[U-Boot-Users] ARM946, u-boot and linux

Shawn Jin shawnxjin at gmail.com
Wed Jul 28 03:36:24 CEST 2004


Dear Wolfgang,

On Wed, 28 Jul 2004 00:00:27 +0200, Wolfgang Denk <wd at denx.de> wrote:
> > 1. uclinux or linux?
>
> Let's rephrase it: the only chance you have on a MMU-less  system  is
> by using uCLinux. For standard Linux a working MMU is mandatory.
> 
> Note that it seens that  uCLinux  has  already  been  ported  to  the
> ARM946.

Thanks. Now I know what I need to focus.
 
> > 2. Boot loader?
> > with MMU, such as 926. Or more general question: does u-boot support
> > processors without MMU? From my ppc experience I know MMU is enabled
> > on u-boot.
> 
> And you are wrong: U-Boot does NOT use the MMU on PPC. [At least  not
> on  all  processors,  and  if then not for virtual memory but just to
> play dirt^H^H^H^Hclever tricks with the data cache.]

Oh. I see.  Enabling MMU on PPC is just some dirt & clever tricks with
the data cache. I saw the code to enable MMU in start.S. Hmmm...maybe
a bit detail is more helpful to understand why MMU is enabled. Maybe I
need to go back to the processor's user guide.

> > Does ELDK support ARM946? ELDK supports arm920. ELDK can be used for
> > arm946 if its core is compatible with arm920's. If ELDK doesn't
> 
> You can use the cross toolchain, but the ative target tools  will  of
> course not run as they require a standard Linux kernel, not uCLinux.

?? What target tools are you talking about? I thought the target tools
refer to cross compiler, debugger, etc..

Best regards,
-Shawn.




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