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| author | Daniel Boulby <daniel.boulby@arm.com> | 2026-08-04 12:22:35 +0100 |
|---|---|---|
| committer | Daniel Boulby <daniel.boulby@arm.com> | 2026-08-05 17:59:15 +0100 |
| commit | 48fbcc72ce2835fd1cbe2179336be2ef70956e2f (patch) | |
| tree | fe45641edfd52766e52ad33e3cf4483d6bc8fbea /docs | |
| parent | 270083cdabaf4e4a2f7a955fa8a61e44779ded47 (diff) | |
| download | arm-trusted-firmware-48fbcc72ce2835fd1cbe2179336be2ef70956e2f.tar.gz arm-trusted-firmware-48fbcc72ce2835fd1cbe2179336be2ef70956e2f.zip | |
docs(el3-spmc): update FFA_VERSION description
With the introduction of locking the version negotiation when a non
FFA_VERSION ABI is called, we need to update the documentation for
FFA_VERSION in the el3 spmc to reflect this.
Signed-off-by: Daniel Boulby <daniel.boulby@arm.com>
Change-Id: I0a7358a3afdfc99587ce7e38becf3c1bfda6ea5d
Diffstat (limited to 'docs')
| -rw-r--r-- | docs/components/el3-spmc.rst | 14 |
1 files changed, 10 insertions, 4 deletions
diff --git a/docs/components/el3-spmc.rst b/docs/components/el3-spmc.rst index fd5324a1c..b461eeff4 100644 --- a/docs/components/el3-spmc.rst +++ b/docs/components/el3-spmc.rst @@ -227,10 +227,16 @@ The following additional interfaces are forwarded from SPMD to support NS Client FFA_VERSION ----------- - -``FFA_VERSION`` requires a *requested_version* parameter from the caller. -SPMD forwards call to SPMC, the SPMC returns its own implemented version. -SPMC asserts SP and SPMC are at same FF-A Version. +For a normal-world endpoint, ``FFA_VERSION`` takes the caller's +*requested_version*. The SPMD forwards the call to the SPMC, which returns +its implemented version. If the requested version is compatible, the SPMC +records it as the endpoint's negotiated version. + +Once an endpoint invokes any FF-A ABI other than ``FFA_VERSION``, version +negotiation is complete and its version cannot be changed for the endpoint's +lifetime. A normal-world endpoint must therefore successfully invoke +``FFA_VERSION`` before invoking another FF-A ABI. An SP's initial version is +obtained from and validated against its manifest. FFA_FEATURES ------------ |