3.5.1. Flash via Fastboot

This application note provides instructions on using Snagfactory tool for flashing.

The Snagfactory tool has two main operations:

  • Snagrecover: Boots the board (recovery) using USB DFU.

  • Snagflash: Flashes binaries to the on-board memory using the Fastboot protocol.

This tool supports flashing multiple boards simultaneously, enhancing efficiency in producion enviroment.

3.5.1.1. Installing Snagfactory

  • Snagfactory tool is hosted here Snagfactory.

  • More info about installation can be found in Snagfactory Readme.

  • Snagfactory also is available on pip.

$ python3 -m pip install --user snagboot

Note

At the time of 11.0 release, the corresponding Snagfactory version was v2.2.

3.5.1.2. Building bootloader binaries for Recovery

For Snagrecover, bootloader images must support DFU boot and fastboot download. In addition to USB DFU fragment config (which enables DFU boot) for the u-boot build, an additional fragment config am6x_a53_snagfactory.config needs to be used, which enables fastboot support in U-Boot and other required configs for snagfactory.

To build bootloader images for recovery using SDK, following change is needed in Rules.make file present in the top level of Linux SDK Installer.

UBOOT_MACHINE_R5=am64x_evm_r5_defconfig

UBOOT_MACHINE_A53=am64x_evm_a53_defconfig am6x_a53_snagfactory.config

Generate the bootloader images using top-level makefile by running following commands on the terminal from the top-level of the Linux SDK installer.

$ make u-boot_clean
$ make u-boot
$ make u-boot_stage

Save the bootloader binaries generated in a separate directory. These bootloader images will be used for recovery and to start flashing the images. The bootloader images after make can be found in board-support/built-images.

For more details regarding USB DFU refer USB Device Firmware Upgrade (DFU).

Note

CONFIG_FASTBOOT_BUF_SIZE is defined in am6x_a53_snagfactory.config and specifies the maximum buffer size for flashing files. Its value must be equal or greater than the largest file size being flashed. If smaller, non-sparse images will not flash correctly due to issues with chunked processing.

3.5.1.3. Connections

  • Power off the EVM and set up the boot mode switches to boot from USB DFU.

SW2-11001100
SW3-00000000

  • Power on the board.

  • Optionally you can also connect host PC to board via UART to read the console logs.

3.5.1.3.1. How to use Snagfactory

Comprehensive instructions for using the Snagfactory tool can be found here.