content: /* ###
   * IP: GHIDRA
   *
   * Licensed under the Apache License, Version 2.0 (the "License");
   * you may not use this file except in compliance with the License.
   * You may obtain a copy of the License at
   *
   *      http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */
  
  package firmware.ifd;
  
  import java.io.IOException;
  
  import ghidra.app.util.bin.BinaryReader;
  import ghidra.app.util.bin.ByteProvider;
  import ghidra.formats.gfilesystem.FSRLRoot;
  import ghidra.formats.gfilesystem.FileSystemService;
  import ghidra.formats.gfilesystem.factory.GFileSystemFactoryByteProvider;
  import ghidra.formats.gfilesystem.factory.GFileSystemProbeByteProvider;
  import ghidra.util.Msg;
  import ghidra.util.task.TaskMonitor;
  
  public class IntelFlashFileSystemFactory implements GFileSystemFactoryByteProvider<IntelFlashFileSystem>,
  		GFileSystemProbeByteProvider {
  	@Override
  	public boolean probe(ByteProvider provider, FileSystemService fsService, TaskMonitor monitor) throws IOException {
  		return findIFDSignatureOffset(provider) != -1;
  	}
  
  	@Override
  	public IntelFlashFileSystem create(FSRLRoot fsrlRoot, ByteProvider provider, FileSystemService fsService,
  			TaskMonitor monitor) throws IOException {
  		IntelFlashFileSystem fs = new IntelFlashFileSystem(fsrlRoot);
  		try {
  			long offset = findIFDSignatureOffset(provider);
  			if (offset < 0) {
  				throw new IOException("IFD signature not found");
  			}
  
  			fs.mount(provider, offset, monitor);
  			return fs;
  		} catch (IOException ioe) {
  			fs.close();
  			throw ioe;
  		}
  	}
  
  	private long findIFDSignatureOffset(ByteProvider provider) throws IOException {
  		long offset = 0;
  		long remainingLength = provider.length();
  		BinaryReader reader = new BinaryReader(provider, true);
  		while (remainingLength >= 4) {
  			int signature = reader.readInt(offset);
  			if (signature == IntelFlashDescriptorConstants.IFD_SIGNATURE) {
  				if (remainingLength <= IntelFlashDescriptorConstants.DESCRIPTOR_SIZE - 16) {
  					// Ignore binaries which lack regions other than the flash descriptor.
  					return -1;
  				}
  
  				Msg.debug(this, String.format("Found IFD signature at 0x%X", offset));
  				return offset;
  			}
  
  			offset += 4;
  			remainingLength -= 4;
  		}
  
  		return -1;
  	}
  }
  