1*4882a593SmuzhiyunHow to Update U-Boot on Pico-imx6ul board 2*4882a593Smuzhiyun----------------------------------------- 3*4882a593Smuzhiyun 4*4882a593SmuzhiyunRequired software on the host PC: 5*4882a593Smuzhiyun 6*4882a593Smuzhiyun- imx_usb_loader: https://github.com/boundarydevices/imx_usb_loader 7*4882a593Smuzhiyun 8*4882a593Smuzhiyun- dfu-util: http://dfu-util.sourceforge.net/releases/ 9*4882a593Smuzhiyun 10*4882a593SmuzhiyunBuild U-Boot for Pico: 11*4882a593Smuzhiyun 12*4882a593Smuzhiyun$ make mrproper 13*4882a593Smuzhiyun$ make pico-imx6ul_defconfig 14*4882a593Smuzhiyun$ make 15*4882a593Smuzhiyun 16*4882a593SmuzhiyunThis will generate the U-Boot binary called u-boot.imx. 17*4882a593Smuzhiyun 18*4882a593SmuzhiyunPut pico board in USB download mode (refer to the document 19*4882a593Smuzhiyunhttp://www.wandboard.org/images/hobbit/hobbitboard-imx6ul-reva1.pdf page 15) 20*4882a593Smuzhiyun 21*4882a593SmuzhiyunConnect a USB to serial adapter between the host PC and pico 22*4882a593Smuzhiyun 23*4882a593SmuzhiyunConnect a USB cable between the OTG pico port and the host PC 24*4882a593Smuzhiyun 25*4882a593SmuzhiyunOpen a terminal program such as minicom 26*4882a593Smuzhiyun 27*4882a593SmuzhiyunCopy u-boot.imx to the imx_usb_loader folder. 28*4882a593Smuzhiyun 29*4882a593SmuzhiyunLoad u-boot.imx via USB: 30*4882a593Smuzhiyun 31*4882a593Smuzhiyun$ sudo ./imx_usb u-boot.imx 32*4882a593Smuzhiyun 33*4882a593SmuzhiyunThen U-Boot should start and its messages will appear in the console program. 34*4882a593Smuzhiyun 35*4882a593SmuzhiyunUse the default environment variables: 36*4882a593Smuzhiyun 37*4882a593Smuzhiyun=> env default -f -a 38*4882a593Smuzhiyun=> saveenv 39*4882a593Smuzhiyun 40*4882a593SmuzhiyunRun the DFU command: 41*4882a593Smuzhiyun=> dfu 0 mmc 0 42*4882a593Smuzhiyun 43*4882a593SmuzhiyunTransfer u-boot.imx that will be flashed into the eMMC: 44*4882a593Smuzhiyun 45*4882a593Smuzhiyun$ sudo dfu-util -D u-boot.imx -a boot 46*4882a593Smuzhiyun 47*4882a593SmuzhiyunThen on the U-Boot prompt the following message should be seen after a 48*4882a593Smuzhiyunsuccessful upgrade: 49*4882a593Smuzhiyun 50*4882a593Smuzhiyun#DOWNLOAD ... OK 51*4882a593SmuzhiyunCtrl+C to exit ... 52*4882a593Smuzhiyun 53*4882a593SmuzhiyunRemove power from the pico board. 54*4882a593Smuzhiyun 55*4882a593SmuzhiyunPut pico board into normal boot mode 56*4882a593Smuzhiyun 57*4882a593SmuzhiyunPower up the board and the new updated U-Boot should boot from eMMC. 58