On Wed, 2009-11-25 at 08:37 -0600, Kevin Hickey wrote: > We use HIGHMEM on the Au1300 to access any memory spaces >256 MB. Our > I/O area starts at 256 MB. We just map the extra DRAM to any area > outside the I/O space, how to do map extra RAM to any ouside I/O space? it is just motify: 1. arch/mips/kernel/setup.c: bootm_init()function, motity the define "HIGHMEM_START", for me: #define HIGHMEM_START 0x2000,0000 //512MB 2. use add_memory_region, for me: add_memory_region(0x20000000, 0x40000000, BOOT_MEM_RAM); //extra 1G RAM is it ok ? Best, Figo.zhang > enable highmem, and register it as BOOT_MEM_RAM > with add_memory_region. Works great. > > =Kevin > -- > Kevin Hickey > Netlogic Microsystems > > > On Wed, 2009-11-25 at 14:34 +0800, figo zhang wrote: > > hi all, > > > > I am using 24KEC SOC, i want to support larger more than 512MB RAM. > > The mips32 architure in Kseg0/Kseg1, > > such as: > > 0x8000,0000 ~ 0x92c0,0000 # 300MB for RAM > > 0x92c0,0000 ~ 0xa000,0000 # 212 for I/O register > > > > so, mips32 only support 300MB memory, i dont how to support more than > > 512MB in linux-mips kernel , such as 2GB memory? it is using HIGHMEM > > strategy > > for kernel(ZONE_HIGHMEM)? > > > > Best, > > Figo.zhang >
