pylibfdt

from pylibfdt import Fdt import os # For demonstration, create a dummy DTB file if it doesn't exist # In a real scenario, you'd load an existing .dtb file dummy_dtb_path = "example.dtb" if not os.path.exists(dummy_dtb_path): # This is a very minimal valid DTB structure (version 16, no nodes) # Actual DTBs are much more complex. This only serves to avoid FdtException on a non-existent file. # A true example would require external tools to generate a valid DTB. # For real use, ensure 'example.dtb' is a valid DTB created by dtc. try: # Attempt to create a placeholder or indicate requirement for a real DTB # Cannot easily generate a valid DTB from scratch within Python for quickstart. # Assume a valid 'test.dtb' exists for proper execution. print(f"Please ensure a valid DTB file named '{dummy_dtb_path}' exists for a meaningful quickstart.") # For strict runnable, we will use a byte literal that is a minimal valid FDT header. # This will load, but won't have any actual nodes or properties. minimal_fdt_bytes = b'\xd0\x0d\xfe\xed\x00\x00\x00\x01\x00\x00\x00\x28\x00\x00\x00\x30\x00\x00\x00\x11\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00' fdt = Fdt(dtb=minimal_fdt_bytes) print("Loaded minimal FDT from bytes.") except Exception as e: print(f"Could not create dummy DTB or load minimal FDT bytes: {e}") print("Skipping quickstart example as no valid DTB could be loaded.") exit() else: try: fdt = Fdt(filename=dummy_dtb_path) print(f"Loaded FDT from file: {dummy_dtb_path}") except Exception as e: print(f"Error loading {dummy_dtb_path}: {e}") print("Skipping quickstart example due to DTB loading error.") exit() # Get the root node root_node = fdt.get_node('/') if root_node: print(f"Root node name: {root_node.name}") # Walk the tree (if there are any nodes in the loaded FDT) print("\nWalking FDT nodes:") found_nodes = False for node in fdt.walk(): print(f" Node: {node.name} (path: {node.path})") for prop in node.properties: # Property values can be bytes, strings, or integers value = prop.value if isinstance(value, bytes): try: value = value.decode('utf-8').strip('\x00') # Try decoding if it's a string except UnicodeDecodeError: pass # Keep as bytes if not a valid utf-8 string print(f" Property: {prop.name} = {value}") found_nodes = True if not found_nodes: print(" No nodes found in the FDT (might be a minimal FDT header).") else: print("Could not get root node.") # Example of getting a specific node and property (if they exist) # This assumes a more complex DTB than the minimal header. # For a real DTB, you might look for '/chosen' or '/aliases' chosen_node = fdt.get_node('/chosen') if chosen_node: print(f"\nFound node: {chosen_node.path}") bootargs_prop = chosen_node.get_property('bootargs') if bootargs_prop: print(f" Bootargs: {bootargs_prop.value.decode('utf-8')}") else: print(" 'bootargs' property not found in /chosen.") else: print("Node '/chosen' not found (this is common for minimal DTBs).")