Folks,
I have over 1GB DIMM RAM on my board running PPC 405.
How can i ioremap that to my OS? As Linux virtual
space starts at 0xC0000000, we have only 1GB more for
all virtual space mappings.
Even if i move 0xC0000000 to 0x80000000, what will
happen to TLB settings? Any problem there to map 1GB
additional RAM?
Any idea as to how i can do this?
Thanks,
Prakash
** Sent via the linuxppc-embedded mail list. See http://lists.linuxppc.org/
Prakash,
The easiest route it to turn on highmem support (CONFIG_HIGHMEM). As far as
I know, this does work for the PowerPC. My understanding is that the kernel
doesn't directly use this memory, but will allow user-space programs to use
it (mapped into their memory space), which should in turn free up the memory
the kernel DOES use.
I think you'll need to start playing with the kernel start address if you
want the kernel to benefit directly from the additional memory. I know this
has been done successfully to 0xA0000000, not sure about all the way down to
0x80000000 (but I can't think of why it wouldn't off the top of my head).
John
On 10/31/03 11:58 AM, "Prakash Kanthi" [off-list ref] wrote:
Folks,
I have over 1GB DIMM RAM on my board running PPC 405.
How can i ioremap that to my OS? As Linux virtual
space starts at 0xC0000000, we have only 1GB more for
all virtual space mappings.
Even if i move 0xC0000000 to 0x80000000, what will
happen to TLB settings? Any problem there to map 1GB
additional RAM?
Any idea as to how i can do this?
Thanks,
Prakash
** Sent via the linuxppc-embedded mail list. See http://lists.linuxppc.org/