On Fri, Jan 16, 2015 at 2:10 AM, Scott Wood scottwood@freescale.com wrote:
On Wed, 2015-01-14 at 19:16 +0530, 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.sharma@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, 1fb 2f+1:
bl apply_a57_core_errata+2:
This is awkward. How often are you expecting to use this macro? Why not just open-code it? Or at least make it "branch_if_not_a57_core". Or fix your lr problem by doing "branch_if_a57_core apply_a57_core_errata" and having it branch back rather than "ret".
But I think opencoding would be best. Just define symbols for the actual core IDs.
How about implementing a table mapping core IDs to entry points (of the "apply_*_core_errata" fns) and iterating over that table here? That will make it easy to add new cores in future too.
Thanks Arnab
+WEAK(apply_a57_core_errata)
Why is this weak?
-Scott
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