Re: 2.2.0 wishlist

Albert Cahalan (albert@ccs.neu.edu)
Wed, 26 Jun 1996 16:04:37 -0400 (EDT)


From: Linus Torvalds <torvalds@cs.helsinki.fi>
> On Sat, 15 Jun 1996, Alan Cox wrote:
>>
>>> - when allocating a single non-DMA free page, try to find one which
>>> has the highest physical address, to keep as much free contiguous
>>> low memory as possible
>>
>> Put the kernel code segment above 16Mb.
>
> Note that due to some PentiumPro issues, I'll make the Pentium Pro
> load the kernel at at least 4MB (and anybody who has a PPro system
> with less than 8MB of RAM can go hang and have to use the Pentium
> settings), and due to that I'll have to make the starting address
> more dynamic (a compile-time option, but we can certainly easily
> support 1MB, 4MB and 16MB addresses).
>
> Obviously it would be best to just always load it at 16MB: then
> Pentium Pro's would be happy and we wouldn't be using any DMA
> memory, but I suspect people with only 16MB of RAM would be less
> than thrilled ;-)
>
> Another option is just to make the whole kernel relocatable, and
> then the same image works fine for everybody. I'd hate to write
> the relocation code, though. Maybe something for lilo..

What do you mean? I thought you planned to map it in at 0xc0000000.
It goes there no matter what the physical address is, so what is
the problem? If only the startup will cause problems, then couldn't
the startup code be made position independent?