[PATCH] ARM: Implement cpu_v7_reset.
Uwe Kleine-König
u.kleine-koenig at pengutronix.de
Thu Sep 2 01:03:49 EDT 2010
Hello,
> > +#ifdef CONFIG_MMU
> > + mcr p15, 0, ip, c8, c7, 0 @ invalidate I & D TLBs
> > +#endif
> > + mrc p15, 0, ip, c1, c0, 0 @ ctrl register
> > + bic ip, ip, #0x000f @ ............wcam
> > + bic ip, ip, #0x1100 @ ...i...s........
> > + mcr p15, 0, ip, c1, c0, 0 @ ctrl register
>
> On a related note, I was always a bit confused since proc-v6 and proc-v7
> don't turn off the MMU in their cpu_reset functions, which doesn't seem
> correct with respect to Documentation/arm/Booting. Is it necessary to
> turn off the MMU when kexec'ing the kernel? Last time I tried kexec'ing
> on a v6 it worked fine without turning off the MMU.
The boot process isn't that strict. Having the MMU off is the safest,
but e.g. having an 1:1 mapping worked OK last time I checked. But this
has to be considered to be by chance and it might not work with 2.6.37.
Best regards
Uwe
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