Not sure what you mean by "system memory". You can turn on CONFIG_HIGHMEM and get access to 512 MB physical memory or more on the BCM with a 32-bit kernel, but you can't access memory above the low 256 MB directly through KSEG0/1, so there are some things that the kernel can't use it for (though it can be allocated to user processes). Also, since CONFIG_DISCONTIGMEM isn't supported, you end up wasting a bunch of RAM on useless page table space (36MB for 512 MB physical), and there's also some caching weirdness if you try and mmap() /dev/mem to get user access to the >0x10000000 I/O registers. Also, your startup will report "1792 MB HIGHMEM available". sf > -----Original Message----- > From: Steve Madsen [mailto:madsen@tadpole.com] > Sent: Friday, August 29, 2003 12:00 PM > To: linux-mips@linux-mips.org > Subject: Using more than 256 MB of memory on SB1250 in 32-bit mode > > > Is it possible to use more than 256 MB of system memory with > the Broadcom > SB1250 in 32-bit mode? The memory map I'm looking at shows > me that the > second 256 MB of memory is at physical address 0x80000000. I > suspect that > due to the 2G/2G split in the kernel, I can't use memory this > high without > moving to the 64-bit kernel. > > Would someone confirm this for me? > > -- > Steve Madsen <madsen@tadpole.com> > Tadpole Computer, Inc. http://www.tadpole.com > >
