Commit f32c053b authored by Kristina Martsenko's avatar Kristina Martsenko Committed by Catalin Marinas
Browse files

arm64: mops: document boot requirements for MOPS 



FEAT_MOPS introduces new instructions, we require that these
instructions not execute as UNDEFINED when we identify that the feature
is supported.

Signed-off-by: default avatarKristina Martsenko <kristina.martsenko@arm.com>
Link: https://lore.kernel.org/r/20230509142235.3284028-5-kristina.martsenko@arm.com


Signed-off-by: default avatarCatalin Marinas <catalin.marinas@arm.com>
parent 306b4c9f

Documentation/arm64/booting.rst

+6 −0
Original line number Diff line number Diff line
@@ -379,6 +379,12 @@ Before jumping into the kernel, the following conditions must be met: 


    - SMCR_EL2.EZT0 (bit 30) must be initialised to 0b1.



  For CPUs with Memory Copy and Memory Set instructions (FEAT_MOPS):



  - If the kernel is entered at EL1 and EL2 is present:



    - HCRX_EL2.MSCEn (bit 11) must be initialised to 0b1.



The requirements described above for CPU mode, caches, MMUs, architected

timers, coherency and system registers apply to all CPUs.  All CPUs must

enter the kernel in the same exception level.  Where the values documented