| 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. |
| |
| Note: Some computers may be a bit strict with USB current draw and will |
| shut down their ports if the draw is too high. The solution for that is |
| to use an externally powered USB hub between the board and the host computer. |
| |
| 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. |
