From mboxrd@z Thu Jan 1 00:00:00 1970 From: nicolas.pitre@linaro.org (Nicolas Pitre) Date: Fri, 5 Oct 2012 21:32:09 -0400 (EDT) Subject: [PATCH v2 2/7] ARM: virt: allow the kernel to be entered in HYP mode In-Reply-To: <20121005235046.GW3874@atomide.com> References: <1347036934-8519-1-git-send-email-marc.zyngier@arm.com> <1347036934-8519-3-git-send-email-marc.zyngier@arm.com> <20121005200822.GQ3874@atomide.com> <20121005230908.GC15246@n2100.arm.linux.org.uk> <20121005232325.GV3874@atomide.com> <20121005235046.GW3874@atomide.com> Message-ID: To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Fri, 5 Oct 2012, Tony Lindgren wrote: > * Tony Lindgren [121005 16:27]: > > * Russell King - ARM Linux [121005 16:10]: > > > 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. > > The same kernel boots on 2430sdp, which is the same ARMv6 core > as 2430 if I remember correctly. So this hints that it has something > to do with the bits set differently by the bootloader? Possibly. What if you apply this on top: diff --git a/arch/arm/include/asm/assembler.h b/arch/arm/include/asm/assembler.h index 683a1e6b60..b276c26e19 100644 --- a/arch/arm/include/asm/assembler.h +++ b/arch/arm/include/asm/assembler.h @@ -254,8 +254,7 @@ mov lr , \reg and lr , lr , #MODE_MASK cmp lr , #HYP_MODE - orr \reg , \reg , #PSR_A_BIT | PSR_I_BIT | PSR_F_BIT - bic \reg , \reg , #MODE_MASK + mov \reg , #PSR_A_BIT | PSR_I_BIT | PSR_F_BIT orr \reg , \reg , #SVC_MODE THUMB( orr \reg , \reg , #PSR_T_BIT ) msr spsr_cxsf, \reg Nicolas