1.3. Flashing Instruction

1.3. DFU Recovery

It’s possible to put the AM62x SK EVM in USB DFU mode, which allows loading bootloaders over DFU. This is done via the snagboot tool.

This is useful for initial flashing or recoverying boards which have broken bootloaders.

1.3. Installation and setup

Install snagboot following the official instructions

Note

Snagboot requires at least Python 3.8, meaning that it can’t run on Ubuntu 18.04 releases. If Snagboot cannot be installed, it’s possible boot the initial bootloaders from an SD card.

Follow Initial Flashing on SD card if you encounter issues with Snagboot.

1.3. eMMC flashing

1.3. Flashing instructions

Once the build is complete, follow the steps below to flash the images to eMMC.

Procedure is for the pre-built images from SDK download page is used

../_images/am62x_sk_evm_setup.jpg

  1. Change the Boot Mode DIP switches to DFU mode.

    Boot mode DIP Switch:
SW1: 11001010 SW2: 00000000

  2. Ensure the device is plugged in with USB Host and Debug UART/Serial Debug

  3. Open a terminal debugger to view console output from the device:

    sudo picocom -b 115200 -r -l /dev/ttyUSB0

  4. run snagrecover for host

    snagrecover -s am625 -f ./am62x-sk-evm.yaml

    In the serial console, you will see:

    SYSFW ABI: 3.1 (firmware rev 0x0009 '9.0.5--v09.00.05 (Kool Koala)')
SPL initial stack usage: 1856 bytes
Trying to boot from DFU

Note

For AM62x LP variant, or HS-FS boards, edit am62x-sk-evm.yaml :

tiboot3:
    # for LP boards, use:
    path: tiboot3-am62x-lp-sk-dfu.bin
    # for LP with HS-FS:
    # path: tiboot3-am62x-lp-sk-dfu-hsfs.bin
    # for HS-FS:
    # path: tiboot3-am62x-sk-dfu-hsfs.bin
tispl:
    # For LP boards, use:
    path: tispl-am62x-lp-sk-dfu.bin
u-boot:
    # For LP boards, use:
    path: u-boot-am62x-lp-sk-dfu.img
  1. Setup default U-Boot environment

Type Ctrl-C in the serial console to continue to U-Boot. From there, we can run fastboot to recover with:

=>  env default -f -a; saveenv;

Note

If you build with TARGET_AVB_ENABLE=true or flash User Images you need to do this command in uboot console:

=> setenv force_avb "1"; saveenv;

Note

By default No Device-Tree Overlays was selected. Please follow this link to set a Device Tree Overlays

  1. Enable fastboot mode on the device through the terminal debugger by executing below command. Before running this command make sure USB-C cable is connected from the host PC to the EVM.

    => fastboot 0

  2. From the host PC run the flashall.sh script to start flashing the binaries to eMMC

    # If you are using binaries built locally
cd out/target/product/am62x
sudo ./flashall.sh --board am62x-sk

(OR)

# If you are using pre-built binaries from SDK download page
cd AM62x_09.00.00_emmc
sudo ./flashall.sh --board am62x-sk

Note

To flash AM62X-LP board you should do:

sudo ./flashall.sh --board am62x-lp-sk

Note

To Flash HS-FS board use flash script with --hsfs arg. For example:

sudo ./flashall.sh --board am62x-sk --hsfs

  1. Once the flashing is complete, power off the board

  2. Change Boot mode DIP switches to boot from eMMC user partitions and power cycle the board:

    Boot mode DIP Switch:
SW1: 11000010 SW2: 00000000

  3. Board should boot the Android images now.

1.3. Flashing the kernel

In order to flash a new kernel, the new boot image should be flashed.

adb reboot bootloader
< Wait for bootloader reboot >

cd <PATH/TO/BOOT/IMAGE>
fastboot flash boot boot.img
fastboot reboot

The board should boot with the new kernel build.