1 How to update U-Boot on pico-imx7d board 2 ---------------------------------------- 3 4 Required software on the host PC: 5 6 - imx_usb_loader: https://github.com/boundarydevices/imx_usb_loader 7 8 Build U-Boot for pico: 9 10 $ make mrproper 11 $ make pico-imx7d_defconfig 12 $ make 13 14 This generates the U-Boot binary called u-boot.imx. 15 16 Put pico board in USB download mode (refer to the PICO-iMX7D Quick Start Guide 17 page 3) 18 19 Connect a USB to serial adapter between the host PC and pico. 20 21 Connect a USB cable between the OTG pico port and the host PC. 22 23 Open a terminal program such as minicom. 24 25 Copy u-boot.imx to the imx_usb_loader folder. 26 27 Load u-boot.imx via USB: 28 29 $ sudo ./imx_usb u-boot.imx 30 31 Then U-Boot starts and its messages appear in the console program. 32 33 Use the default environment variables: 34 35 => env default -f -a 36 => saveenv 37 38 Run the UMS command: 39 => ums 0 mmc 0 40 41 Transfer u-boot.imx to be flashed into the eMMC: 42 43 $ sudo dd if=u-boot.imx of=/dev/sdX bs=1K seek=1; sync 44 45 Remove power from the pico board. 46 47 Put pico board into normal boot mode. 48 49 Power up the board and the new updated U-Boot should boot from eMMC. 50 51 Building U-Boot to boot with NXP 4.1 kernel: 52 53 The NXP 4.1 kernel boots only in secure boot mode on mx7. 54 55 Follow the next steps to enable secure boot: 56 57 $ make mrproper 58 $ make pico-imx7d_defconfig 59 $ make menuconfig 60 -> ARM architecture 61 -> [*] Enable support for booting in non-secure mode 62 -> [*] Boot in secure mode by default 63 -> Exit 64 $ make 65 66 Flash u-boot.imx using the imx_usb_loader tool. 67
