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Diffstat (limited to 'docs/design/firmware-design.rst')
-rw-r--r-- | docs/design/firmware-design.rst | 11 |
1 files changed, 10 insertions, 1 deletions
diff --git a/docs/design/firmware-design.rst b/docs/design/firmware-design.rst index 00e199a200..dc08208262 100644 --- a/docs/design/firmware-design.rst +++ b/docs/design/firmware-design.rst @@ -2581,7 +2581,16 @@ Armv8.5-A ~~~~~~~~~ - Branch Target Identification feature is selected by ``BRANCH_PROTECTION`` - option set to 1. This option defaults to 0 and this is an experimental feature. + option set to 1. This option defaults to 0 and this is an experimental + feature. + +- Memory Tagging Extension feature is unconditionally enabled for both worlds + (at EL0 and S-EL0) if it is only supported at EL0. If instead it is + implemented at all ELs, it is unconditionally enabled for only the normal + world. To enable it for the secure world as well, the build option + ``CTX_INCLUDE_MTE_REGS`` is required. If the hardware does not implement + MTE support at all, it is always disabled, no matter what build options + are used. Armv7-A ~~~~~~~ |