On Wed, Jan 21, 2004 at 03:58:24PM -0600, Nils Larson wrote: > Hi, > We currently have a mips platform running Linux with 256MB of > RAM starting at 0x8000_0000. We would like to add an additional > 1GB of RAM, maybe starting at 0x4000_0000, that would be used > for user apps (user virtual memory). The memory map is: > 0x8000_0000 - 256MB RAM > 0xA000_0000 - uncached version of the same 256MB > 0xB000_0000 - PCI memory windows. > This is a diskless setup booting from a ramdisk. > So, the (sort of newbie) questions are: > 1. How do we tell Linux to use the new memory? > 2. Is this feasible? > 3. Is there a better way to add more memory? > We need more space for user data. > Thanks, > Nils > People have done this before in 2.4 with CONFIG_HIGHMEM. See arch/mips/sibyte/cfe/setup.c for more details. However, if the CPU suffers from virtual aliasing problem, I think this won't work at all. I think that is pretty much only way to get more RAM in 32bit system. With 64bit kernel of course you don't have any problems at all. Jun
