Stephen & Albert,
-----Original Message----- From: Stephen Warren [mailto:swarren@wwwdotorg.org] Sent: Friday, March 01, 2013 2:54 PM To: Tom Warren Cc: u-boot@lists.denx.de; Stephen Warren Subject: Re: [U-Boot] [PATCH 1/3] ARM: implement some Cortex-A9 errata workarounds
On 02/28/2013 10:08 AM, Stephen Warren wrote:
On 02/26/2013 03:28 PM, Stephen Warren wrote:
From: Stephen Warren swarren@nvidia.com
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().
Hmmm. Lets hold off on this series; there are some conditions under which the kernel has to be able to apply these WARs anyway (e.g. SMP CPU power saving), which may impact which of the WARs the bootloader should apply even when booting the initial CPU 0. I'll repost once that's been resolved.
Tom,
It looks like the bootloader should always apply these WARs for CPU 0. We just have to make sure that the kernel applies them for CPUs 1..n if/when running in secure mode.
In other words, I think these patches are good to go in as-is. Since there are no changes to the patches, I won't repost them, unless you need me to.
I can take these in via the Tegra tree, but the bulk of the changes are for ARM, not Tegra. Albert - do you want to take this directly into the ARM repo, or would you prefer me to take it?
Tom -- nvpublic