Residual data is useful for things like finding the memory size, and for
chips designed inside Apple. For almost everything else Linux already
contains a device tree, built by PCI probing when the kernel boots^*. I
don't see much need for a parallel, architecture specific, device tree.
In the case of Apple HW, the OF device tree is the only way to know about:
- Interrupt routing & sense type (level/edge)
- Machine model (for the machine device-specific stuffs we have)
- Bits inside Apple ASICs (we could hard code everything, but that doesn't
sound like a good idea, and the device tree also provide things like the
MAC address of the eth chip)
- Firmware boot path (to setup the OF boot and configure the bootloader)
- PCI hierarchy with the Uni-N chip
- Memory size (of course)
- What else did I forget ?
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