[PATCH v2 0/7] Add support to boot TI K3 HSM M4 core

[Andrew Davis]

On 5/6/25 12:19 PM, Tom Rini wrote:
> On Tue, May 06, 2025 at 10:47:57PM +0530, Kumar, Udit wrote:
>>
>> On 5/6/2025 8:38 PM, Andrew Davis wrote:
>>> On 5/6/25 9:51 AM, Beleswar Prasad Padhi wrote:
>>>> Hi Andrew,
>>>>
>>>> On 5/6/2025 4:38 PM, Andrew Davis wrote:
>>>>> On 5/6/25 5:41 AM, Beleswar Padhi wrote:
>>>>>> Some TI K3 SoCs like J721S2, and J784S4 have a HSM (High Security
>>>>>> Module) M4F core in the Wakeup Voltage Domain which could be used to
>>>>>> run secure services like Authentication. Boot flow for HSM M4 core is
>>>>>> different than the general purpose M4F cores, and is as below:
>>>>>>
>>>>>
>>>>> The below flow looks exactly like the general purpose M4F cores..
>>>>> Why is the HSM core treated differently and this loader not made into
>>>>> a normal remote proc driver?
>>>>
>>>>
>>>> Not exactly, HSM core is treated differently because of following
>>>> exceptions:
>>>> 1. Device operations for HSM core (like reset/reset release) are not
>>>> handled by DM. TIFS handles that with proc_boot_ctrl TI-SCI calls.
>>>
>>> This could be added to the commit message then.
>>>
>>>> 2. The HSM firmware is not an ELF image. So we can't use rproc elf
>>>> loader with it. Manual memcpy has to be done.
>>>>
>>>
>>> Why is the HSM firmware not an ELF image?
>>
>>
>> HSM firmwares are loaded by TIFS (in non-GP) flow, and TIFS does not have
>> elf parser.
> 
> And to be clear, why is that? Since it's preventing the use other
> existing workflows...
> 

Even if the firmware is only delivered as a raw blob we should still
be able to use existing workflows and make a proper rproc driver for
this HSM core here.

TF-A, TIFS, and PMMC firmware are all raw bins and we have
ti_k3_arm64_rproc.c / k3_system_controller.c / ti_power_proc.c
rproc drivers.

Andrew