RAP file support.

This is the initial addition of support for LZ77 RTEMS applications
in the RAP format.

The change add support for different formats to the loader. Each
format type is asked to check the file being loading and if
it matches the format's loader is called to load the file.

Support has been added to stream LZ77 files via the object file
cache.

1 files changed, 113 insertions, 0 deletions

diff --git a/rtl-obj-comp.h b/rtl-obj-comp.h
new file mode 100644
index 0000000..eb4ba55
--- /dev/null
+++ b/rtl-obj-comp.h
@@ -0,0 +1,113 @@
+/*
+ *  COPYRIGHT (c) 2012 Chris Johns <chrisj@rtems.org>
+ *
+ *  The license and distribution terms for this file may be
+ *  found in the file LICENSE in this distribution or at
+ *  http://www.rtems.com/license/LICENSE.
+ */
+/**
+ * @file
+ *
+ * @ingroup rtems_rtl
+ *
+ * @brief RTEMS Run-Time Linker Object File Compression manages a
+ *        compressed stream of data.
+ *
+ * This is a simple interface to the object file cache to stream data from
+ * from a compressed object file. There is no ability to seek with the
+ * data from a compressed file. The module exists to allocate the output
+ * buffer when the loader starts and use the cache buffers will have been
+ * allocated.
+ */
+
+#if !defined (_RTEMS_RTL_OBJ_COMP_H_)
+#define _RTEMS_RTL_OBJ_COMP_H_
+
+#include <rtl-obj-cache.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif /* __cplusplus */
+
+/**
+ * The amount of input data read at a time from the file.
+ */
+#define RTEMS_RTL_DECOMP_INPUT_SIZE (256)
+
+/**
+ * The types of supported compression.
+ */
+#define RTEMS_RTL_COMP_NONE (0)
+#define RTEMS_RTL_COMP_LZ77 (1)
+
+/**
+ * The compressed file.
+ */
+typedef struct rtems_rtl_obj_cpmp_s
+{
+  rtems_rtl_obj_cache_t* cache;       /**< The cache provides the input
+                                       *   buffer. */
+  int                    fd;          /**< The file descriptor. */
+  int                    compression; /**< The type of compression. */
+  off_t                  offset;      /**< The base offset of the buffer. */
+  size_t                 size;        /**< The size of the output buffer. */
+  size_t                 level;       /**< The amount of data in the buffer. */
+  uint8_t*               buffer;      /**< The buffer */
+} rtems_rtl_obj_comp_t;
+
+/**
+ * Open a compressor allocating the output buffer.
+ *
+ * @param comp The compressor  to initialise.
+ * @param size The size of the compressor's output buffer.
+ * @retval true The compressor is open.
+ * @retval false The compressor is not open. The RTL error is set.
+ */
+bool rtems_rtl_obj_comp_open (rtems_rtl_obj_comp_t*  comp,
+                              size_t                 size);
+
+/**
+ * Close a compressor.
+ *
+ * @param comp The compressor to close.
+ */
+void rtems_rtl_obj_comp_close (rtems_rtl_obj_comp_t* comp);
+
+/**
+ * Set the cache and offset in the file the compressed stream starts.
+ *
+ * @param comp The compressor to set the offset in.
+ * @param cache The cache to read the file in by.
+ * @param fd The file descriptor. Must be an open file.
+ * @param compression The type of compression being streamed.
+ * @param offset The offset in the file the compressed stream starts.
+ */
+void rtems_rtl_obj_comp_set (rtems_rtl_obj_comp_t*  comp,
+                             rtems_rtl_obj_cache_t* cache,
+                             int                    fd,
+                             int                    compression,
+                             off_t                  offset);
+
+/**
+ * Read decompressed data. The length contains the amount of data that should
+ * be available in the cache and referenced by the buffer handle. It must be
+ * less than or equal to the size of the cache. This call will return the
+ * amount of data that is available. It can be less than you ask if the offset
+ * and size is past the end of the file.
+ *
+ * @param comp The compressor to read data from.
+ * @param buffer The buffer the output is written too.
+ * @param length The length of data to read. Can be modified to a
+ *               lesser value and true is still returned so check it.
+ * @retval true The data referenced is in the cache.
+ * @retval false The read failed and the RTL error has been set.
+ */
+bool rtems_rtl_obj_comp_read (rtems_rtl_obj_comp_t* comp,
+                              void*                 buffer,
+                              size_t                length);
+
+#ifdef __cplusplus
+}
+#endif /* __cplusplus */
+
+#endif