Multiple page size support for AU1xxx

Multiple page size support for AU1xxx

[hemanth.venkatesh]

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Has anyone been able to configure and boot kernel with page sizes other
that 4kb i.e. 16KB and 64KB on any AU1xxx based boards.

 

Thanks

Hemanth


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Multiple page size support for AU1xxx

[hemanth.venkatesh]

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Has anyone been able to configure and boot kernel with page sizes other
that 4kb i.e. 16KB and 64KB on any AU1xxx based boards.

 

Thanks

Hemanth


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Re: Multiple page size support for AU1xxx

[Ralf Baechle]

On Mon, Jul 24, 2006 at 08:24:13PM +0530, hemanth.venkatesh@wipro.com wrote:

> Has anyone been able to configure and boot kernel with page sizes other
> that 4kb i.e. 16KB and 64KB on any AU1xxx based boards.

Currently only 16kB works and only for 64-bit kernels.  I'm planning to
fix that rsn.

64K pagesize is extremly large for embedded systems of the size of the
typical Alchemy system due to the memory overhead.

  Ralf

RE: Multiple page size support for AU1xxx

[hemanth.venkatesh]

Hi Ralf,

>>Currently only 16kB works and only for 64-bit kernels.  I'm planning
to
>> fix that rsn.

Thanks for the info, did u mean 16KB would be supported for 32 bit
kernel also. I also saw code changes in arch/mips/mm/tlb-r8k.c only, is
there a plan to port it to r4k TLB also.


Help on 2.6.14 and 2.6.17 kernels provide the below info. Does it mean
some changes are required at user level also.

config PAGE_SIZE_16KB
        help
          Note that you will need a suitable Linux distribution to
support 
          this.
          There are also issues with compatibility of user applications

Thanks
Hemanth

  

RE: Multiple page size support for AU1xxx

[hemanth.venkatesh]

Hi Ralf,

>>Currently only 16kB works and only for 64-bit kernels.  I'm planning
to
>> fix that rsn.

Thanks for the info, did u mean 16KB would be supported for 32 bit
kernel also. I also saw code changes in arch/mips/mm/tlb-r8k.c only, is
there a plan to port it to r4k TLB also.


Help on 2.6.14 and 2.6.17 kernels provide the below info. Does it mean
some changes are required at user level also.

config PAGE_SIZE_16KB
        help
          Note that you will need a suitable Linux distribution to
support 
          this.
          There are also issues with compatibility of user applications

Thanks
Hemanth

  

Re: Multiple page size support for AU1xxx

[Thiemo Seufer]

hemanth.venkatesh@wipro.com wrote:
> Hi Ralf,
> 
> >>Currently only 16kB works and only for 64-bit kernels.  I'm planning
> to
> >> fix that rsn.
> 
> Thanks for the info, did u mean 16KB would be supported for 32 bit
> kernel also. I also saw code changes in arch/mips/mm/tlb-r8k.c only, is
> there a plan to port it to r4k TLB also.
> 
> 
> Help on 2.6.14 and 2.6.17 kernels provide the below info. Does it mean
> some changes are required at user level also.

Old binutils (2.14 and earlier) didn't put enough alignment between code
and data section, it this case a re-link with a newer linker is needed.

Some userland applications hardcode a specific pagesize, typically 4kB,
instead of querying sysconf(_SC_PAGESIZE). Those applications will need
fixing.


Thiemo