An early version of this is available upstream. Bring it in as a starting point. This is from dtc upstream commit e56f2b0.
Future work will plumb it into dtoc and remove the now-unnecessary local libraries.
Signed-off-by: Simon Glass sjg@chromium.org ---
Changes in v3: None Changes in v2: None
lib/libfdt/pylibfdt/libfdt.i | 389 +++++++++++++++++++++++++++++++++++++++++++ lib/libfdt/pylibfdt/setup.py | 123 ++++++++++++++ 2 files changed, 512 insertions(+) create mode 100644 lib/libfdt/pylibfdt/libfdt.i create mode 100755 lib/libfdt/pylibfdt/setup.py
diff --git a/lib/libfdt/pylibfdt/libfdt.i b/lib/libfdt/pylibfdt/libfdt.i new file mode 100644 index 0000000000..3b11bb0c95 --- /dev/null +++ b/lib/libfdt/pylibfdt/libfdt.i @@ -0,0 +1,389 @@ +/* + * pylibfdt - Flat Device Tree manipulation in Python + * Copyright (C) 2017 Google, Inc. + * Written by Simon Glass sjg@chromium.org + * + * SPDX-License-Identifier: GPL-2.0+ BSD-2-Clause + */ + +%module libfdt + +%{ +#define SWIG_FILE_WITH_INIT +#include "libfdt.h" +%} + +%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 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 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_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 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]) + + 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 subnode 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 subnode found or other error occurs + """ + return check_err(fdt_next_subnode(self._fdt, nodeoffset), quiet) + + 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 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 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 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 bytearray, 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 bytearray(pdata[0]) + + +class Property: + """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: Proper value as a bytearray + """ + def __init__(self, name, value): + self.name = name + self.value = value +%} + +%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(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#", $1, *arg4); +} + +/* We have both struct fdt_property and a function fdt_property() */ +%warnfilter(302) fdt_property; + +/* These are macros in the header so have to be redefined here */ +int fdt_magic(const void *fdt); +int fdt_totalsize(const void *fdt); +int fdt_off_dt_struct(const void *fdt); +int fdt_off_dt_strings(const void *fdt); +int fdt_off_mem_rsvmap(const void *fdt); +int fdt_version(const void *fdt); +int fdt_last_comp_version(const void *fdt); +int fdt_boot_cpuid_phys(const void *fdt); +int fdt_size_dt_strings(const void *fdt); +int fdt_size_dt_struct(const void *fdt); + +%include <../libfdt/libfdt.h> diff --git a/lib/libfdt/pylibfdt/setup.py b/lib/libfdt/pylibfdt/setup.py new file mode 100755 index 0000000000..38a844cb6d --- /dev/null +++ b/lib/libfdt/pylibfdt/setup.py @@ -0,0 +1,123 @@ +#!/usr/bin/env python + +""" +setup.py file for SWIG libfdt +Copyright (C) 2017 Google, Inc. +Written by Simon Glass sjg@chromium.org + +SPDX-License-Identifier: GPL-2.0+ BSD-2-Clause + +Files to be built into the extension are provided in SOURCES +C flags to use are provided in CPPFLAGS +Object file directory is provided in OBJDIR +Version is provided in VERSION + +If these variables are not given they are parsed from the Makefiles. This +allows this script to be run stand-alone, e.g.: + + ./pylibfdt/setup.py install [--prefix=...] +""" + +from distutils.core import setup, Extension +import os +import re +import sys + +# Decodes a Makefile assignment line into key and value (and plus for +=) +RE_KEY_VALUE = re.compile('(?P<key>\w+) *(?P<plus>[+])?= *(?P<value>.*)$') + + +def ParseMakefile(fname): + """Parse a Makefile to obtain its variables. + + This collects variable assigments of the form: + + VAR = value + VAR += more + + It does not pick out := assignments, as these are not needed here. It does + handle line continuation. + + Returns a dict: + key: Variable name (e.g. 'VAR') + value: Variable value (e.g. 'value more') + """ + makevars = {} + with open(fname) as fd: + prev_text = '' # Continuation text from previous line(s) + for line in fd.read().splitlines(): + if line and line[-1] == '\': # Deal with line continuation + prev_text += line[:-1] + continue + elif prev_text: + line = prev_text + line + prev_text = '' # Continuation is now used up + m = RE_KEY_VALUE.match(line) + if m: + value = m.group('value') or '' + key = m.group('key') + + # Appending to a variable inserts a space beforehand + if 'plus' in m.groupdict() and key in makevars: + makevars[key] += ' ' + value + else: + makevars[key] = value + return makevars + +def GetEnvFromMakefiles(): + """Scan the Makefiles to obtain the settings we need. + + This assumes that this script is being run from the top-level directory, + not the pylibfdt directory. + + Returns: + Tuple with: + List of swig options + Version string + List of files to build + List of extra C preprocessor flags needed + Object directory to use (always '') + """ + basedir = os.path.dirname(os.path.dirname(os.path.abspath(sys.argv[0]))) + swig_opts = ['-I%s' % basedir] + makevars = ParseMakefile(os.path.join(basedir, 'Makefile')) + version = '%s.%s.%s' % (makevars['VERSION'], makevars['PATCHLEVEL'], + makevars['SUBLEVEL']) + makevars = ParseMakefile(os.path.join(basedir, 'libfdt', 'Makefile.libfdt')) + files = makevars['LIBFDT_SRCS'].split() + files = [os.path.join(basedir, 'libfdt', fname) for fname in files] + files.append('pylibfdt/libfdt.i') + cflags = ['-I%s' % basedir, '-I%s/libfdt' % basedir] + objdir = '' + return swig_opts, version, files, cflags, objdir + + +progname = sys.argv[0] +files = os.environ.get('SOURCES', '').split() +cflags = os.environ.get('CPPFLAGS', '').split() +objdir = os.environ.get('OBJDIR') +version = os.environ.get('VERSION') +swig_opts = [] + +# If we were called directly rather than through our Makefile (which is often +# the case with Python module installation), read the settings from the +# Makefile. +if not all((version, files, cflags, objdir)): + swig_opts, version, files, cflags, objdir = GetEnvFromMakefiles() + +libfdt_module = Extension( + '_libfdt', + sources = files, + extra_compile_args = cflags, + swig_opts = swig_opts, +) + +setup( + name='libfdt', + version= version, + author='Simon Glass sjg@chromium.org', + description='Python binding for libfdt', + ext_modules=[libfdt_module], + package_dir={'': objdir}, + py_modules=['pylibfdt/libfdt'], +)