Re: Issue with dcahe enabling.

[Dave Hylands <dhylands@xxxxxxxxx>]

Hi Karthiik,

On Tue, Mar 27, 2012 at 5:12 AM, KARTHIK SEKURU
<karthik.sekuru@xxxxxxxxx> wrote:
> Hi,
>
> I'm doing kernel porting to arm926 based FPGA board, very minimal setup.
...snip...
> If I enable data cache and debug with JTAG, Kernel ends up in
> ENTRY(__delay).

So you mentioned enabling the data cache. So on the ARM, enabling the
data cache means that the MMU has to be enabled.

There is a "rule" that the MMU MUST be off when the kernel starts, or
things won't work properly.
http://lxr.linux.no/linux+v3.3/Documentation/arm/Booting#L159

You didn't mention exactly when you're enabling the data cache. If
it's prior to executing the kernel, then your code needs to make sure
that the MMU (and hence the data cache) has been disabled prior to
running the kernel itself.

The kernel will then turn the MMU, data and instruction caches on as
part of its own initialization.

-- 
Dave Hylands
Shuswap, BC, Canada
http://www.davehylands.com

_______________________________________________
Kernelnewbies mailing list
Kernelnewbies@xxxxxxxxxxxxxxxxx
http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies