According to the documentation, the function should default to the very
common property name <reg> when none is "specified". However, neither
passing NULL (ends up calling strlen(NULL) and segfaults) nor ""
(appends a property with an empty name) implements this behavior.
Furthermore, the test case supposed to cover this default value actually
passes the value to the function, somewhat defeating its own purpose:
/* 2. default property name */
// ...
err = fdt_appendprop_addrrange(fdt, 0, offset, "reg", addr, size);
if (err)
FAIL("Failed to set \"reg\": %s", fdt_strerror(err));
check_getprop_addrrange(fdt, 0, offset, "reg", 1);
Finally, nothing in the implementation of the function seems to attempt
to cover that use-case.
As the feature can't ever have been used by clients and as the resulting
reduced readability of the caller seems (IMO) to outweigh any potential
benefit this API would bring, remove the erroneous documentation instead
of trying to fix the function.
Reported-by: Mostafa Saleh <smostafa@google.com>
Signed-off-by: Pierre-Clément Tosi <ptosi@google.com>
Message-ID: <20230831123918.rf54emwkzgtcb7aw@google.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
The function mentioned in the comment, fdt_finished(), should be
changed to fdt_finish().
Signed-off-by: Yan-Jie Wang <yanjiewtw@gmail.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
The current documentation doesn't mention the possibility of passing a
non-absolute path and having that treated as an alias. Add that
information, along with an example (which will further be expanded in
a subsequent patch), and clarify when -FDT_ERR_BADPATH can be returned.
Signed-off-by: Rasmus Villemoes <rasmus.villemoes@prevas.dk>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
The fdt_get_symbol_namelen() function will be used in a subsequent
patch.
Signed-off-by: Rasmus Villemoes <rasmus.villemoes@prevas.dk>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Add a new fdt_get_property_by_offset_w helper function.
It is a wrapper on fdt_get_property_by_offset that returns
a writable pointer to a property at a given offset.
Signed-off-by: Tadeusz Struk <tadeusz.struk@linaro.org>
Message-Id: <20221011182611.116011-1-tadeusz.struk@linaro.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
This is done to get the target path for the overlay nodes which is very useful
in many cases. For example, Xen hypervisor needs it when applying overlays
because Xen needs to do further processing of the overlay nodes, e.g. mapping of
resources(IRQs and IOMMUs) to other VMs, creation of SMMU pagetables, etc.
Signed-off-by: Vikram Garhwal <fnu.vikram@xilinx.com>
Message-Id: <1637204036-382159-2-git-send-email-fnu.vikram@xilinx.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
With -Wsign-compare, compilers warn about a mismatching signedness in
the different legs of the conditional operator, in fdtget.c.
In the questionable expression, we are constructing a 16-bit value out of
two unsigned 8-bit values, however are relying on the compiler's
automatic expansion of the uint8_t to a larger type, to survive the left
shift. This larger type happens to be an "int", so this part of the
expression becomes signed.
Fix this by explicitly blowing up the uint8_t to a larger *unsigned* type,
before doing the left shift. And while we are at it, convert the hardly
readable conditional operator usage into a sane switch/case expression.
This fixes "make fdtget", when compiled with -Wsign-compare.
Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Message-Id: <20210618172030.9684-3-andre.przywara@arm.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Changes in v3:
- Remove noop version sets
- Set version correctly on loaded fdt in fdt_open_into
Fixes: f1879e1a50 ("Add limited read-only support for older (V2 and V3) device tree to libfdt.")
Signed-off-by: Justin Covell <jujugoboom@gmail.com>
Message-Id: <20201229041749.2187-1-jujugoboom@gmail.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Commits 6dcb8ba4 "libfdt: Add helpers for accessing unaligned words"
introduced changes to support unaligned reads for ARM platforms and
11738cf01f "libfdt: Don't use memcpy to handle unaligned reads on ARM"
improved the performance of these helpers.
On further discussion, while there are potential cases where we could be
used on platforms that do not fixup unaligned reads for us, making this
choice the default is very expensive in terms of binary size and access
time. To address this, introduce and use new fdt{32,64}_ld_ functions
that call fdt{32,64}_to_cpu() as was done prior to the above mentioned
commits. Leave the existing load functions as unaligned-safe and
include comments in both cases.
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Tom Rini <trini@konsulko.com>
Message-Id: <20201211022736.31657-1-trini@konsulko.com>
Tested-by: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
The device tree must be loaded in to memory at an 8-byte aligned
address. Add a check for this condition in fdt_ro_probe_() and a new
error code to return if we are not.
Signed-off-by: Tom Rini <trini@konsulko.com>
Message-Id: <20201104130605.28874-1-trini@konsulko.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
The API documentation in libfdt.h seems to follow the Linux kernel's
kernel-doc format[1].
Running "scripts/kernel-doc -v -none" on the file reports some problems,
mostly missing return values and missing parameter descriptions.
Fix those up by providing the missing bits, and fixing the other small
issues reported by the script.
Signed-off-by: Andre Przywara <andre.przywara@arm.com>
[1] https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/Documentation/doc-guide/kernel-doc.rst
Message-Id: <20201012165331.25016-1-andre.przywara@arm.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Patrick Oppenlander <patrick.oppenlander@gmail.com>
Message-Id: <20200616011217.15253-1-patrick.oppenlander@gmail.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
There does not seem to be a strong reason to inline this function. Also
we are about to add some extra code to it which will increase its size.
Move it into fdt.c and use a simple declaration in libfdt.h
Signed-off-by: Simon Glass <sjg@chromium.org>
Message-Id: <20200220214557.176528-2-sjg@chromium.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Including libfdt.h in a C++ project fails during compilation with recent
version of GCC or Clang.
This simple example:
extern "C" {
#include <libfdt.h>
}
int main(void) { return 0; }
leads to the following errors with GCC 9.1.0:
/usr/include/libfdt.h: In function ‘void fdt32_st(void*, uint32_t)’:
/usr/include/libfdt.h:139:16: error: invalid conversion from ‘void*’ to ‘uint8_t*’ {aka ‘unsigned char*’} [-fpermissive]
139 | uint8_t *bp = property;
| ^~~~~~~~
| |
| void*
/usr/include/libfdt.h: In function ‘void fdt64_st(void*, uint64_t)’:
/usr/include/libfdt.h:163:16: error: invalid conversion from ‘void*’ to ‘uint8_t*’ {aka ‘unsigned char*’} [-fpermissive]
163 | uint8_t *bp = property;
| ^~~~~~~~
| |
| void*
This commit adds an explicit cast to uint8_t* to fix this issue.
Signed-off-by: Luc Michel <luc.michel@greensocs.com>
Message-Id: <20190910104824.1321594-1-luc.michel@greensocs.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Replace instances of dual GPLv2 or BSD license boilerplate with SPDX tags.
Signed-off-by: Rob Herring <robh@kernel.org>
Message-Id: <20190620211944.9378-3-robh@kernel.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Searching for duplicate names scales O(n^2) with the number of names
added to a fdt, which can cause a noticable slowdown with larger device
trees and very slow CPU cores.
Add FDT_CREATE_FLAG_NO_NAME_DEDUP that allow the caller to trade fdt size
for speed in the creation process.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Message-Id: <20190509094122.834-4-npiggin@gmail.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
There is a need to be able to specify some options when building an FDT
with the SW interface. This can be accomplished with minimal changes by
storing intermediate data in the fdt header itself, in fields that are
not otherwise needed during the creation process and can be set by
fdt_finish().
The fdt.magic field is already used exactly this way, as a state to
check with callers that the FDT has been created but not yet finished.
fdt.version and fdt.last_comp_version are used to make room for more
intermediate state. These are adjacent and unused during the building
process. last_comp_version is not yet used for intermediate state, but
it is zeroed and treated as used, so as to allow future growth easily.
A new interface, fdt_create_with_flags() is added, which takes 32-bit
flag value to control creation.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Message-Id: <20190509094122.834-3-npiggin@gmail.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
It's now a trivial wrapper around fdt_find_max_phandle() so we might as
well inline it. We also remove it from the versioning linker script.
Theoretically, that's a breaking ABI change except that we haven't yet
released a version with it exposed in the shared object, so we can get
away with it.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
The new fdt_generate_phandle() function can be used to generate a new,
unused phandle given a specific device tree blob. The implementation is
somewhat naive in that it simply walks the entire device tree to find
the highest phandle value and then returns a phandle value one higher
than that. A more clever implementation might try to find holes in the
current set of phandle values and fill them. But this implementation is
relatively simple and works reliably.
Also add a test that validates that phandles generated by this new API
are indeed unique.
Signed-off-by: Thierry Reding <treding@nvidia.com>
Message-Id: <20190326153302.17109-3-thierry.reding@gmail.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
The fdt_get_max_phandle() function has some shortcomings. On one hand
it returns just a uint32_t which means to check for the "negative"
error code a caller has to explicitly check against the error code
(uint32_t)-1. In addition, the -1 is the only error code that can be
returned, so a caller cannot tell the difference between the various
failures.
Fix this by adding a new fdt_find_max_phandle() function that returns an
error code on failure and 0 on success, just like other APIs, and stores
the maximum phandle value in an output argument on success.
This also refactors fdt_get_max_phandle() to use the new function. Add a
note pointing out that the new fdt_find_max_phandle() function should be
preferred over fdt_get_max_phandle().
Signed-off-by: Thierry Reding <treding@nvidia.com>
Message-Id: <20190326153302.17109-1-thierry.reding@gmail.com>
[dwg: Reword for some inaccuracies in the commit message]
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
This function will append an address range property using parent node's
"#address-cells" and "#size-cells" properties.
It will be used in implementing kdump with kexec_file_load system call
at linux kernel for arm64 once it is merged into kernel tree.
Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org>
Message-Id: <20190327061552.17170-2-takahiro.akashi@linaro.org>
[dwg: Correct a SEGV error in the testcase]
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
The new fdt_generate_phandle() function can be used to generate a new,
unused phandle given a specific device tree blob. The implementation is
somewhat naive in that it simply walks the entire device tree to find
the highest phandle value and then returns a phandle value one higher
than that. A more clever implementation might try to find holes in the
current set of phandle values and fill them. But this implementation is
relatively simple and works reliably.
Also add a test that validates that phandles generated by this new API
are indeed unique.
Signed-off-by: Thierry Reding <treding@nvidia.com>
Message-Id: <20190320151003.28941-1-thierry.reding@gmail.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
The actual error is FDT_ERR_NOTFOUND, not FDT_ERR_NOT_FOUND.
Fixes: d29126c90a ("libfdt: Add iterator over properties")
Fixes: 902d0f0953 ("libfdt: Add a subnodes iterator macro")
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
The second parameter of fdt_getprop_by_offset() is called "offset", not
"ffset".
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
6dcb8ba4 "libfdt: Add helpers for accessing unaligned words" introduced
the fdt32_ld() and fdt64_ld() helpers for loading values from the FDT blob
which might not be naturally aligned. This matters for ARM, where
attempting a plain unaligned load will often cause an exception.
However, it seems the memcpy() we used here was surprisingly expensive,
making libfdt nearly 6x slower on at least some ARM platforms.
This patch takes an alternative approach, using a bunch of 1-byte loads
and shifts to implement the helpers.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
According to the device tree specification, the default value for
#size-cells is 1, but fdt_size_cells() was returning 2 if this property
was not present.
This patch also makes fdt_address_cells() and fdt_size_cells() conform
to the behaviour documented in libfdt.h. The defaults are only returned
if fdt_getprop() returns -FDT_ERR_NOTFOUND, otherwise the actual error
is returned.
Signed-off-by: John Clarke <johnc@kirriwa.net>
Add internal fdt_cells() to avoid copy and paste. Test error cases and
default values. Fix typo in fdt_size_cells() documentation comment.
Signed-off-by: Sebastian Huber <sebastian.huber@embedded-brains.de>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
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>
Pierre-Clément Tosi