README
1How to update U-Boot on pico-imx7d board
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4Required software on the host PC:
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6- imx_usb_loader: https://github.com/boundarydevices/imx_usb_loader
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8Build U-Boot for pico:
9
10$ make mrproper
11$ make pico-imx7d_defconfig
12$ make
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14This generates the SPL and u-boot.img binaries.
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161. Loading U-Boot via USB Serial Download Protocol
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18Note: This method is convenient for development purposes.
19If the eMMC has already a U-Boot flashed with DFU support then
20the user can go to step 2 below in order to update U-Boot.
21
22Put pico board in USB download mode (refer to the PICO-iMX7D Quick Start Guide
23page 3)
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25Connect a USB to serial adapter between the host PC and pico.
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27Connect a USB cable between the OTG pico port and the host PC.
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29Open a terminal program such as minicom.
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31Copy SPL and u-boot.img to the imx_usb_loader folder.
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33Load the SPL binary via USB:
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35$ sudo ./imx_usb SPL
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37Load the u-boot.img binary via USB:
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39$ sudo ./imx_usb u-boot.img
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41Then U-Boot starts and its messages appear in the console program.
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43Use the default environment variables:
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45=> env default -f -a
46=> saveenv
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482. Flashing U-Boot into the eMMC
49
50Run the DFU agent so we can flash the new images using dfu-util tool:
51
52=> dfu 0 mmc 0
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54Flash SPL and u-boot.img into the eMMC running the following commands on a PC:
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56$ sudo dfu-util -D SPL -a spl
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58$ sudo dfu-util -D u-boot.img -a u-boot
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60Remove power from the pico board.
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62Put pico board into normal boot mode.
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64Power up the board and the new updated U-Boot should boot from eMMC.
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