/* SPDX-License-Identifier: GPL-2.0+ OR BSD-2-Clause */ /* * pylibfdt - Flat Device Tree manipulation in Python * Copyright (C) 2017 Google, Inc. * Written by Simon Glass */ %module libfdt %include %{ #define SWIG_FILE_WITH_INIT #include "libfdt.h" /* * We rename this function here to avoid problems with swig, since we also have * a struct called fdt_property. That struct causes swig to create a class in * libfdt.py called fdt_property(), which confuses things. */ static int _fdt_property(void *fdt, const char *name, const char *val, int len) { return fdt_property(fdt, name, val, len); } %} %pythoncode %{ import struct # Error codes, corresponding to FDT_ERR_... in libfdt.h (NOTFOUND, EXISTS, NOSPACE, BADOFFSET, BADPATH, BADPHANDLE, BADSTATE, TRUNCATED, BADMAGIC, BADVERSION, BADSTRUCTURE, BADLAYOUT, INTERNAL, BADNCELLS, BADVALUE, BADOVERLAY, NOPHANDLES) = QUIET_ALL = range(1, 18) # QUIET_ALL can be passed as the 'quiet' parameter to avoid exceptions # altogether. All # functions passed this value will return an error instead # of raising an exception. # Pass this as the 'quiet' parameter to return -ENOTFOUND on NOTFOUND errors, # instead of raising an exception. QUIET_NOTFOUND = (NOTFOUND,) class FdtException(Exception): """An exception caused by an error such as one of the codes above""" def __init__(self, err): self.err = err def __str__(self): return 'pylibfdt error %d: %s' % (self.err, fdt_strerror(self.err)) def strerror(fdt_err): """Get the string for an error number Args: fdt_err: Error number (-ve) Returns: String containing the associated error """ return fdt_strerror(fdt_err) def check_err(val, quiet=()): """Raise an error if the return value is -ve This is used to check for errors returned by libfdt C functions. Args: val: Return value from a libfdt function quiet: Errors to ignore (empty to raise on all errors) Returns: val if val >= 0 Raises FdtException if val < 0 """ if val < 0: if -val not in quiet: raise FdtException(val) return val def check_err_null(val, quiet=()): """Raise an error if the return value is NULL This is used to check for a NULL return value from certain libfdt C functions Args: val: Return value from a libfdt function quiet: Errors to ignore (empty to raise on all errors) Returns: val if val is a list, None if not Raises FdtException if val indicates an error was reported and the error is not in @quiet. """ # Normally a list is returned which contains the data and its length. # If we get just an integer error code, it means the function failed. if not isinstance(val, list): if -val not in quiet: raise FdtException(val) return val class Fdt: """Device tree class, supporting all operations The Fdt object is created is created from a device tree binary file, e.g. with something like: fdt = Fdt(open("filename.dtb").read()) Operations can then be performed using the methods in this class. Each method xxx(args...) corresponds to a libfdt function fdt_xxx(fdt, args...). All methods raise an FdtException if an error occurs. To avoid this behaviour a 'quiet' parameter is provided for some functions. This defaults to empty, but you can pass a list of errors that you expect. If one of these errors occurs, the function will return an error number (e.g. -NOTFOUND). """ def __init__(self, data): self._fdt = bytearray(data) check_err(fdt_check_header(self._fdt)); def as_bytearray(self): """Get the device tree contents as a bytearray This can be passed directly to libfdt functions that access a const void * for the device tree. Returns: bytearray containing the device tree """ return bytearray(self._fdt) def next_node(self, nodeoffset, depth, quiet=()): """Find the next subnode Args: nodeoffset: Node offset of previous node depth: On input, the depth of the node at nodeoffset. On output, the depth of the returned node quiet: Errors to ignore (empty to raise on all errors) Returns: The offset of the next node, if any Raises: FdtException if no more nodes found or other error occurs """ return check_err(fdt_next_node(self._fdt, nodeoffset, depth), quiet) def first_subnode(self, nodeoffset, quiet=()): """Find the first subnode of a parent node Args: nodeoffset: Node offset of parent node quiet: Errors to ignore (empty to raise on all errors) Returns: The offset of the first subnode, if any Raises: FdtException if no subnodes found or other error occurs """ return check_err(fdt_first_subnode(self._fdt, nodeoffset), quiet) def next_subnode(self, nodeoffset, quiet=()): """Find the next subnode Args: nodeoffset: Node offset of previous subnode quiet: Errors to ignore (empty to raise on all errors) Returns: The offset of the next subnode, if any Raises: FdtException if no more subnodes found or other error occurs """ return check_err(fdt_next_subnode(self._fdt, nodeoffset), quiet) def magic(self): """Return the magic word from the header Returns: Magic word """ return fdt_magic(self._fdt) & 0xffffffff def totalsize(self): """Return the total size of the device tree Returns: Total tree size in bytes """ return check_err(fdt_totalsize(self._fdt)) def off_dt_struct(self): """Return the start of the device-tree struct area Returns: Start offset of struct area """ return check_err(fdt_off_dt_struct(self._fdt)) def off_dt_strings(self): """Return the start of the device-tree string area Returns: Start offset of string area """ return check_err(fdt_off_dt_strings(self._fdt)) def off_mem_rsvmap(self): """Return the start of the memory reserve map Returns: Start offset of memory reserve map """ return check_err(fdt_off_mem_rsvmap(self._fdt)) def version(self): """Return the version of the device tree Returns: Version number of the device tree """ return check_err(fdt_version(self._fdt)) def last_comp_version(self): """Return the last compatible version of the device tree Returns: Last compatible version number of the device tree """ return check_err(fdt_last_comp_version(self._fdt)) def boot_cpuid_phys(self): """Return the physical boot CPU ID Returns: Physical boot CPU ID """ return check_err(fdt_boot_cpuid_phys(self._fdt)) def size_dt_strings(self): """Return the start of the device-tree string area Returns: Start offset of string area """ return check_err(fdt_size_dt_strings(self._fdt)) def size_dt_struct(self): """Return the start of the device-tree struct area Returns: Start offset of struct area """ return check_err(fdt_size_dt_struct(self._fdt)) def num_mem_rsv(self, quiet=()): """Return the number of memory reserve-map records Returns: Number of memory reserve-map records """ return check_err(fdt_num_mem_rsv(self._fdt), quiet) def get_mem_rsv(self, index, quiet=()): """Return the indexed memory reserve-map record Args: index: Record to return (0=first) Returns: Number of memory reserve-map records """ return check_err(fdt_get_mem_rsv(self._fdt, index), quiet) def subnode_offset(self, parentoffset, name, quiet=()): """Get the offset of a named subnode Args: parentoffset: Offset of the parent node to check name: Name of the required subnode, e.g. 'subnode@1' quiet: Errors to ignore (empty to raise on all errors) Returns: The node offset of the found node, if any Raises FdtException if there is no node with that name, or other error """ return check_err(fdt_subnode_offset(self._fdt, parentoffset, name), quiet) def path_offset(self, path, quiet=()): """Get the offset for a given path Args: path: Path to the required node, e.g. '/node@3/subnode@1' quiet: Errors to ignore (empty to raise on all errors) Returns: Node offset Raises FdtException if the path is not valid or not found """ return check_err(fdt_path_offset(self._fdt, path), quiet) def get_name(self, nodeoffset): """Get the name of a node Args: nodeoffset: Offset of node to check Returns: Node name Raises: FdtException on error (e.g. nodeoffset is invalid) """ return check_err_null(fdt_get_name(self._fdt, nodeoffset))[0] def first_property_offset(self, nodeoffset, quiet=()): """Get the offset of the first property in a node offset Args: nodeoffset: Offset to the node to check quiet: Errors to ignore (empty to raise on all errors) Returns: Offset of the first property Raises FdtException if the associated node has no properties, or some other error occurred """ return check_err(fdt_first_property_offset(self._fdt, nodeoffset), quiet) def next_property_offset(self, prop_offset, quiet=()): """Get the next property in a node Args: prop_offset: Offset of the previous property quiet: Errors to ignore (empty to raise on all errors) Returns: Offset of the next property Raises: FdtException if the associated node has no more properties, or some other error occurred """ return check_err(fdt_next_property_offset(self._fdt, prop_offset), quiet) def get_property_by_offset(self, prop_offset, quiet=()): """Obtains a property that can be examined Args: prop_offset: Offset of property (e.g. from first_property_offset()) quiet: Errors to ignore (empty to raise on all errors) Returns: Property object, or None if not found Raises: FdtException on error (e.g. invalid prop_offset or device tree format) """ pdata = check_err_null( fdt_get_property_by_offset(self._fdt, prop_offset), quiet) if isinstance(pdata, (int)): return pdata return Property(pdata[0], pdata[1]) @staticmethod def create_empty_tree(size, quiet=()): """Create an empty device tree ready for use Args: size: Size of device tree in bytes Returns: Fdt object containing the device tree """ data = bytearray(size) err = check_err(fdt_create_empty_tree(data, size), quiet) if err: return err return Fdt(data) def open_into(self, size, quiet=()): """Move the device tree into a larger or smaller space This creates a new device tree of size @size and moves the existing device tree contents over to that. It can be used to create more space in a device tree. Args: size: Required new size of device tree in bytes """ fdt = bytearray(size) fdt[:len(self._fdt)] = self._fdt err = check_err(fdt_open_into(self._fdt, fdt, size), quiet) if err: return err self._fdt = fdt def pack(self, quiet=()): """Pack the device tree to remove unused space This adjusts the tree in place. Args: quiet: Errors to ignore (empty to raise on all errors) Raises: FdtException if any error occurs """ return check_err(fdt_pack(self._fdt), quiet) def getprop(self, nodeoffset, prop_name, quiet=()): """Get a property from a node Args: nodeoffset: Node offset containing property to get prop_name: Name of property to get quiet: Errors to ignore (empty to raise on all errors) Returns: Value of property as a string, or -ve error number Raises: FdtError if any error occurs (e.g. the property is not found) """ pdata = check_err_null(fdt_getprop(self._fdt, nodeoffset, prop_name), quiet) if isinstance(pdata, (int)): return pdata return str(pdata[0]) def getprop_obj(self, nodeoffset, prop_name, quiet=()): """Get a property from a node as a Property object Args: nodeoffset: Node offset containing property to get prop_name: Name of property to get quiet: Errors to ignore (empty to raise on all errors) Returns: Property object, or None if not found Raises: FdtError if any error occurs (e.g. the property is not found) """ pdata = check_err_null(fdt_getprop(self._fdt, nodeoffset, prop_name), quiet) if isinstance(pdata, (int)): return None return Property(prop_name, bytearray(pdata[0])) def get_phandle(self, nodeoffset): """Get the phandle of a node Args: nodeoffset: Node offset to check Returns: phandle of node, or 0 if the node has no phandle or another error occurs """ return fdt_get_phandle(self._fdt, nodeoffset) def parent_offset(self, nodeoffset, quiet=()): """Get the offset of a node's parent Args: nodeoffset: Node offset to check quiet: Errors to ignore (empty to raise on all errors) Returns: The offset of the parent node, if any Raises: FdtException if no parent found or other error occurs """ return check_err(fdt_parent_offset(self._fdt, nodeoffset), quiet) def set_name(self, nodeoffset, name, quiet=()): """Set the name of a node Args: nodeoffset: Node offset of node to update name: New node name Returns: Error code, or 0 if OK Raises: FdtException if no parent found or other error occurs """ return check_err(fdt_set_name(self._fdt, nodeoffset, name), quiet) def setprop(self, nodeoffset, prop_name, val, quiet=()): """Set the value of a property Args: nodeoffset: Node offset containing the property to create/update prop_name: Name of property val: Value to write (string or bytearray) quiet: Errors to ignore (empty to raise on all errors) Returns: Error code, or 0 if OK Raises: FdtException if no parent found or other error occurs """ return check_err(fdt_setprop(self._fdt, nodeoffset, prop_name, val, len(val)), quiet) def setprop_u32(self, nodeoffset, prop_name, val, quiet=()): """Set the value of a property Args: nodeoffset: Node offset containing the property to create/update prop_name: Name of property val: Value to write (integer) quiet: Errors to ignore (empty to raise on all errors) Returns: Error code, or 0 if OK Raises: FdtException if no parent found or other error occurs """ return check_err(fdt_setprop_u32(self._fdt, nodeoffset, prop_name, val), quiet) def setprop_u64(self, nodeoffset, prop_name, val, quiet=()): """Set the value of a property Args: nodeoffset: Node offset containing the property to create/update prop_name: Name of property val: Value to write (integer) quiet: Errors to ignore (empty to raise on all errors) Returns: Error code, or 0 if OK Raises: FdtException if no parent found or other error occurs """ return check_err(fdt_setprop_u64(self._fdt, nodeoffset, prop_name, val), quiet) def setprop_str(self, nodeoffset, prop_name, val, quiet=()): """Set the string value of a property The property is set to the string, with a nul terminator added Args: nodeoffset: Node offset containing the property to create/update prop_name: Name of property val: Value to write (string without nul terminator) quiet: Errors to ignore (empty to raise on all errors) Returns: Error code, or 0 if OK Raises: FdtException if no parent found or other error occurs """ val += '\0' return check_err(fdt_setprop(self._fdt, nodeoffset, prop_name, val, len(val)), quiet) def delprop(self, nodeoffset, prop_name): """Delete a property from a node Args: nodeoffset: Node offset containing property to delete prop_name: Name of property to delete Raises: FdtError if the property does not exist, or another error occurs """ return check_err(fdt_delprop(self._fdt, nodeoffset, prop_name)) def node_offset_by_phandle(self, phandle, quiet=()): """Get the offset of a node with the given phandle Args: phandle: Phandle to search for quiet: Errors to ignore (empty to raise on all errors) Returns: The offset of node with that phandle, if any Raises: FdtException if no node found or other error occurs """ return check_err(fdt_node_offset_by_phandle(self._fdt, phandle), quiet) class Property(bytearray): """Holds a device tree property name and value. This holds a copy of a property taken from the device tree. It does not reference the device tree, so if anything changes in the device tree, a Property object will remain valid. Properties: name: Property name value: Property value as a bytearray """ def __init__(self, name, value): bytearray.__init__(self, value) self.name = name def as_cell(self, fmt): return struct.unpack('>' + fmt, self)[0] def as_uint32(self): return self.as_cell('L') def as_int32(self): return self.as_cell('l') def as_uint64(self): return self.as_cell('Q') def as_int64(self): return self.as_cell('q') def as_str(self): return self[:-1] class FdtSw(object): """Software interface to create a device tree from scratch The methods in this class work by adding to an existing 'partial' device tree buffer of a fixed size created by instantiating this class. When the tree is complete, call finish() to complete the device tree so that it can be used. Similarly with nodes, a new node is started with begin_node() and finished with end_node(). The context manager functions can be used to make this a bit easier: # First create the device tree with a node and property: with FdtSw(small_size) as sw: with sw.AddNode('node'): sw.property_u32('reg', 2) fdt = sw.AsFdt() # Now we can use it as a real device tree fdt.setprop_u32(0, 'reg', 3) """ def __init__(self, size, quiet=()): fdtrw = bytearray(size) err = check_err(fdt_create(fdtrw, size)) if err: return err self._fdtrw = fdtrw def __enter__(self): """Contact manager to use to create a device tree via software""" return self def __exit__(self, type, value, traceback): check_err(fdt_finish(self._fdtrw)) def AsFdt(self): """Convert a FdtSw into an Fdt so it can be accessed as normal Note that finish() must be called before this function will work. If you are using the context manager (see 'with' code in the FdtSw class comment) then this will happen automatically. Returns: Fdt object allowing access to the newly created device tree """ return Fdt(self._fdtrw) def resize(self, size, quiet=()): """Resize the buffer to accommodate a larger tree Args: size: New size of tree quiet: Errors to ignore (empty to raise on all errors) Raises: FdtException if no node found or other error occurs """ fdt = bytearray(size) fdt[:len(self._fdtrw)] = self._fdtrw err = check_err(fdt_resize(self._fdtrw, fdt, size), quiet) if err: return err self._fdtrw = fdt def add_reservemap_entry(self, addr, size, quiet=()): """Add a new memory reserve map entry Once finished adding, you must call finish_reservemap(). Args: addr: 64-bit start address size: 64-bit size quiet: Errors to ignore (empty to raise on all errors) Raises: FdtException if no node found or other error occurs """ return check_err(fdt_add_reservemap_entry(self._fdtrw, addr, size), quiet) def finish_reservemap(self, quiet=()): """Indicate that there are no more reserve map entries to add Args: quiet: Errors to ignore (empty to raise on all errors) Raises: FdtException if no node found or other error occurs """ return check_err(fdt_finish_reservemap(self._fdtrw), quiet) def begin_node(self, name, quiet=()): """Begin a new node Use this before adding properties to the node. Then call end_node() to finish it. You can also use the context manager as shown in the FdtSw class comment. Args: name: Name of node to begin quiet: Errors to ignore (empty to raise on all errors) Raises: FdtException if no node found or other error occurs """ return check_err(fdt_begin_node(self._fdtrw, name), quiet) def property_string(self, name, string, quiet=()): """Add a property with a string value The string will be nul-terminated when written to the device tree Args: name: Name of property to add string: String value of property quiet: Errors to ignore (empty to raise on all errors) Raises: FdtException if no node found or other error occurs """ return check_err(fdt_property_string(self._fdtrw, name, string), quiet) def property_u32(self, name, val, quiet=()): """Add a property with a 32-bit value Write a single-cell value to the device tree Args: name: Name of property to add val: Value of property quiet: Errors to ignore (empty to raise on all errors) Raises: FdtException if no node found or other error occurs """ return check_err(fdt_property_u32(self._fdtrw, name, val), quiet) def property_u64(self, name, val, quiet=()): """Add a property with a 64-bit value Write a double-cell value to the device tree in big-endian format Args: name: Name of property to add val: Value of property quiet: Errors to ignore (empty to raise on all errors) Raises: FdtException if no node found or other error occurs """ return check_err(fdt_property_u64(self._fdtrw, name, val), quiet) def property_cell(self, name, val, quiet=()): """Add a property with a single-cell value Write a single-cell value to the device tree Args: name: Name of property to add val: Value of property quiet: Errors to ignore (empty to raise on all errors) Raises: FdtException if no node found or other error occurs """ return check_err(fdt_property_cell(self._fdtrw, name, val), quiet) def property(self, name, val, quiet=()): """Add a property Write a new property with the given value to the device tree. The value is taken as is and is not nul-terminated Args: name: Name of property to add val: Value of property quiet: Errors to ignore (empty to raise on all errors) Raises: FdtException if no node found or other error occurs """ return check_err(_fdt_property(self._fdtrw, name, val, len(val)), quiet) def end_node(self, quiet=()): """End a node Use this after adding properties to a node to close it off. You can also use the context manager as shown in the FdtSw class comment. Args: quiet: Errors to ignore (empty to raise on all errors) Raises: FdtException if no node found or other error occurs """ return check_err(fdt_end_node(self._fdtrw), quiet) def finish(self, quiet=()): """Finish writing the device tree This closes off the device tree ready for use Args: quiet: Errors to ignore (empty to raise on all errors) Raises: FdtException if no node found or other error occurs """ return check_err(fdt_finish(self._fdtrw), quiet) def AddNode(self, name): """Create a new context for adding a node When used in a 'with' clause this starts a new node and finishes it afterward. Args: name: Name of node to add """ return NodeAdder(self._fdtrw, name) class NodeAdder(): """Class to provide a node context This allows you to add nodes in a more natural way: with fdtsw.AddNode('name'): fdtsw.property_string('test', 'value') The node is automatically completed with a call to end_node() when the context exits. """ def __init__(self, fdt, name): self._fdt = fdt self._name = name def __enter__(self): check_err(fdt_begin_node(self._fdt, self._name)) def __exit__(self, type, value, traceback): check_err(fdt_end_node(self._fdt)) %} %rename(fdt_property) fdt_property_func; typedef int fdt32_t; %include "libfdt/fdt.h" %include "typemaps.i" /* Most functions don't change the device tree, so use a const void * */ %typemap(in) (const void *)(const void *fdt) { if (!PyByteArray_Check($input)) { SWIG_exception_fail(SWIG_TypeError, "in method '" "$symname" "', argument " "$argnum"" of type '" "$type""'"); } $1 = (void *)PyByteArray_AsString($input); fdt = $1; fdt = fdt; /* avoid unused variable warning */ } /* Some functions do change the device tree, so use void * */ %typemap(in) (void *)(const void *fdt) { if (!PyByteArray_Check($input)) { SWIG_exception_fail(SWIG_TypeError, "in method '" "$symname" "', argument " "$argnum"" of type '" "$type""'"); } $1 = PyByteArray_AsString($input); fdt = $1; fdt = fdt; /* avoid unused variable warning */ } /* typemap used for fdt_get_property_by_offset() */ %typemap(out) (struct fdt_property *) { PyObject *buff; if ($1) { resultobj = PyString_FromString( fdt_string(fdt1, fdt32_to_cpu($1->nameoff))); buff = PyByteArray_FromStringAndSize( (const char *)($1 + 1), fdt32_to_cpu($1->len)); resultobj = SWIG_Python_AppendOutput(resultobj, buff); } } %apply int *OUTPUT { int *lenp }; /* typemap used for fdt_getprop() */ %typemap(out) (const void *) { if (!$1) $result = Py_None; else $result = Py_BuildValue("s#", $1, *arg4); } /* typemap used for fdt_setprop() */ %typemap(in) (const void *val) { $1 = PyString_AsString($input); /* char *str */ } /* typemap used for fdt_add_reservemap_entry() */ %typemap(in) uint64_t { $1 = PyLong_AsUnsignedLong($input); } /* typemaps used for fdt_next_node() */ %typemap(in, numinputs=1) int *depth (int depth) { depth = (int) PyInt_AsLong($input); $1 = &depth; } %typemap(argout) int *depth { PyObject *val = Py_BuildValue("i", *arg$argnum); resultobj = SWIG_Python_AppendOutput(resultobj, val); } %apply int *depth { int *depth }; /* typemaps for fdt_get_mem_rsv */ %typemap(in, numinputs=0) uint64_t * (uint64_t temp) { $1 = &temp; } %typemap(argout) uint64_t * { PyObject *val = PyLong_FromUnsignedLong(*arg$argnum); if (!result) { if (PyTuple_GET_SIZE(resultobj) == 0) resultobj = val; else resultobj = SWIG_Python_AppendOutput(resultobj, val); } } /* We have both struct fdt_property and a function fdt_property() */ %warnfilter(302) fdt_property; /* These are macros in the header so have to be redefined here */ int fdt_magic(const void *fdt); int fdt_totalsize(const void *fdt); int fdt_off_dt_struct(const void *fdt); int fdt_off_dt_strings(const void *fdt); int fdt_off_mem_rsvmap(const void *fdt); int fdt_version(const void *fdt); int fdt_last_comp_version(const void *fdt); int fdt_boot_cpuid_phys(const void *fdt); int fdt_size_dt_strings(const void *fdt); int fdt_size_dt_struct(const void *fdt); int fdt_property_string(void *fdt, const char *name, const char *val); int fdt_property_cell(void *fdt, const char *name, uint32_t val); /* * This function has a stub since the name fdt_property is used for both a * function and a struct, which confuses SWIG. */ int _fdt_property(void *fdt, const char *name, const char *val, int len); %include <../libfdt/libfdt.h>