[U-Boot] [PATCH v3 31/62] dm: Add a more efficient libfdt library
Simon Glass
sjg at chromium.org
Mon Jul 4 19:58:11 CEST 2016
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. It
requires the 'swig' to build.
Signed-off-by: Simon Glass <sjg at chromium.org>
---
Changes in v3:
- Fix handling of boolean value (no impact, but it is more correct)
- Enhance widening to handle array size changes
Changes in v2: None
lib/libfdt/libfdt.swig | 89 +++++++++++++++++++++++
lib/libfdt/setup.py | 38 ++++++++++
lib/libfdt/test_libfdt.py | 14 ++++
scripts/Makefile.host | 9 ++-
tools/Makefile | 11 +++
tools/dtoc/fdt.py | 180 ++++++++++++++++++++++++++++++++++++++++++++++
6 files changed, 339 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..14f583d
--- /dev/null
+++ b/lib/libfdt/libfdt.swig
@@ -0,0 +1,89 @@
+/* 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];
+};
+
+/*
+ * This is a work-around since I'm not sure of a better way to copy out the
+ * contents of a string. This is used in dtoc/GetProps(). The intent is to
+ * pass in a pointer to a property and access the data field at the end of
+ * it. Ideally the Data() function above would be able to do this directly,
+ * but I'm not sure how to do that.
+ */
+#pragma SWIG nowarn=454
+%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 $@ $<
+
# TODO(sjg at chromium.org): Is this correct on Mac OS?
ifneq ($(CONFIG_MX23)$(CONFIG_MX28),)
diff --git a/tools/dtoc/fdt.py b/tools/dtoc/fdt.py
new file mode 100644
index 0000000..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 at 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
--
2.8.0.rc3.226.g39d4020
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