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>
libfdt_env.h in the device tree compiler currently defines a _B() macro. This is in the
namespace reserved for the implementation, and Cygwin's ctype.h actually defines a macro
with this name. This renames _B to EXTRACT_BYTE.
Signed-off-by: Bert Kenward <bert.kenward@broadcom.com>
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>
This utility routine will be used in the variable size cell literal
append code. It is a straightforward adaptation of the fdt32_to_cpu
function.
Signed-off-by: Anton Staaf <robotboy@chromium.org>
Acked-by: David Gibson <david@gibson.dropbear.id.au>
The libfdt shared library is only installed by its unversioned name.
Including it properly in a distribution requires installation of both
the versioned name (used in the binary-only package) and the unversioned
name (used in the development package). The latter is just a symbolic
link, so you need to change the soname in turn to include the version.
While at it, use Makefile variables to shorten some lines and avoid
cut-and-paste typos; and clean up remnants of when shared libraries were
not supported on Darwin.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.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>
Currently, the Linux kernel, libfdt and dtc, when using flattened
device trees encode a node's phandle into a property named
"linux,phandle". The ePAPR specification, however - aiming as it is
to not be a Linux specific spec - requires that phandles be encoded in
a property named simply "phandle".
This patch adds support for this newer approach to dtc and libfdt.
Specifically:
- fdt_get_phandle() will now return the correct phandle if it
is supplied in either of these properties
- fdt_node_offset_by_phandle() will correctly find a node with
the given phandle encoded in either property.
- By default, when auto-generating phandles, dtc will encode
it into both properties for maximum compatibility. A new -H
option allows either only old-style or only new-style
properties to be generated.
- If phandle properties are explicitly supplied in the dts
file, dtc will not auto-generate ones in the alternate format.
- If both properties are supplied, dtc will check that they
have the same value.
- Some existing testcases are updated to use a mix of old and
new-style phandles, partially testing the changes.
- A new phandle_format test further tests the libfdt support,
and the -H option.
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>
.../dtc/libfdt/fdt_sw.c: In function 'fdt_end_node':
.../dtc/libfdt/fdt_sw.c:81: error: assuming signed overflow does not occur when assuming that (X + c) < X is always false
Signed-off-by: Emil Medve <Emilian.Medve@Freescale.com>
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>
David Gibson