Self modifying code in ARM 11 architectures

Self modifying code in ARM 11 architectures

[Vimal Singh]

CC'ing correct ARM mailing list.

On Tue, May 24, 2011 at 3:48 PM, Ashok Babu <ashok3d@gmail.com> wrote:
> Hi All,
>
> I am no success in booting up the ARM1176 processor with the
> linux-2.6.32 kernel.
> While googling about the ARM?Harvard?architecture, I came to know that
> we have to flush/invalidate the D-Cache and I-Cache
> when using the self modifying codes.
>
> So here my questions/doubts :
> 1) Is'nt it the kernel itself is self modifying code with lots of
> function pointers ?
> ? ? If yes, how is synchronization b/w d-cache and i-cache handled in
> the kernel ?
> 2) Can this be the reason for the kernel not booting for me ?
> ? ? Because If i disable the I-Cache in the config, then the kernel
> boots up without any issues.
> Any pointers on this will be of great help.
>
> Thanks & Best Regards
> Ashok
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-- 
Regards,
Vimal Singh

Self modifying code in ARM 11 architectures

[Uwe Kleine-König]

Hello,

On Wed, May 25, 2011 at 01:18:37PM +0530, Vimal Singh wrote:
> CC'ing correct ARM mailing list.
> 
> On Tue, May 24, 2011 at 3:48 PM, Ashok Babu <ashok3d@gmail.com> wrote:
> > Hi All,
> >
> > I am no success in booting up the ARM1176 processor with the
> > linux-2.6.32 kernel.
> > While googling about the ARM?Harvard?architecture, I came to know that
> > we have to flush/invalidate the D-Cache and I-Cache
> > when using the self modifying codes.
> >
> > So here my questions/doubts :
> > 1) Is'nt it the kernel itself is self modifying code with lots of
> > function pointers ?
Code that uses function pointer isn't usually called self-modifying.

> > ? ? If yes, how is synchronization b/w d-cache and i-cache handled in
> > the kernel ?
> > 2) Can this be the reason for the kernel not booting for me ?
> > ? ? Because If i disable the I-Cache in the config, then the kernel
> > boots up without any issues.
> > Any pointers on this will be of great help.
Does your bootloader correctly disables the I-Cache before giving control
to Linux?

Best regards
Uwe

-- 
Pengutronix e.K.                           | Uwe Kleine-K?nig            |
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