ARM: implement some Cortex-A9 errata workarounds
Various errata exist in the Cortex-A9 CPU, and may be worked around by
setting some bits in a CP15 diagnostic register. Add code to implement
the workarounds, enabled by new CONFIG_ options.
This code was taken from the Linux kernel, v3.8, arch/arm/mm/proc-v7.S,
and modified to remove the logic to conditionally apply the WAR (since we
know exactly which CPU we're running on given the U-Boot configuration),
and use r0 instead of r10 for consistency with the rest of U-Boot's
cpu_init_cp15().
Signed-off-by: Stephen Warren <swarren@nvidia.com>
Acked-by: Simon Glass <sjg@chromium.org>
diff --git a/README b/README
index d51ece9..e45ae4a 100644
--- a/README
+++ b/README
@@ -485,6 +485,16 @@
Thumb2 this flag will result in Thumb2 code generated by
GCC.
+ CONFIG_ARM_ERRATA_742230
+ CONFIG_ARM_ERRATA_743622
+ CONFIG_ARM_ERRATA_751472
+
+ If set, the workarounds for these ARM errata are applied early
+ during U-Boot startup. Note that these options force the
+ workarounds to be applied; no CPU-type/version detection
+ exists, unlike the similar options in the Linux kernel. Do not
+ set these options unless they apply!
+
- Linux Kernel Interface:
CONFIG_CLOCKS_IN_MHZ