On Tue, Sep 20, 2011 at 11:58 AM, Grant Likely <[email protected]> wrote: > On Tue, Sep 20, 2011 at 05:31:52PM +0000, Cohen, Eugene wrote: >> [sorry if this is the wrong list, please direct me to the right one as >> needed] >> >> I'm trying to get my head wrapped around FDT to understand how UEFI firmware >> can produce this (and possibly use it internally) and pass it to the OS. >> >> I've been trying to find the authoritative specification describing >> DT and FDT. My experience searching resulted in a lot of dead >> links. Is the spec the ePAPR specification? How does this >> specification get updated to provide compatibility or enhancements >> that the current spec does not address like ARM architecture >> additions? > > ePAPR is definitely the starting place. power.org is responsible for > the spec, and they released version 1.1 earlier this year. It does a > good job of capturing all the important information from the old Open > Firmware IEEE specification in a single document. > > However, as you point out it is focused on the power architecture. > There aren't any ARM bindings described in it. For specific bindings, > and for extensions to the spec, you actually need to go and look in > the Documentation/devicetree/ directory in the Linux kernel source. > This is *temporary* though. All of that documentation will be split > out into a completely independent repository in the very near future > (in a few weeks). The only reason it was in with the kernel source is > that the Linux kernel is where most of the development focus has been, > so it happened to be convenient. > >> Also is there a central registry, if any, of strings for vendors or >> compatible hardware? For example if I have a property 'compatible = >> "hp,widget123";' who determines whether 'hp' standard for >> Hewlett-Packard or Henry's Pickles? Along the same lines if there >> is a standard interface like a "gic" where is the spec/document >> describing what a "gic" is and how is it updated? > > It will be in the same documentation repository; There isn't currently > a single file listing all the prefixes, but it can be easily added.
Update on this; There is now a vendor prefix file that is in my devicetree/next branch which will be merged in the LInux v3.2 merge window. g. _______________________________________________ boot-architecture mailing list [email protected] http://lists.linaro.org/mailman/listinfo/boot-architecture
