libmisc/rtems-fdt: Add RTEMS FDT wrapper and shell command to libmisc.

- Provide application support for handling FDT blobs in RTEMS. This
  is useful when interfacing FPGA fabrics.
- Provide a shell command to list a blob as well as provide read
  and write access to addresses in the FTB.

Closes #3099.

1 files changed, 1191 insertions, 0 deletions

diff --git a/cpukit/libmisc/rtems-fdt/rtems-fdt.c b/cpukit/libmisc/rtems-fdt/rtems-fdt.c
new file mode 100644
index 0000000000..cbdb656fcc
--- /dev/null
+++ b/cpukit/libmisc/rtems-fdt/rtems-fdt.c
@@ -0,0 +1,1191 @@
+/*
+ *  COPYRIGHT (c) 2013-2017 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.org/license/LICENSE.
+ */
+
+#include <errno.h>
+#include <fcntl.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+
+#include <libfdt.h>
+#include <zlib.h>
+
+#include <rtems/rtems-fdt.h>
+#include <rtems/libio_.h>
+
+/**
+ * An index for quick access to the FDT by name or offset.
+ */
+
+typedef struct
+{
+  const char *             name;         /**< The full path of the FDT item. */
+  int                      offset;       /**< The offset of the item in the FDT blob. */
+} rtems_fdt_index_entry;
+
+typedef struct
+{
+  int                    num_entries;    /**< The number of entries in this index. */
+  rtems_fdt_index_entry* entries;        /**< An ordered set of entries which we
+                                          *  can binary search. */
+  char*                  names;          /**< Storage allocated for all the path names. */
+} rtems_fdt_index;
+
+
+/**
+ * A blob descriptor.
+ */
+struct rtems_fdt_blob
+{
+  rtems_chain_node node;        /**< The node's link in the chain. */
+  const void*      blob;        /**< The FDT blob. */
+  const char*      name;        /**< The name of the blob. */
+  int              refs;        /**< The number of active references of the blob. */
+  rtems_fdt_index  index;       /**< The index used for quick access to items in the blob. */
+};
+
+/**
+ * The global FDT data. This structure is allocated on the heap when the first
+ * call to load a FDT blob is made and released when all blobs have been
+ * unloaded..
+ */
+typedef struct
+{
+  rtems_id            lock;     /**< The FDT lock id */
+  rtems_chain_control blobs;    /**< List if loaded blobs. */
+  const char*         paths;    /**< Search paths for blobs. */
+} rtems_fdt_data;
+
+/**
+ * Semaphore configuration to create a mutex.
+ */
+#define RTEMS_MUTEX_ATTRIBS                                           \
+  (RTEMS_PRIORITY | RTEMS_BINARY_SEMAPHORE |                          \
+   RTEMS_INHERIT_PRIORITY | RTEMS_NO_PRIORITY_CEILING | RTEMS_LOCAL)
+
+/**
+ * The FDT data.
+ */
+static rtems_fdt_data* fdt_data;
+
+static bool
+rtems_fdt_unlock (void)
+{
+  /*
+   * Not sure any error should be returned or an assert.
+   */
+  rtems_status_code sc;
+  sc = rtems_semaphore_release (fdt_data->lock);
+  if ((sc != RTEMS_SUCCESSFUL) && (errno == 0))
+  {
+    errno = EINVAL;
+    return false;
+  }
+  return true;
+}
+
+static bool
+rtems_fdt_data_init (void)
+{
+  /*
+   * Lock the FDT. We only create a lock if a call is made. First we test if a
+   * lock is present. If one is present we lock it. If not the libio lock is
+   * locked and we then test the lock again. If not present we create the lock
+   * then release libio lock.
+   */
+  if (!fdt_data)
+  {
+    rtems_libio_lock ();
+
+    if (!fdt_data)
+    {
+      rtems_status_code sc;
+      rtems_id          lock;
+
+      /*
+       * Always in the heap.
+       */
+      fdt_data = malloc (sizeof (rtems_fdt_data));
+      if (!fdt_data)
+      {
+        errno = ENOMEM;
+        return false;
+      }
+
+      *fdt_data = (rtems_fdt_data) { 0 };
+
+      /*
+       * Create the FDT lock.
+       */
+      sc = rtems_semaphore_create (rtems_build_name ('F', 'D', 'T', ' '),
+                                   1, RTEMS_MUTEX_ATTRIBS,
+                                   RTEMS_NO_PRIORITY, &lock);
+      if (sc != RTEMS_SUCCESSFUL)
+      {
+        free (fdt_data);
+        return false;
+      }
+
+      sc = rtems_semaphore_obtain (lock, RTEMS_WAIT, RTEMS_NO_TIMEOUT);
+      if (sc != RTEMS_SUCCESSFUL)
+      {
+        rtems_semaphore_delete (lock);
+        free (fdt_data);
+        return false;
+      }
+
+      fdt_data->lock = lock;
+
+      /*
+       * Initialise the blob list.
+       */
+      rtems_chain_initialize_empty (&fdt_data->blobs);
+    }
+
+    rtems_libio_unlock ();
+
+    rtems_fdt_unlock ();
+  }
+
+  return true;
+}
+
+static rtems_fdt_data*
+rtems_fdt_lock (void)
+{
+  rtems_status_code sc;
+
+  if (!rtems_fdt_data_init ())
+    return NULL;
+
+  sc = rtems_semaphore_obtain (fdt_data->lock,
+                               RTEMS_WAIT, RTEMS_NO_TIMEOUT);
+  if (sc != RTEMS_SUCCESSFUL)
+  {
+    errno = EINVAL;
+    return NULL;
+  }
+
+  return fdt_data;
+}
+
+/**
+ * Create an index based on the contents of an FDT blob.
+ */
+static int
+rtems_fdt_init_index (rtems_fdt_handle* fdt, rtems_fdt_blob* blob)
+{
+  rtems_fdt_index_entry* entries = NULL;
+  int                    num_entries = 0;
+  int                    entry = 0;
+  size_t                 total_name_memory = 0;
+  char                   node_path[256];
+  int                    depth_path[32];
+  int                    start_offset = 0;
+  int                    start_depth = 0;
+  int                    offset = 0;
+  int                    depth = 0;
+  char*                  names = NULL;
+  char*                  names_pos = NULL;
+
+  /*
+   * Count the number of entries in the blob first.
+   */
+  memset(&node_path, 0, sizeof(node_path));
+  strcpy(node_path, "/");
+  depth_path[0] = strlen(node_path);
+
+  start_offset = fdt_path_offset(fdt->blob->blob, node_path);
+  if (start_offset < 0)
+  {
+    return start_offset;
+  }
+
+  start_offset = fdt_next_node(fdt->blob->blob, start_offset, &start_depth);
+  if (start_offset < 0)
+  {
+    return start_offset;
+  }
+
+  offset = start_offset;
+  depth = start_depth;
+
+  while (depth > 0)
+  {
+    /*
+     * Construct the node path name.
+     */
+    int         namelen = 0;
+    const char* name = fdt_get_name(blob->blob, offset, &namelen);
+    strncpy(&node_path[depth_path[depth-1]],
+            name,
+            sizeof(node_path) - depth_path[depth-1] - 1);
+
+    total_name_memory += strlen(node_path) + 1;
+    num_entries++;
+
+    if (depth_path[depth-1] + namelen + 2 <= (int)sizeof(node_path))
+    {
+      strcpy(&node_path[depth_path[depth-1] + namelen], "/");
+    }
+
+    depth_path[depth] = depth_path[depth-1] + namelen + 1;
+
+    /*
+     * Get the next node.
+     */
+    offset = fdt_next_node(fdt->blob->blob, offset, &depth);
+    if (offset < 0)
+    {
+      return offset;
+    }
+  }
+
+  /*
+   * Create the index.
+   */
+  entries = calloc(num_entries, sizeof(rtems_fdt_index_entry));
+  if (!entries)
+  {
+    return -RTEMS_FDT_ERR_NO_MEMORY;
+  }
+
+  names = calloc(1, total_name_memory);
+  if (!entries)
+  {
+    free(entries);
+    return -RTEMS_FDT_ERR_NO_MEMORY;
+  }
+
+  /*
+   * Populate the index.
+   */
+  offset = start_offset;
+  depth = start_depth;
+  entry = 0;
+  names_pos = names;
+
+  while (depth > 0)
+  {
+    /*
+     * Record this node in an entry.
+     */
+    int         namelen = 0;
+    const char* name = fdt_get_name(blob->blob, offset, &namelen);
+    strncpy(&node_path[depth_path[depth-1]],
+            name,
+            sizeof(node_path) - depth_path[depth-1] - 1);
+    strcpy(names_pos, node_path);
+
+    entries[entry].name = names_pos;
+    entries[entry].offset = offset;
+
+    names_pos += strlen(node_path) + 1;
+    entry++;
+
+    if (depth_path[depth-1] + namelen + 2 <= (int)sizeof(node_path))
+    {
+      strcpy(&node_path[depth_path[depth-1] + namelen], "/");
+    }
+
+    depth_path[depth] = depth_path[depth-1] + namelen + 1;
+
+    /*
+     * Get the next node.
+     */
+    offset = fdt_next_node(fdt->blob->blob, offset, &depth);
+    if (offset < 0)
+    {
+      free(entries);
+      free(names);
+      return offset;
+    }
+  }
+
+  fdt->blob->index.entries = entries;
+  fdt->blob->index.num_entries = num_entries;
+  fdt->blob->index.names = names;
+
+  return 0;
+}
+
+/**
+ * Release the contents of the index, freeing memory.
+ */
+static void
+rtems_fdt_release_index (rtems_fdt_index* index)
+{
+  if (index->entries)
+  {
+    free(index->entries);
+    free(index->names);
+
+    index->num_entries = 0;
+    index->entries = NULL;
+    index->names = NULL;
+  }
+}
+
+/**
+ * For a given FDT path, find the corresponding offset.
+ * Returns -1 if not found;
+ */
+static int
+rtems_fdt_index_find_by_name(rtems_fdt_index* index,
+                             const char*      name)
+{
+  int         min = 0;
+  int         max = index->num_entries;
+  char        path[256];
+  const char* cmp_name = name;
+
+  /*
+   * Handle trailing slash case.
+   */
+  int namelen = strlen(name);
+  if (namelen > 0 && name[namelen-1] == '/')
+  {
+    namelen--;
+
+    if (namelen >= (int)sizeof(path) - 1)
+    {
+      namelen = sizeof(path) - 1;
+    }
+
+    strncpy(path, name, namelen);
+    path[namelen] = 0;
+    cmp_name = path;
+  }
+
+  /* Binary search for the name. */
+  while (min < max)
+  {
+    int middle = (min + max) / 2;
+    int cmp = strcmp(cmp_name, index->entries[middle].name);
+    if (cmp < 0)
+    {
+      /* Look lower than here. */
+      max = middle;
+    }
+    else if (cmp > 0)
+    {
+      /* Look higher than here. */
+      min = middle + 1;
+    }
+    else
+    {
+      /* Found it. */
+      return index->entries[middle].offset;
+    }
+  }
+
+  /* Didn't find it. */
+  return -FDT_ERR_NOTFOUND;
+}
+
+/**
+ * For a given FDT offset, find the corresponding path name.
+ */
+static const char *
+rtems_fdt_index_find_name_by_offset(rtems_fdt_index* index,
+                                    int              offset)
+{
+  int min = 0;
+  int max = index->num_entries;
+
+  /*
+   * Binary search for the offset.
+   */
+  while (min < max)
+  {
+    int middle = (min + max) / 2;
+    if (offset < index->entries[middle].offset)
+    {
+      /* Look lower than here. */
+      max = middle;
+    }
+    else if (offset > index->entries[middle].offset)
+    {
+      /* Look higher than here. */
+      min = middle + 1;
+    }
+    else
+    {
+      /* Found it. */
+      return index->entries[middle].name;
+    }
+  }
+
+  /* Didn't find it. */
+  return NULL;
+}
+
+void
+rtems_fdt_init_handle (rtems_fdt_handle* handle)
+{
+  if (handle)
+    handle->blob = NULL;
+}
+
+void
+rtems_fdt_dup_handle (rtems_fdt_handle* from, rtems_fdt_handle* to)
+{
+  if (from && to)
+  {
+    (void) rtems_fdt_lock ();
+    to->blob = from->blob;
+    ++to->blob->refs;
+    rtems_fdt_unlock ();
+  }
+}
+
+void
+rtems_fdt_release_handle (rtems_fdt_handle* handle)
+{
+  if (handle && handle->blob)
+  {
+    rtems_fdt_data*   fdt;
+    rtems_chain_node* node;
+
+    fdt = rtems_fdt_lock ();
+
+    node = rtems_chain_first (&fdt->blobs);
+
+    while (!rtems_chain_is_tail (&fdt->blobs, node))
+    {
+      rtems_fdt_blob* blob = (rtems_fdt_blob*) node;
+      if (handle->blob == blob)
+      {
+        if (blob->refs)
+          --blob->refs;
+        break;
+      }
+      node = rtems_chain_next (node);
+    }
+
+    rtems_fdt_unlock ();
+
+    handle->blob = NULL;
+  }
+}
+
+bool
+rtems_fdt_valid_handle (const rtems_fdt_handle* handle)
+{
+  if (handle && handle->blob)
+  {
+    rtems_fdt_data*   fdt;
+    rtems_chain_node* node;
+
+    fdt = rtems_fdt_lock ();
+
+    node = rtems_chain_first (&fdt->blobs);
+
+    while (!rtems_chain_is_tail (&fdt->blobs, node))
+    {
+      rtems_fdt_blob* blob = (rtems_fdt_blob*) node;
+      if (handle->blob == blob)
+      {
+        rtems_fdt_unlock ();
+        return true;
+      }
+      node = rtems_chain_next (node);
+    }
+
+    rtems_fdt_unlock ();
+  }
+
+  return false;
+}
+
+int
+rtems_fdt_find_path_offset (rtems_fdt_handle* handle, const char* path)
+{
+  rtems_fdt_data*   fdt;
+  rtems_chain_node* node;
+
+  rtems_fdt_release_handle (handle);
+
+  fdt = rtems_fdt_lock ();
+
+  node = rtems_chain_first (&fdt->blobs);
+
+  while (!rtems_chain_is_tail (&fdt->blobs, node))
+  {
+    rtems_fdt_handle temp_handle;
+    int              offset;
+
+    temp_handle.blob = (rtems_fdt_blob*) node;
+
+    offset = rtems_fdt_path_offset (&temp_handle, path);
+
+    if (offset >= 0)
+    {
+      ++temp_handle.blob->refs;
+      handle->blob = temp_handle.blob;
+      rtems_fdt_unlock ();
+      return offset;
+    }
+
+    node = rtems_chain_next (node);
+  }
+
+  rtems_fdt_unlock ();
+
+  return -FDT_ERR_NOTFOUND;
+}
+
+int
+rtems_fdt_load (const char* filename, rtems_fdt_handle* handle)
+{
+  rtems_fdt_data* fdt;
+  rtems_fdt_blob* blob;
+  size_t          bsize;
+  int             bf;
+  ssize_t         r;
+  size_t          name_len;
+  int             fe;
+  struct stat     sb;
+  uint8_t         gzip_id[2];
+  uint8_t*        cdata;
+  size_t          size;
+
+  rtems_fdt_release_handle (handle);
+
+  if (stat (filename, &sb) < 0)
+  {
+    return -RTEMS_FDT_ERR_NOT_FOUND;
+  }
+
+  bf = open(filename, O_RDONLY);
+  if (bf < 0)
+  {
+    return -RTEMS_FDT_ERR_READ_FAIL;
+  }
+
+  r = read(bf, &gzip_id, sizeof(gzip_id));
+  if (r < 0)
+  {
+    close(bf);
+    return -RTEMS_FDT_ERR_READ_FAIL;
+  }
+
+  if ((gzip_id[0] == 0x1f) && (gzip_id[1] == 0x8b))
+  {
+    size_t offset;
+
+    cdata = malloc(sb.st_size);
+    if (!cdata)
+    {
+      close (bf);
+      return -RTEMS_FDT_ERR_NO_MEMORY;
+    }
+
+    if (lseek(bf, 0, SEEK_SET) < 0)
+    {
+      free(cdata);
+      close(bf);
+      return -RTEMS_FDT_ERR_READ_FAIL;
+    }
+
+    size = sb.st_size;
+    offset = 0;
+    while (size)
+    {
+      r = read(bf, cdata + offset, size);
+      if (r < 0)
+      {
+        free(cdata);
+        close(bf);
+        return -RTEMS_FDT_ERR_READ_FAIL;
+      }
+      size -= r;
+      offset += r;
+    }
+
+    offset = sb.st_size - 4;
+    bsize = ((cdata[offset + 3] << 24) | (cdata[offset + 2] << 16) |
+             (cdata[offset + 1] << 8) | cdata[offset + 0]);
+  }
+  else
+  {
+    cdata = NULL;
+    bsize = sb.st_size;
+  }
+
+  name_len = strlen (filename) + 1;
+
+  blob = malloc(sizeof (rtems_fdt_blob) + name_len + bsize);
+  if (!blob)
+  {
+    free(cdata);
+    close (bf);
+    return -RTEMS_FDT_ERR_NO_MEMORY;
+  }
+
+  blob->name = (const char*) (blob + 1);
+  blob->blob = blob->name + name_len + 1;
+
+  strcpy ((char*) blob->name, filename);
+
+  if ((gzip_id[0] == 0x1f) && (gzip_id[1] == 0x8b))
+  {
+    z_stream stream;
+    int      err;
+    stream.next_in = (Bytef*) cdata;
+    stream.avail_in = (uInt) sb.st_size;
+    stream.next_out = (void*) (blob->name + name_len + 1);
+    stream.avail_out = (uInt) bsize;
+    stream.zalloc = (alloc_func) 0;
+    stream.zfree = (free_func) 0;
+    err = inflateInit(&stream);
+    if (err == Z_OK)
+      err = inflateReset2(&stream, 31);
+    if (err == Z_OK)
+      err = inflate(&stream, Z_FINISH);
+    if ((err == Z_OK) || (err == Z_STREAM_END))
+      err = inflateEnd(&stream);
+    if ((err != Z_OK) || (bsize != stream.total_out))
+    {
+      free (blob);
+      free(cdata);
+      close (bf);
+      return -RTEMS_FDT_ERR_READ_FAIL;
+    }
+    free(cdata);
+    cdata = NULL;
+  }
+  else
+  {
+    char* buf = (char*) blob->name + name_len + 1;
+    size = bsize;
+    while (size)
+    {
+      r = read (bf, buf, size);
+      if (r < 0)
+      {
+        free (blob);
+        close (bf);
+        return -RTEMS_FDT_ERR_READ_FAIL;
+      }
+      r -= size;
+      buf += r;
+    }
+  }
+
+  fe = fdt_check_header(blob->blob);
+  if (fe < 0)
+  {
+    free (blob);
+    close (bf);
+    return fe;
+  }
+
+  fdt = rtems_fdt_lock ();
+
+  rtems_chain_append_unprotected (&fdt->blobs, &blob->node);
+
+  blob->refs = 1;
+
+  rtems_fdt_unlock ();
+
+  handle->blob = blob;
+
+  fe = rtems_fdt_init_index(handle, blob);
+  if (fe < 0)
+  {
+    free (blob);
+    close (bf);
+    return fe;
+  }
+
+  return 0;
+}
+
+int
+rtems_fdt_register (const void* dtb, rtems_fdt_handle* handle)
+{
+  rtems_fdt_data* fdt;
+  rtems_fdt_blob* blob;
+  int             fe;
+
+  rtems_fdt_release_handle (handle);
+
+  fe = fdt_check_header(dtb);
+  if (fe < 0)
+  {
+    return fe;
+  }
+
+  blob = malloc(sizeof (rtems_fdt_blob));
+  if (!blob)
+  {
+    return -RTEMS_FDT_ERR_NO_MEMORY;
+  }
+
+  blob->blob = dtb;
+  blob->name = NULL;
+  fdt = rtems_fdt_lock ();
+
+  rtems_chain_append_unprotected (&fdt->blobs, &blob->node);
+
+  blob->refs = 1;
+
+  rtems_fdt_unlock ();
+
+  handle->blob = blob;
+
+  fe = rtems_fdt_init_index(handle, blob);
+  if (fe < 0)
+  {
+    free(blob);
+    return -RTEMS_FDT_ERR_NO_MEMORY;
+  }
+
+  return 0;
+}
+
+int
+rtems_fdt_unload (rtems_fdt_handle* handle)
+{
+  (void) rtems_fdt_lock ();
+
+  if (!rtems_fdt_valid_handle (handle))
+  {
+    rtems_fdt_unlock ();
+    return -RTEMS_FDT_ERR_INVALID_HANDLE;
+  }
+
+  if (handle->blob->refs > 1)
+  {
+    rtems_fdt_unlock ();
+    return -RTEMS_FDT_ERR_REFERENCED;
+  }
+
+  rtems_chain_extract_unprotected (&handle->blob->node);
+
+  free (handle->blob);
+
+  handle->blob = NULL;
+
+  rtems_fdt_unlock ();
+
+  rtems_fdt_release_index(&handle->blob->index);
+
+  return 0;
+}
+
+int
+rtems_fdt_num_mem_rsv (rtems_fdt_handle* handle)
+{
+  if (!handle->blob)
+    return -RTEMS_FDT_ERR_INVALID_HANDLE;
+  return fdt_num_mem_rsv (handle->blob->blob);
+}
+
+int
+rtems_fdt_get_mem_rsv (rtems_fdt_handle* handle,
+                       int               n,
+                       uint64_t*         address,
+                       uint64_t*         size)
+{
+  if (!handle->blob)
+    return -RTEMS_FDT_ERR_INVALID_HANDLE;
+  return fdt_get_mem_rsv (handle->blob->blob, n, address, size);
+}
+
+int
+rtems_fdt_subnode_offset_namelen (rtems_fdt_handle* handle,
+                                  int               parentoffset,
+                                  const char*       name,
+                                  int               namelen)
+{
+  if (!handle->blob)
+    return -RTEMS_FDT_ERR_INVALID_HANDLE;
+  return fdt_subnode_offset_namelen (handle->blob->blob,
+                                     parentoffset,
+                                     name,
+                                     namelen);
+}
+
+int
+rtems_fdt_subnode_offset (rtems_fdt_handle* handle,
+                          int               parentoffset,
+                          const char*       name)
+{
+  char full_name[256];
+  const char *path;
+
+  if (!handle->blob)
+    return -RTEMS_FDT_ERR_INVALID_HANDLE;
+
+  path = rtems_fdt_index_find_name_by_offset(&handle->blob->index, parentoffset);
+  snprintf(full_name, sizeof(full_name), "%s/%s", path, name);
+
+  return rtems_fdt_index_find_by_name(&handle->blob->index, full_name);
+}
+
+int
+rtems_fdt_path_offset (rtems_fdt_handle* handle, const char* path)
+{
+  return rtems_fdt_index_find_by_name(&handle->blob->index, path);
+}
+
+const char*
+rtems_fdt_get_name (rtems_fdt_handle* handle, int nodeoffset, int* length)
+{
+  if (!handle->blob)
+    return NULL;
+
+  const char *name = rtems_fdt_index_find_name_by_offset(&handle->blob->index, nodeoffset);
+  if (name && length)
+  {
+    *length = strlen(name);
+  }
+
+  return name;
+}
+
+const void*
+rtems_fdt_getprop_namelen (rtems_fdt_handle* handle,
+                           int               nodeoffset,
+                           const char*       name,
+                           int               namelen,
+                           int*              length)
+{
+  if (!handle->blob)
+    return NULL;
+  return fdt_getprop_namelen (handle->blob->blob,
+                              nodeoffset,
+                              name,
+                              namelen,
+                              length);
+}
+
+const void*
+rtems_fdt_getprop (rtems_fdt_handle* handle,
+                   int               nodeoffset,
+                   const char*       name,
+                   int*              length)
+{
+  if (!handle->blob)
+    return NULL;
+  return fdt_getprop (handle->blob->blob,
+                      nodeoffset,
+                      name,
+                      length);
+}
+
+uint32_t
+rtems_fdt_get_phandle (rtems_fdt_handle* handle, int nodeoffset)
+{
+  if (!handle->blob)
+    return -RTEMS_FDT_ERR_INVALID_HANDLE;
+  return fdt_get_phandle (handle->blob->blob, nodeoffset);
+}
+
+const char*
+rtems_fdt_get_alias_namelen (rtems_fdt_handle* handle,
+                             const char*       name,
+                             int               namelen)
+{
+  if (!handle->blob)
+    return NULL;
+  return fdt_get_alias_namelen (handle->blob->blob, name, namelen);
+}
+
+const char*
+rtems_fdt_get_alias (rtems_fdt_handle* handle, const char* name)
+{
+  if (!handle->blob)
+    return NULL;
+  return fdt_get_alias (handle->blob->blob, name);
+}
+
+int
+rtems_fdt_get_path (rtems_fdt_handle* handle,
+                    int               nodeoffset,
+                    char*             buf,
+                    int               buflen)
+{
+  if (!handle->blob)
+    return -RTEMS_FDT_ERR_INVALID_HANDLE;
+  return fdt_get_path (handle->blob->blob, nodeoffset, buf, buflen);
+}
+
+int
+rtems_fdt_supernode_atdepth_offset (rtems_fdt_handle* handle,
+                                    int               nodeoffset,
+                                    int               supernodedepth,
+                                    int*              nodedepth)
+{
+  if (!handle->blob)
+    return -RTEMS_FDT_ERR_INVALID_HANDLE;
+  return fdt_supernode_atdepth_offset(handle,
+                                      nodeoffset,
+                                      supernodedepth,
+                                      nodedepth);
+}
+
+int
+rtems_fdt_node_depth (rtems_fdt_handle* handle, int nodeoffset)
+{
+  if (!handle->blob)
+    return -RTEMS_FDT_ERR_INVALID_HANDLE;
+  return fdt_node_depth (handle->blob->blob, nodeoffset);
+}
+
+int
+rtems_fdt_parent_offset (rtems_fdt_handle* handle, int nodeoffset)
+{
+  if (!handle->blob)
+    return -RTEMS_FDT_ERR_INVALID_HANDLE;
+  return fdt_parent_offset (handle->blob->blob, nodeoffset);
+}
+
+int
+rtems_fdt_node_offset_by_prop_value (rtems_fdt_handle* handle,
+                                     int               startoffset,
+                                     const char*       propname,
+                                     const void*       propval,
+                                     int               proplen)
+{
+  if (!handle->blob)
+    return -RTEMS_FDT_ERR_INVALID_HANDLE;
+  return fdt_node_offset_by_prop_value (handle,
+                                        startoffset,
+                                        propname,
+                                        propval,
+                                        proplen);
+}
+
+int
+rtems_fdt_node_offset_by_phandle (rtems_fdt_handle* handle, uint32_t phandle)
+{
+  if (!handle->blob)
+    return -RTEMS_FDT_ERR_INVALID_HANDLE;
+  return fdt_node_offset_by_phandle (handle->blob->blob, phandle);
+}
+
+int
+rtems_fdt_node_check_compatible (rtems_fdt_handle* handle,
+                                 int               nodeoffset,
+                                 const char*       compatible)
+{
+  if (!handle->blob)
+    return -RTEMS_FDT_ERR_INVALID_HANDLE;
+  return fdt_node_check_compatible (handle, nodeoffset, compatible);
+}
+
+int
+rtems_fdt_node_offset_by_compatible (rtems_fdt_handle* handle,
+                                     int               startoffset,
+                                     const char*       compatible)
+{
+  if (!handle->blob)
+    return -RTEMS_FDT_ERR_INVALID_HANDLE;
+  return fdt_node_offset_by_compatible (handle->blob->blob,
+                                        startoffset,
+                                        compatible);
+}
+
+int
+rtems_fdt_next_node (rtems_fdt_handle* handle, int offset, int* depth)
+{
+  if (!handle->blob)
+    return -RTEMS_FDT_ERR_INVALID_HANDLE;
+  return fdt_next_node (handle->blob->blob, offset, depth);
+}
+
+const char*
+rtems_fdt_strerror (int errval)
+{
+  const char* errors[] = {
+    "invalid handle",
+    "no memory",
+    "file not found",
+    "DTB read fail",
+    "blob has references"
+  };
+  if (errval > -RTEMS_FDT_ERR_RTEMS_MIN)
+    return fdt_strerror (errval);
+  if (errval < -RTEMS_FDT_ERR_MAX)
+    return "invalid error code";
+  return errors[(-errval) - RTEMS_FDT_ERR_RTEMS_MIN];
+}
+
+int
+rtems_fdt_prop_value(const char* const path,
+                     const char* const propname,
+                     void*             value,
+                     size_t*           size)
+{
+  rtems_fdt_handle fdt;
+  int              node;
+  const void*      prop;
+  int              length;
+
+  rtems_fdt_init_handle (&fdt);
+
+  node = rtems_fdt_find_path_offset (&fdt, path);
+  if (node < 0)
+    return node;
+
+  prop = rtems_fdt_getprop(&fdt, node, propname, &length);
+  if (length < 0)
+  {
+    rtems_fdt_release_handle (&fdt);
+    return length;
+  }
+
+  if (length > (int) *size)
+  {
+    rtems_fdt_release_handle (&fdt);
+    return RTEMS_FDT_ERR_BADPATH;
+  }
+
+  *size = length;
+
+  memcpy (value, prop, length);
+
+  return 0;
+}
+
+int
+rtems_fdt_prop_map(const char* const path,
+                   const char* const propname,
+                   const char* const names[],
+                   uint32_t*         values,
+                   size_t            count)
+{
+  rtems_fdt_handle fdt;
+  int              node;
+  size_t           item;
+
+  rtems_fdt_init_handle (&fdt);
+
+  node = rtems_fdt_find_path_offset (&fdt, path);
+  if (node < 0)
+    return node;
+
+  for (item = 0; item < count; item++)
+  {
+    const void*    prop;
+    const uint8_t* p;
+    int            length;
+    int            subnode;
+
+    subnode = rtems_fdt_subnode_offset (&fdt, node, names[item]);
+    if (subnode < 0)
+    {
+      rtems_fdt_release_handle (&fdt);
+      return subnode;
+    }
+
+    prop = rtems_fdt_getprop(&fdt, subnode, propname, &length);
+    if (length < 0)
+    {
+      rtems_fdt_release_handle (&fdt);
+      return length;
+    }
+
+    if (length != sizeof (uint32_t))
+    {
+      rtems_fdt_release_handle (&fdt);
+      return RTEMS_FDT_ERR_BADPATH;
+    }
+
+    p = prop;
+
+    values[item] = ((((uint32_t) p[0]) << 24) |
+                    (((uint32_t) p[1]) << 16) |
+                    (((uint32_t) p[2]) << 8)  |
+                    (uint32_t) p[3]);
+  }
+
+  return 0;
+}
+
+uint32_t
+rtems_fdt_get_uint32 (const void* prop)
+{
+  const uint8_t* p = prop;
+  uint32_t       value;
+  value = ((((uint32_t) p[0]) << 24) |
+           (((uint32_t) p[1]) << 16) |
+           (((uint32_t) p[2]) << 8)  |
+           (uint32_t) p[3]);
+  return value;
+}
+
+int
+rtems_fdt_get_value (const char* path,
+                     const char* property,
+                     size_t      size,
+                     uint32_t*   value)
+{
+  rtems_fdt_handle fdt;
+  const void*      prop;
+  int              node;
+  int              length;
+
+  rtems_fdt_init_handle (&fdt);
+
+  node = rtems_fdt_find_path_offset (&fdt, path);
+  if (node < 0)
+  {
+    rtems_fdt_release_handle (&fdt);
+    return node;
+  }
+
+  prop = rtems_fdt_getprop(&fdt, node, property, &length);
+  if (length < 0)
+  {
+    rtems_fdt_release_handle (&fdt);
+    return length;
+  }
+
+  if (length == sizeof (uint32_t))
+    *value = rtems_fdt_get_uint32 (prop);
+  else
+    *value = 0;
+
+  rtems_fdt_release_handle (&fdt);
+
+  return 0;
+}
+
+/**
+ * Get the number of entries in an FDT handle.
+ */
+int
+rtems_fdt_num_entries(rtems_fdt_handle* handle)
+{
+  return handle->blob->index.num_entries;
+}
+
+/**
+ * Get the numbered entry name. Note that the id isn't the same as
+ * the offset - it's numbered 0, 1, 2 ... num_entries-1
+ */
+const char *
+rtems_fdt_entry_name(rtems_fdt_handle* handle, int id)
+{
+  return handle->blob->index.entries[id].name;
+}
+
+/**
+ * Get the numbered entry offset. Note that the id isn't the same as
+ * the offset - it's numbered 0, 1, 2 ... num_entries-1
+ */
+int
+rtems_fdt_entry_offset(rtems_fdt_handle* handle, int id)
+{
+  return handle->blob->index.entries[id].offset;
+}