Hi,friends, I plug in 2GB DDR-1 in my MPC8360 board,there are two DIMM-184 slots,each DIMM-184 slot hold 1GB.Could you tell me how to let the linux know about those 2GB? In uboot, I set up each DDR CS to visit 512MB, total 4 CS signal. DDR window range is 2GB. I think the uboot has passed those DDR parameter to linux. I once did a test that config the bootargs with mem=512M, then the linux just only find 512MB, but if I config the mem=2048M, the linux still find about 750MB. How to make the linux find the total 2GB memory?
>From: Scott Wood <[EMAIL PROTECTED]> >Reply-To: >To: vijay baskar <[EMAIL PROTECTED]> >Subject: Re: The question about the high memory support on MPC8360? >Date:Wed, 28 Nov 2007 10:57:38 -0600 > >vijay baskar wrote: >> Hi, "The kernel also allows hardcoded mapping of IO regions into its >> virtual address space through the io_block_mapping interface." >> >> Can u tell me how this is in current arch/powerpc. > >Everything is explicitly ioremapped. > >> Also does it mean that whatever be the size of the ram > 768 MB there >> is not going to be much improvement in performance in kernel space >> irrespective of invoking CONFIG_HIGHMEM or not? > >Well, the kernel can use highmem for cache... I'm not sure what you >mean by "in kernel space". > >> Also do you think this low mem be enough if i have lots of kernel >> space processes each invoking lots of kmallocs. > >That depends on what you mean by "lots". :-) > >You'll have 768MB of lowmem, and kmallocs can only use lowmem. > >> Will there be bottle necks?? Also what alternative do we have if low >> mem of 768 MB is not enough?? > >You'll need to change the user/kernel split, and deal with anything that >breaks in the process. > >Or get a 64-bit chip. :-) > >-Scott > _______________________________________________ Linuxppc-embedded mailing list [email protected] https://ozlabs.org/mailman/listinfo/linuxppc-embedded
