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>master
parent
46bac66b20
commit
cf2064d785
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/* |
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* pylibfdt - Flat Device Tree manipulation in Python |
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* Copyright (C) 2017 Google, Inc. |
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* Written by Simon Glass <sjg@chromium.org> |
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* |
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* SPDX-License-Identifier: GPL-2.0+ BSD-2-Clause |
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*/ |
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|
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%module libfdt |
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|
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%{ |
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#define SWIG_FILE_WITH_INIT |
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#include "libfdt.h" |
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%} |
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|
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%pythoncode %{ |
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|
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import struct |
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|
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# Error codes, corresponding to FDT_ERR_... in libfdt.h |
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(NOTFOUND, |
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EXISTS, |
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NOSPACE, |
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BADOFFSET, |
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BADPATH, |
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BADPHANDLE, |
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BADSTATE, |
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TRUNCATED, |
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BADMAGIC, |
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BADVERSION, |
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BADSTRUCTURE, |
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BADLAYOUT, |
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INTERNAL, |
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BADNCELLS, |
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BADVALUE, |
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BADOVERLAY, |
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NOPHANDLES) = QUIET_ALL = range(1, 18) |
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# QUIET_ALL can be passed as the 'quiet' parameter to avoid exceptions |
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# altogether. All # functions passed this value will return an error instead |
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# of raising an exception. |
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|
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# Pass this as the 'quiet' parameter to return -ENOTFOUND on NOTFOUND errors, |
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# instead of raising an exception. |
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QUIET_NOTFOUND = (NOTFOUND,) |
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|
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|
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class FdtException(Exception): |
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"""An exception caused by an error such as one of the codes above""" |
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def __init__(self, err): |
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self.err = err |
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|
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def __str__(self): |
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return 'pylibfdt error %d: %s' % (self.err, fdt_strerror(self.err)) |
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|
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def strerror(fdt_err): |
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"""Get the string for an error number |
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|
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Args: |
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fdt_err: Error number (-ve) |
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|
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Returns: |
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String containing the associated error |
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""" |
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return fdt_strerror(fdt_err) |
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|
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def check_err(val, quiet=()): |
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"""Raise an error if the return value is -ve |
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|
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This is used to check for errors returned by libfdt C functions. |
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|
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Args: |
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val: Return value from a libfdt function |
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quiet: Errors to ignore (empty to raise on all errors) |
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|
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Returns: |
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val if val >= 0 |
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|
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Raises |
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FdtException if val < 0 |
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""" |
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if val < 0: |
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if -val not in quiet: |
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raise FdtException(val) |
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return val |
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|
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def check_err_null(val, quiet=()): |
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"""Raise an error if the return value is NULL |
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|
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This is used to check for a NULL return value from certain libfdt C |
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functions |
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|
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Args: |
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val: Return value from a libfdt function |
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quiet: Errors to ignore (empty to raise on all errors) |
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|
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Returns: |
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val if val is a list, None if not |
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|
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Raises |
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FdtException if val indicates an error was reported and the error |
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is not in @quiet. |
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""" |
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# Normally a list is returned which contains the data and its length. |
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# If we get just an integer error code, it means the function failed. |
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if not isinstance(val, list): |
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if -val not in quiet: |
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raise FdtException(val) |
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return val |
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|
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class Fdt: |
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"""Device tree class, supporting all operations |
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|
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The Fdt object is created is created from a device tree binary file, |
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e.g. with something like: |
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fdt = Fdt(open("filename.dtb").read()) |
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|
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Operations can then be performed using the methods in this class. Each |
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method xxx(args...) corresponds to a libfdt function fdt_xxx(fdt, args...). |
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|
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All methods raise an FdtException if an error occurs. To avoid this |
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behaviour a 'quiet' parameter is provided for some functions. This |
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defaults to empty, but you can pass a list of errors that you expect. |
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If one of these errors occurs, the function will return an error number |
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(e.g. -NOTFOUND). |
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""" |
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def __init__(self, data): |
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self._fdt = bytearray(data) |
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check_err(fdt_check_header(self._fdt)); |
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|
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def path_offset(self, path, quiet=()): |
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"""Get the offset for a given path |
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|
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Args: |
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path: Path to the required node, e.g. '/node@3/subnode@1' |
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quiet: Errors to ignore (empty to raise on all errors) |
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|
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Returns: |
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Node offset |
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|
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Raises |
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FdtException if the path is not valid or not found |
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""" |
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return check_err(fdt_path_offset(self._fdt, path), quiet) |
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|
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def first_property_offset(self, nodeoffset, quiet=()): |
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"""Get the offset of the first property in a node offset |
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|
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Args: |
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nodeoffset: Offset to the node to check |
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quiet: Errors to ignore (empty to raise on all errors) |
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|
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Returns: |
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Offset of the first property |
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|
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Raises |
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FdtException if the associated node has no properties, or some |
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other error occurred |
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""" |
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return check_err(fdt_first_property_offset(self._fdt, nodeoffset), |
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quiet) |
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|
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def next_property_offset(self, prop_offset, quiet=()): |
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"""Get the next property in a node |
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|
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Args: |
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prop_offset: Offset of the previous property |
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quiet: Errors to ignore (empty to raise on all errors) |
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|
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Returns: |
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Offset of the next property |
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|
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Raises: |
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FdtException if the associated node has no more properties, or |
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some other error occurred |
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""" |
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return check_err(fdt_next_property_offset(self._fdt, prop_offset), |
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quiet) |
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|
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def get_name(self, nodeoffset): |
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"""Get the name of a node |
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Args: |
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nodeoffset: Offset of node to check |
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Returns: |
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Node name |
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Raises: |
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FdtException on error (e.g. nodeoffset is invalid) |
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""" |
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return check_err_null(fdt_get_name(self._fdt, nodeoffset))[0] |
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|
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def get_property_by_offset(self, prop_offset, quiet=()): |
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"""Obtains a property that can be examined |
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Args: |
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prop_offset: Offset of property (e.g. from first_property_offset()) |
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quiet: Errors to ignore (empty to raise on all errors) |
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Returns: |
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Property object, or None if not found |
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Raises: |
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FdtException on error (e.g. invalid prop_offset or device |
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tree format) |
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""" |
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pdata = check_err_null( |
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fdt_get_property_by_offset(self._fdt, prop_offset), quiet) |
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if isinstance(pdata, (int)): |
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return pdata |
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return Property(pdata[0], pdata[1]) |
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|
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def first_subnode(self, nodeoffset, quiet=()): |
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"""Find the first subnode of a parent node |
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Args: |
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nodeoffset: Node offset of parent node |
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quiet: Errors to ignore (empty to raise on all errors) |
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Returns: |
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The offset of the first subnode, if any |
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Raises: |
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FdtException if no subnode found or other error occurs |
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""" |
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return check_err(fdt_first_subnode(self._fdt, nodeoffset), quiet) |
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|
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def next_subnode(self, nodeoffset, quiet=()): |
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"""Find the next subnode |
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Args: |
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nodeoffset: Node offset of previous subnode |
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quiet: Errors to ignore (empty to raise on all errors) |
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Returns: |
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The offset of the next subnode, if any |
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|
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Raises: |
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FdtException if no more subnode found or other error occurs |
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""" |
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return check_err(fdt_next_subnode(self._fdt, nodeoffset), quiet) |
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|
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def totalsize(self): |
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"""Return the total size of the device tree |
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Returns: |
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Total tree size in bytes |
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""" |
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return check_err(fdt_totalsize(self._fdt)) |
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def off_dt_struct(self): |
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"""Return the start of the device tree struct area |
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Returns: |
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Start offset of struct area |
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""" |
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return check_err(fdt_off_dt_struct(self._fdt)) |
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def pack(self, quiet=()): |
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"""Pack the device tree to remove unused space |
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This adjusts the tree in place. |
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Args: |
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quiet: Errors to ignore (empty to raise on all errors) |
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|
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Raises: |
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FdtException if any error occurs |
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""" |
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return check_err(fdt_pack(self._fdt), quiet) |
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def delprop(self, nodeoffset, prop_name): |
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"""Delete a property from a node |
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Args: |
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nodeoffset: Node offset containing property to delete |
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prop_name: Name of property to delete |
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|
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Raises: |
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FdtError if the property does not exist, or another error occurs |
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""" |
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return check_err(fdt_delprop(self._fdt, nodeoffset, prop_name)) |
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|
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def getprop(self, nodeoffset, prop_name, quiet=()): |
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"""Get a property from a node |
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|
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Args: |
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nodeoffset: Node offset containing property to get |
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prop_name: Name of property to get |
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quiet: Errors to ignore (empty to raise on all errors) |
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|
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Returns: |
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Value of property as a bytearray, or -ve error number |
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|
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Raises: |
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FdtError if any error occurs (e.g. the property is not found) |
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""" |
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pdata = check_err_null(fdt_getprop(self._fdt, nodeoffset, prop_name), |
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quiet) |
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if isinstance(pdata, (int)): |
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return pdata |
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return bytearray(pdata[0]) |
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|
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class Property: |
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"""Holds a device tree property name and value. |
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|
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This holds a copy of a property taken from the device tree. It does not |
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reference the device tree, so if anything changes in the device tree, |
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a Property object will remain valid. |
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|
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Properties: |
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name: Property name |
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value: Proper value as a bytearray |
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""" |
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def __init__(self, name, value): |
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self.name = name |
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self.value = value |
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%} |
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%rename(fdt_property) fdt_property_func; |
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typedef int fdt32_t; |
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%include "libfdt/fdt.h" |
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%include "typemaps.i" |
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/* Most functions don't change the device tree, so use a const void * */ |
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%typemap(in) (const void *)(const void *fdt) { |
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if (!PyByteArray_Check($input)) { |
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SWIG_exception_fail(SWIG_TypeError, "in method '" "$symname" |
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"', argument " "$argnum"" of type '" "$type""'"); |
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} |
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$1 = (void *)PyByteArray_AsString($input); |
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fdt = $1; |
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fdt = fdt; /* avoid unused variable warning */ |
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} |
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|
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/* Some functions do change the device tree, so use void * */ |
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%typemap(in) (void *)(const void *fdt) { |
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if (!PyByteArray_Check($input)) { |
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SWIG_exception_fail(SWIG_TypeError, "in method '" "$symname" |
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"', argument " "$argnum"" of type '" "$type""'"); |
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} |
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$1 = PyByteArray_AsString($input); |
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fdt = $1; |
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fdt = fdt; /* avoid unused variable warning */ |
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} |
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%typemap(out) (struct fdt_property *) { |
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PyObject *buff; |
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|
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if ($1) { |
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resultobj = PyString_FromString( |
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fdt_string(fdt1, fdt32_to_cpu($1->nameoff))); |
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buff = PyByteArray_FromStringAndSize( |
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(const char *)($1 + 1), fdt32_to_cpu($1->len)); |
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resultobj = SWIG_Python_AppendOutput(resultobj, buff); |
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} |
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} |
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|
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%apply int *OUTPUT { int *lenp }; |
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|
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/* typemap used for fdt_getprop() */ |
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%typemap(out) (const void *) { |
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if (!$1) |
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$result = Py_None; |
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else |
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$result = Py_BuildValue("s#", $1, *arg4); |
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} |
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|
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/* We have both struct fdt_property and a function fdt_property() */ |
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%warnfilter(302) fdt_property; |
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|
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/* These are macros in the header so have to be redefined here */ |
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int fdt_magic(const void *fdt); |
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int fdt_totalsize(const void *fdt); |
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int fdt_off_dt_struct(const void *fdt); |
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int fdt_off_dt_strings(const void *fdt); |
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int fdt_off_mem_rsvmap(const void *fdt); |
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int fdt_version(const void *fdt); |
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int fdt_last_comp_version(const void *fdt); |
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int fdt_boot_cpuid_phys(const void *fdt); |
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int fdt_size_dt_strings(const void *fdt); |
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int fdt_size_dt_struct(const void *fdt); |
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|
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%include <../libfdt/libfdt.h> |
@ -0,0 +1,123 @@ |
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#!/usr/bin/env python |
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|
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""" |
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setup.py file for SWIG libfdt |
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Copyright (C) 2017 Google, Inc. |
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Written by Simon Glass <sjg@chromium.org> |
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|
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SPDX-License-Identifier: GPL-2.0+ BSD-2-Clause |
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|
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Files to be built into the extension are provided in SOURCES |
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C flags to use are provided in CPPFLAGS |
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Object file directory is provided in OBJDIR |
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Version is provided in VERSION |
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|
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If these variables are not given they are parsed from the Makefiles. This |
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allows this script to be run stand-alone, e.g.: |
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|
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./pylibfdt/setup.py install [--prefix=...] |
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""" |
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|
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from distutils.core import setup, Extension |
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import os |
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import re |
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import sys |
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|
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# Decodes a Makefile assignment line into key and value (and plus for +=) |
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RE_KEY_VALUE = re.compile('(?P<key>\w+) *(?P<plus>[+])?= *(?P<value>.*)$') |
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|
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|
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def ParseMakefile(fname): |
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"""Parse a Makefile to obtain its variables. |
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|
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This collects variable assigments of the form: |
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|
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VAR = value |
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VAR += more |
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|
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It does not pick out := assignments, as these are not needed here. It does |
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handle line continuation. |
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|
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Returns a dict: |
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key: Variable name (e.g. 'VAR') |
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value: Variable value (e.g. 'value more') |
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""" |
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makevars = {} |
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with open(fname) as fd: |
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prev_text = '' # Continuation text from previous line(s) |
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for line in fd.read().splitlines(): |
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if line and line[-1] == '\\': # Deal with line continuation |
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prev_text += line[:-1] |
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continue |
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elif prev_text: |
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line = prev_text + line |
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prev_text = '' # Continuation is now used up |
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m = RE_KEY_VALUE.match(line) |
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if m: |
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value = m.group('value') or '' |
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key = m.group('key') |
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|
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# Appending to a variable inserts a space beforehand |
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if 'plus' in m.groupdict() and key in makevars: |
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makevars[key] += ' ' + value |
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else: |
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makevars[key] = value |
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return makevars |
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|
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def GetEnvFromMakefiles(): |
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"""Scan the Makefiles to obtain the settings we need. |
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|
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This assumes that this script is being run from the top-level directory, |
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not the pylibfdt directory. |
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|
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Returns: |
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Tuple with: |
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List of swig options |
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Version string |
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List of files to build |
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List of extra C preprocessor flags needed |
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Object directory to use (always '') |
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""" |
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basedir = os.path.dirname(os.path.dirname(os.path.abspath(sys.argv[0]))) |
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swig_opts = ['-I%s' % basedir] |
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makevars = ParseMakefile(os.path.join(basedir, 'Makefile')) |
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version = '%s.%s.%s' % (makevars['VERSION'], makevars['PATCHLEVEL'], |
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makevars['SUBLEVEL']) |
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makevars = ParseMakefile(os.path.join(basedir, 'libfdt', 'Makefile.libfdt')) |
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files = makevars['LIBFDT_SRCS'].split() |
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files = [os.path.join(basedir, 'libfdt', fname) for fname in files] |
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files.append('pylibfdt/libfdt.i') |
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cflags = ['-I%s' % basedir, '-I%s/libfdt' % basedir] |
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objdir = '' |
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return swig_opts, version, files, cflags, objdir |
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|
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|
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progname = sys.argv[0] |
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files = os.environ.get('SOURCES', '').split() |
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cflags = os.environ.get('CPPFLAGS', '').split() |
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objdir = os.environ.get('OBJDIR') |
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version = os.environ.get('VERSION') |
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swig_opts = [] |
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|
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# If we were called directly rather than through our Makefile (which is often |
||||
# the case with Python module installation), read the settings from the |
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# Makefile. |
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if not all((version, files, cflags, objdir)): |
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swig_opts, version, files, cflags, objdir = GetEnvFromMakefiles() |
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|
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libfdt_module = Extension( |
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'_libfdt', |
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sources = files, |
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extra_compile_args = cflags, |
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swig_opts = swig_opts, |
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) |
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|
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setup( |
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name='libfdt', |
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version= version, |
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author='Simon Glass <sjg@chromium.org>', |
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description='Python binding for libfdt', |
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ext_modules=[libfdt_module], |
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package_dir={'': objdir}, |
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py_modules=['pylibfdt/libfdt'], |
||||
) |
Loading…
Reference in new issue