l4sigma0_map_iomem Allowed Addresses

Adam Lackorzynski adam at os.inf.tu-dresden.de
Sun Oct 2 23:02:44 CEST 2011


On Thu Sep 29, 2011 at 15:34:38 -0700, Wesley Miaw wrote:
> I'm having some trouble understanding the acceptable values usable in a
> call to l4sigma0_map_iomem. It looks like the way for me to request a map
> from an available physical address block to a virtual memory address that
> can be used by the program. Perhaps I am lacking a more fundamental
> understanding of the ARM memory model.
> 
> But what addresses should be allowed? My Verstaile Express board has 1GB
> RAM starting at physical address 0x60000000 but I can't use this address.
> I immediately get an error. I also tried starting at 0x80000000. (The L4
> Bootloader seems to be using memory at 0x60000000 for its own purposes
> anyway.)
> 
> Error: Cannot map physical memory: (-2147451404) No fpage received
> 
> If I try to get size 0x04000000 from address 0x08000000 it works fine. I
> am going off the memory map of the CoreTile A9x4.

l4sigma0_map_iomem is used to map IO-mem, i.e. non-RAM. For RAM
(0x60000000-0x9fffffff) use l4sigma0_map_anypage()/l4sigma0_map_mem().


Adam
-- 
Adam                 adam at os.inf.tu-dresden.de
  Lackorzynski         http://os.inf.tu-dresden.de/~adam/




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