Add a Python version of the libfdt library which contains enough features to support the dtoc tool. This is only a very bare-bones implementation.
Signed-off-by: Simon Glass sjg@chromium.org ---
lib/libfdt/libfdt.swig | 81 +++++++++++++++++++++ lib/libfdt/setup.py | 38 ++++++++++ lib/libfdt/test_libfdt.py | 14 ++++ scripts/Makefile.host | 9 ++- tools/Makefile | 11 +++ tools/dtoc/fdt.py | 174 ++++++++++++++++++++++++++++++++++++++++++++++ 6 files changed, 325 insertions(+), 2 deletions(-) create mode 100644 lib/libfdt/libfdt.swig create mode 100644 lib/libfdt/setup.py create mode 100644 lib/libfdt/test_libfdt.py create mode 100644 tools/dtoc/fdt.py
diff --git a/lib/libfdt/libfdt.swig b/lib/libfdt/libfdt.swig new file mode 100644 index 0000000..95c3e9e --- /dev/null +++ b/lib/libfdt/libfdt.swig @@ -0,0 +1,81 @@ +/* File: libfdt.i */ +%module libfdt + +%{ +#define SWIG_FILE_WITH_INIT +#include "libfdt.h" +%} + +%pythoncode %{ +def Raise(errnum): + raise ValueError('Error %s' % fdt_strerror(errnum)) + +def Name(fdt, offset): + name, len = fdt_get_name(fdt, offset) + return name + +def String(fdt, offset): + offset = fdt32_to_cpu(offset) + name = fdt_string(fdt, offset) + return name + +def swap32(x): + return (((x << 24) & 0xFF000000) | + ((x << 8) & 0x00FF0000) | + ((x >> 8) & 0x0000FF00) | + ((x >> 24) & 0x000000FF)) + +def fdt32_to_cpu(x): + return swap32(x) + +def Data(prop): + set_prop(prop) + return get_prop_data() +%} + +%include "typemaps.i" +%include "cstring.i" + +%typemap(in) void* = char*; + +typedef int fdt32_t; + +struct fdt_property { + fdt32_t tag; + fdt32_t len; + fdt32_t nameoff; + char data[0]; +}; + +%inline %{ + static struct fdt_property *cur_prop; + + void set_prop(struct fdt_property *prop) { + cur_prop = prop; + } +%} + +%cstring_output_allocate_size(char **s, int *sz, free(*$1)); +%inline %{ + void get_prop_data(char **s, int *sz) { + *sz = fdt32_to_cpu(cur_prop->len); + *s = (char *)malloc(*sz); + if (!*s) + *sz = 0; + else + memcpy(*s, cur_prop + 1, *sz); + } +%} + +const void *fdt_offset_ptr(const void *fdt, int offset, unsigned int checklen); +int fdt_path_offset(const void *fdt, const char *path); +int fdt_first_property_offset(const void *fdt, int nodeoffset); +int fdt_next_property_offset(const void *fdt, int offset); +const char *fdt_strerror(int errval); +const struct fdt_property *fdt_get_property_by_offset(const void *fdt, + int offset, + int *OUTPUT); +const char *fdt_get_name(const void *fdt, int nodeoffset, int *OUTPUT); +const char *fdt_string(const void *fdt, int stroffset); +int fdt_first_subnode(const void *fdt, int offset); +int fdt_next_subnode(const void *fdt, int offset); diff --git a/lib/libfdt/setup.py b/lib/libfdt/setup.py new file mode 100644 index 0000000..62e7bcc --- /dev/null +++ b/lib/libfdt/setup.py @@ -0,0 +1,38 @@ +#!/usr/bin/env python + +""" +setup.py file for SWIG libfdt +""" + +from distutils.core import setup, Extension +import os +import sys + +# Don't cross-compile - always use the host compiler. +del os.environ['CROSS_COMPILE'] +del os.environ['CC'] + +progname = sys.argv[0] +cflags = sys.argv[1] +files = sys.argv[2:] + +if cflags: + cflags = [flag for flag in cflags.split(' ') if flag] +else: + cflags = None + +libfdt_module = Extension( + '_libfdt', + sources = files, + extra_compile_args = cflags +) + +sys.argv = [progname, '--quiet', 'build_ext', '--inplace'] + +setup (name = 'libfdt', + version = '0.1', + author = "SWIG Docs", + description = """Simple swig libfdt from docs""", + ext_modules = [libfdt_module], + py_modules = ["libfdt"], + ) diff --git a/lib/libfdt/test_libfdt.py b/lib/libfdt/test_libfdt.py new file mode 100644 index 0000000..14d0da4 --- /dev/null +++ b/lib/libfdt/test_libfdt.py @@ -0,0 +1,14 @@ +#!/usr/bin/python + +import os +import sys + +our_path = os.path.dirname(os.path.realpath(__file__)) +sys.path.append(os.path.join(our_path, '../../b/sandbox_spl/tools')) + +import libfdt + +with open('b/sandbox_spl/u-boot.dtb') as fd: + fdt = fd.read() + +print libfdt.fdt_path_offset(fdt, "/aliases") diff --git a/scripts/Makefile.host b/scripts/Makefile.host index bff8b5b..763a699 100644 --- a/scripts/Makefile.host +++ b/scripts/Makefile.host @@ -28,12 +28,16 @@ __hostprogs := $(sort $(hostprogs-y) $(hostprogs-m)) # C code # Executables compiled from a single .c file host-csingle := $(foreach m,$(__hostprogs), \ - $(if $($(m)-objs)$($(m)-cxxobjs),,$(m))) + $(if $($(m)-objs)$($(m)-cxxobjs)$($(m)-sharedobjs),,$(m)))
# C executables linked based on several .o files host-cmulti := $(foreach m,$(__hostprogs),\ $(if $($(m)-cxxobjs),,$(if $($(m)-objs),$(m))))
+# Shared object libraries +host-shared := $(foreach m,$(__hostprogs),\ + $(if $($(m)-sharedobjs),$(m)))) + # Object (.o) files compiled from .c files host-cobjs := $(sort $(foreach m,$(__hostprogs),$($(m)-objs)))
@@ -59,6 +63,7 @@ host-cmulti := $(addprefix $(obj)/,$(host-cmulti)) host-cobjs := $(addprefix $(obj)/,$(host-cobjs)) host-cxxmulti := $(addprefix $(obj)/,$(host-cxxmulti)) host-cxxobjs := $(addprefix $(obj)/,$(host-cxxobjs)) +host-shared := $(addprefix $(obj)/,$(host-shared)) host-objdirs := $(addprefix $(obj)/,$(host-objdirs))
obj-dirs += $(host-objdirs) @@ -128,4 +133,4 @@ $(host-cxxobjs): $(obj)/%.o: $(src)/%.cc FORCE $(call if_changed_dep,host-cxxobjs)
targets += $(host-csingle) $(host-cmulti) $(host-cobjs)\ - $(host-cxxmulti) $(host-cxxobjs) + $(host-cxxmulti) $(host-cxxobjs) $(host-shared) diff --git a/tools/Makefile b/tools/Makefile index 63355aa..a813217 100644 --- a/tools/Makefile +++ b/tools/Makefile @@ -107,6 +107,17 @@ mkimage-objs := $(dumpimage-mkimage-objs) mkimage.o fit_info-objs := $(dumpimage-mkimage-objs) fit_info.o fit_check_sign-objs := $(dumpimage-mkimage-objs) fit_check_sign.o
+hostprogs-$(CONFIG_SPL_OF_PLATDATA) += _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/fdt.py b/tools/dtoc/fdt.py new file mode 100644 index 0000000..3787cb5 --- /dev/null +++ b/tools/dtoc/fdt.py @@ -0,0 +1,174 @@ +#!/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 + 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 = newprop.value + + +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