Messages in this thread | | | Date | Wed, 6 Nov 2013 11:30:41 -0800 | From | Guenter Roeck <> | Subject | Re: [PATCH 0/3 - V2] Introducing Device Tree Overlays |
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On Wed, Nov 06, 2013 at 08:01:52PM +0100, Sebastian Andrzej Siewior wrote: > On 05.11.13, Pantelis Antoniou wrote: > > The following patchset introduces Device Tree overlays, a method > > of dynamically altering the kernel's live Device Tree, along with > > a generic interface to use it in a board agnostic manner. > > In case this has been discussed and I missed it: Why are we doing this? > Isn't it possible to d o the overlay thingy in u-boot and pass a > complete device tree to the kernel? > Are you trying to do something like hotplug-PCI where the PCI card can > be replaced at runtime? >
At least that is our use case. u-boot doesn't know which cards are going to be inserted at runtime. Even PCIe hotplug itself is insufficient, as the PCIe configuration differs per card, and the cards support a variety of i2c devices as well as other card specific devices such LEDs and multi-function FPGAs.
Guenter
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