16. NXP i.MX 8 Series

The i.MX 8 series of applications processors is a feature- and performance-scalable multi-core platform that includes single-, dual-, and quad-core families based on the Arm® Cortex® architecture—including combined Cortex-A72 + Cortex-A53, Cortex-A35, and Cortex-M4 based solutions for advanced graphics, imaging, machine vision, audio, voice, video, and safety-critical applications.

The i.MX8QM is with 2 Cortex-A72 ARM core, 4 Cortex-A53 ARM core and 1 Cortex-M4 system controller.

The i.MX8QX is with 4 Cortex-A35 ARM core and 1 Cortex-M4 system controller.

The System Controller (SC) represents the evolution of centralized control for system-level resources on i.MX8. The heart of the system controller is a Cortex-M4 that executes system controller firmware.

16.1. Boot Sequence

Bootrom –> BL31 –> BL33(u-boot) –> Linux kernel

16.2. How to build

16.2.1. Build Procedure

  • Prepare AARCH64 toolchain.

  • Build System Controller Firmware and u-boot firstly, and get binary images: scfw_tcm.bin and u-boot.bin

  • Build TF-A

    Build bl31:

    CROSS_COMPILE=aarch64-linux-gnu- make PLAT=<Target_SoC> bl31

    Target_SoC should be “imx8qm” for i.MX8QM SoC. Target_SoC should be “imx8qx” for i.MX8QX SoC.

16.2.2. Deploy TF-A Images

TF-A binary(bl31.bin), scfw_tcm.bin and u-boot.bin are combined together to generate a binary file called flash.bin, the imx-mkimage tool is used to generate flash.bin, and flash.bin needs to be flashed into SD card with certain offset for BOOT ROM. The system controller firmware, u-boot and imx-mkimage will be upstreamed soon, this doc will be updated once they are ready, and the link will be posted.