Add LZO compression support for initramfs and old-style initrd (cacb246f) · Commits · 戴 / test

lib/Kconfig

+4 −0

Original line number	Diff line number	Diff line
		@@ -117,6 +117,10 @@ config DECOMPRESS_BZIP2
		config DECOMPRESS_LZMA
		tristate

		config DECOMPRESS_LZO
		select LZO_DECOMPRESS
		tristate

		#
		# Generic allocator support is selected if needed
		#

lib/Makefile

+1 −0

Original line number	Diff line number	Diff line
		@@ -69,6 +69,7 @@ obj-$(CONFIG_LZO_DECOMPRESS) += lzo/
		lib-$(CONFIG_DECOMPRESS_GZIP) += decompress_inflate.o
		lib-$(CONFIG_DECOMPRESS_BZIP2) += decompress_bunzip2.o
		lib-$(CONFIG_DECOMPRESS_LZMA) += decompress_unlzma.o
		lib-$(CONFIG_DECOMPRESS_LZO) += decompress_unlzo.o

		obj-$(CONFIG_TEXTSEARCH) += textsearch.o
		obj-$(CONFIG_TEXTSEARCH_KMP) += ts_kmp.o

lib/decompress.c

+5 −0

Original line number	Diff line number	Diff line
		@@ -9,6 +9,7 @@
		#include <linux/decompress/bunzip2.h>
		#include <linux/decompress/unlzma.h>
		#include <linux/decompress/inflate.h>
		#include <linux/decompress/unlzo.h>

		#include <linux/types.h>
		#include <linux/string.h>
		@@ -22,6 +23,9 @@
		#ifndef CONFIG_DECOMPRESS_LZMA
		# define unlzma NULL
		#endif
		#ifndef CONFIG_DECOMPRESS_LZO
		# define unlzo NULL
		#endif

		static const struct compress_format {
		unsigned char magic[2];
		@@ -32,6 +36,7 @@ static const struct compress_format {
		{ {037, 0236}, "gzip", gunzip },
		{ {0x42, 0x5a}, "bzip2", bunzip2 },
		{ {0x5d, 0x00}, "lzma", unlzma },
		{ {0x89, 0x4c}, "lzo", unlzo },
		{ {0, 0}, NULL, NULL }
		};

usr/Kconfig

+21 −5

Original line number	Diff line number	Diff line
		@@ -72,6 +72,15 @@ config RD_LZMA
		Support loading of a LZMA encoded initial ramdisk or cpio buffer
		If unsure, say N.

		config RD_LZO
		bool "Support initial ramdisks compressed using LZO" if EMBEDDED
		default !EMBEDDED
		depends on BLK_DEV_INITRD
		select DECOMPRESS_LZO
		help
		Support loading of a LZO encoded initial ramdisk or cpio buffer
		If unsure, say N.

		choice
		prompt "Built-in initramfs compression mode" if INITRAMFS_SOURCE!=""
		help
		@@ -108,16 +117,15 @@ config INITRAMFS_COMPRESSION_GZIP
		bool "Gzip"
		depends on RD_GZIP
		help
		The old and tried gzip compression. Its compression ratio is
		the poorest among the 3 choices; however its speed (both
		compression and decompression) is the fastest.
		The old and tried gzip compression. It provides a good balance
		between compression ratio and decompression speed.

		config INITRAMFS_COMPRESSION_BZIP2
		bool "Bzip2"
		depends on RD_BZIP2
		help
		Its compression ratio and speed is intermediate.
		Decompression speed is slowest among the three. The initramfs
		Decompression speed is slowest among the four. The initramfs
		size is about 10% smaller with bzip2, in comparison to gzip.
		Bzip2 uses a large amount of memory. For modern kernels you
		will need at least 8MB RAM or more for booting.
		@@ -128,7 +136,15 @@ config INITRAMFS_COMPRESSION_LZMA
		help
		The most recent compression algorithm.
		Its ratio is best, decompression speed is between the other
		two. Compression is slowest. The initramfs size is about 33%
		three. Compression is slowest. The initramfs size is about 33%
		smaller with LZMA in comparison to gzip.

		config INITRAMFS_COMPRESSION_LZO
		bool "LZO"
		depends on RD_LZO
		help
		Its compression ratio is the poorest among the four. The kernel
		size is about about 10% bigger than gzip; however its speed
		(both compression and decompression) is the fastest.

		endchoice

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