Re: Profanity in the Linux Kernel?!?!?
Arvind Sankar (arvinds@mit.edu)
Fri, 11 Jun 1999 10:41:54 -0400
On Fri, Jun 11, 1999 at 01:32:06AM -0400, Alexander Viro wrote:
> Since this is the time-critical path (paging and copy-on-write go
> here) nobody sane would share it with floppy IRQ handling. On 8086-based
> boxen reserved range is much smaller - 0--5 instead of 0--0x11, so IBM
> guys originally mapped the IRQs to range 8--0x0f. The rest is history -
> many DOS programs depend on that setup and even on post-80286 boxen BIOS
> uses the same mapping for compatibility reasons. That's it. Nobody sane
> would use it in protected mode and IRQs are remapped by the kernel on
> very early stages of bootup.
iirc, Intel actually reserved interrupts 0-0x1f even on the 8086, but IBM went
ahead and used 'em anyway.
-- arvind
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.rutgers.edu
Please read the FAQ at http://www.tux.org/lkml/