1How to update U-Boot on pico-imx7d board 2---------------------------------------- 3 4Required software on the host PC: 5 6- imx_usb_loader: https://github.com/boundarydevices/imx_usb_loader 7 8Build U-Boot for pico: 9 10$ make mrproper 11$ make pico-imx7d_defconfig 12$ make 13 14This generates the U-Boot binary called u-boot.imx. 15 16Put pico board in USB download mode (refer to the PICO-iMX7D Quick Start Guide 17page 3) 18 19Connect a USB to serial adapter between the host PC and pico. 20 21Connect a USB cable between the OTG pico port and the host PC. 22 23Open a terminal program such as minicom. 24 25Copy u-boot.imx to the imx_usb_loader folder. 26 27Load u-boot.imx via USB: 28 29$ sudo ./imx_usb u-boot.imx 30 31Then U-Boot starts and its messages appear in the console program. 32 33Use the default environment variables: 34 35=> env default -f -a 36=> saveenv 37 38Run the DFU agent so we can flash the new images using dfu-util tool: 39 40=> dfu 0 mmc 0 41 42Flash SPL into the eMMC: 43 44$ sudo dfu-util -D SPL -a spl 45 46Flash u-boot.img into the eMMC: 47 48$ sudo dfu-util -D u-boot.img -a u-boot 49 50Remove power from the pico board. 51 52Put pico board into normal boot mode. 53 54Power up the board and the new updated U-Boot should boot from eMMC. 55