Re: [PATCH edk2-platforms v1 1/1] Platform/Arm: Disable memmap platform timers for JunoR0

["Sudeep Holla" <sudeep.holla@arm.com>]

On Fri, Jun 16, 2023 at 01:40:59PM +0100, Sami Mujawar wrote:
> Juno includes a system-level wakeup timer which is an implementation
> of the ARM Generic Timer architecture.
> The CNTCTL frame contains some registers that are accessible using a
> Non-Secure access. Juno R0 incorrectly limits these accesses to Secure
> access only. This issue is documented in the Juno Errata
> 832219: APB port security breaks SBSA compliance
> https://developer.arm.com/documentation/epm008857/latest
> 
> This results in a crash when the OS tries to access these registers.
> Therefore, disable memory mapped platform timers for Juno R0.
> 
> Cc: Ard Biesheuvel <ardb+tianocore@kernel.org>
> Cc: Thomas Abraham <thomas.abraham@arm.com>
> Cc: Sudeep Holla <Sudeep.Holla@arm.com>
>

Tested-by: Sudeep Holla <Sudeep.Holla@arm.com>

(fixes the ACPI based Linux boot on Juno R0 platform)


-- 
Regards,
Sudeep