This implements the API defined in <linux/decompress/generic.h> which is used for kernel, initramfs, and initrd decompression. This patch together with the first patch is enough for XZ-compressed initramfs and initrd; XZ-compressed kernel will need arch-specific changes. The buffering requirements described in decompress_unxz.c are stricter than with gzip, so the relevant changes should be done to the arch-specific code when adding support for XZ-compressed kernel. Similarly, the heap size in arch-specific pre-boot code may need to be increased (30 KiB is enough). The XZ decompressor needs memmove(), memeq() (memcmp() == 0), and memzero() (memset(ptr, 0, size)), which aren't available in all arch-specific pre-boot environments. I'm including simple versions in decompress_unxz.c, but a cleaner solution would naturally be nicer. Signed-off-by: Lasse Collin <lasse.collin@tukaani.org> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Alain Knaff <alain@knaff.lu> Cc: Albin Tonnerre <albin.tonnerre@free-electrons.com> Cc: Phillip Lougher <phillip@lougher.demon.co.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
		
			
				
	
	
		
			69 lines
		
	
	
	
		
			2.3 KiB
			
		
	
	
	
		
			Makefile
		
	
	
	
	
	
			
		
		
	
	
			69 lines
		
	
	
	
		
			2.3 KiB
			
		
	
	
	
		
			Makefile
		
	
	
	
	
	
#
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# kbuild file for usr/ - including initramfs image
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#
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klibcdirs:;
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PHONY += klibcdirs
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# Gzip
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suffix_$(CONFIG_INITRAMFS_COMPRESSION_GZIP)   = .gz
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# Bzip2
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suffix_$(CONFIG_INITRAMFS_COMPRESSION_BZIP2)  = .bz2
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# Lzma
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suffix_$(CONFIG_INITRAMFS_COMPRESSION_LZMA)   = .lzma
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# XZ
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suffix_$(CONFIG_INITRAMFS_COMPRESSION_XZ)     = .xz
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# Lzo
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suffix_$(CONFIG_INITRAMFS_COMPRESSION_LZO)   = .lzo
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AFLAGS_initramfs_data.o += -DINITRAMFS_IMAGE="usr/initramfs_data.cpio$(suffix_y)"
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# Generate builtin.o based on initramfs_data.o
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obj-$(CONFIG_BLK_DEV_INITRD) := initramfs_data.o
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# initramfs_data.o contains the compressed initramfs_data.cpio image.
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# The image is included using .incbin, a dependency which is not
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# tracked automatically.
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$(obj)/initramfs_data.o: $(obj)/initramfs_data.cpio$(suffix_y) FORCE
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#####
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# Generate the initramfs cpio archive
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hostprogs-y := gen_init_cpio
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initramfs   := $(CONFIG_SHELL) $(srctree)/scripts/gen_initramfs_list.sh
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ramfs-input := $(if $(filter-out "",$(CONFIG_INITRAMFS_SOURCE)), \
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			$(shell echo $(CONFIG_INITRAMFS_SOURCE)),-d)
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ramfs-args  := \
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        $(if $(CONFIG_INITRAMFS_ROOT_UID), -u $(CONFIG_INITRAMFS_ROOT_UID)) \
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        $(if $(CONFIG_INITRAMFS_ROOT_GID), -g $(CONFIG_INITRAMFS_ROOT_GID))
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# .initramfs_data.cpio.d is used to identify all files included
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# in initramfs and to detect if any files are added/removed.
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# Removed files are identified by directory timestamp being updated
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# The dependency list is generated by gen_initramfs.sh -l
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ifneq ($(wildcard $(obj)/.initramfs_data.cpio.d),)
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	include $(obj)/.initramfs_data.cpio.d
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endif
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quiet_cmd_initfs = GEN     $@
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      cmd_initfs = $(initramfs) -o $@ $(ramfs-args) $(ramfs-input)
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targets := initramfs_data.cpio.gz initramfs_data.cpio.bz2 initramfs_data.cpio.lzma initramfs_data.cpio.xz initramfs_data.cpio.lzo initramfs_data.cpio
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# do not try to update files included in initramfs
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$(deps_initramfs): ;
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$(deps_initramfs): klibcdirs
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# We rebuild initramfs_data.cpio if:
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# 1) Any included file is newer then initramfs_data.cpio
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# 2) There are changes in which files are included (added or deleted)
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# 3) If gen_init_cpio are newer than initramfs_data.cpio
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# 4) arguments to gen_initramfs.sh changes
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$(obj)/initramfs_data.cpio$(suffix_y): $(obj)/gen_init_cpio $(deps_initramfs) klibcdirs
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	$(Q)$(initramfs) -l $(ramfs-input) > $(obj)/.initramfs_data.cpio.d
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	$(call if_changed,initfs)
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