Messages in this thread | | | Date | Fri, 15 May 2009 10:36:19 -0500 | From | Scott Wood <> | Subject | Re: [PATCH] [PowerPC] MPC8272ADS: fix device tree for 8 MB flash, size |
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On Fri, May 15, 2009 at 07:54:51AM +0200, Heiko Schocher wrote: > Scott Wood wrote: > > We should proabbly leave out the ranges altogether, and have u-boot > > populate it from the mappings it establishes. > > No, I vote for manipulating just the entries, which u-boot dynamically > detect, and let the other entries untouched. It is possible that > there is a device which u-boot didn;t use/know, and there is in the DTS > an ranges entry for it (Maybe not on the MPC8727ADS, but we should > define a rule, how a bootloader has to manipulate entries). So if > u-boot build the complete ranges entry, it maybe miss something.
If u-boot doesn't know about it, then it didn't create the mapping, and thus it's not accessible (if something later on creates a mapping, it can update ranges itself). The devices themselves would still be described, just not the non-existent mapping.
The benefit is that you would have just one place that reads out the localbus config into the device tree, with no error-prone duplication of data, or separate hacks for each board that has something that is variable.
We could leave ranges in the dts for cuImage, and have u-boot just overwrite the entire thing rather than patch up individual entries.
> > I don't see how current u-boot would accomodate more than 8MiB flash on > > this board (there's some detection in board/freescale/mpc8260ads/flash.c, > > Didn;t this board uses the CFI driver? :-(
Not yet, unfortunately. This is pretty old code.
-Scott
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