Re: Problem with 1G RAM

Jakub Jelinek (
Sat, 5 Dec 1998 19:48:45 +0100 (CET)

> the problem with this is that x86 CISC instructions are inherently more
> difficult to fix up runtime :(

In what sense? I mean the linker is able to resolve it, so why should
BTFIXUP not be able to do the same? I think there are just few i386
relocation types, far less than on sparc.
And BTFIXUP really works that way:
on Intel, you'd
#define PAGE_OFFSET (&__nonexistant_page_offset_object)
then partially link the kernel (you'll get a bunch of undefined relocations
to the __npoo). Then, you just record all the places where such undefined
relocation happens, in the linker script define
__nonexistant_page_offset_object to 0xC0000000 and link again.
At runtime you just relocate what you've recorded. I think there will be at
most two different reloc types for it, if not only one, so it will be really

Jakub Jelinek | |
Administrator of SunSITE Czech Republic, MFF, Charles University
Ultralinux - first 64bit OS to take full power of the UltraSparc
Linux version 2.1.130 on a sparc64 machine (3958.37 BogoMips)

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