1dab14934SVanessa MaegimaHow to Update U-Boot on Pico-imx6ul board
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4dab14934SVanessa MaegimaRequired software on the host PC:
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6dab14934SVanessa Maegima- imx_usb_loader: https://github.com/boundarydevices/imx_usb_loader
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8dab14934SVanessa Maegima- dfu-util: http://dfu-util.sourceforge.net/releases/
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10dab14934SVanessa MaegimaBuild U-Boot for Pico:
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12dab14934SVanessa Maegima$ make mrproper
13dab14934SVanessa Maegima$ make pico-imx6ul_defconfig
14dab14934SVanessa Maegima$ make
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16*c97c9e08SFabio EstevamThis generates the SPL and u-boot.img binaries.
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18*c97c9e08SFabio Estevam1. Loading U-Boot via USB Serial Download Protocol
19*c97c9e08SFabio Estevam
20*c97c9e08SFabio EstevamNote: This method is convenient for development purposes.
21*c97c9e08SFabio EstevamIf the eMMC has already a U-Boot flashed with DFU support then
22*c97c9e08SFabio Estevamthe user can go to step 2 below in order to update U-Boot.
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24dab14934SVanessa MaegimaPut pico board in USB download mode (refer to the document
25dab14934SVanessa Maegimahttp://www.wandboard.org/images/hobbit/hobbitboard-imx6ul-reva1.pdf page 15)
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27dab14934SVanessa MaegimaConnect a USB to serial adapter between the host PC and pico
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29dab14934SVanessa MaegimaConnect a USB cable between the OTG pico port and the host PC
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31dab14934SVanessa MaegimaOpen a terminal program such as minicom
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33*c97c9e08SFabio EstevamCopy SPL and u-boot.img to the imx_usb_loader folder.
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35*c97c9e08SFabio EstevamLoad the SPL binary via USB:
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37*c97c9e08SFabio Estevam$ sudo ./imx_usb SPL
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39*c97c9e08SFabio EstevamLoad the u-boot.img binary via USB:
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41*c97c9e08SFabio Estevam$ sudo ./imx_usb u-boot.img
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43dab14934SVanessa MaegimaThen U-Boot should start and its messages will appear in the console program.
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45dab14934SVanessa MaegimaUse the default environment variables:
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47dab14934SVanessa Maegima=> env default -f -a
48dab14934SVanessa Maegima=> saveenv
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50*c97c9e08SFabio Estevam2. Flashing U-Boot into the eMMC
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52dab14934SVanessa MaegimaRun the DFU command:
53dab14934SVanessa Maegima=> dfu 0 mmc 0
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55*c97c9e08SFabio EstevamFlash SPL and u-boot.img into the eMMC running the following commands on a PC:
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57*c97c9e08SFabio Estevam$ sudo dfu-util -D SPL -a spl
58*c97c9e08SFabio Estevam
59*c97c9e08SFabio Estevam$ sudo dfu-util -D u-boot.img -a u-boot
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61dab14934SVanessa MaegimaThen on the U-Boot prompt the following message should be seen after a
62dab14934SVanessa Maegimasuccessful upgrade:
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64dab14934SVanessa Maegima#DOWNLOAD ... OK
65dab14934SVanessa MaegimaCtrl+C to exit ...
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67dab14934SVanessa MaegimaRemove power from the pico board.
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69dab14934SVanessa MaegimaPut pico board into normal boot mode
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71dab14934SVanessa MaegimaPower up the board and the new updated U-Boot should boot from eMMC.
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