diff options
Diffstat (limited to 'tools')
| -rw-r--r-- | tools/Makefile | 14 | ||||
| -rw-r--r-- | tools/dtoc/.gitignore | 1 | ||||
| l--------- | tools/dtoc/dtoc | 1 | ||||
| -rwxr-xr-x | tools/dtoc/dtoc.py | 394 | ||||
| -rw-r--r-- | tools/dtoc/fdt.py | 180 | ||||
| -rw-r--r-- | tools/dtoc/fdt_fallback.py | 207 | ||||
| -rw-r--r-- | tools/dtoc/fdt_util.py | 86 |
7 files changed, 883 insertions, 0 deletions
diff --git a/tools/Makefile b/tools/Makefile index f72294a..421414b 100644 --- a/tools/Makefile +++ b/tools/Makefile @@ -107,6 +107,20 @@ mkimage-objs := $(dumpimage-mkimage-objs) mkimage.o fit_info-objs := $(dumpimage-mkimage-objs) fit_info.o fit_check_sign-objs := $(dumpimage-mkimage-objs) fit_check_sign.o +# Build a libfdt Python module if swig is available +# Use 'sudo apt-get install swig libpython-dev' to enable this +hostprogs-$(CONFIG_SPL_OF_PLATDATA) += \ + $(if $(shell which swig),_libfdt.so) +_libfdt.so-sharedobjs += $(LIBFDT_OBJS) +libfdt: + +tools/_libfdt.so: $(patsubst %.o,%.c,$(LIBFDT_OBJS)) tools/libfdt_wrap.c + python $(srctree)/lib/libfdt/setup.py "$(_hostc_flags)" $^ + mv _libfdt.so $@ + +tools/libfdt_wrap.c: $(srctree)/lib/libfdt/libfdt.swig + swig -python -o $@ $< + # TODO(sjg@chromium.org): Is this correct on Mac OS? ifneq ($(CONFIG_MX23)$(CONFIG_MX28),) diff --git a/tools/dtoc/.gitignore b/tools/dtoc/.gitignore new file mode 100644 index 0000000..0d20b64 --- /dev/null +++ b/tools/dtoc/.gitignore @@ -0,0 +1 @@ +*.pyc diff --git a/tools/dtoc/dtoc b/tools/dtoc/dtoc new file mode 120000 index 0000000..896ca44 --- /dev/null +++ b/tools/dtoc/dtoc @@ -0,0 +1 @@ +dtoc.py
\ No newline at end of file diff --git a/tools/dtoc/dtoc.py b/tools/dtoc/dtoc.py new file mode 100755 index 0000000..ec80abe --- /dev/null +++ b/tools/dtoc/dtoc.py @@ -0,0 +1,394 @@ +#!/usr/bin/python +# +# Copyright (C) 2016 Google, Inc +# Written by Simon Glass <sjg@chromium.org> +# +# SPDX-License-Identifier: GPL-2.0+ +# + +import copy +from optparse import OptionError, OptionParser +import os +import sys + +import fdt_util + +# Bring in the patman libraries +our_path = os.path.dirname(os.path.realpath(__file__)) +sys.path.append(os.path.join(our_path, '../patman')) + +# Bring in either the normal fdt library (which relies on libfdt) or the +# fallback one (which uses fdtget and is slower). Both provide the same +# interfface for this file to use. +try: + from fdt import Fdt + import fdt + have_libfdt = True +except ImportError: + have_libfdt = False + from fdt_fallback import Fdt + import fdt_fallback as fdt + +import struct + +# When we see these properties we ignore them - i.e. do not create a structure member +PROP_IGNORE_LIST = [ + '#address-cells', + '#gpio-cells', + '#size-cells', + 'compatible', + 'linux,phandle', + "status", + 'phandle', + 'u-boot,dm-pre-reloc', +] + +# C type declarations for the tyues we support +TYPE_NAMES = { + fdt_util.TYPE_INT: 'fdt32_t', + fdt_util.TYPE_BYTE: 'unsigned char', + fdt_util.TYPE_STRING: 'const char *', + fdt_util.TYPE_BOOL: 'bool', +}; + +STRUCT_PREFIX = 'dtd_' +VAL_PREFIX = 'dtv_' + +def Conv_name_to_c(name): + """Convert a device-tree name to a C identifier + + Args: + name: Name to convert + Return: + String containing the C version of this name + """ + str = name.replace('@', '_at_') + str = str.replace('-', '_') + str = str.replace(',', '_') + str = str.replace('/', '__') + return str + +def TabTo(num_tabs, str): + if len(str) >= num_tabs * 8: + return str + ' ' + return str + '\t' * (num_tabs - len(str) / 8) + +class DtbPlatdata: + """Provide a means to convert device tree binary data to platform data + + The output of this process is C structures which can be used in space- + constrained encvironments where the ~3KB code overhead of device tree + code is not affordable. + + Properties: + fdt: Fdt object, referencing the device tree + _dtb_fname: Filename of the input device tree binary file + _valid_nodes: A list of Node object with compatible strings + _options: Command-line options + _phandle_node: A dict of nodes indexed by phandle number (1, 2...) + _outfile: The current output file (sys.stdout or a real file) + _lines: Stashed list of output lines for outputting in the future + _phandle_node: A dict of Nodes indexed by phandle (an integer) + """ + def __init__(self, dtb_fname, options): + self._dtb_fname = dtb_fname + self._valid_nodes = None + self._options = options + self._phandle_node = {} + self._outfile = None + self._lines = [] + + def SetupOutput(self, fname): + """Set up the output destination + + Once this is done, future calls to self.Out() will output to this + file. + + Args: + fname: Filename to send output to, or '-' for stdout + """ + if fname == '-': + self._outfile = sys.stdout + else: + self._outfile = open(fname, 'w') + + def Out(self, str): + """Output a string to the output file + + Args: + str: String to output + """ + self._outfile.write(str) + + def Buf(self, str): + """Buffer up a string to send later + + Args: + str: String to add to our 'buffer' list + """ + self._lines.append(str) + + def GetBuf(self): + """Get the contents of the output buffer, and clear it + + Returns: + The output buffer, which is then cleared for future use + """ + lines = self._lines + self._lines = [] + return lines + + def GetValue(self, type, value): + """Get a value as a C expression + + For integers this returns a byte-swapped (little-endian) hex string + For bytes this returns a hex string, e.g. 0x12 + For strings this returns a literal string enclosed in quotes + For booleans this return 'true' + + Args: + type: Data type (fdt_util) + value: Data value, as a string of bytes + """ + if type == fdt_util.TYPE_INT: + return '%#x' % fdt_util.fdt32_to_cpu(value) + elif type == fdt_util.TYPE_BYTE: + return '%#x' % ord(value[0]) + elif type == fdt_util.TYPE_STRING: + return '"%s"' % value + elif type == fdt_util.TYPE_BOOL: + return 'true' + + def GetCompatName(self, node): + """Get a node's first compatible string as a C identifier + + Args: + node: Node object to check + Return: + C identifier for the first compatible string + """ + compat = node.props['compatible'].value + if type(compat) == list: + compat = compat[0] + return Conv_name_to_c(compat) + + def ScanDtb(self): + """Scan the device tree to obtain a tree of notes and properties + + Once this is done, self.fdt.GetRoot() can be called to obtain the + device tree root node, and progress from there. + """ + self.fdt = Fdt(self._dtb_fname) + self.fdt.Scan() + + def ScanTree(self): + """Scan the device tree for useful information + + This fills in the following properties: + _phandle_node: A dict of Nodes indexed by phandle (an integer) + _valid_nodes: A list of nodes we wish to consider include in the + platform data + """ + node_list = [] + self._phandle_node = {} + for node in self.fdt.GetRoot().subnodes: + if 'compatible' in node.props: + status = node.props.get('status') + if (not options.include_disabled and not status or + status.value != 'disabled'): + node_list.append(node) + phandle_prop = node.props.get('phandle') + if phandle_prop: + phandle = phandle_prop.GetPhandle() + self._phandle_node[phandle] = node + + self._valid_nodes = node_list + + def IsPhandle(self, prop): + """Check if a node contains phandles + + We have no reliable way of detecting whether a node uses a phandle + or not. As an interim measure, use a list of known property names. + + Args: + prop: Prop object to check + Return: + True if the object value contains phandles, else False + """ + if prop.name in ['clocks']: + return True + return False + + def ScanStructs(self): + """Scan the device tree building up the C structures we will use. + + Build a dict keyed by C struct name containing a dict of Prop + object for each struct field (keyed by property name). Where the + same struct appears multiple times, try to use the 'widest' + property, i.e. the one with a type which can express all others. + + Once the widest property is determined, all other properties are + updated to match that width. + """ + structs = {} + for node in self._valid_nodes: + node_name = self.GetCompatName(node) + fields = {} + + # Get a list of all the valid properties in this node. + for name, prop in node.props.iteritems(): + if name not in PROP_IGNORE_LIST and name[0] != '#': + fields[name] = copy.deepcopy(prop) + + # If we've seen this node_name before, update the existing struct. + if node_name in structs: + struct = structs[node_name] + for name, prop in fields.iteritems(): + oldprop = struct.get(name) + if oldprop: + oldprop.Widen(prop) + else: + struct[name] = prop + + # Otherwise store this as a new struct. + else: + structs[node_name] = fields + + upto = 0 + for node in self._valid_nodes: + node_name = self.GetCompatName(node) + struct = structs[node_name] + for name, prop in node.props.iteritems(): + if name not in PROP_IGNORE_LIST and name[0] != '#': + prop.Widen(struct[name]) + upto += 1 + return structs + + def GenerateStructs(self, structs): + """Generate struct defintions for the platform data + + This writes out the body of a header file consisting of structure + definitions for node in self._valid_nodes. See the documentation in + README.of-plat for more information. + """ + self.Out('#include <stdbool.h>\n') + self.Out('#include <libfdt.h>\n') + + # Output the struct definition + for name in sorted(structs): + self.Out('struct %s%s {\n' % (STRUCT_PREFIX, name)); + for pname in sorted(structs[name]): + prop = structs[name][pname] + if self.IsPhandle(prop): + # For phandles, include a reference to the target + self.Out('\t%s%s[%d]' % (TabTo(2, 'struct phandle_2_cell'), + Conv_name_to_c(prop.name), + len(prop.value) / 2)) + else: + ptype = TYPE_NAMES[prop.type] + self.Out('\t%s%s' % (TabTo(2, ptype), + Conv_name_to_c(prop.name))) + if type(prop.value) == list: + self.Out('[%d]' % len(prop.value)) + self.Out(';\n') + self.Out('};\n') + + def GenerateTables(self): + """Generate device defintions for the platform data + + This writes out C platform data initialisation data and + U_BOOT_DEVICE() declarations for each valid node. See the + documentation in README.of-plat for more information. + """ + self.Out('#include <common.h>\n') + self.Out('#include <dm.h>\n') + self.Out('#include <dt-structs.h>\n') + self.Out('\n') + node_txt_list = [] + for node in self._valid_nodes: + struct_name = self.GetCompatName(node) + var_name = Conv_name_to_c(node.name) + self.Buf('static struct %s%s %s%s = {\n' % + (STRUCT_PREFIX, struct_name, VAL_PREFIX, var_name)) + for pname, prop in node.props.iteritems(): + if pname in PROP_IGNORE_LIST or pname[0] == '#': + continue + ptype = TYPE_NAMES[prop.type] + member_name = Conv_name_to_c(prop.name) + self.Buf('\t%s= ' % TabTo(3, '.' + member_name)) + + # Special handling for lists + if type(prop.value) == list: + self.Buf('{') + vals = [] + # For phandles, output a reference to the platform data + # of the target node. + if self.IsPhandle(prop): + # Process the list as pairs of (phandle, id) + it = iter(prop.value) + for phandle_cell, id_cell in zip(it, it): + phandle = fdt_util.fdt32_to_cpu(phandle_cell) + id = fdt_util.fdt32_to_cpu(id_cell) + target_node = self._phandle_node[phandle] + name = Conv_name_to_c(target_node.name) + vals.append('{&%s%s, %d}' % (VAL_PREFIX, name, id)) + else: + for val in prop.value: + vals.append(self.GetValue(prop.type, val)) + self.Buf(', '.join(vals)) + self.Buf('}') + else: + self.Buf(self.GetValue(prop.type, prop.value)) + self.Buf(',\n') + self.Buf('};\n') + + # Add a device declaration + self.Buf('U_BOOT_DEVICE(%s) = {\n' % var_name) + self.Buf('\t.name\t\t= "%s",\n' % struct_name) + self.Buf('\t.platdata\t= &%s%s,\n' % (VAL_PREFIX, var_name)) + self.Buf('\t.platdata_size\t= sizeof(%s%s),\n' % + (VAL_PREFIX, var_name)) + self.Buf('};\n') + self.Buf('\n') + + # Output phandle target nodes first, since they may be referenced + # by others + if 'phandle' in node.props: + self.Out(''.join(self.GetBuf())) + else: + node_txt_list.append(self.GetBuf()) + + # Output all the nodes which are not phandle targets themselves, but + # may reference them. This avoids the need for forward declarations. + for node_txt in node_txt_list: + self.Out(''.join(node_txt)) + + +if __name__ != "__main__": + pass + +parser = OptionParser() +parser.add_option('-d', '--dtb-file', action='store', + help='Specify the .dtb input file') +parser.add_option('--include-disabled', action='store_true', + help='Include disabled nodes') +parser.add_option('-o', '--output', action='store', default='-', + help='Select output filename') +(options, args) = parser.parse_args() + +if not args: + raise ValueError('Please specify a command: struct, platdata') + +plat = DtbPlatdata(options.dtb_file, options) +plat.ScanDtb() +plat.ScanTree() +plat.SetupOutput(options.output) +structs = plat.ScanStructs() + +for cmd in args[0].split(','): + if cmd == 'struct': + plat.GenerateStructs(structs) + elif cmd == 'platdata': + plat.GenerateTables() + else: + raise ValueError("Unknown command '%s': (use: struct, platdata)" % cmd) diff --git a/tools/dtoc/fdt.py b/tools/dtoc/fdt.py new file mode 100644 index 0000000..1d913a9 --- /dev/null +++ b/tools/dtoc/fdt.py @@ -0,0 +1,180 @@ +#!/usr/bin/python +# +# Copyright (C) 2016 Google, Inc +# Written by Simon Glass <sjg@chromium.org> +# +# SPDX-License-Identifier: GPL-2.0+ +# + +import fdt_util +import libfdt +import sys + +# This deals with a device tree, presenting it as a list of Node and Prop +# objects, representing nodes and properties, respectively. +# +# This implementation uses a libfdt Python library to access the device tree, +# so it is fairly efficient. + +class Prop: + """A device tree property + + Properties: + name: Property name (as per the device tree) + value: Property value as a string of bytes, or a list of strings of + bytes + type: Value type + """ + def __init__(self, name, bytes): + self.name = name + self.value = None + if not bytes: + self.type = fdt_util.TYPE_BOOL + self.value = True + return + self.type, self.value = fdt_util.BytesToValue(bytes) + + def GetPhandle(self): + """Get a (single) phandle value from a property + + Gets the phandle valuie from a property and returns it as an integer + """ + return fdt_util.fdt32_to_cpu(self.value[:4]) + + def Widen(self, newprop): + """Figure out which property type is more general + + Given a current property and a new property, this function returns the + one that is less specific as to type. The less specific property will + be ble to represent the data in the more specific property. This is + used for things like: + + node1 { + compatible = "fred"; + value = <1>; + }; + node1 { + compatible = "fred"; + value = <1 2>; + }; + + He we want to use an int array for 'value'. The first property + suggests that a single int is enough, but the second one shows that + it is not. Calling this function with these two propertes would + update the current property to be like the second, since it is less + specific. + """ + if newprop.type < self.type: + self.type = newprop.type + + if type(newprop.value) == list and type(self.value) != list: + self.value = [self.value] + + if type(self.value) == list and len(newprop.value) > len(self.value): + val = fdt_util.GetEmpty(self.type) + while len(self.value) < len(newprop.value): + self.value.append(val) + + +class Node: + """A device tree node + + Properties: + offset: Integer offset in the device tree + name: Device tree node tname + path: Full path to node, along with the node name itself + _fdt: Device tree object + subnodes: A list of subnodes for this node, each a Node object + props: A dict of properties for this node, each a Prop object. + Keyed by property name + """ + def __init__(self, fdt, offset, name, path): + self.offset = offset + self.name = name + self.path = path + self._fdt = fdt + self.subnodes = [] + self.props = {} + + def Scan(self): + """Scan a node's properties and subnodes + + This fills in the props and subnodes properties, recursively + searching into subnodes so that the entire tree is built. + """ + self.props = self._fdt.GetProps(self.path) + + offset = libfdt.fdt_first_subnode(self._fdt.GetFdt(), self.offset) + while offset >= 0: + sep = '' if self.path[-1] == '/' else '/' + name = libfdt.Name(self._fdt.GetFdt(), offset) + path = self.path + sep + name + node = Node(self._fdt, offset, name, path) + self.subnodes.append(node) + + node.Scan() + offset = libfdt.fdt_next_subnode(self._fdt.GetFdt(), offset) + + +class Fdt: + """Provides simple access to a flat device tree blob. + + Properties: + fname: Filename of fdt + _root: Root of device tree (a Node object) + """ + + def __init__(self, fname): + self.fname = fname + with open(fname) as fd: + self._fdt = fd.read() + + def GetFdt(self): + """Get the contents of the FDT + + Returns: + The FDT contents as a string of bytes + """ + return self._fdt + + def Scan(self): + """Scan a device tree, building up a tree of Node objects + + This fills in the self._root property + """ + self._root = Node(self, 0, '/', '/') + self._root.Scan() + + def GetRoot(self): + """Get the root Node of the device tree + + Returns: + The root Node object + """ + return self._root + + def GetProps(self, node): + """Get all properties from a node. + + Args: + node: Full path to node name to look in. + + Returns: + A dictionary containing all the properties, indexed by node name. + The entries are Prop objects. + + Raises: + ValueError: if the node does not exist. + """ + offset = libfdt.fdt_path_offset(self._fdt, node) + if offset < 0: + libfdt.Raise(offset) + props_dict = {} + poffset = libfdt.fdt_first_property_offset(self._fdt, offset) + while poffset >= 0: + dprop, plen = libfdt.fdt_get_property_by_offset(self._fdt, poffset) + prop = Prop(libfdt.String(self._fdt, dprop.nameoff), libfdt.Data(dprop)) + props_dict[prop.name] = prop + + poffset = libfdt.fdt_next_property_offset(self._fdt, poffset) + return props_dict diff --git a/tools/dtoc/fdt_fallback.py b/tools/dtoc/fdt_fallback.py new file mode 100644 index 0000000..14decf3 --- /dev/null +++ b/tools/dtoc/fdt_fallback.py @@ -0,0 +1,207 @@ +#!/usr/bin/python +# +# Copyright (C) 2016 Google, Inc +# Written by Simon Glass <sjg@chromium.org> +# +# SPDX-License-Identifier: GPL-2.0+ +# + +import command +import fdt_util +import sys + +# This deals with a device tree, presenting it as a list of Node and Prop +# objects, representing nodes and properties, respectively. +# +# This implementation uses the fdtget tool to access the device tree, so it +# is not very efficient for larger trees. The tool is called once for each +# node and property in the tree. + +class Prop: + """A device tree property + + Properties: + name: Property name (as per the device tree) + value: Property value as a string of bytes, or a list of strings of + bytes + type: Value type + """ + def __init__(self, name, byte_list_str): + self.name = name + self.value = None + if not byte_list_str.strip(): + self.type = fdt_util.TYPE_BOOL + return + bytes = [chr(int(byte, 16)) for byte in byte_list_str.strip().split(' ')] + self.type, self.value = fdt_util.BytesToValue(''.join(bytes)) + + def GetPhandle(self): + """Get a (single) phandle value from a property + + Gets the phandle valuie from a property and returns it as an integer + """ + return fdt_util.fdt32_to_cpu(self.value[:4]) + + def Widen(self, newprop): + """Figure out which property type is more general + + Given a current property and a new property, this function returns the + one that is less specific as to type. The less specific property will + be ble to represent the data in the more specific property. This is + used for things like: + + node1 { + compatible = "fred"; + value = <1>; + }; + node1 { + compatible = "fred"; + value = <1 2>; + }; + + He we want to use an int array for 'value'. The first property + suggests that a single int is enough, but the second one shows that + it is not. Calling this function with these two propertes would + update the current property to be like the second, since it is less + specific. + """ + if newprop.type < self.type: + self.type = newprop.type + + if type(newprop.value) == list and type(self.value) != list: + self.value = newprop.value + +class Node: + """A device tree node + + Properties: + name: Device tree node tname + path: Full path to node, along with the node name itself + _fdt: Device tree object + subnodes: A list of subnodes for this node, each a Node object + props: A dict of properties for this node, each a Prop object. + Keyed by property name + """ + def __init__(self, fdt, name, path): + self.name = name + self.path = path + self._fdt = fdt + self.subnodes = [] + self.props = {} + + def Scan(self): + """Scan a node's properties and subnodes + + This fills in the props and subnodes properties, recursively + searching into subnodes so that the entire tree is built. + """ + for name, byte_list_str in self._fdt.GetProps(self.path).iteritems(): + prop = Prop(name, byte_list_str) + self.props[name] = prop + + for name in self._fdt.GetSubNodes(self.path): + sep = '' if self.path[-1] == '/' else '/' + path = self.path + sep + name + node = Node(self._fdt, name, path) + self.subnodes.append(node) + + node.Scan() + + +class Fdt: + """Provides simple access to a flat device tree blob. + + Properties: + fname: Filename of fdt + _root: Root of device tree (a Node object) + """ + + def __init__(self, fname): + self.fname = fname + + def Scan(self): + """Scan a device tree, building up a tree of Node objects + + This fills in the self._root property + """ + self._root = Node(self, '/', '/') + self._root.Scan() + + def GetRoot(self): + """Get the root Node of the device tree + + Returns: + The root Node object + """ + return self._root + + def GetSubNodes(self, node): + """Returns a list of sub-nodes of a given node + + Args: + node: Node name to return children from + + Returns: + List of children in the node (each a string node name) + + Raises: + CmdError: if the node does not exist. + """ + out = command.Output('fdtget', self.fname, '-l', node) + return out.strip().splitlines() + + def GetProps(self, node, convert_dashes=False): + """Get all properties from a node + + Args: + node: full path to node name to look in + convert_dashes: True to convert - to _ in node names + + Returns: + A dictionary containing all the properties, indexed by node name. + The entries are simply strings - no decoding of lists or numbers + is done. + + Raises: + CmdError: if the node does not exist. + """ + out = command.Output('fdtget', self.fname, node, '-p') + props = out.strip().splitlines() + props_dict = {} + for prop in props: + name = prop + if convert_dashes: + prop = re.sub('-', '_', prop) + props_dict[prop] = self.GetProp(node, name) + return props_dict + + def GetProp(self, node, prop, default=None, typespec=None): + """Get a property from a device tree. + + This looks up the given node and property, and returns the value as a + string, + + If the node or property does not exist, this will return the default + value. + + Args: + node: Full path to node to look up. + prop: Property name to look up. + default: Default value to return if nothing is present in the fdt, + or None to raise in this case. This will be converted to a + string. + typespec: Type character to use (None for default, 's' for string) + + Returns: + string containing the property value. + + Raises: + CmdError: if the property does not exist and no default is provided. + """ + args = [self.fname, node, prop, '-t', 'bx'] + if default is not None: + args += ['-d', str(default)] + if typespec is not None: + args += ['-t%s' % typespec] + out = command.Output('fdtget', *args) + return out.strip() diff --git a/tools/dtoc/fdt_util.py b/tools/dtoc/fdt_util.py new file mode 100644 index 0000000..929b524 --- /dev/null +++ b/tools/dtoc/fdt_util.py @@ -0,0 +1,86 @@ +#!/usr/bin/python +# +# Copyright (C) 2016 Google, Inc +# Written by Simon Glass <sjg@chromium.org> +# +# SPDX-License-Identifier: GPL-2.0+ +# + +import struct + +# A list of types we support +(TYPE_BYTE, TYPE_INT, TYPE_STRING, TYPE_BOOL) = range(4) + +def BytesToValue(bytes): + """Converts a string of bytes into a type and value + + Args: + A string containing bytes + + Return: + A tuple: + Type of data + Data, either a single element or a list of elements. Each element + is one of: + TYPE_STRING: string value from the property + TYPE_INT: a byte-swapped integer stored as a 4-byte string + TYPE_BYTE: a byte stored as a single-byte string + """ + size = len(bytes) + strings = bytes.split('\0') + is_string = True + count = len(strings) - 1 + if count > 0 and not strings[-1]: + for string in strings[:-1]: + if not string: + is_string = False + break + for ch in string: + if ch < ' ' or ch > '~': + is_string = False + break + else: + is_string = False + if is_string: + if count == 1: + return TYPE_STRING, strings[0] + else: + return TYPE_STRING, strings[:-1] + if size % 4: + if size == 1: + return TYPE_BYTE, bytes[0] + else: + return TYPE_BYTE, list(bytes) + val = [] + for i in range(0, size, 4): + val.append(bytes[i:i + 4]) + if size == 4: + return TYPE_INT, val[0] + else: + return TYPE_INT, val + +def GetEmpty(type): + """Get an empty / zero value of the given type + + Returns: + A single value of the given type + """ + if type == TYPE_BYTE: + return chr(0) + elif type == TYPE_INT: + return struct.pack('<I', 0); + elif type == TYPE_STRING: + return '' + else: + return True + +def fdt32_to_cpu(val): + """Convert a device tree cell to an integer + + Args: + Value to convert (4-character string representing the cell value) + + Return: + A native-endian integer value + """ + return struct.unpack(">I", val)[0] |