Re: Address mapping PPC 405
From: Grant Likely <hidden>
Date: 2005-08-29 00:26:07
On 8/28/05, Jon Masters [off-list ref] wrote:
On 8/26/05, P. Sadik [off-list ref] wrote: =20 Lovely. We don't do it that way on 405 but we could - since the MMU is heavy soft assisted we could do that - we actually have everything run through the MMU once we've done initial MMU setup, but we do have the ability to mark ranges of addresses for IO and have the concept of TLB pinning to lock ranges of kernel addresses in large translated (BAT like for bigger PPC users) regions using just a few TLB slots. There is also a ZPR (zone protection register), but that's mostly used to fake the usual USER/KERNEL page distinction.
I believe TLB pinning was removed in 2.6 in favor of large TLB entries for kernel space. Matt Porter pointed this out to me about a week ago. This will not matter of course if you're not using 2.6. Matt, is there any documentation covering the new design in the kernel tree= ? Cheers, g.