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, M4 cores.
The bootloader makes use of 6 appimages
- A Linux appimage containing the Linux binaries (ATF, OPTEE, A53 SPL).
- tiboot3.bin with SBL stage1, TIFS, BoardConfig
- Appimage for SBL stage2
- Appimage for MCU M4
- Appimage for HSM M4
- DM firmware appimage for DM R5
Boots R5F, MCU-M4, HSM-M4 cores and Linux on A53 from eMMC.
SBL booting Linux can be used when early booting of R5F, HSM-M4 and MCU-M4 cores are required. When using uBoot, the application will start running on R5F, HSM-M4 and MCU-M4 cores only after booting Linux
The Linux appimage can be generated by using Linux Appimage Generator Tool
The appimages will be flashed to the offset on eMMC specified by SysCfg, the SBL parses the appimages from these locations, loads and run the cores.

Bootflow for SBL booting linux from eMMC

Note: The binaries for R5F, M4F cores need not be in the linux root partition (root/lib/firmware), when SBL is booting Linux.

Bootflow for SBL booting Linux

Note: The default SD card image for AM62x-evm can be used to boot Linux using SBL; The tiboot3.bin, tispl.bin will not be used for booting Linux when using SBL booting Linux.; The M4 binary in the root partition (eg : root/lib/firmware/am62-mcu-m4f0_0-fw) will not be used when SBL boots Linux and M4 cores.