Hi Mark, > -----Original Message----- > From: Mark Rutland [mailto:mark.rutl...@arm.com] > Sent: Friday, January 16, 2015 12:35 AM > To: Sharma Bhupesh-B45370 > Cc: Sun York-R58495; u-boot@lists.denx.de; albert.u.b...@aribaud.net; > Wood Scott-B07421; Yoder Stuart-B08248 > Subject: Re: [U-Boot] [PATCH v2 1/2] Errata/ARM57: Add basic constructs > to handle and apply A57 specific erratas > > On Thu, Jan 15, 2015 at 06:10:57AM +0000, bhupesh.sha...@freescale.com > wrote: > > Hi York, > > > > > -----Original Message----- > > > From: Sun York-R58495 > > > Sent: Wednesday, January 14, 2015 9:44 PM On 01/14/2015 05:46 AM, > > > Bhupesh Sharma wrote: > > > > This patch adds basic constructs in the ARMv8 u-boot code to > > > > handle and apply Cortex-A57 specific erratas. > > > > > > > > As and example, the framework showcases how erratas 833069, 826974 > > > > and > > > > 828024 can be handled and applied. > > > > > > > > Later on this framework can be extended to include other erratas. > > > > > > > > Signed-off-by: Bhupesh Sharma <bhupesh.sha...@freescale.com> > > > > --- > > > > Changes from v1: > > > > - Addressed York's comment about x29 usage and calling the > > > > core errata fxup function before the lowlevel_init function > > > > is called. > > > > > > > > arch/arm/cpu/armv8/start.S | 51 > > > ++++++++++++++++++++++++++++++++++++++++++ > > > > arch/arm/include/asm/macro.h | 20 +++++++++++++++++ > > > > 2 files changed, 71 insertions(+) > > > > > > > > diff --git a/arch/arm/cpu/armv8/start.S > > > > b/arch/arm/cpu/armv8/start.S index 4b11aa4..df532f9 100644 > > > > --- a/arch/arm/cpu/armv8/start.S > > > > +++ b/arch/arm/cpu/armv8/start.S > > > > @@ -67,6 +67,9 @@ reset: > > > > msr cpacr_el1, x0 /* Enable FP/SIMD */ > > > > 0: > > > > > > > > + /* Apply ARM core specific erratas */ > > > > + bl apply_core_errata > > > > + > > > > /* > > > > * Cache/BPB/TLB Invalidate > > > > * i-cache is invalidated before enabled in icache_enable() > @@ - > > > 97,6 > > > > +100,54 @@ master_cpu: > > > > > > > > > > > > /*---------------------------------------------------------------- > > > > ---- > > > > ---*/ > > > > > > > > +WEAK(apply_core_errata) > > > > + > > > > + /* For now, we support Cortex-A57 specific errata only */ > > > > + > > > > + /* Check if we are running on a Cortex-A57 core */ > > > > + branch_if_a57_core x0, 1f > > > > + b 2f > > > > +1: > > > > + bl apply_a57_core_errata > > > > + > > > > +2: > > > > + ret > > > > +ENDPROC(apply_core_errata) > > > > + > > > > > > Bhupesh, > > > > > > Have you tested the new code? I don't think it handles LR correctly. > > > Your code will be stuck. > > > > > > > Yes, I have tested this on both the LS2085A simulator and emulator > platforms. > > On emulator I tried u-boot boot-to-prompt and on simulator I tried > linux boot-to-prompt. > > Both seem to be working fine. > > Has the apply_a57_core_errata function definitely been called in your > tests? > > If so the lr should point immediately after it (i.e. at the ret), and so > the ret should branch to itself, repeatedly. >
Thanks for the pointers. Let me connect a debugger and see the step-by-step flow through the apply_a57_core_errata. I will revert with the findings soon. Regards, Bhupesh _______________________________________________ U-Boot mailing list U-Boot@lists.denx.de http://lists.denx.de/mailman/listinfo/u-boot
