Hi Tom, On 18 April 2017 at 10:33, Tom Rini <tr...@konsulko.com> wrote: > On Tue, Apr 18, 2017 at 10:27:37AM -0600, Simon Glass wrote: >> Hi Tom, >> >> On 18 April 2017 at 10:25, Tom Rini <tr...@konsulko.com> wrote: >> > >> > On Sun, Apr 16, 2017 at 08:22:14PM -0600, Simon Glass wrote: >> > >> > > Python libfdt bindings have recently been accepted upstream. While the >> > > internals have changed a fair bit most of the API remains the same. >> > > Still, >> > > a few functions are different from how they are used in U-Boot so changes >> > > are needed to make this work. >> > > >> > > At present in U-Boot there are two libraries for accessing a device tree >> > > file: >> > > >> > > - FdtNormal which uses U-Boot's own Python bindings >> > > - FdtFallback which uses the fdtget command-line utility >> > > >> > > The latter is not a great solution: it is fairly slow since the DT is >> > > re-read for every access and it cannot provide DT offsets or packing of >> > > the DT. >> > > >> > > In addition, U-Boot now builds the libfdt module if swig is available, >> > > meaning that the fallback module is not used in that case. >> > > >> > > Finally, at some point in the future distributions may start packaging >> > > the >> > > libfdt Python module and it will be available without U-Boot needing to >> > > build it itself. >> > > >> > > Therefore it seems like a good idea to take this opportunity to drop the >> > > fallback module and just require that the Python libfdt bindings be >> > > present (at least if need by the build). >> > > >> > > The bindings are needed in two situations: >> > > - When dtoc is used to convert a device tree into C code. This is enabled >> > > by CONFIG_SPL_OF_PLATDATA >> > > - When binman is used to produce a firmware image. This is used on all >> > > x86 >> > > and sunxi boards at present >> > > >> > > This series: >> > > - Plumbs in building the Python libfdt module to the U-Boot build system >> > > - Ensures that the module is always built if needed, print an error if >> > > swig is not available (and thus the module cannot be built) >> > > - Allows use of a libfdt.py module already installed on the machine >> > > - Drops the FdtFallback support >> > > - Moves fdt.h and libfdt.h into lib/libfdt to aid with syncing with >> > > upstream, building the Python bindings and to keep the code together >> > > - Merges Fdt and FdtNormal to simplify the code >> > > - Adjusts the Fdt library to work with the new libfdt module >> > > - Adds a few more tests to check access to properties in the DT >> > > - Adjusts binman and dtoc to work with the new approach >> > > >> > > It should be possible to easily sync libfdt's Python bindings with U-Boot >> > > in the future, as development there proceeds. >> > >> > While this came in late, my gut feeling is that it would be best to have >> > this change in the next release (so that various upstreams can get used >> > to the idea of basically always needing python installed to build). >> >> I'm a little worried that it might cause problems. I made it so that >> it only *requires* python if is it actually needed, though it always >> builds libfdt.py if it can. Or perhaps that is what you are saying, >> that the only way to flush out upstream issues is to apply it? > > What I'm saying is that distros (Fedora, openSUSE, OpenEmbedded) are > going to make a blanket change (if they haven't already) to say that > building U-Boot requires python to be installed (since they aren't > likely to try and optimize it on a board-by-board basis when it's "easy" > to just say it's an always dependency). If you think there's risk with > the change itself, we can wait a release, that's fine too. Thanks!
I see. I'm not sure what is best. I checked for build errors and added some more tests so I'm fairly confident. But it is late (sorry, it was more work than I expected). I'll leave this up to you. > > -- > Tom Regards, Simon _______________________________________________ U-Boot mailing list U-Boot@lists.denx.de https://lists.denx.de/listinfo/u-boot
