summaryrefslogtreecommitdiffstats
path: root/lib/decompress.c
diff options
context:
space:
mode:
authorThomas Gleixner <tglx@linutronix.de>2009-03-23 14:50:03 +0100
committerThomas Gleixner <tglx@linutronix.de>2009-03-23 21:20:20 +0100
commit80c5520811d3805adcb15c570ea5e2d489fa5d0b (patch)
treeae797a7f4af39f80e77526533d06ac23b439f0ab /lib/decompress.c
parentb3e3b302cf6dc8d60b67f0e84d1fa5648889c038 (diff)
parent8c083f081d0014057901c68a0a3e0f8ca7ac8d23 (diff)
Merge branch 'cpus4096' into irq/threaded
Conflicts: arch/parisc/kernel/irq.c kernel/irq/handle.c Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Diffstat (limited to 'lib/decompress.c')
-rw-r--r--lib/decompress.c54
1 files changed, 54 insertions, 0 deletions
diff --git a/lib/decompress.c b/lib/decompress.c
new file mode 100644
index 00000000000..d2842f57167
--- /dev/null
+++ b/lib/decompress.c
@@ -0,0 +1,54 @@
+/*
+ * decompress.c
+ *
+ * Detect the decompression method based on magic number
+ */
+
+#include <linux/decompress/generic.h>
+
+#include <linux/decompress/bunzip2.h>
+#include <linux/decompress/unlzma.h>
+#include <linux/decompress/inflate.h>
+
+#include <linux/types.h>
+#include <linux/string.h>
+
+#ifndef CONFIG_DECOMPRESS_GZIP
+# define gunzip NULL
+#endif
+#ifndef CONFIG_DECOMPRESS_BZIP2
+# define bunzip2 NULL
+#endif
+#ifndef CONFIG_DECOMPRESS_LZMA
+# define unlzma NULL
+#endif
+
+static const struct compress_format {
+ unsigned char magic[2];
+ const char *name;
+ decompress_fn decompressor;
+} compressed_formats[] = {
+ { {037, 0213}, "gzip", gunzip },
+ { {037, 0236}, "gzip", gunzip },
+ { {0x42, 0x5a}, "bzip2", bunzip2 },
+ { {0x5d, 0x00}, "lzma", unlzma },
+ { {0, 0}, NULL, NULL }
+};
+
+decompress_fn decompress_method(const unsigned char *inbuf, int len,
+ const char **name)
+{
+ const struct compress_format *cf;
+
+ if (len < 2)
+ return NULL; /* Need at least this much... */
+
+ for (cf = compressed_formats; cf->name; cf++) {
+ if (!memcmp(inbuf, cf->magic, 2))
+ break;
+
+ }
+ if (name)
+ *name = cf->name;
+ return cf->decompressor;
+}