[PATCH 0/5] stm32mp1: handle TF-A boot with FIP

[Patrick DELAUNAY]

Hi Simon

On 7/11/21 2:01 AM, Simon Glass wrote:
> Hi Patrick,
>
> On Thu, 8 Jul 2021 at 03:17, Patrick Delaunay
> <patrick.delaunay at foss.st.com> wrote:
>>
>> In next TF-A version the stm32mp1 platform will support the Firmware
>> Image Package (FIP) [1], a container filled with:
>> - the U-Boot binary = u-boot-nodtb.bin
>> - the U-Boot device tree = u-boot.dtb
>> - the Secure OS (OP-TEE) or the secure monitor (SP_MIN)
> That sounds like a job for FIT?


Yes it is the same purpose but at TF-A BL2 level, so before U-Boot 
execution.


In the STM32MP boot chain with TF-A, we have:

1/ Rom code load TF-A BL2 in embedded RAM

       => it running in secure world, initializing the DDR

2/ TF-A BL2 load the next SW component from FIP containers in DDR

     a) secure world, OP-TEE for example, including key infrastructure.

     b) normal world = OS loader : U-Boot + device tree


But SPL is not used....


TF-A BL2 can be see as SPL a remplacant and

a FIP loaded by TF-A BL2 is equivalent to FIT loaded by SPL,

it the container supported by trusted firmware


But even in this use case FIT can be use to load kernel by U-Boot...


It was a long debate on the preferred first stage bootloader

for STMicroelectronics ARMv7 platform, between TF-A BL2 and SPL .


Today the preferred solution is TF-A BL2 with FIP, for secure boot

support and long term integration with  OP-TEE, even is we lost

the falcon mode.


>
> Regards,
> Simon


Regards

Patrick