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>
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>
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>
There is a bug in the sw_tree1 testcase / utility which puts two
"compatible" properties in one node in the output tree. This patch
fixes the bug, and also adds a new test checking that the sw_tree1
output is equal to test_tree1.dtb as its supposed to be, which should
catch future errors of this type.
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>
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>
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>
At present fdt.h #includes stdint.h. This makes some sense, because fdt.h
uses the standard fixed-width integer types. However, this can make life
difficult when building in different environments which may not have a
stdint.h. Therefore, this patch removes the #include from fdt.h, instead
requiring that users of fdt.h define the fixed-width integer types before
including fdt.h, either by themselves including stdint.h, or by any other
means.
At present, the blob containing a device tree is passed to the various
fdt_*() functions as a (struct fdt_header *) i.e. a pointer to the
header structure at the beginning of the blob.
This patch changes all the functions so that they instead take a (void
*) pointing to the blob. Under some circumstances can avoid the need
for the caller to cast a blob pointer into a (struct fdt_header *)
before passing it to the fdt_*() functions.
Using a (void *) also reduce the temptation for users of the library
to directly dereference toe (struct fdt_header *) to access header
fields. Instead they must use the fdt_get_header() or
fdt_set_header() macros, or the fdt_magic(), fdt_totalsize()
etc. wrappers around them which are safer, since they will always
handle endian conversion.
With this change, the whole-tree moving, or manipulating functions:
fdt_move(), fdt_open_into() and fdt_pack() no longer need to return a
pointer to the "new" tree. The given (void *) buffer pointer they
take can instead be used directly by the caller as the new tree.
Those functions are thus changed to instead return an error code
(which in turn reduces the number of functions using the ugly encoding
of error values into pointers).
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
David Gibson