x86/dom0: support bzip2 and lzma compressed bzImage payloads

This matches functionality in the tools already supporting the same
for DomU-s.

Code taken from Linux 2.6.32-rc and adjusted as little as possible to
be usable in Xen.

The question is whether, particularly for non-Linux Dom0-s, plain ELF
images compressed by bzip2 or lzma should also be supported.

Signed-off-by: Jan Beulich <jbeulich@novell.com>

1 files changed, 38 insertions, 0 deletions

diff --git a/xen/include/xen/decompress.h b/xen/include/xen/decompress.h
new file mode 100644
index 0000000000..db74c00d24
--- /dev/null
+++ b/xen/include/xen/decompress.h
@@ -0,0 +1,38 @@
+#ifndef __XEN_GENERIC_H
+#define __XEN_GENERIC_H
+
+typedef int decompress_fn(unsigned char *inbuf, unsigned int len,
+                          int (*fill)(void*, unsigned int),
+                          int (*flush)(void*, unsigned int),
+                          unsigned char *outbuf, unsigned int *posp,
+                          void (*error)(const char *x));
+
+/* inbuf   - input buffer
+ * len     - len of pre-read data in inbuf
+ * fill    - function to fill inbuf when empty
+ * flush   - function to write out outbuf
+ * outbuf  - output buffer
+ * posp    - if non-null, input position (number of bytes read) will be
+ *           returned here
+ * error   - error reporting function
+ *
+ * If len != 0, inbuf should contain all the necessary input data, and fill
+ * should be NULL
+ * If len = 0, inbuf can be NULL, in which case the decompressor will allocate
+ * the input buffer.  If inbuf != NULL it must be at least XXX_IOBUF_SIZE bytes.
+ * fill will be called (repeatedly...) to read data, at most XXX_IOBUF_SIZE
+ * bytes should be read per call.  Replace XXX with the appropriate decompressor
+ * name, i.e. LZMA_IOBUF_SIZE.
+ *
+ * If flush = NULL, outbuf must be large enough to buffer all the expected
+ * output.  If flush != NULL, the output buffer will be allocated by the
+ * decompressor (outbuf = NULL), and the flush function will be called to
+ * flush the output buffer at the appropriate time (decompressor and stream
+ * dependent).
+ */
+
+decompress_fn bunzip2, unlzma;
+
+int decompress(void *inbuf, unsigned int len, void *outbuf);
+
+#endif