path: root/lib/decompress.c
diff options
authorLasse Collin <>2011-01-12 17:01:23 -0800
committerLinus Torvalds <>2011-01-13 08:03:25 -0800
commit3ebe12439ba7fc62e1d6ecb569b7287771716ca1 (patch)
tree65945a63ad1474489d80c8ca1fb1c1c8091fb7a2 /lib/decompress.c
parent24fa0402a9b6a537e87e38341e78b7da86486846 (diff)
decompressors: add boot-time XZ support
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 <> Cc: "H. Peter Anvin" <> Cc: Alain Knaff <> Cc: Albin Tonnerre <> Cc: Phillip Lougher <> Signed-off-by: Andrew Morton <> Signed-off-by: Linus Torvalds <>
Diffstat (limited to 'lib/decompress.c')
1 files changed, 5 insertions, 0 deletions
diff --git a/lib/decompress.c b/lib/decompress.c
index a7606815541f..3d766b7f60ab 100644
--- a/lib/decompress.c
+++ b/lib/decompress.c
@@ -8,6 +8,7 @@
#include <linux/decompress/bunzip2.h>
#include <linux/decompress/unlzma.h>
+#include <linux/decompress/unxz.h>
#include <linux/decompress/inflate.h>
#include <linux/decompress/unlzo.h>
@@ -23,6 +24,9 @@
# define unlzma NULL
+# define unxz NULL
# define unlzo NULL
@@ -36,6 +40,7 @@ static const struct compress_format {
{ {037, 0236}, "gzip", gunzip },
{ {0x42, 0x5a}, "bzip2", bunzip2 },
{ {0x5d, 0x00}, "lzma", unlzma },
+ { {0xfd, 0x37}, "xz", unxz },
{ {0x89, 0x4c}, "lzo", unlzo },
{ {0, 0}, NULL, NULL }