How to update U-Boot on pico-imx7d board ---------------------------------------- Required software on the host PC: - imx_usb_loader: https://github.com/boundarydevices/imx_usb_loader Build U-Boot for pico: $ make mrproper $ make pico-imx7d_defconfig $ make This generates the SPL and u-boot.img binaries. 1. Loading U-Boot via USB Serial Download Protocol Note: This method is convenient for development purposes. If the eMMC has already a U-Boot flashed with DFU support then the user can go to step 2 below in order to update U-Boot. Put pico board in USB download mode (refer to the PICO-iMX7D Quick Start Guide page 3) Connect a USB to serial adapter between the host PC and pico. Connect a USB cable between the OTG pico port and the host PC. Open a terminal program such as minicom. Copy SPL and u-boot.img to the imx_usb_loader folder. Load the SPL binary via USB: $ sudo ./imx_usb SPL Load the u-boot.img binary via USB: $ sudo ./imx_usb u-boot.img Then U-Boot starts and its messages appear in the console program. Use the default environment variables: => env default -f -a => saveenv 2. Flashing U-Boot into the eMMC Run the DFU agent so we can flash the new images using dfu-util tool: => dfu 0 mmc 0 Flash SPL and u-boot.img into the eMMC running the following commands on a PC: $ sudo dfu-util -D SPL -a spl $ sudo dfu-util -D u-boot.img -a u-boot Remove power from the pico board. Put pico board into normal boot mode. Power up the board and the new updated U-Boot should boot from eMMC.