diff --git a/docs/user-guide.rst b/docs/user-guide.rst index 4068c9a..b67a82d 100644 --- a/docs/user-guide.rst +++ b/docs/user-guide.rst @@ -359,12 +359,17 @@ registers to be included when saving and restoring the CPU context. Default is 0. -- ``CTX_INCLUDE_PAUTH_REGS``: Boolean option that, when set to 1, enables - Pointer Authentication for Secure world. This will cause the ARMv8.3-PAuth - registers to be included when saving and restoring the CPU context as - part of world switch. Default value is 0 and this is an experimental feature. - Note that Pointer Authentication is enabled for Non-secure world irrespective - of the value of this flag if the CPU supports it. +- ``CTX_INCLUDE_PAUTH_REGS``: Boolean option that, when set to 1, allows + Pointer Authentication for **Secure world**. This will cause the + Armv8.3-PAuth registers to be included when saving and restoring the CPU + context as part of a world switch. Default value is 0. Pointer Authentication + is an experimental feature. + + Note that, if the CPU supports it, Pointer Authentication is allowed for + Non-secure world irrespectively of the value of this flag. "Allowed" means + that accesses to PAuth-related registers or execution of PAuth-related + instructions will not be trapped to EL3. As such, usage or not of PAuth in + Non-secure world images, depends on those images themselves. - ``DEBUG``: Chooses between a debug and release build. It can take either 0 (release) or 1 (debug) as values. 0 is the default. @@ -417,12 +422,12 @@ partitioning in EL3, however. Platform initialisation code should configure and use partitions in EL3 as required. This option defaults to ``0``. -- ``ENABLE_PAUTH``: Boolean option to enable ARMv8.3 Pointer Authentication - support for TF-A BL images itself. If enabled, it is needed to use a compiler - that supports the option ``-msign-return-address``. This flag defaults to 0 - and this is an experimental feature. - Note that Pointer Authentication is enabled for Non-secure world irrespective - of the value of this flag if the CPU supports it. +- ``ENABLE_PAUTH``: Boolean option to enable Armv8.3 Pointer Authentication + for **TF-A BL images themselves**. If enabled, the compiler must support the + ``-msign-return-address`` option. This flag defaults to 0. Pointer + Authentication is an experimental feature. + + If this flag is enabled, ``CTX_INCLUDE_PAUTH_REGS`` must also be enabled. - ``ENABLE_PIE``: Boolean option to enable Position Independent Executable(PIE) support within generic code in TF-A. This option is currently only supported