Lexra' s MMU

Lexra' s MMU

[Nemanja Popov]

Hi all !
  Does Lexra's CPU LX4280 has MMU. I've found from dateaheet LX4280 that
there is only SMMU (S stands for Simple) which does not include TLB and
exceptions related to that.
  I've noticed port for lexra (among others also for LX4280) on cvs. Is it
possible to run linux on that kind of processor, and if so will it manage
user space application as it should  with mmu.
  Thanx.

Lexra' s MMU

[Nemanja Popov]

Hi all !
  Does Lexra's CPU LX4280 has MMU. I've found from dateaheet LX4280 that
there is only SMMU (S stands for Simple) which does not include TLB and
exceptions related to that.
  I've noticed port for lexra (among others also for LX4280) on cvs. Is it
possible to run linux on that kind of processor, and if so will it manage
user space application as it should  with mmu.
  Thanx.

Re: Lexra' s MMU

[Ralf Baechle]

On Mon, Feb 03, 2003 at 09:57:02AM +0100, Nemanja Popov wrote:

>   Does Lexra's CPU LX4280 has MMU. I've found from dateaheet LX4280 that
> there is only SMMU (S stands for Simple) which does not include TLB and
> exceptions related to that.
>   I've noticed port for lexra (among others also for LX4280) on cvs. Is it
> possible to run linux on that kind of processor, and if so will it manage
> user space application as it should  with mmu.

TLB-less processors aren't supported at all by Linux 2.4.  Linux 2.5 has
the infrastructure in place to support TLB-less processors but we don't
support that on MIPS.  I guess it's probably not interesting because
TLB-less CPUs tend to be part of systems that are too resource constrained
to be of interest for use with Linux but I certainly wouldn't refuse such
patches.

The CVS kernel does not support Lexra processors.  There are a bit over one
year old Lexra patches for 2.4.  Me and the author agreed to not merge those
patches into the CVS kernel because Lexra is a dead company.

  Ralf