No description
d75b33af67
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>
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|---|---|---|
| Documentation | ||
| libfdt | ||
| scripts | ||
| tests | ||
| .gitignore | ||
| checks.c | ||
| convert-dtsv0-lexer.l | ||
| data.c | ||
| dtc-lexer.l | ||
| dtc-parser.y | ||
| dtc.c | ||
| dtc.h | ||
| flattree.c | ||
| fstree.c | ||
| ftdump.c | ||
| GPL | ||
| livetree.c | ||
| Makefile | ||
| Makefile.convert-dtsv0 | ||
| Makefile.dtc | ||
| Makefile.ftdump | ||
| README.license | ||
| srcpos.c | ||
| srcpos.h | ||
| TODO | ||
| treesource.c | ||
| util.c | ||
| util.h | ||
Licensing and contribution policy of dtc and libfdt =================================================== This dtc package contains two pieces of software: dtc itself, and libfdt which comprises the files in the libfdt/ subdirectory. These two pieces of software, although closely related, are quite distinct. dtc does not incoporate or rely on libfdt for its operation, nor vice versa. It is important that these two pieces of software have different license conditions. As the copyright banners in each source file attest, dtc is licensed under the GNU GPL. The full text of the GPL can be found in the file entitled 'GPL' which should be included in this package. dtc code, therefore, may not be incorporated into works which do not have a GPL compatible license. libfdt, however, is GPL/BSD dual-licensed. That is, it may be used either under the terms of the GPL, or under the terms of the 2-clause BSD license (aka the ISC license). The full terms of that license are given in the copyright banners of each of the libfdt source files. This is, in practice, equivalent to being BSD licensed, since the terms of the BSD license are strictly more permissive than the GPL. I made the decision to license libfdt in this way because I want to encourage widespread and correct usage of flattened device trees, including by proprietary or otherwise GPL-incompatible firmware or tools. Allowing libfdt to be used under the terms of the BSD license makes that it easier for vendors or authors of such software to do so. This does mean that libfdt code could be "stolen" - say, included in a proprietary fimware and extended without contributing those extensions back to the libfdt mainline. While I hope that doesn't happen, I believe the goal of allowing libfdt to be widely used is more important than avoiding that. libfdt is quite small, and hardly rocket science; so the incentive for such impolite behaviour is small, and the inconvenience caused therby is not dire. Licenses such as the LGPL which would allow code to be used in non-GPL software, but also require contributions to be returned were considered. However, libfdt is designed to be used in firmwares and other environments with unusual technical constraints. It's difficult to anticipate all possible changes which might be needed to meld libfdt into such environments and so difficult to suitably word a license that puts the boundary between what is and isn't permitted in the intended place. Again, I judged encouraging widespread use of libfdt by keeping the license terms simple and familiar to be the more important goal. **IMPORTANT** It's intended that all of libfdt as released remain permissively licensed this way. Therefore only contributions which are released under these terms can be merged into the libfdt mainline. David Gibson <david@gibson.dropbear.id.au> (principal original author of dtc and libfdt) 2 November 2007