Add documentation to briefly explain the role of TIFS Stub in relevant K3 SoC's. This also sheds light on why TIFS Stub isn't package with the DM firmware itself.
Signed-off-by: Dhruva Gole <d-g...@ti.com> --- doc/board/ti/k3.rst | 11 +++++++++++ 1 file changed, 11 insertions(+) diff --git a/doc/board/ti/k3.rst b/doc/board/ti/k3.rst index 67b066a07d3a..c80060662074 100644 --- a/doc/board/ti/k3.rst +++ b/doc/board/ti/k3.rst @@ -193,6 +193,17 @@ online device resources such as power, clock, interrupts, dma etc. This firmware runs on a dedicated or multi-use microcontroller outside the security enclave. + * **TIFS Stub** - A small piece of code that helps restore the remaining + context and resume the TIFS firmware when resuming from Low Power Modes + like Suspend-to-RAM/ Deep Sleep. It is loaded into the ATCM (Tightly + Coupled Memory 'A' of the DM R5) during DM startup. The reason it isn't + merged with DM is because in HS devices we need to sign the tifs-stub with + customer key. The DM cannot have a component signed using a customer key + because a HS device customer owns the customer key and only customer + has the access for the customer key. Since TIFS Stub signing has to happen + from the customer side but DM is released by TI, we need to allow binman to + sign the TIFS Stub and only then package it alongside other firmwares. + This applies only to AM62x, AM62A and AM62P based devices. OR -- 2.34.1