> Question: does NetBSD allocate the *physical* memory from the highest
> addresses downwards or from the lowest addresses upwards? The faster
> memory is at a higher address. My RiscPC has physical memory blocks
> as follows:
>     0x10000000  4096 pages
>     0x18000000  4096 pages
>     0x20400000  7168 pages
>     0x30000000  8192 pages

I thought BSD just used the memory blocks provided by the RISC OS 
bootloader application. So if you only provided the last 2 SDRAM blocks 
then BSD would use the SDRAM exclusively and would completely ignore 
the old slow DRAM. It has been quite a while since I poked around the 
init code so I could be wrong though. 

Mike