1How to Update U-Boot on Pico-imx6ul board
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3
4Required software on the host PC:
5
6- imx_usb_loader: https://github.com/boundarydevices/imx_usb_loader
7
8- dfu-util: http://dfu-util.sourceforge.net/releases/
9
10Build U-Boot for Pico:
11
12$ make mrproper
13$ make pico-imx6ul_defconfig
14$ make
15
16This generates the SPL and u-boot.img binaries.
17
181. Loading U-Boot via USB Serial Download Protocol
19
20Note: This method is convenient for development purposes.
21If the eMMC has already a U-Boot flashed with DFU support then
22the user can go to step 2 below in order to update U-Boot.
23
24Put pico board in USB download mode (refer to the document
25http://www.wandboard.org/images/hobbit/hobbitboard-imx6ul-reva1.pdf
26page 15).
27
28Connect a USB to serial adapter between the host PC and pico.
29
30Connect a USB cable between the OTG pico port and the host PC.
31
32Open a terminal program such as minicom.
33
34Copy SPL and u-boot.img to the imx_usb_loader folder.
35
36Load the SPL binary via USB:
37
38$ sudo ./imx_usb SPL
39
40Load the u-boot.img binary via USB:
41
42$ sudo ./imx_usb u-boot.img
43
44Then U-Boot starts and its messages appear in the console program.
45
46Use the default environment variables:
47
48=> env default -f -a
49=> saveenv
50
512. Flashing U-Boot into the eMMC
52
53Run the DFU agent so we can flash the new images using dfu-util tool:
54
55=> dfu 0 mmc 0
56
57Flash SPL and u-boot.img into the eMMC running the following commands on a PC:
58
59$ sudo dfu-util -D SPL -a spl
60
61$ sudo dfu-util -D u-boot.img -a u-boot
62
63Remove power from the pico board.
64
65Put pico board into normal boot mode.
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67Power up the board and the new updated U-Boot should boot from eMMC.
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