SPRADK5 June   2025 TDA4VM

 

  1.   1
  2.   Abstract
  3.   Trademarks
  4. 1Introduction
  5. 2Physical Boot Mode DIP Switch Configuration
    1. 2.1 eMMC Boot Mode Switch for Primary Boot Mode
    2. 2.2 MMC/SD Boot Mode Switch for Backup Boot Mode
  6. 3Experiment
    1. 3.1 Prepare eMMC Boot Images for Primary Boot Mode
    2. 3.2 Prepare MMC/SD Boot Images for Backup Boot Mode
    3. 3.3 eMMC Memory Layout
    4. 3.4 Verify Redundant Boot
  7. 4Summary
  8. 5References

1 Introduction

TI’s TDA4x Jacinto devices support booting from a variety of media such as Octal Serial Peripheral Interface (OSPI) flash memory, eMMC, universal asynchronous receiver-transmitter (UART), and so on. After power-on, the microcontroller unit (MCU) ROM code initiates the boot sequence by reading the physical boot mode, typically configured physically. Based on this configuration, the ROM code determines which boot media to access to locate the required boot images.

By default, the ROM code first attempts to load images from the primary boot media. If the primary boot images are valid and pass integrity and authentication checks, the system boots successfully using these images. However, if the primary boot images are missing or corrupted, the ROM code automatically proceeds to try the backup boot media. The boot process for the backup media follows the same sequence and validation steps as the primary. This dual-path boot mechanism provides the system with two opportunities to boot, greatly improving overall reliability and fault tolerance particularly critical for ADAS applications. The high-level boot sequence follows this process:

  1. Power is applied, starting the boot process of the MCU ROM.
  2. The MCU ROM code reads the boot mode pins to identify the primary boot source.
  3. The MCU ROM code requests the Device Management and Security Controller (DMSC) to verify the integrity of the boot images.
  4. If the integrity check passes, the system boots using the primary images.
  5. If the integrity check fails, the MCU ROM code reads the boot mode pins again to identify the backup boot source.
  6. The DMSC performs integrity checks on the backup images.
  7. If successful, the system boots from the backup media.

This process provides redundant boot capability, enabling robust recovery in the event of image corruption or update failure.

The following sections of this application note describe how to configure this redundant boot mechanism using a single eMMC device, eliminating the need to switch physical boot modes or use multiple memory devices.