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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29Note: Some computers may be a bit strict with USB current draw and will
30shut down their ports if the draw is too high. The solution for that is
31to use an externally powered USB hub between the board and the host computer.
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33Open a terminal program such as minicom.
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35Copy SPL and u-boot.img to the imx_usb_loader folder.
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37Load the SPL binary via USB:
38
39$ sudo ./imx_usb SPL
40
41Load the u-boot.img binary via USB:
42
43$ sudo ./imx_usb u-boot.img
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45Then U-Boot starts and its messages appear in the console program.
46
47Use the default environment variables:
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49=> env default -f -a
50=> saveenv
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522. Flashing U-Boot into the eMMC
53
54Run the DFU agent so we can flash the new images using dfu-util tool:
55
56=> dfu 0 mmc 0
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58Flash SPL and u-boot.img into the eMMC running the following commands on a PC:
59
60$ sudo dfu-util -D SPL -a spl
61
62$ sudo dfu-util -D u-boot.img -a u-boot
63
64Remove power from the pico board.
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66Put pico board into normal boot mode.
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68Power up the board and the new updated U-Boot should boot from eMMC.
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