This adds some helpers to load (32 or 64 bit) words from an fdt blob, even
if they're unaligned and we're on a platform that doesn't like plain
unaligned loads and stores. We then use the helpers in a number of places.
There are two purposes for this:
1) This makes libfdt more robust against a blob loaded at an unaligned
address. It's usually good practice to load a blob at a 64-bit
alignment, but it's nice to work even then.
2) Users can use these helpers to load integer values from within property
values. These can often be unaligned, even if the blob as a whole is
aligned, since some property encodings have integers and strings mixed
together without any alignment gaps.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Allow updating and creating properties, including special methods for
integers.
Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
This new function implements a complete and thorough check of an fdt blob's
structure. Given a buffer containing an fdt, it should return 0 only if
the fdt within is structurally sound in all regards. It doesn't check
anything about the blob's contents (i.e. the actual values of the nodes and
properties), of course.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Tested-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Reviewed-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Reviewed-by: Simon Glass <sjg@chromium.org>
We have a couple of places within libfdt and its tests where we need to
find the size of the header, based on the version. Add a helper function
for it.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Reviewed-by: Simon Glass <sjg@chromium.org>
Tested-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Reviewed-by: Alexey Kardashevskiy <aik@ozlabs.ru>
fdt_string() is used to retrieve strings from a DT blob's strings section.
It's rarely used directly, but is widely used internally.
However, it doesn't do any bounds checking, which means in the case of a
corrupted blob it could access bad memory, which libfdt is supposed to
avoid.
This write a safe alternative to fdt_string, fdt_get_string(). It checks
both that the given offset is within the string section and that the string
it points to is properly \0 terminated within the section. It also returns
the string's length as a convenience (since it needs to determine to do the
checks anyway).
fdt_string() is rewritten in terms of fdt_get_string() for compatibility.
Most of the diff here is actually testing infrastructure.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Tested-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Reviewed-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Currently fdt_check_header() performs only some rudimentary checks, which
is not really what the name suggests. This strengthens fdt_check_header()
to check as much about the blob as is possible from the header alone: as
well as checking the magic number and version, it checks that the total
size is sane, and that all the sub-blocks within the blob lie within the
total size.
* This broadens the meaning of FDT_ERR_TRUNCATED to cover all sorts of
improperly terminated blocks as well as just a structure block without
FDT_END.
* This makes fdt_check_header() only succeed on "complete" blobs, not
in-progress sequential write blobs. The only reason this didn't fail
before was that this function used to be called by many RO functions
which are supposed to also work on incomplete SW blobs.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Tested-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Reviewed-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Reviewed-by: Simon Glass <sjg@chromium.org>
This can be useful in particular in the kernel when booting on systems
with FDT-emitting firmware that is out of date. Releases of kexec-tools
on ppc64 prior to the end of 2014 are notable examples of such.
Signed-off-by: Nathan Whitehorn <nwhitehorn@freebsd.org>
[dwg: Some whitespace cleanups]
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
In a lot of places libfdt uses a leading _ character to mark an identifier
as "internal" (not part of the published libfdt API). This is a bad idea,
because identifiers with a leading _ are generally reserved by the C
library or system. It's particularly dangerous for libfdt, because it's
designed to be able to be integrated into lots of different environments.
In some cases the leading _ has no purpose, so we simply drop it. In most
cases we move it to the end, as our new convention for marking internal
identifiers.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
A comment in tests/stringlist.c refers to fdt_get_string(), which is not a
function that exists. From the content, it's supposed to be referring to
fdt_getprop_string().
A comment in libfdt.h has an extraneous space in a function name.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
In some cases you need to add a property but the contents of it
are not known at creation time, merely the extend of it.
This method allows you to create a property of a given size (filled
with garbage) while a pointer to the property data will be provided.
Signed-off-by: Pantelis Antoniou <pantelis.antoniou@konsulko.com>
[dwg: Corrected commit message]
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
The existing function to add a new property to a tree being built requires
that the entire contents of the new property be passed in. For some
applications it is more convenient to be able to add the property contents
later, perhaps by reading from a file. This avoids double-buffering of the
contents.
Add a new function to support this and adjust the existing fdt_property() to
use it.
Signed-off-by: Simon Glass <sjg@chromium.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
There are a few places where libfdt.h cannot be used as is with swig:
- macros like fdt_totalsize() have to be defined as C declarations
- fdt_offset_ptr() and fdt_getprop_namelen() need special treatment due to
a TODO in the wrapper for fdt_getprop(). However they are not useful to
Python so can be removed
Add #ifdefs to work around these problem.
Signed-off-by: Simon Glass <sjg@chromium.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Device trees can contain empty (zero length) properties, which are often
used as boolean flags. These can already be created using fdt_setprop()
passing a length of zero and a pointer which is ignored. It is safe to
pass NULL, but that may not be obvious from the interface. To make it
clearer, add an fdt_setprop_empty() helper macro.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
The device tree overlays are a good way to deal with user-modifyable
boards or boards with some kind of an expansion mechanism where we can
easily plug new board in (like the BBB, the Raspberry Pi or the CHIP).
Add a new function to merge overlays with a base device tree.
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
So far, the BADPHANDLE error was only used for incorrect phandle values.
Extend that meaning to an improperly formatted phandle property.
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Add a few new error codes to report the failure conditions we might
encounter in the overlay application code:
- FDT_ERR_BADOVERLAY, when an overlay cannot be parsed, even though its
structure is correct
- FDT_ERR_NOPHANDLES, when we ran out of available phandles and we
cannot use a new phandle without either using an invalid one (-1 or
0), or one already used.
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Correct some typos discovered with the codespell utility.
Signed-off-by: Thomas Huth <thuth@redhat.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Add a function to modify inplace only a portion of a property..
This is especially useful when the property is an array of values, and you
want to update one of them without changing the DT size.
Acked-by: Simon Glass <sjg@chromium.org>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
[dwg: Remove unnecessary unsigned qualifier, correct a comment]
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Add a function to retrieve a writeable property only by the first
characters of its name.
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Add a function to retrieve the highest phandle in a given device tree.
Acked-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Stefan Agner <stefan@agner.ch>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Implement a macro based on fdt_first_property_offset and
fdt_next_property_offset that provides a convenience to iterate over all
the properties of a given node.
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Acked-by: Simon Glass <sjg@chromium.org>
[dwg: Removed a stray trailing blank line]
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
The fdt_for_each_subnode() iterator macro provided by this patch can be
used to iterate over a device tree node's subnodes. At each iteration a
loop variable will be set to the next subnode.
Signed-off-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
The code style here is slightly incorrect. Fix it.
Signed-off-by: Simon Glass <sjg@chromium.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
There are a few lines that are over 80 columns. Fix these.
Signed-off-by: Simon Glass <sjg@chromium.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
There are a few places with a space before a tab in this file. Fix them.
Signed-off-by: Simon Glass <sjg@chromium.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Given a device tree node, a property name and an index, the new function
fdt_stringlist_get() will return a pointer to the index'th string in the
property's value and return its length (or an error code on failure) in
an output argument.
Signed-off-by: Thierry Reding <treding@nvidia.com>
[Fix some -Wshadow warnings --dwg]
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
The new fdt_stringlist_search() function will look up a given string in
the list contained in the value of a named property of a given device
tree node and return its index.
Signed-off-by: Thierry Reding <treding@nvidia.com>
[Fix some -Wshadow warnings --dwg]
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Given a device tree node and a property name, the fdt_stringlist_count()
function counts the number of strings found in the property value.
This also adds a new error code, FDT_ERR_BADVALUE, that the function
returns when it encounters a non-NUL-terminated string list.
Signed-off-by: Thierry Reding <treding@nvidia.com>
[Changed testcase name --dwg]
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
The statement "Identical to fdt_get_property_namelen() ..." does not
make sense for the comment of fdt_get_property_namelen() itself.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Properties may contain path names which are not NUL-terminated.
For example, the 'stdout-path' property allows the form 'path:options',
where the ':' character terminates the path specifier.
Allow these path names to be used in-place for path descending;
add fdt_path_offset_namelen(), which limits the path name to 'namelen'
characters.
Reimplement fdt_path_offset() as a trivial wrapper.
Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
This patch makes a small start on libfdt functions which actually help to
parse the contents of device trees, rather than purely manipulating the
tree's structure.
We add simple helpers to read and sanity check the #address-cells and
#size-cells values for a given node.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
At present, when using sequential write mode, there's no straightforward
means of resizing the buffer the fdt is being built into. This patch
adds an fdt_resize() function for this purpose.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Iterating through subnodes with libfdt is a little painful to write as we
need something like this:
for (depth = 0, count = 0,
offset = fdt_next_node(fdt, parent_offset, &depth);
(offset >= 0) && (depth > 0);
offset = fdt_next_node(fdt, offset, &depth)) {
if (depth == 1) {
/* code body */
}
}
Using fdt_next_subnode() we can instead write this, which is shorter and
easier to get right:
for (offset = fdt_first_subnode(fdt, parent_offset);
offset >= 0;
offset = fdt_next_subnode(fdt, offset)) {
/* code body */
}
Also, it doesn't require two levels of indentation for the loop body.
Signed-off-by: Simon Glass <sjg@chromium.org>
Acked-by: David Gibson <david@gibson.dropbear.id.au>
This function is useful outside libfdt, so export it.
Signed-off-by: Simon Glass <sjg@chromium.org>
Acked-by: David Gibson <david@gibson.dropbear.id.au>
libfdt/fdt.c:104:28: warning: incorrect type in argument 1 (different base types)
libfdt/fdt.c:104:28: expected restricted fdt32_t [usertype] x
libfdt/fdt.c:104:28: got unsigned int const [unsigned] [usertype] <noident>
libfdt/fdt.c:124:40: warning: incorrect type in argument 1 (different base types)
libfdt/fdt.c:124:40: expected restricted fdt32_t [usertype] x
libfdt/fdt.c:124:40: got unsigned int const [unsigned] [usertype] <noident>
libfdt/fdt_ro.c:337:29: warning: incorrect type in argument 1 (different base types)
libfdt/fdt_ro.c:337:29: expected restricted fdt32_t [usertype] x
libfdt/fdt_ro.c:337:29: got unsigned int const [unsigned] [usertype] <noident>
libfdt/fdt_rw.c:370:17: warning: incorrect type in assignment (different base types)
libfdt/fdt_rw.c:370:17: expected unsigned int [unsigned] [usertype] <noident>
libfdt/fdt_rw.c:370:17: got restricted fdt32_t
libfdt/fdt_sw.c:164:13: warning: incorrect type in assignment (different base types)
libfdt/fdt_sw.c:164:13: expected unsigned int [unsigned] [usertype] <noident>
libfdt/fdt_sw.c:164:13: got restricted fdt32_t
libfdt/fdt_sw.c:227:14: warning: incorrect type in assignment (different base types)
libfdt/fdt_sw.c:227:14: expected unsigned int [unsigned] [usertype] <noident>
libfdt/fdt_sw.c:227:14: got restricted fdt32_t
libfdt/fdt_wip.c:80:20: warning: incorrect type in assignment (different base types)
libfdt/fdt_wip.c:80:20: expected unsigned int [unsigned] [usertype] <noident>
libfdt/fdt_wip.c:80:20: got restricted fdt32_t
libfdt/libfdt.h:1001:13: warning: incorrect type in assignment (different base types)
libfdt/libfdt.h:1001:13: expected unsigned long [unsigned] [usertype] val
libfdt/libfdt.h:1001:13: got restricted fdt64_t
libfdt/libfdt.h:1157:13: warning: incorrect type in assignment (different base types)
libfdt/libfdt.h:1157:13: expected unsigned int [unsigned] [usertype] val
libfdt/libfdt.h:1157:13: got restricted fdt32_t
libfdt/libfdt.h:1192:13: warning: incorrect type in assignment (different base types)
libfdt/libfdt.h:1192:13: expected unsigned long [unsigned] [usertype] val
libfdt/libfdt.h:1192:13: got restricted fdt64_t
libfdt/libfdt.h:1299:13: warning: incorrect type in assignment (different base types)
libfdt/libfdt.h:1299:13: expected unsigned int [unsigned] [usertype] val
libfdt/libfdt.h:1299:13: got restricted fdt32_t
libfdt/libfdt.h:1334:13: warning: incorrect type in assignment (different base types)
libfdt/libfdt.h:1334:13: expected unsigned long [unsigned] [usertype] val
libfdt/libfdt.h:1334:13: got restricted fdt64_t
libfdt/libfdt.h:885:13: warning: incorrect type in assignment (different base types)
libfdt/libfdt.h:885:13: expected unsigned int [unsigned] [usertype] val
libfdt/libfdt.h:885:13: got restricted fdt32_t
libfdt/libfdt.h:920:13: warning: incorrect type in assignment (different base types)
libfdt/libfdt.h:920:13: expected unsigned long [unsigned] [usertype] val
libfdt/libfdt.h:920:13: got restricted fdt64_t
libfdt/libfdt.h:996:13: warning: incorrect type in assignment (different base types)
libfdt/libfdt.h:996:13: expected unsigned int [unsigned] [usertype] val
libfdt/libfdt.h:996:13: got restricted fdt32_t
Signed-off-by: Kim Phillips <kim.phillips@freescale.com>
The libfdt read/write functions are now usable enough that it's become a
moderately common pattern to use them to build and manipulate a device
tree from scratch. For example, we do so ourself in our rw_tree1 testcase,
and qemu is starting to use this model when building device trees for some
targets such as e500.
However, the read/write functions require some sort of valid tree to begin
with, so this necessitates either having a trivial canned dtb to begin with
or, more commonly, creating an empty tree using the serial-write functions
first.
This patch adds a helper function which uses the serial-write functions to
create a trivial, empty but complete and valid tree in a supplied buffer,
ready for manipulation with the read/write functions.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
In device trees in the world, properties consisting of a single 64-bit
integer are not as common as those consisting of a single 32-bit, cell
sized integer, but they're common enough that they're worth including
convenience functions for.
This patch adds helper wrappers of fdt_setprop_inplace(), fdt_setprop() and
fdt_appendprop() for handling 64-bit integer quantities in properties. For
better consistency with the names of these new *_u64() functions we also
add *_u32() functions as alternative names for the existing *_cell()
functions handling 32-bit integers.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Some properties may contain multiple values, these values may need
to be added to the property respectively. this patch provides this
functionality. The main purpose of fdt_append_prop() is to append
the values to a existing property, or create a new property if it
dose not exist.
Signed-off-by: Minghuan Lian <Minghuan.Lian@freescale.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
For ages, we've been talking about adding functions to libfdt to allow
iteration through properties. So, finally, here are some.
I got bogged down on this for a long time because I didn't want to
expose offsets directly to properties to the callers. But without
that, attempting to make reasonable iteration functions just became
horrible. So eventually, I settled on an interface which does now
expose property offsets. fdt_first_property_offset() and
fdt_next_property_offset() are used to step through the offsets of the
properties starting from a particularly node offset. The details of
the property at each offset can then be retrieved with either
fdt_get_property_by_offset() or fdt_getprop_by_offset() which have
interfaces similar to fdt_get_property() and fdt_getprop()
respectively.
No explicit testcases are included, but we do use the new functions to
reimplement the existing fdt_get_property() function.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Allow the inclusion of libfdt.h in C++ source.
Signed-off-by: Laurent Gregoire <laurent.gregoire@tomtom.com>
Acked-by: David Gibson <david@gibson.dropbear.id.au>
Oops, screwed up the function name in the documenting comment for this
function. Trivial correction in this patch.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Kumar has already added alias expansion to fdt_path_offset().
However, in some circumstances it may be convenient for the user of
libfdt to explicitly get the string expansion of an alias. This patch
adds a function to do this, fdt_get_alias(), and uses it to implement
fdt_path_offset().
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Using Gcc 4.3 detected this problem:
../dtc/libfdt/fdt.c: In function 'fdt_next_tag':
../dtc/libfdt/fdt.c:82: error: assuming signed overflow does not
occur when assuming that (X + c) < X is always false
To fix the problem, treat the offset as an unsigned int.
The problem report and proposed fix were provided
by Steve Papacharalambous <stevep@freescale.com>.
Signed-off-by: Jon Loeliger <jdl@freescale.com>
As well as fdt_subnode_offset(), libfdt includes an
fdt_subnode_offset_namelen() function that takes the subnode name to
look up not as a NUL-terminated string, but as a string with an
explicit length. This can be useful when the caller has the name as
part of a longer string, such as a full path.
However, we don't have corresponding 'namelen' versions for
fdt_get_property() and fdt_getprop(). There are less obvious use
cases for these variants on property names, but there are
circumstances where they can be useful e.g. looking up property names
which need to be parsed from a longer string buffer such as user input
or a configuration file, or looking up an alias in a path with
IEEE1275 style aliases.
So, since it's very easy to implement such variants, this patch does
so. The original NUL-terminated variants are, of course, implemented
in terms of the namelen versions.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Enabling -Wcast-qual warnings in dtc shows up a number of places where
we are incorrectly discarding a const qualification. There are also
some places where we are intentionally discarding the 'const', and we
need an ugly cast through uintptr_t to suppress the warning. However,
most of these are pretty well isolated with the *_w() functions. So
in the interests of maximum safety with const qualifications, this
patch enables the warnings and fixes the existing complaints.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
This patch adds an fdt_next_node() function which can be used to
iterate through nodes of the tree while keeping track of depth. This
function is used to simplify the iteration code in a lot of other
functions, and is also exported for use by library users.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
This patch adds an fdt_set_name() function to libfdt, mirroring
fdt_get_name(). This is a r/w function which alters the name of a
given device tree node.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
This patch adds more documenting comments to libfdt.h. Specifically,
these document the read/write functions (not including fdt_open_into()
and fdt_pack(), for now).
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
