[U-Boot] Enabling cache on ARM

[U-Boot] Enabling cache on ARM

[Fabio Estevam]

Hi Stefano and Albert,

I would like to enable cache on some i.MX boards (ARM9, ARM11 and Cortex-A8).

Are there any boards I could use as a reference on how to properly
implement this?

I thought I should simply do:

#undef CONFIG_SYS_ICACHE_OFF
#undef CONFIG_SYS_DCACHE_OFF

,but still I get a 'WARNING: Caches not enabled' message when I do this.

Thanks,

Fabio Estevam

[U-Boot] Enabling cache on ARM

[Stefano Babic]

On 10/31/2011 03:36 PM, Fabio Estevam wrote:
> Hi Stefano and Albert,
> 
> I would like to enable cache on some i.MX boards (ARM9, ARM11 and Cortex-A8).
> 
> Are there any boards I could use as a reference on how to properly
> implement this?
> 
> I thought I should simply do:
> 
> #undef CONFIG_SYS_ICACHE_OFF
> #undef CONFIG_SYS_DCACHE_OFF

This is not enough, at least for systems where cache is not yet supported.

> 
> ,but still I get a 'WARNING: Caches not enabled' message when I do this.

The reason is that enable_caches is missing for i.MX targets. You can
try to add enable_caches inside your board file, and implement it
calling dcache_enable().

However, i.MX drivers are actually proofed to be faulty when the cache
is enabled. At least the FEC driver and the MMC driver must be changed
to make them working when cache is on.

Best regards,
Stefano Babic

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