It is useful to be able to create a device tree from scratch using
software. This is supported in libfdt but not currently available in the
Python bindings.
Add a new FdtSw class to handle this, with various methods corresponding
to the libfdt functions. When the tree is complete, calling AsFdt() will
return the completed device-tree object.
Signed-off-by: Simon Glass <sjg@xxxxxxxxxxxx>
---
Changes in v2: None
pylibfdt/libfdt.i | 269 ++++++++++++++++++++++++++++++++++++++++
tests/pylibfdt_tests.py | 91 +++++++++++++-
2 files changed, 357 insertions(+), 3 deletions(-)
diff --git a/pylibfdt/libfdt.i b/pylibfdt/libfdt.i
index 566a401..6f9593d 100644
--- a/pylibfdt/libfdt.i
+++ b/pylibfdt/libfdt.i
@@ -57,6 +57,17 @@
%{
#define SWIG_FILE_WITH_INIT
#include "libfdt.h"
+
+/*
+ * We rename this function here to avoid problems with swig, since we also have
+ * a struct called fdt_property. That struct causes swig to create a class in
+ * libfdt.py called fdt_property(), which confuses things.
+ */
+static int _fdt_property(void *fdt, const char *name, const char *val, int len)
+{
+ return fdt_property(fdt, name, val, len);
+}
+
%}
%pythoncode %{
@@ -690,6 +701,251 @@ class Property(bytearray):
def __init__(self, name, value):
bytearray.__init__(self, value)
self.name = name
+
+
+class FdtSw(object):
+ """Software interface to create a device tree from scratch
+
+ The methods in this class work by adding to an existing 'partial' device
+ tree buffer of a fixed size created by instantiating this class. When the
+ tree is complete, call finish() to complete the device tree so that it can
+ be used.
+
+ Similarly with nodes, a new node is started with begin_node() and finished
+ with end_node().
+
+ The context manager functions can be used to make this a bit easier:
+
+ # First create the device tree with a node and property:
+ with FdtSw(small_size) as sw:
+ with sw.AddNode('node'):
+ sw.property_u32('reg', 2)
+ fdt = sw.AsFdt()
+
+ # Now we can use it as a real device tree
+ fdt.setprop_u32(0, 'reg', 3)
+ """
+ def __init__(self, size, quiet=()):
+ fdtrw = bytearray(size)
+ err = check_err(fdt_create(fdtrw, size))
+ if err:
+ return err
+ self._fdtrw = fdtrw
+
+ def __enter__(self):
+ """Contact manager to use to create a device tree via software"""
+ return self
+
+ def __exit__(self, type, value, traceback):
+ check_err(fdt_finish(self._fdtrw))
+
+ def AsFdt(self):
+ """Convert a FdtSw into an Fdt so it can be accessed as normal
+
+ Note that finish() must be called before this function will work. If
+ you are using the context manager (see 'with' code in the FdtSw class
+ comment) then this will happen automatically.
+
+ Returns:
+ Fdt object allowing access to the newly created device tree
+ """
+ return Fdt(self._fdtrw)
+
+ def resize(self, size, quiet=()):
+ """Resize the buffer to accommodate a larger tree
+
+ Args:
+ size: New size of tree
+ quiet: Errors to ignore (empty to raise on all errors)
+
+ Raises:
+ FdtException if no node found or other error occurs
+ """
+ fdt = bytearray(size)
+ fdt[:len(self._fdtrw)] = self._fdtrw
+ err = check_err(fdt_resize(self._fdtrw, fdt, size), quiet)
+ if err:
+ return err
+ self._fdtrw = fdt
+
+ def add_reservemap_entry(self, addr, size, quiet=()):
+ """Add a new memory reserve map entry
+
+ Once finished adding, you must call finish_reservemap().
+
+ Args:
+ addr: 64-bit start address
+ size: 64-bit size
+ quiet: Errors to ignore (empty to raise on all errors)
+
+ Raises:
+ FdtException if no node found or other error occurs
+ """
+ return check_err(fdt_add_reservemap_entry(self._fdtrw, addr, size),
+ quiet)
+
+ def finish_reservemap(self, quiet=()):
+ """Indicate that there are no more reserve map entries to add
+
+ Args:
+ quiet: Errors to ignore (empty to raise on all errors)
+
+ Raises:
+ FdtException if no node found or other error occurs
+ """
+ return check_err(fdt_finish_reservemap(self._fdtrw), quiet)
+
+ def begin_node(self, name, quiet=()):
+ """Begin a new node
+
+ Use this before adding properties to the node. Then call end_node() to
+ finish it. You can also use the context manager as shown in the FdtSw
+ class comment.
+
+ Args:
+ name: Name of node to begin
+ quiet: Errors to ignore (empty to raise on all errors)
+
+ Raises:
+ FdtException if no node found or other error occurs
+ """
+ return check_err(fdt_begin_node(self._fdtrw, name), quiet)
+
+ def property_string(self, name, string, quiet=()):
+ """Add a property with a string value
+
+ The string will be nul-terminated when written to the device tree
+
+ Args:
+ name: Name of property to add
+ string: String value of property
+ quiet: Errors to ignore (empty to raise on all errors)
+
+ Raises:
+ FdtException if no node found or other error occurs
+ """
+ return check_err(fdt_property_string(self._fdtrw, name, string), quiet)
+
+ def property_u32(self, name, val, quiet=()):
+ """Add a property with a 32-bit value
+
+ Write a single-cell value to the device tree
+
+ Args:
+ name: Name of property to add
+ val: Value of property
+ quiet: Errors to ignore (empty to raise on all errors)
+
+ Raises:
+ FdtException if no node found or other error occurs
+ """
+ return check_err(fdt_property_u32(self._fdtrw, name, val), quiet)
+
+ def property_u64(self, name, val, quiet=()):
+ """Add a property with a 64-bit value
+
+ Write a double-cell value to the device tree in big-endian format
+
+ Args:
+ name: Name of property to add
+ val: Value of property
+ quiet: Errors to ignore (empty to raise on all errors)
+
+ Raises:
+ FdtException if no node found or other error occurs
+ """
+ return check_err(fdt_property_u64(self._fdtrw, name, val), quiet)
+
+ def property_cell(self, name, val, quiet=()):
+ """Add a property with a single-cell value
+
+ Write a single-cell value to the device tree
+
+ Args:
+ name: Name of property to add
+ val: Value of property
+ quiet: Errors to ignore (empty to raise on all errors)
+
+ Raises:
+ FdtException if no node found or other error occurs
+ """
+ return check_err(fdt_property_cell(self._fdtrw, name, val), quiet)
+
+ def property(self, name, val, quiet=()):
+ """Add a property
+
+ Write a new property with the given value to the device tree. The value
+ is taken as is and is not nul-terminated
+
+ Args:
+ name: Name of property to add
+ val: Value of property
+ quiet: Errors to ignore (empty to raise on all errors)
+
+ Raises:
+ FdtException if no node found or other error occurs
+ """
+ return check_err(_fdt_property(self._fdtrw, name, val, len(val)), quiet)
+
+ def end_node(self, quiet=()):
+ """End a node
+
+ Use this after adding properties to a node to close it off. You can also
+ use the context manager as shown in the FdtSw class comment.
+
+ Args:
+ quiet: Errors to ignore (empty to raise on all errors)
+
+ Raises:
+ FdtException if no node found or other error occurs
+ """
+ return check_err(fdt_end_node(self._fdtrw), quiet)
+
+ def finish(self, quiet=()):
+ """Finish writing the device tree
+
+ This closes off the device tree ready for use
+
+ Args:
+ quiet: Errors to ignore (empty to raise on all errors)
+
+ Raises:
+ FdtException if no node found or other error occurs
+ """
+ return check_err(fdt_finish(self._fdtrw), quiet)
+
+ def AddNode(self, name):
+ """Create a new context for adding a node
+
+ When used in a 'with' clause this starts a new node and finishes it
+ afterward.
+
+ Args:
+ name: Name of node to add
+ """
+ return NodeAdder(self._fdtrw, name)
+
+
+class NodeAdder():
+ """Class to provide a node context
+
+ This allows you to add nodes in a more natural way:
+
+ with fdtsw.AddNode('name'):
+ fdtsw.property_string('test', 'value')
+
+ The node is automatically completed with a call to end_node() when the
+ context exits.
+ """
+ def __init__(self, fdt, name):
+ self._fdt = fdt
+ self._name = name
+
+ def __enter__(self):
+ check_err(fdt_begin_node(self._fdt, self._name))
+
+ def __exit__(self, type, value, traceback):
+ check_err(fdt_end_node(self._fdt))
%}
%rename(fdt_property) fdt_property_func;
@@ -750,6 +1006,11 @@ typedef int fdt32_t;
$1 = PyString_AsString($input); /* char *str */
}
+/* typemap used for fdt_add_reservemap_entry() */
+%typemap(in) uint64_t {
+ $1 = PyLong_AsUnsignedLong($input);
+}
+
/* typemaps used for fdt_next_node() */
%typemap(in, numinputs=1) int *depth (int depth) {
depth = (int) PyInt_AsLong($input);
@@ -792,5 +1053,13 @@ 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);
+int fdt_property_string(void *fdt, const char *name, const char *val);
+int fdt_property_cell(void *fdt, const char *name, uint32_t val);
+
+/*
+ * This function has a stub since the name fdt_property is used for both a
+ * function and a struct, which confuses SWIG.
+ */
+int _fdt_property(void *fdt, const char *name, const char *val, int len);
%include <../libfdt/libfdt.h>
diff --git a/tests/pylibfdt_tests.py b/tests/pylibfdt_tests.py
index 18a583d..2d132d9 100644
--- a/tests/pylibfdt_tests.py
+++ b/tests/pylibfdt_tests.py
@@ -56,17 +56,34 @@ import unittest
sys.path.insert(0, '../pylibfdt')
import libfdt
-from libfdt import Fdt, FdtException, QUIET_NOTFOUND, QUIET_ALL
+from libfdt import Fdt, FdtSw, FdtException, QUIET_NOTFOUND, QUIET_ALL
small_size = 160
full_size = 1024
+TEST_ADDR_1H = 0xdeadbeef
+TEST_ADDR_1L = 0x00000000
+TEST_ADDR_1 = (TEST_ADDR_1H << 32) | TEST_ADDR_1L
+TEST_ADDR_1 = 0x8000000000000000
+TEST_SIZE_1H = 0x00000000
+TEST_SIZE_1L = 0x00100000
+TEST_SIZE_1 = (TEST_SIZE_1H << 32) | TEST_SIZE_1L
+TEST_ADDR_2H = 0
+TEST_ADDR_2L = 123456789
+TEST_ADDR_2 = (TEST_ADDR_2H << 32) | TEST_ADDR_2L
+TEST_SIZE_2H = 0
+TEST_SIZE_2L = 010000
+TEST_SIZE_2 = (TEST_SIZE_2H << 32) | TEST_SIZE_2L
TEST_VALUE_1 = 0xdeadbeef
+TEST_VALUE_2 = 123456789
TEST_VALUE64_1H = 0xdeadbeef
TEST_VALUE64_1L = 0x01abcdef
TEST_VALUE64_1 = (TEST_VALUE64_1H << 32) | TEST_VALUE64_1L
+PHANDLE_1 = 0x2000
+PHANDLE_2 = 0x2001
+
TEST_STRING_1 = 'hello world'
TEST_STRING_2 = 'hi world'
TEST_STRING_3 = u'unicode ' + unichr(467)
@@ -94,8 +111,8 @@ def _ReadFdt(fname):
"""
return libfdt.Fdt(open(fname).read())
-class PyLibfdtTests(unittest.TestCase):
- """Test class for pylibfdt
+class PyLibfdtBasicTests(unittest.TestCase):
+ """Test class for basic pylibfdt access functions
Properties:
fdt: Device tree file used for testing
@@ -479,5 +496,73 @@ class PyLibfdtTests(unittest.TestCase):
self.assertIn('embedded nul', str(e.exception))
+class PyLibfdtSwTests(unittest.TestCase):
+ """Test class for pylibfdt sequential-write DT creation
+ """
+ def assertOk(self, err_code):
+ self.assertEquals(0, err_code)
+
+ def testCreate(self):
+ # First check the minimum size and also the Fdt() constructor
+ with self.assertRaisesRegexp(FdtException, get_err(libfdt.NOSPACE)):
+ self.assertEquals(-libfdt.NOSPACE, FdtSw(3))
+ _= FdtSw(small_size)
+
+ # Now use the context-manager version
+ with FdtSw(small_size) as sw:
+ sw.add_reservemap_entry(TEST_ADDR_1, TEST_SIZE_1)
+ sw.add_reservemap_entry(TEST_ADDR_2, TEST_SIZE_2)
+ sw.finish_reservemap()
+
+ sw.begin_node('')
+ sw.property_string('compatible', 'test_tree1')
+ with self.assertRaisesRegexp(FdtException, get_err(libfdt.NOSPACE)):
+ sw.property_u32('prop-int', TEST_VALUE_1)
+
+ # Check we can resize to its current size. Then make it bigger.
+ sw.resize(small_size)
+ sw.resize(full_size)
+ sw.property_u32('prop-int', TEST_VALUE_1)
+ sw.property_u64('prop-int64', TEST_VALUE64_1)
+ sw.property_string('prop-str', TEST_STRING_1)
+ sw.property_u32('#address-cells', 1)
+ sw.property_u32('#size-cells', 0)
+
+ # Now that it is bigger we can't shrink it back
+ with self.assertRaisesRegexp(FdtException, get_err(libfdt.NOSPACE)):
+ sw.resize(small_size)
+
+ sw.begin_node('subnode@1')
+ sw.property_string('compatible', 'subnode1')
+ sw.property_u32('reg', 1)
+ sw.property_cell('prop-int', TEST_VALUE_1)
+ sw.begin_node('subsubnode')
+ sw.property('compatible', 'subsubnode1\0subsubnode')
+ sw.property_cell('prop-int', TEST_VALUE_1)
+ sw.end_node()
+ sw.begin_node('ss1')
+ sw.end_node()
+ sw.end_node()
+
+ with sw.AddNode('subnode@2'):
+ sw.property_u32('reg', 2)
+ sw.property_cell('linux,phandle', PHANDLE_1)
+ sw.property_cell('prop-int', TEST_VALUE_2)
+ sw.property_u32('#address-cells', 1)
+ sw.property_u32('#size-cells', 0)
+ with sw.AddNode('subsubnode@0'):
+ sw.property_u32('reg', 0)
+ sw.property_cell('phandle', PHANDLE_2)
+ sw.property('compatible', 'subsubnode2\0subsubnode')
+ sw.property_cell('prop-int', TEST_VALUE_2)
+ with sw.AddNode('ss2'):
+ pass
+ sw.end_node()
+
+ fdt = sw.AsFdt()
+ self.assertEqual(2, fdt.num_mem_rsv())
+ self.assertEqual([TEST_ADDR_1, TEST_SIZE_1], fdt.get_mem_rsv(0))
+
+
if __name__ == "__main__":
unittest.main()
--
2.17.1.1185.g55be947832-goog
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