8.3. Boot using secondary boot loader (SBL) for J721e

8.3.1. Building the SBL

Important

Make sure GCC compiler is installed. The GCC compiler is installed as part of running the script shown here [LINK]

  • The secondary boot loader (SBL) prebuilt images are not currently packaged with the PSDKRA package. This needs to be built from source.

  • Do below to build SBL

    cd vision_apps
make pdk_sbl

  • The generated pdk binaries will be present at

    pdk/packages/ti/boot/sbl/binary/j721e_evm

8.3.2. SD Boot Mode

8.3.2.1. Prepare a bootable SD card

Important

  • In Linux GUI tool like gparted (sudo apt install gparted) can be used.
  • Below instruction are for windows, in Linux, apply same parameters when formating the SD card

8.3.2.1.1. Option 1: Using windows command prompt

  • Ensure empty SD card (at least 256MB, preferably 8GB SDHC) is available.

  • Ensure SD memory card reader is available.

  • Create a primary FAT partition on MMC/SD card (FAT32 format with sector size 512) and mark it as Active. A partition manager utility has to be used for the same.

  • Format SD card from DOS command line as below.

    format <drive> /A:512 /FS:FAT32

  • Make SD card partition as active using tool at this page http://www.pcdisk.com/download.html

8.3.2.1.2. Option 2: Using Diskpart

  • Open windows 7 Command prompt and Run as Administrator mode

  • Enter command “diskpart.exe”

    C:\Windows\system32>diskpart.exe will take you DISKPART prompt
Warning: Enter below command carefully w.r.t your computer/laptop SD card disk number. Choosing wrong disk number may delete data present in other drive
To list all disk drive present on computer
DISKPART> list disk
Select the SD card disk number, in my case it is disk 1
DISKPART> select disk 1
Now all next command applicable only to disk 1(SD card)
Delete entire partition
DISKPART> clean
To create Primary partition
DISKPART> create partition primary
To list partition
DISKPART> list partition
Select partition
DISKPART> select partition 1
To list volume
DISKPART> list volume
Select volume associated with SD card, In my case its 3
DISKPART> select volume 3
Format SD card, please wait this may take few seconds
DISKPART>format quick fs=fat32 unit=512 label=SD_BOOT
Make disk active
DISKPART> active
To exit utility
DISKPART> exit

8.3.2.2. Copy files to SD card

When the boot switches are set to the SD boot mode, (see SD Boot Mode), ROM bootloader will look for the bootable images in the SD card. We need to put the bootloader image, system firmware image and the application images in the SD card.

  1. bootloader Image for SD boot is

    pdk/packages/ti/boot/sbl/binary/j721e_evm/mmcsd/bin/sbl_mmcsd_img_mcu1_0_release.tiimage
    • Rename this file to tiboot3.bin

  2. The system firmware image is

    pdk/packages/ti/sciclient/soc/V1/sysfw.bin

  3. The Application image to boot should be renamed to app

  4. Copy the files ** tiboot3.bin, sysfw.bin and app ** to the SD card root folder to boot from SD card.

8.3.3. OSPI Boot Mode

Note

  1. Use 2nd COM port of MCU UART port (J43) for programming.
  2. When using UART boot mode for programming the flash writer make sure you are using “-i 0” in command e.g. “dslite.bat –mode processors -c <COM_Port> -f <Path_to_the_flash_writer_to_be_transfered> -i 0”