11541d7a6SVanessa MaegimaHow to update U-Boot on pico-imx7d board 21541d7a6SVanessa Maegima---------------------------------------- 31541d7a6SVanessa Maegima 41541d7a6SVanessa MaegimaRequired software on the host PC: 51541d7a6SVanessa Maegima 61541d7a6SVanessa Maegima- imx_usb_loader: https://github.com/boundarydevices/imx_usb_loader 71541d7a6SVanessa Maegima 81541d7a6SVanessa MaegimaBuild U-Boot for pico: 91541d7a6SVanessa Maegima 101541d7a6SVanessa Maegima$ make mrproper 111541d7a6SVanessa Maegima$ make pico-imx7d_defconfig 121541d7a6SVanessa Maegima$ make 131541d7a6SVanessa Maegima 144cdeda51SFabio EstevamThis generates the SPL and u-boot.img binaries. 154cdeda51SFabio Estevam 164cdeda51SFabio Estevam1. Loading U-Boot via USB Serial Download Protocol 174cdeda51SFabio Estevam 184cdeda51SFabio EstevamNote: This method is convenient for development purposes. 194cdeda51SFabio EstevamIf the eMMC has already a U-Boot flashed with DFU support then 204cdeda51SFabio Estevamthe user can go to step 2 below in order to update U-Boot. 211541d7a6SVanessa Maegima 221541d7a6SVanessa MaegimaPut pico board in USB download mode (refer to the PICO-iMX7D Quick Start Guide 231541d7a6SVanessa Maegimapage 3) 241541d7a6SVanessa Maegima 251541d7a6SVanessa MaegimaConnect a USB to serial adapter between the host PC and pico. 261541d7a6SVanessa Maegima 271541d7a6SVanessa MaegimaConnect a USB cable between the OTG pico port and the host PC. 281541d7a6SVanessa Maegima 29*00102ae5SFabio EstevamNote: Some computers may be a bit strict with USB current draw and will 30*00102ae5SFabio Estevamshut down their ports if the draw is too high. The solution for that is 31*00102ae5SFabio Estevamto use an externally powered USB hub between the board and the host computer. 32*00102ae5SFabio Estevam 331541d7a6SVanessa MaegimaOpen a terminal program such as minicom. 341541d7a6SVanessa Maegima 354cdeda51SFabio EstevamCopy SPL and u-boot.img to the imx_usb_loader folder. 361541d7a6SVanessa Maegima 374cdeda51SFabio EstevamLoad the SPL binary via USB: 381541d7a6SVanessa Maegima 394cdeda51SFabio Estevam$ sudo ./imx_usb SPL 404cdeda51SFabio Estevam 414cdeda51SFabio EstevamLoad the u-boot.img binary via USB: 424cdeda51SFabio Estevam 434cdeda51SFabio Estevam$ sudo ./imx_usb u-boot.img 441541d7a6SVanessa Maegima 451541d7a6SVanessa MaegimaThen U-Boot starts and its messages appear in the console program. 461541d7a6SVanessa Maegima 471541d7a6SVanessa MaegimaUse the default environment variables: 481541d7a6SVanessa Maegima 491541d7a6SVanessa Maegima=> env default -f -a 501541d7a6SVanessa Maegima=> saveenv 511541d7a6SVanessa Maegima 524cdeda51SFabio Estevam2. Flashing U-Boot into the eMMC 534cdeda51SFabio Estevam 54619fc167SOtavio SalvadorRun the DFU agent so we can flash the new images using dfu-util tool: 551541d7a6SVanessa Maegima 56619fc167SOtavio Salvador=> dfu 0 mmc 0 571541d7a6SVanessa Maegima 584cdeda51SFabio EstevamFlash SPL and u-boot.img into the eMMC running the following commands on a PC: 59619fc167SOtavio Salvador 60619fc167SOtavio Salvador$ sudo dfu-util -D SPL -a spl 61619fc167SOtavio Salvador 62619fc167SOtavio Salvador$ sudo dfu-util -D u-boot.img -a u-boot 631541d7a6SVanessa Maegima 641541d7a6SVanessa MaegimaRemove power from the pico board. 651541d7a6SVanessa Maegima 661541d7a6SVanessa MaegimaPut pico board into normal boot mode. 671541d7a6SVanessa Maegima 681541d7a6SVanessa MaegimaPower up the board and the new updated U-Boot should boot from eMMC. 69