| How to update U-Boot on pico-imx7d board |
| ---------------------------------------- |
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| Required software on the host PC: |
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| - imx_usb_loader: https://github.com/boundarydevices/imx_usb_loader |
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| Build U-Boot for pico: |
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| $ make mrproper |
| $ make pico-imx7d_defconfig |
| $ make |
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| This generates the U-Boot binary called u-boot.imx. |
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| Put pico board in USB download mode (refer to the PICO-iMX7D Quick Start Guide |
| page 3) |
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| Connect a USB to serial adapter between the host PC and pico. |
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| Connect a USB cable between the OTG pico port and the host PC. |
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| Open a terminal program such as minicom. |
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| Copy u-boot.imx to the imx_usb_loader folder. |
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| Load u-boot.imx via USB: |
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| $ sudo ./imx_usb u-boot.imx |
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| Then U-Boot starts and its messages appear in the console program. |
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| Use the default environment variables: |
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| => env default -f -a |
| => saveenv |
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| Run the DFU agent so we can flash the new images using dfu-util tool: |
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| => dfu 0 mmc 0 |
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| Flash SPL into the eMMC: |
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| $ sudo dfu-util -D SPL -a spl |
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| Flash u-boot.img into the eMMC: |
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| $ sudo dfu-util -D u-boot.img -a u-boot |
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| Remove power from the pico board. |
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| Put pico board into normal boot mode. |
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| Power up the board and the new updated U-Boot should boot from eMMC. |
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| Building U-Boot to boot with NXP 4.1 kernel: |
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| The NXP 4.1 kernel boots only in secure boot mode on mx7. |
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| Follow the next steps to enable secure boot: |
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| $ make mrproper |
| $ make pico-imx7d_defconfig |
| $ make menuconfig |
| -> ARM architecture |
| -> [*] Enable support for booting in non-secure mode |
| -> [*] Boot in secure mode by default |
| -> Exit |
| $ make |
| |
| Flash u-boot.imx using the imx_usb_loader tool. |