rtems-fdt: refactor rtems_fdt_load to separate gzip

Updates #5607
2026-09-20 19:58:32 +08:00 · 2026-06-05 23:23:51 +00:00
parent 097cfabe0a
commit faded1b847
3 changed files with 214 additions and 103 deletions
@@ -233,21 +233,51 @@ bool rtems_fdt_valid_handle( const rtems_fdt_handle *handle );
 int rtems_fdt_find_path_offset( rtems_fdt_handle *handle, const char *path );

 /**
- * Load a device tree blob or DTB file into memory and register it on the chain
- * of blobs.
+ * @brief Loads a device tree blob (DTB) file into memory and registers it on
+ *        the chain of blobs. The DTB may be gzip compressed or binary format.
 *
 * @param filename The name of the blob file to load.
 * @param handle The handle returns the reference to the blob once load.
- * @return int If less than 0 it is an error code else it is the blob descriptor.
+ * @return int If less than 0 an error code else successful.
 */
 int rtems_fdt_load( const char *const filename, rtems_fdt_handle *handle );

+/**
+ * @brief Loads a raw DTB file int memory and registers it on the
+ *        chain of blobs.
+ *
+ * @param filename The name of the raw blob file to load.
+ * @param handle The handle returns the reference to the blob once load.
+ * @return int If less than 0 an error code else successful.
+ *
+ * @see rtems_fdt_load
+ */
+int rtems_fdt_load_blob_file_binary(
+  const char *filename,
+  rtems_fdt_handle *handle
+);
+
+/**
+ * @brief Loads a gzip compressed DTB file int memory and registers it on the
+ *        chain of blobs.
+ *
+ * @param filename The name of the compressed blob file to load.
+ * @param handle The handle returns the reference to the blob once load.
+ * @return int If less than 0 an error code else successful.
+ *
+ * @see rtems_fdt_load
+ */
+int rtems_fdt_load_blob_file_gzip(
+  const char *filename,
+  rtems_fdt_handle *handle
+);
+
 /**
 * Register a device tree blob or DTB on to the chain of blobs.
 *
 * @param blob_desc A pointer to the blob.
 * @param handle The handle returns the reference to the blob once load.
- * @return int If less than 0 it is an error code else it is the blob descriptor.
+ * @return int If less than 0 an error code else successful.
 */
 int rtems_fdt_register( const void *blob, rtems_fdt_handle *handle );

@@ -47,6 +47,8 @@
 #ifndef RTEMS_FDTIMPL_H
 #define RTEMS_FDTIMPL_H

+#include <zlib.h>
+
 #include <rtems/chain.h>

 /**
@@ -122,4 +124,70 @@ static inline bool rtems_fdt_valid_handle_unprotected(
  return false;
 }

+static inline int rtems_fdt_deflate(
+  void *dtb,
+  size_t dtb_size,
+  void *cdata,
+  size_t c_size
+)
+{
+  z_stream stream;
+  int      err;
+  stream.next_in = (Bytef *) cdata;
+  stream.avail_in = (uInt) c_size;
+  stream.next_out = (void *) dtb;
+  stream.avail_out = (uInt) dtb_size;
+  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 ) || ( dtb_size != stream.total_out ) ) {
+    return -RTEMS_FDT_ERR_READ_FAIL;
+  }
+  return 0;
+}
+
+static inline int rtems_fdt_read_file( int fp, void *data, size_t size )
+{
+  size_t offset = 0;
+  int    r;
+
+  while ( size ) {
+    r = read( fp, data + offset, size );
+    if ( r < 0 ) {
+      return r;
+    }
+    size -= r;
+    offset += r;
+  }
+
+  return offset;
+}
+
+static inline int rtems_fdt_load_file(
+  const char *filename,
+  struct stat *stat_buf
+)
+{
+  int bf;
+  if ( stat( filename, stat_buf ) < 0 ) {
+    return -RTEMS_FDT_ERR_NOT_FOUND;
+  }
+
+  bf = open( filename, O_RDONLY );
+  if ( bf < 0 ) {
+    return -RTEMS_FDT_ERR_READ_FAIL;
+  }
+
+  return bf;
+}
+
 #endif
@@ -31,7 +31,6 @@
 #include <sys/types.h>

 #include <libfdt.h>
-#include <zlib.h>

 #include <rtems/malloc.h>
 #include <rtems/rtems-fdt.h>
@@ -381,120 +380,36 @@ int rtems_fdt_find_path_offset( rtems_fdt_handle *handle, const char *path )
  return -FDT_ERR_NOTFOUND;
 }

-int rtems_fdt_load( const char *filename, rtems_fdt_handle *handle )
+int rtems_fdt_load_blob_file_binary(
+  const char *filename,
+  rtems_fdt_handle *handle
+)
 {
+  struct stat sb;
+  int         bf;
  void       *dtb;
  size_t      bsize;
-  int         bf;
  ssize_t     r;
  int         fe;
-  struct stat sb;
-  uint8_t     gzip_id[ 2 ];
-  uint8_t    *cdata;
-  size_t      size;

-  if ( stat( filename, &sb ) < 0 ) {
-    return -RTEMS_FDT_ERR_NOT_FOUND;
-  }
-
-  bf = open( filename, O_RDONLY );
+  bf = rtems_fdt_load_file( filename, &sb );
  if ( bf < 0 ) {
-    return -RTEMS_FDT_ERR_READ_FAIL;
+    return bf;
  }

-  /* peek for a gzip header */
-  r = read( bf, &gzip_id, sizeof( gzip_id ) );
-  if ( r < 0 ) {
-    close( bf );
-    return -RTEMS_FDT_ERR_READ_FAIL;
-  }
-
-  /* reset file pointer after peek */
-  if ( lseek( bf, 0, SEEK_SET ) < 0 ) {
-    close( bf );
-    return -RTEMS_FDT_ERR_READ_FAIL;
-  }
-
-  /* determine size of the dtb blob */
-  if ( ( gzip_id[ 0 ] == 0x1f ) && ( gzip_id[ 1 ] == 0x8b ) ) {
-    size_t offset;
-
-    cdata = rtems_malloc( sb.st_size );
-    if ( !cdata ) {
-      close( bf );
-      return -RTEMS_FDT_ERR_NO_MEMORY;
-    }
-
-    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;
-  }
+  bsize = sb.st_size;

  dtb = rtems_malloc( bsize );
  if ( !dtb ) {
-    free( cdata );
    close( bf );
    return -RTEMS_FDT_ERR_NO_MEMORY;
  }

-  /* read the blob */
-  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 *) dtb;
-    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( dtb );
-      free( cdata );
-      close( bf );
-      return -RTEMS_FDT_ERR_READ_FAIL;
-    }
-    free( cdata );
-    cdata = NULL;
-  } else {
-    char *buf = (char *) dtb;
-    size = bsize;
-    while ( size ) {
-      r = read( bf, buf, size );
-      if ( r < 0 ) {
-        free( dtb );
-        close( bf );
-        return -RTEMS_FDT_ERR_READ_FAIL;
-      }
-      size -= r;
-      buf += r;
-    }
+  r = rtems_fdt_read_file( bf, dtb, bsize );
+  if ( r < 0 ) {
+    free( dtb );
+    close( bf );
+    return -RTEMS_FDT_ERR_READ_FAIL;
  }

  fe = rtems_fdt_register( dtb, handle );
@@ -510,6 +425,104 @@ int rtems_fdt_load( const char *filename, rtems_fdt_handle *handle )
  return 0;
 }

+int rtems_fdt_load_blob_file_gzip(
+  const char *filename,
+  rtems_fdt_handle *handle
+)
+{
+  struct stat sb;
+  int         bf;
+  uint8_t     gzip_id[ 2 ];
+  uint8_t    *cdata;
+  void       *dtb;
+  size_t      bsize;
+  ssize_t     r;
+  int         fe;
+  size_t      offset;
+
+  bf = rtems_fdt_load_file( filename, &sb );
+  if ( bf < 0 ) {
+    return bf;
+  }
+
+  /* peek for a gzip header */
+  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 ) {
+    close( bf );
+    return -RTEMS_FDT_ERR_READ_FAIL;
+  }
+
+  /* reset file pointer after peek */
+  if ( lseek( bf, 0, SEEK_SET ) < 0 ) {
+    close( bf );
+    return -RTEMS_FDT_ERR_READ_FAIL;
+  }
+
+  cdata = rtems_malloc( sb.st_size );
+  if ( !cdata ) {
+    close( bf );
+    return -RTEMS_FDT_ERR_NO_MEMORY;
+  }
+
+  r = rtems_fdt_read_file( bf, cdata, sb.st_size );
+  if ( r < 0 ) {
+    free( cdata );
+    close( bf );
+    return -RTEMS_FDT_ERR_READ_FAIL;
+  }
+
+  offset = sb.st_size - 4;
+  bsize = ( ( cdata[ offset + 3 ] << 24 ) | ( cdata[ offset + 2 ] << 16 ) |
+            ( cdata[ offset + 1 ] << 8 ) | cdata[ offset + 0 ] );
+
+  dtb = rtems_malloc( bsize );
+  if ( !dtb ) {
+    free( cdata );
+    close( bf );
+    return -RTEMS_FDT_ERR_NO_MEMORY;
+  }
+
+  if ( rtems_fdt_deflate( dtb, bsize, cdata, sb.st_size ) < 0 ) {
+    free( dtb );
+    free( cdata );
+    close( bf );
+    return -RTEMS_FDT_ERR_READ_FAIL;
+  }
+
+  free( cdata );
+  cdata = NULL;
+
+  fe = rtems_fdt_register( dtb, handle );
+  if ( fe < 0 ) {
+    free( dtb );
+    close( bf );
+    return fe;
+  }
+
+  handle->blob->name = strdup( filename );
+
+  close( bf );
+  return 0;
+}
+
+int rtems_fdt_load( const char *filename, rtems_fdt_handle *handle )
+{
+  int rc;
+
+  rc = rtems_fdt_load_blob_file_gzip( filename, handle );
+
+  if ( rc < 0 ) {
+    rc = rtems_fdt_load_blob_file_binary( filename, handle );
+  }
+
+  return rc;
+}
+
 int rtems_fdt_register( const void *dtb, rtems_fdt_handle *handle )
 {
  rtems_fdt_data *fdt;