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
