AM62Px MCU+ SDK  09.01.00
SBL Booting Linux From SD CARD

Table of Contents

Introduction

  • SBL booting Linux from eMMC (see SBL EMMC Linux Multistage) is a secondary bootloader application that boots Linux on A53 core and RTOS/NORTOS application on R5 core.
  • The bootloader makes use of 4 appimages
    • A Linux appimage containing the Linux binaries (ATF, OPTEE, A53 SPL).
    • tiboot3.bin with SBL SD, TIFS, BoardConfig
    • Appimage for MCU R5
    • Appimage for WKUP R5
  • The Linux appimage can be generated by using Linux Appimage Generator Tool
  • The appimages will be copied to SD card, the SBL parses the appimages from the boot partition, loads and run the cores.

Bootflow for SBL booting linux from SD Card

  • The bootflow for SBL booting Linux is as follows

Bootflow for SBL booting Linux

SD Card Partitioning

  • SD card uses two partitions to boot Linux
    • A boot partition
      • tiboot3.bin
      • mcu_r5_image
      • wkup_r5_image
      • linux_a53_image
    • A ext4 partition in the user data area containing
      • Linux Kernel image
      • Linux DTB
      • Linux file system

See Also