SBL EMMC Linux

Table of Contents

• Introduction
• Supported Combinations
• Steps to Run the Example
  • Build the example
  • Flash the eMMC with the default linux image
  • Create Linux Appimage
  • Run the example
• See Also
• Sample Output

Note

SBL EMMC Linux boots from the boot partition 1 of eMMC and does not use a filesystem boot. The appimage is flashed to the offsets in eMMC as configured using syscfg.

Attention

Care should be taken to ensure that the R5, M4 appimage and the Linux appimage flashed does NOT overwrite the Linux binaries in eMMC.

Note

The load address of resource table for R5 and M4 cores must be consistant with the address in the Linux dts file.

Introduction

This is a bootloader example, which shows an example of booting Linux on A53 core and RTOS/NORTOS applications on R5 and M4 cores from eMMC.

The SBL uses two appimages

• A Linux appimage containing the Linux binaries (ATF, OPTEE, SPL).
• A muticore appimage containing the RTOS/NORTOS applications for R5 and M4 cores.

The bootloader does SOC initializations and parses the multicore appimage present at 0x800000 in eMMC boot partition 1, splits it into RPRCs for each core applicable. Each core is then initialized, RPRC image is loaded, entry points are set and the core is released from reset.

For booting Linux, SBL parses the Linux appimage present at 0xA00000 in eMMC boot partition, splits it into individual linux binaries (ATF, OPTEE, SPL). SBL loads the Linux binaries, entry point is set to the start address of ATF and A53 core is released from reset.

Supported Combinations

Parameter	Value
CPU + OS	r5fss0-0 nortos
Toolchain	ti-arm-clang
Board	am64x-evm
Example folder	examples/drivers/boot/sbl_emmc_linux

Steps to Run the Example

Build the example

• When using CCS projects to build, import the CCS project for the required combination and build it using the CCS project menu (see Using SDK with CCS Projects).
• When using makefiles to build, note the required combination and build using make command (see Using SDK with Makefiles)

Flash the eMMC with the default linux image

Note

This needs to be the first step as later the tiboot3.bin at the starting of the bootpartition will be overwritten by sbl_emmc_linux.tiimage .

• For booting A53 with linux, eMMC needs to be flashed with the Linux image. Refer to Processor SDK Linux user guide on how to flash eMMC to boot Linux.

Create Linux Appimage

• Create a Linux Appimage containing the Linux binaries (ATF, OPTEE, SPL)
• This can be done by running the makefile at {SDK_INSTALL_PATH}/tools/boot/linuxAppimageGen after setting the PSDK path in file config.mak
• Refer Linux Appimage Generator Tool for more details

Run the example

• This example is the SBL which needs to be flashed on the eMMC, along with sample application images for R5, M4 CPUs and Linux Appimage.
• There is a default flash config file as shown below which flashes this SBL and the IPC RPMsg Linux echo applications

    ${SDK_INSTALL_PATH}/examples/drivers/boot/sbl_emmc_linux/am64x-evm/{cpu}_{os}/default_sbl_emmc_linux.cfg
  

• Make sure IPC rpmsg linux echo application is built before running the flash script. (see IPC RP Message Linux Echo)

Note

For IPC rpmsg linux echo, the resource table entity must be placed at the beginning of remoteproc memory section as mentoined in Linux dts file.

• To flash to the EVM, refer to Flash a Hello World example . Only when giving the flash config file, point to the default_sbl_emmc_linux.cfg shown above.
• Example, assuming SDK is installed at C:/ti/mcu_plus_sdk and this example and IPC application is built using makefiles, and Linux Appimage is already created, in Windows,

    cd C:/ti/mcu_plus_sdk/tools/boot
    C:/ti/mcu_plus_sdk/tools/boot>python uart_uniflash.py -p COM13 --cfg=C:/ti/mcu_plus_sdk/examples/drivers/boot/sbl_emmc_linux/am64x-evm/r5fss0-0_nortos/default_sbl_emmc_linux.cfg
  

• Boot the EVM in eMMC boot mode to boot Linux on A53 and RTOS/Baremetal application on R5 and M4 cores.

Note

User might be required to set environmet variables from uBooot prompt to boot linux kernel from eMMC. Refer to Processor SDK Linux user guide for details.

See Also

BOOTLOADER

Sample Output

After flashing and booting the EVM, you will see below output on the UART console (Complete log is not shown)

[BOOTLOADER PROFILE] SYSFW Load                       :      17592us
[BOOTLOADER PROFILE] System_init                      :      18177us
[BOOTLOADER PROFILE] Drivers_open                     :     764669us
[BOOTLOADER PROFILE] Board_driversOpen                :          0us
[BOOTLOADER PROFILE] App_loadImages                   :     479465us
[BOOTLOADER_PROFILE] SBL Total Time Taken             :    1431232us

Image loading done, switching to application ...
Starting linux and RTOS/Baremetal applications

NOTICE:  BL31: v2.5(release):08.00.00.004-dirty
NOTICE:  BL31: Built : 14:02:03, Aug  5 2021

U-Boot SPL 2021.01-g53e79d0e89 (Aug 05 2021 - 14:03:40 +0000)
SYSFW ABI: 3.1 (firmware rev 0x0015 '21.5.0--v2021.05 (Terrific Llam')
Trying to boot from MMC1


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Arago Project http://arago-project.org am64xx-evm ttyS2

Arago 2020.09 am64xx-evm ttyS2

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