xzmisc = cat $(real-prereqs) | $(XZ) --check=crc32 --lzma2=dict=1MiB > $@ +# ZSTD +# --------------------------------------------------------------------------- +# Appends the uncompressed size of the data using size_append. The .zst +# format has the size information available at the beginning of the file too, +# but it's in a more complex format and it's good to avoid changing the part +# of the boot code that reads the uncompressed size. +# +# Note that the bytes added by size_append will make the zstd tool think that +# the file is corrupt. This is expected. +# +# zstd uses a maximum window size of 8 MB. zstd22 uses a maximum window size of +# 128 MB. zstd22 is used for kernel compression because it is decompressed in a +# single pass, so zstd doesn't need to allocate a window buffer. When streaming +# decompression is used, like initramfs decompression, zstd22 should likely not +# be used because it would require zstd to allocate a 128 MB buffer. + +quiet_cmd_zstd = ZSTD $@ + cmd_zstd = { cat $(real-prereqs) | $(ZSTD) -19; $(size_append); } > $@ + +quiet_cmd_zstd22 = ZSTD22 $@ + cmd_zstd22 = { cat $(real-prereqs) | $(ZSTD) -22 --ultra; $(size_append); } > $@ + # ASM offsets # --------------------------------------------------------------------------- |