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, 171 insertions, 0 deletions

diff --git a/rtl-obj-comp.c b/rtl-obj-comp.c
new file mode 100644
index 0000000..451d1cb
--- /dev/null
+++ b/rtl-obj-comp.c
@@ -0,0 +1,171 @@
+/*
+ *  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 Compression manages a compress
+ *        stream of data.
+ */
+
+#if HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#include <errno.h>
+#include <string.h>
+#include <unistd.h>
+
+#include <rtl-allocator.h>
+#include <rtl-obj-comp.h>
+#include <rtl-error.h>
+
+#include "fastlz.h"
+
+#include <stdio.h>
+
+bool
+rtems_rtl_obj_comp_open (rtems_rtl_obj_comp_t*  comp,
+                         size_t                 size)
+{
+  comp->cache  = NULL;
+  comp->fd = -1;
+  comp->compression = RTEMS_RTL_COMP_LZ77;
+  comp->offset = 0;
+  comp->size   = size;
+  comp->level  = 0;
+  comp->buffer = rtems_rtl_alloc_new (RTEMS_RTL_ALLOC_OBJECT, size, false);
+  if (!comp->buffer)
+  {
+    rtems_rtl_set_error (ENOMEM, "no memory for compressor buffer");
+    return false;
+  }
+  return true;
+}
+
+void
+rtems_rtl_obj_comp_close (rtems_rtl_obj_comp_t* comp)
+{
+  rtems_rtl_alloc_del (RTEMS_RTL_ALLOC_OBJECT, comp->buffer);
+  comp->cache = NULL;
+  comp->fd = -1;
+  comp->compression = RTEMS_RTL_COMP_LZ77;
+  comp->level = 0;
+  comp->size = 0;
+  comp->offset = 0;
+}
+
+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)
+{
+  comp->cache = cache;
+  comp->fd = fd;
+  comp->compression = compression;
+  comp->offset = offset;
+  comp->level = 0;
+}
+
+bool
+rtems_rtl_obj_comp_read (rtems_rtl_obj_comp_t* comp,
+                         void*                 buffer,
+                         size_t                length)
+{
+  if (!comp->cache)
+  {
+    rtems_rtl_set_error (EINVAL, "not open");
+    return false;
+  }
+
+  if (comp->fd != comp->cache->fd)
+  {
+    comp->level = 0;
+  }
+
+  while (length)
+  {
+    size_t buffer_level;
+
+    buffer_level = length > comp->level ? comp->level : length;
+
+    if (buffer_level)
+    {
+      memcpy (buffer, comp->buffer, buffer_level);
+
+      length -= buffer_level;
+
+      if ((comp->level - buffer_level) != 0)
+      {
+        memmove (comp->buffer,
+                 comp->buffer + buffer_level,
+                 comp->level - buffer_level);
+      }
+
+      comp->level -= buffer_level;
+    }
+
+    if (length)
+    {
+      uint8_t* input = NULL;
+      size_t   in_length;
+      uint16_t block_size;
+      int      decompressed;
+
+      if (!rtems_rtl_obj_cache_read (comp->cache, comp->fd, comp->offset,
+                                     (void**) &input, &in_length))
+        return false;
+
+      block_size = (input[0] << 8) | input[1];
+
+      comp->offset += sizeof (block_size);
+
+      in_length = block_size;
+
+      if (!rtems_rtl_obj_cache_read (comp->cache, comp->fd, comp->offset,
+                                     (void**) &input, &in_length))
+        return false;
+
+      if (in_length != block_size)
+      {
+        rtems_rtl_set_error (EIO, "compressed read failed");
+        return false;
+      }
+
+      switch (comp->compression)
+      {
+        case RTEMS_RTL_COMP_NONE:
+          memcpy (comp->buffer, input, in_length);
+          decompressed = in_length;
+          break;
+
+        case RTEMS_RTL_COMP_LZ77:
+          decompressed = fastlz_decompress (input, in_length,
+                                            comp->buffer, comp->size);
+          if (decompressed == 0)
+          {
+            rtems_rtl_set_error (EBADF, "decompression failed");
+            return false;
+          }
+          break;
+        default:
+          rtems_rtl_set_error (EINVAL, "bad compression type");
+          return false;
+      }
+
+      comp->offset += block_size;
+
+      comp->level = decompressed;
+    }
+  }
+
+  return true;
+}