[PATCH V6 2/6] doc: ti: k3: Add TIFS Stub documentation

[Nishanth Menon]

On 12:33-20240719, Dhruva Gole wrote:
> +
> +.. k3_rst_include_end_boot_firmwares
> +.. k3_rst_include_start_lpm_firmware
	s/lpm/tifsstub ?
> +
> +* **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 the DM is released by TI or built by customer
> +  optionally using publicly available sources, we need to allow binman to
> +  sign the TIFS Stub and only then package it alongside other firmwares.

How about:

The TIFS stub is a small piece of binary designed to help restore the
required security context and resume the TIFS firmware when the system
resumes from low-power modes such as suspend-to-RAM/Deep Sleep. This
stub uses the same encryption and customer key signing model as TIFS
and is loaded into the ATCM (Tightly Coupled Memory 'A' of the DM R5)
during DM startup. Due to the independent certificate signing process,
the stub is maintained separately from DM.


> +
> +.. k3_rst_include_end_lpm_firmware
-- 
Regards,
Nishanth Menon
Key (0xDDB5849D1736249D) / Fingerprint: F8A2 8693 54EB 8232 17A3  1A34 DDB5 849D 1736 249D