Messages in this thread | | | Date | Fri, 26 Jul 2013 09:47:20 -0400 | From | Jason Cooper <> | Subject | Re: [Ksummit-2013-discuss] DT bindings as ABI [was: Do we have people interested in device tree janitoring / cleanup?] |
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On Fri, Jul 26, 2013 at 02:41:10PM +0100, David Woodhouse wrote: > On Fri, 2013-07-26 at 09:27 -0400, Jason Cooper wrote: > > > > The other dynamic change that bears mentioning here is attributes which > > have been configured by the bootloader. For example, in mvebu, we have > > the Schrodinger's Cat register. It allows you to reconfigure the base > > address of the registers from *within* that register range. If the > > bootloader does this, the DT needs to be updated to reflect the current > > hardware configuration. Otherwise, the kernel is stuck poking around at > > memory addresses hoping to find something sane. > > > > But this falls into the same category as you mentioned, but outside of > > chosen {};. > > Yeah, /chosen was given as an example of stuff that's almost > *exclusively* "configuration" stuff. > > But there's plenty outside there that can reasonably change. > > It's OK to change the data, and of *course* the base address reported in > the DT should actually match reality *today*, if it changes on the fly. > > It's not OK to change the *schema* in which those data are expressed. > That's the ABI we're talking about.
Agreed, much more clear than what I was saying.
thx,
Jason.
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