path: root/include/linux/decompress/generic.h
diff options
authorAlain Knaff <>2009-01-04 22:46:16 +0100
committerH. Peter Anvin <>2009-01-04 15:53:34 -0800
commitbc22c17e12c130dc929218a95aa347e0f3fd05dc (patch)
treee5dfd433dbf2fec27a033ee729236e63fbe3a1ad /include/linux/decompress/generic.h
parent7d3b56ba37a95f1f370f50258ed3954c304c524b (diff)
bzip2/lzma: library support for gzip, bzip2 and lzma decompression
Impact: Replaces inflate.c with a wrapper around zlib_inflate; new library code This is the first part of the bzip2/lzma patch The bzip patch is based on an idea by Christian Ludwig, includes support for compressing the kernel with bzip2 or lzma rather than gzip. Both compressors give smaller sizes than gzip. Lzma's decompresses faster than bzip2. It also supports ramdisks and initramfs' compressed using these two compressors. The functionality has been successfully used for a couple of years by the udpcast project This version applies to "tip" kernel 2.6.28 This part contains: - changed inflate.c to accomodate rest of patch - implementation of bzip2 compression (not used at this stage yet) - implementation of lzma compression (not used at this stage yet) - Makefile routines to support bzip2 and lzma kernel compression Signed-off-by: Alain Knaff <> Signed-off-by: H. Peter Anvin <>
Diffstat (limited to 'include/linux/decompress/generic.h')
1 files changed, 30 insertions, 0 deletions
diff --git a/include/linux/decompress/generic.h b/include/linux/decompress/generic.h
new file mode 100644
index 000000000000..f847f514f78e
--- /dev/null
+++ b/include/linux/decompress/generic.h
@@ -0,0 +1,30 @@
+/* Minimal chunksize to be read.
+ *Bzip2 prefers at least 4096
+ *Lzma prefers 0x10000 */
+#define COMPR_IOBUF_SIZE 4096
+typedef int (*decompress_fn) (unsigned char *inbuf, int len,
+ int(*fill)(void*, unsigned int),
+ int(*writebb)(void*, unsigned int),
+ unsigned char *output,
+ int *posp,
+ void(*error)(char *x));
+/* inbuf - input buffer
+ *len - len of pre-read data in inbuf
+ *fill - function to fill inbuf if empty
+ *writebb - function to write out outbug
+ *posp - if non-null, input position (number of bytes read) will be
+ * returned here
+ *
+ *If len != 0, the inbuf is initialized (with as much data), and fill
+ *should not be called
+ *If len = 0, the inbuf is allocated, but empty. Its size is IOBUF_SIZE
+ *fill should be called (repeatedly...) to read data, at most IOBUF_SIZE
+ */