Looking at the Kernel memory layout for ARM Linux, I can see that virtual address 0xffff1000 – 0xffff7fff is “Reserved. Platforms must not use this address range”. I can’t seem to find any documentation or anything in the source.
I am doing some experiments on the Linux kernel 2.6 where I want it to run on top of a hypervisor.
I was thinking that the hypervisor could get the virtual address space from 0xfff00000 – 0xffffffff on the Integrator CP ARM platform. Does anyone know if these addresses can be used? It seems that the high virtual addresses are for specific platforms like XScale and other stuff that I’m not using. The Cpu vector page still gets 0xffff0000.
The memory layout is available here http://www.kernel.org/doc/Documentation/arm/memory.txt
I e-mailed Russell King, the maintainer of that document. He replied that it’s reserved for usage of the ARM MM layer (even on architectures without VIPT caches), and not to use it.