From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pg1-f195.google.com ([209.85.215.195]:45218 "EHLO mail-pg1-f195.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727328AbgCYT67 (ORCPT ); Wed, 25 Mar 2020 15:58:59 -0400 From: Nick Terrell Subject: [PATCH v3 4/8] init: add support for zstd compressed kernel Date: Wed, 25 Mar 2020 12:58:45 -0700 Message-Id: <20200325195849.407900-5-nickrterrell@gmail.com> In-Reply-To: <20200325195849.407900-1-nickrterrell@gmail.com> References: <20200325195849.407900-1-nickrterrell@gmail.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-kbuild-owner@vger.kernel.org List-ID: To: Nick Terrell Cc: linux-kernel@vger.kernel.org, Chris Mason , linux-kbuild@vger.kernel.org, x86@kernel.org, gregkh@linuxfoundation.org, Petr Malat , Kees Cook , Kernel Team , Nick Terrell , Adam Borowski , Patrick Williams , rmikey@fb.com, mingo@kernel.org, Patrick Williams From: Nick Terrell * Adds the zstd cmd to scripts/Makefile.lib * Adds the HAVE_KERNEL_ZSTD and KERNEL_ZSTD options Architecture specific support is still needed for decompression. Signed-off-by: Nick Terrell --- init/Kconfig | 15 ++++++++++++++- scripts/Makefile.lib | 15 +++++++++++++++ 2 files changed, 29 insertions(+), 1 deletion(-) diff --git a/init/Kconfig b/init/Kconfig index 20a6ac33761c..9b646a25918e 100644 --- a/init/Kconfig +++ b/init/Kconfig @@ -173,13 +173,16 @@ 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 @@ -258,6 +261,16 @@ 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 tools 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 752ff0a225a9..4b99893efa3d 100644 --- a/scripts/Makefile.lib +++ b/scripts/Makefile.lib @@ -394,6 +394,21 @@ 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. + +quiet_cmd_zstd = ZSTD $@ +cmd_zstd = (cat $(filter-out FORCE,$^) | \ + zstd -19 && \ + $(call size_append, $(filter-out FORCE,$^))) > $@ || \ + (rm -f $@ ; false) + # ASM offsets # --------------------------------------------------------------------------- -- 2.25.1