On 15 Oct 2002, H. Peter Anvin wrote:
> Oh no, the x86 madness is spreading!!!!
>
> (It's depressing this happening on a MIPS system, which has been 64
> bits since who-knows-when...)
Yep, but the reasons are different -- the embedded people are paranoid on
cutting away any possible bit of silicon and, admittedly, they are right,
to some extent. Why do they need 36-bit physical addressing in 32-bit
cores remains a mystery to me, though, yet the MIPS32 ISA spec permits up
to 36 bits (implementation-specific) here. Even more interesting is why
an implementation chose mapping of I/O devices there -- it's usually
easier for an OS to have them mapped within the low 29-bit address space
where they can be accessed bypassing the TLB.
-- + Maciej W. Rozycki, Technical University of Gdansk, Poland + +--------------------------------------------------------------+ + e-mail: macro@ds2.pg.gda.pl, PGP key available +- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
This archive was generated by hypermail 2b29 : Wed Oct 23 2002 - 22:00:27 EST