to detail Thomas' note... On Tue, 6 Mar 2007, Franck Bui-Huu wrote: > Date: Tue, 6 Mar 2007 22:39:59 +0100 > From: Franck Bui-Huu <vagabon.xyz@xxxxxxxxx> > To: mbizon@xxxxxxxxxx > Cc: linux-mips <linux-mips@xxxxxxxxxxxxxx> > Subject: Re: [PATCH 0/2] FLATMEM: allow memory to start at pfn != 0 [take > #2] > ... > In your case, you said: > > PAGE_OFFSET = 0x80000000 > PHYS_OFFSET = 0x10000000 > > this means that the first kernel virtual address is 0x80000000 and the > corresponding physical address is 0x10000000. If you load your kernel > at 0x9000xxxx, it will be loaded in physical memory located at > 0x2000xxxx which is obviously not what you want. > Never. If the kernel virtual address is 0x80000000+off with 0 <= off <= 0x1fffffff (aka kseg0, defined by bits 31..29), the corresponding physical address is always 0+off, no matter what PHYS_OFFSET you invent. Physical memory at 0x20000000 is not reachable from kesg0/1. > ... regards peter
