I am currently flashing a custom mickledore distro on a STM32MP151CAA3T and after the fsbl1 i get this error : ERROR: DDR addr bus test: can't access memory @ 0xc0000004 PANIC at PC : 0x2ffdf9d9 Can someone explain how to solve this issue?

Hi everyone,i am creating a custom machine on a STM32MP151CAA3T using mickledore as yocto layer.when i flash my image, the falshing stops on the first partition, when uses tf-a-usb.stm32 file.What is this file, how is generated and how i customize it...