Hi Prabhu, On Tue, Jul 10, 2012 at 6:56 AM, Prabhu nath <gprabhunath@xxxxxxxxx> wrote: > For E.g. I have a device whose physical address range is 0x80008000 to > 0x80008FFF. > Is it possible to map this device physical address to a known > virtual address range 0xF0008000 to 0xF0008FFF. I don't think this is possible, because these virtual address ranges are handled by the kernel VMA system and are allocated dynamically, so that is not just a bitmask or something to change. > My hardware configuration has 128 MB of system RAM which will have been > MAPPED to the Kernel virtual address from 0xC0000000 to 0xC7FFFFFF > > Also is it possible to configure the vmalloc kernel virtual address region > to a fixed range of 128 MB from 0xC8000000 to 0xCFFFFFFF You could change PAGE_OFFSET. From [1]: PHYS_OFFSET Physical start address of the first bank of RAM. PAGE_OFFSET Virtual start address of the first bank of RAM. During the kernel boot phase, virtual address PAGE_OFFSET will be mapped to physical address PHYS_OFFSET, along with any other mappings you supply. This should be the same value as TASK_SIZE. But I'm curious: Why do you want to change it? Greetings, Philipp [1]: http://www.kernelport.org/defines.html _______________________________________________ Kernelnewbies mailing list Kernelnewbies@xxxxxxxxxxxxxxxxx http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
