[PATCH v2 2/7] ARM: virt: allow the kernel to be entered in HYP mode

[Russell King - ARM Linux]

On Fri, Oct 05, 2012 at 01:08:22PM -0700, Tony Lindgren wrote:
> Just bisected this down in linux-next for breaking booting of
> my omap2420 ARMv6 based n8x0..
> 
> > --- a/arch/arm/kernel/head.S
> > +++ b/arch/arm/kernel/head.S
> > @@ -83,8 +83,12 @@ ENTRY(stext)
> >   THUMB(	.thumb			)	@ switch to Thumb now.
> >   THUMB(1:			)
> >  
> > -	setmode	PSR_F_BIT | PSR_I_BIT | SVC_MODE, r9 @ ensure svc mode
> > -						@ and irqs disabled
> > +#ifdef CONFIG_ARM_VIRT_EXT
> > +	bl	__hyp_stub_install
> > +#endif
> > +	@ ensure svc mode and all interrupts masked
> > +	safe_svcmode_maskall r9
> > +
> >  	mrc	p15, 0, r9, c0, c0		@ get processor id
> >  	bl	__lookup_processor_type		@ r5=procinfo r9=cpuid
> >  	movs	r10, r5				@ invalid processor (r5=0)?
> 
> ..and looks like undoing this part fixes it. Any ideas?
> 
> I quickly tried disabling ARCH_OMAP3 and ARCH_OMAP4 so it's
> ARMv6 but that does not help.

You really should Cc me when you hit something like this.  I was
thinking about sending my tree (which contains these changes) this
evening but if they're breaking stuff, I'd prefer to delay that
stuff at least for a while.