Currently, callers of fdt_next_tag() must usually follow the call with
some sort of call to fdt_offset_ptr() to verify that the blob isn't
truncated in the middle of the tag data they're going to process.
This is a bit silly, since fdt_next_tag() generally has to call
fdt_offset_ptr() on at least some of the data following the tag for
its own operation.
This patch alters fdt_next_tag() to always use fdt_offset_ptr() to
verify the data between its starting offset and the offset it returns
in nextoffset. This simplifies fdt_get_property() which no longer has
to verify itself that the property data is all present.
At the same time, I neaten and clarify the error handling for
fdt_next_tag(). Previously, fdt_next_tag() could return -1 instead of
a tag value in some circumstances - which almost none of the callers
checked for. Also, fdt_next_tag() could return FDT_END either because
it encountered an FDT_END tag, or because it reached the end of the
structure block - no way was provided to tell between these cases.
With this patch, fdt_next_tag() always returns FDT_END with a negative
value in nextoffset for an error. This means the several places which
loop looking for FDT_END will still work correctly - they only need to
check for errors at the end. The errors which fdt_next_tag() can
report are:
- -FDT_ERR_TRUNCATED if it reached the end of the structure
block instead of finding a tag.
- -FDT_BADSTRUCTURE if a bad tag was encountered, or if the
tag data couldn't be verified with fdt_offset_ptr().
This patch also updates the callers of fdt_next_tag(), where
appropriate, to make use of the new error reporting.
Finally, the prototype for the long gone _fdt_next_tag() is removed
from libfdt_internal.h.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Currently fdt_next_node() will find the next node in the blob
regardless of whether it is above, below or at the same level in the
tree as the starting node - the depth parameter is updated to indicate
which is the case. When a depth parameter is supplied, this patch
makes it instead terminate immediately when it finds the END_NODE tag
for a node at depth 0. In this case it returns the offset immediately
past the END_NODE tag.
This has a couple of advantages. First, this slightly simplifies
fdt_subnode_offset(), which no longer needs to explicitly check that
fdt_next_node()'s iteration hasn't left the starting node. Second,
this allows fdt_next_node() to be used to implement
_fdt_node_end_offset() considerably simplifying the latter function.
The other users of fdt_next_node() either don't need to iterate out of
the starting node, or don't pass a depth parameter at all. Any
callers that really need to iterate out of the starting node, but keep
tracking depth can do so by biasing the initial depth value.
This is a semantic change, but I think it's very unlikely to break any
existing library users.
Signed-off-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>
Build a libfdt shared library in addition to the existing .a that is
created. Symbol versioning is used from the libfdt/version.lds script.
Signed-off-by: Josh Boyer <jwboyer@linux.vnet.ibm.com>
There's currently an off-by-one bug in fdt_subnode_offset_namelen()
which causes it to keep searching after it's finished the subnodes of
the given parent, and into the subnodes of siblings of the original
node which come after it in the tree.
This patch fixes the bug. It also extends the subnode_offset testcase
(updating all of the 'test_tree1' example trees in the process) to
catch it.
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>
The current implementation of fdt_get_path() has a couple of bugs,
fixed by this patch.
First, contrary to its documentation, on success it returns the length
of the node's path, rather than 0. The testcase is correspondingly
wrong, and the patch fixes this as well.
Second, in some circumstances, it will return -FDT_ERR_BADOFFSET
instead of -FDT_ERR_NOSPACE when given insufficient buffer space.
Specifically this happens when there is insufficient space even to
hold the path's second last component. This behaviour is corrected,
and the testcase updated to check it.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
If the path doesn't start with '/' check to see if it matches some alias
under "/aliases" and substitute the matching alias value in the path
and retry the lookup.
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
Acked-by: David Gibson <david@gibson.dropbear.id.au>
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>
In commit b6d80a20fc, we renamed all
libfdt functions to be prefixed with fdt_ or _fdt_ to minimise the
chance of collisions with things from whatever package libfdt is
embedded in, pulled into the libfdt build via that environment's
libfdt_env.h.
Except... I missed one. This patch applies the same treatment to
_stringlist_contains(). While we're at it, also make it static since
it's only used in the same file.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
The definition of LIBFDT_INCLUDES was accidentally dropped.
Put it back and add srcdir prefix handling for it.
Signed-off-by: Jon Loeliger <jdl@freescale.com>
libfdt is supposed to easy to embed in projects all and sundry.
Often, it won't be practical to separate the embedded libfdt's
namespace from that of the surrounding project. Which means there can
be namespace conflicts between even libfdt's internal/static functions
and functions or macros coming from the surrounding project's headers
via libfdt_env.h.
This patch, therefore, renames a bunch of libfdt internal functions
and macros and makes a few other chances to reduce the chances of
namespace collisions with embedding projects. Specifically:
- Internal functions (even static ones) are now named _fdt_*()
- The type and (static) global for the error table in
fdt_strerror() gain an fdt_ prefix
- The unused macro PALIGN is removed
- The memeq and streq macros are removed and open-coded in the
users (they were only used once each)
- Other macros gain an FDT_ prefix
- To save some of the bulk from the previous change, an
FDT_TAGALIGN() macro is introduced, where FDT_TAGALIGN(x) ==
FDT_ALIGN(x, FDT_TAGSIZE)
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 turns on the -Wpointer-arith option in the dtc Makefile,
and fixes the resulting warnings due to using (void *) in pointer
arithmetic. While convenient, pointer arithmetic on void * is not
portable, so it's better that we avoid it, particularly in libfdt.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
I've recently worked with a FreeBSD developer, getting dtc and libfdt
working on FreeBSD. This showed up a number of portability problems
in the dtc package which this patch addresses. Changes are as
follows:
- the parent_offset and supernode_atdepth_offset testcases
used the glibc extension functions strchrnul() and strndupa(). Those
are removed, using slightly longer coding with standard C functions
instead.
- some other testcases had a #define _GNU_SOURCE for no
particular reason. This is removed.
- run_tests.sh has bash specific constructs removed, and the
interpreter changed to /bin/sh. This apparently now runs fine on
FreeBSD's /bin/sh, and I've also tested it with both ash and dash.
- convert-dtsv0-lexer.l has some extra #includes added. These
must have been included indirectly with Linux and glibc, but aren't on
FreeBSD.
- the endian handling functions in libfdt_env.h, based on
endian.h and byteswap.h are replaced with some portable open-coded
versions. Unfortunately, these result in fairly crappy code when
compiled, but as far as I can determine there doesn't seem to be any
POSIX, SUS or de facto standard way of determining endianness at
compile time, nor standard names for byteswapping functions.
- some more endian handling, from testdata.h using the
problematic endian.h is simply removed, since it wasn't actually being
used anyway.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
This patch makes a couple of small cleanups to parameter checking of
libfdt functions.
- In several functions which take a node offset, we use an
idiom involving fdt_next_tag() first to check that we have indeed been
given a node offset. This patch adds a helper function
_fdt_check_node_offset() to encapsulate this usage of fdt_next_tag().
- In fdt_rw.c in several places we have the expanded version
of the RW_CHECK_HEADER() macro for no particular reason. This patch
replaces those instances with an invocation of the macro; that's what
it's for.
- In fdt_sw.c we rename the check_header_sw() function to
sw_check_header() to match the analgous function in fdt_rw.c, and we
provide an SW_CHECK_HEADER() wrapper macro as RW_CHECK_HEADER()
functions in fdt_rw.c
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Currently the Makefile.dtc and Makefile.libfdt fragments include a
number of things that seemed like they might be useful for other
projects embedding the pieces, or for a make dist target.
Well, we have no make dist target, it's become fairly unclear that
these things would actually be useful to embedders (the kernel
certainly doesn't use them), and it's a bunch of stuff with no current
users.
This patch, therefore, removes a bunch of unused definitions from the
Makefile fragments. It also removes a dependency declared in
Makefile.libfdt (of libfdt.a on the constituent .o files) which was
incorrect (wrong path), and if corrected would be redundant with the
similar dependency in the top-level makefile.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Since fdt_node_offset_by_compatible() was converted to the new
fdt_next_node() iterator, a chunk of initialization code became
redundant, but was not removed by oversight. This patch cleans it up.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Currently the CHECK_HEADER() macro is defined local to fdt_ro.c.
However, there are a handful of functions (fdt_move, rw_check_header,
fdt_open_into) from other files which could also use it (currently
they open-code something more-or-less identical). Therefore, this
patch moves CHECK_HEADER() to libfdt_internal.h and uses it in those
places.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
fdt_add_subnode_namelen() has a bug if asked to add a subnode to a
node which has NOP tags interspersed with its properties. In this
case fdt_add_subnode_namelen() will put the new subnode before the
first NOP tag, even if there are properties after it, which will
result in an invalid blob.
This patch fixes the bug, and adds a testcase for it.
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 makes a bunch of updates to the TODO files for dtc and
libfdt, some of them rather overdue.
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>
This patch adds some more documenting comments to libfdt.h.
Specifically this documents all the write-in-place functions.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
This patch adds some options to the run_tests.sh script allowing it to
run all the testcases under valgrind to check for pointer corruption
bugs and memory leaks. Invoking "make checkm" will run the testsuite
with valgrind.
It include a mechanism for specifying valgrind errors to be suppressed
on a per-testcase basis, and adds a couple of such suppression files
for the mangle-layout and open_pack testcases which dump for use by
other testcases a buffer which may contain uninitialized sections. We
use suppressions rather than initializing the buffer so that valgrind
will catch any internal access s to the uninitialized data, which
would be a bug.
The patch also fixes one genuine bug caught by valgrind -
_packblocks() in fdt_rw.c was using memcpy() where it should have been
using memmove().
At present the valgrinding won't do anything useful for testcases
invoked via a shell script - which includes all the dtc testcases. I
plan to fix that later.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
The fdt_offset_ptr_typed() macro seemed like a good idea at the time.
However, it's not actually used all that often, it can silently throw
away const qualifications and it uses a gcc extension (typeof) which
I'd prefer to avoid for portability.
Therefore, this patch gets rid of it (and the fdt_offset_ptr_typed_w()
variant which was never used at all). It also makes a few variables
const in testcases, which always should have been const, but weren't
caught before because of the aforementioned silent discards.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
In a number of places through libfdt and its tests, we have *_typed()
macro variants on functions which use gcc's typeof and statement
expression extensions to allow passing literals where the underlying
function takes a buffer and size.
These seemed like a good idea at the time, but in fact they have some
problems. They use typeof and statement expressions, extensions I'd
prefer to avoid for portability. Plus, they have potential gotchas -
although they'll deal with the size of the thing passed, they won't
deal with other representation issues (like endianness) and results
could be very strange if the type of the expression passed isn't what
you think it is.
In fact, the only users of these _typed() macros were when the value
passed is a single cell (32-bit integer). Therefore, this patch
removes all these _typed() macros and replaces them with explicit
_cell() variants which handle a single 32-bit integer, and which also
perform endian convesions as appropriate.
With this in place, it now becomes easy to use standardized big-endian
representation for integer valued properties in the testcases,
regardless of the platform we're running on. We therefore do that,
which has the additional advantage that all the example trees created
during a test run are now byte-for-byte identical regardless of
platform.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
This patch adds fdt_get_phandle() and fdt_node_offset_by_phandle()
functions to libfdt. fdt_get_phandle() will retreive the phandle
value of a given node, and fdt_node_offset_by_phandle() will locate a
node given a phandle.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
This patch documents a few more functions in libfdt.h. All the
read-only functions are now documented.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
This patch documents a few more functions in libfdt.h. It also makes
a slight update to the description of the FDT_ERR_INTERNAL error code.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
libfdt: Add more documentation (patch the third)
This patch adds documentation in libfdt.h for a few more libfdt
functions. It also makes a slight update to the documentation of
fdt_get_name().
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Currently all the read/write functions in libfdt require that the
given tree be v17, and further, that the tree has the memory
reservation block, structure block and strings block stored in that
physical order.
This patch eases these constraints, by making fdt_open_int() reorder
the blocks, and/or convert the tree to v17, so that it will then be
ready for the other read-write functions.
It also extends fdt_pack() to actually remove any gaps between blocks
that might be present.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
If future dtb version > 17 are defined, that are still backwards
compatible with v16, libfdt will of course be able to read and
understand them. However, when modifying such a tree, it can't
guarantee that it won't clobber additional structure from the new
version which it doesn't know about. Therefore, before making
modifications to a tree of version >17, we must change it's version to
be exactly 17.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
The fdt_set_header() macro casts an arbitrary pointer into (struct
fdt_header *) to set fdt header fields. While we need to change the
type, so that we can use this macro on the usual (void *) used to
represent a device tree blob, the current macro also casts away any
const on the input pointer, which loses an important check.
This patch replaces the fdt_set_header() macro with a set of inline
functions, one for each header field which do a similar thing, but
which won't silently remove const from a given pointer. This approach
is also more in keeping with the individual accessor macros we use for
reading fdt header fields.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
This patch adds some internal documentation in libfdt.h, in the form
of comments on the error codes and some functions. Only a couple of
functions are covered so far, leaving the documentation still woefully
inadequate, but hey, it's a start.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Although it's a low-level function that shouldn't normally be needed,
there are circumstances where it's useful for users of libfdt to use
the _fdt_next_tag() function. Therefore, this patch renames it to
fdt_next_tag() and publishes it in libfdt.h.
In addition, this patch adds a new testcase using fdt_next_tag(),
dtbs_equal_ordered. This testcase tests for structural equality of
two dtbs, including the order of properties and subnodes, but ignoring
NOP tags, the order of the dtb sections and the layout of strings in
the strings block. This will be useful for testing other dtc
functionality in the future.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
It's potentially useful for users of libfdt to sanity check a device
tree (or, rather, a blob of data which may or may not be a device
tree) before processing it in more detail with libfdt.
This patch renames the libfdt internal function _fdt_check_header() to
fdt_check_header() and makes it a published function, so it can now be
used for this purpose.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
fdt_del_node(), unlike most of the rw functions does not check the
fdt's header with RW_CHECK_HEADER. However, it could make a mess of
things if the conditions in RW_CHECK_HEADER aren't met. So, this
patch adds the omitted check.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Currently, fdt_string() returns a (non-const) char *, despite taking a
const void *fdt. This is inconsistent with all the other read-only
functions which all return const pointers into the blob.
This patch fixes that.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
This patch adds functions for dealing with the compatible property.
fdt_node_check_compatible() can be used to determine whether a node is
compatible with a given string and fdt_node_offset_by_compatible()
locates nodes with a given compatible string.
Testcases for these functions are also included.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
libfdt.h currently includes fdt.h, then libfdt_env.h. This is
incorrect, because depending on the environment into which libfdt is
embedded, libfdt_env.h may be needed to define datatypes used in
fdt.h. This patch corrects the problem.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
This patch adds functions to libfdt for accessing the memory
reservation map section of a device tree blob. fdt_num_mem_rsv()
retreives the number of reservation entries in a dtb, and
fdt_get_mem_rsv() retreives a specific reservation entry.
fdt_add_mem_rsv() adds a new entry, and fdt_del_mem_rsv() removes a
specific numbered entry.
Testcases for these new functions are also included.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
This patch makes a number of Makefile cleanups and improvements:
- We use more generic rules to invoke flex and bison, which is
useful for some of the other changes.
- We use the name dtc-lexer.lex.c for the flex output, instead
of the default lex.yy.c. That means less potential for confusion if
dtc is embedded into other projects (e.g. the kernel).
- We separate out a Makefile.dtc designed for embedding into
other projects, analagous to Makefile.libfdt.
- Makefile.libfdt is cleaned up to be more useful based on
some actual trial runs of embedding libfdt in the kernel bootwrapper.
- Versioning related rules and variables are collected into
one place in the Makefile.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
At present, the fdt_subnode_offset() and fdt_path_offset() functions
in libfdt require the exact name of the nodes in question be passed,
including unit address.
This is contrary to traditional OF-like finddevice() behaviour, which
allows the unit address to be omitted (which is useful when the device
name is unambiguous without the address).
This patch introduces similar behaviour to
fdt_subnode_offset_namelen(), and hence to fdt_subnode_offset() and
fdt_path_offset() which are implemented in terms of the former. The
unit address can be omitted from the given node name. If this is
ambiguous, the first such node in the flattened tree will be selected
(this behaviour is consistent with IEEE1275 which specifies only that
an arbitrary node matching the given information be selected).
This very small change is then followed by many more diffs which
change the test examples and testcases to exercise this behaviour.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
David Gibson