Below are the environment variables that can be set in the u-boot console to boot the porter board in various configurations ################## Common options ##################### # these options are common to all configurations: setenv 'bootkfile' 'uImage+dtb' setenv 'bootkaddr' '0x40007fc0' setenv 'bootifile' 'initramfs-netboot-image-porter.ext4.gz.u-boot' setenv 'bootiaddr' '0x50000000' setenv 'bootargs_console' 'console=ttySC6,38400 ignore_loglevel' setenv 'bootargs_video' 'vmalloc=384M video=HDMI-A-1:1280x960-32@60' setenv 'bootargs_extra' 'rw rootfstype=ext4 rootwait rootdelay=2' ################ Boot on MMC (SDcard) ################# setenv 'bootargs_root' 'root=/dev/mmcblk0p1' setenv 'bootmmc' '1:1' setenv 'bootkload_sd' 'ext4load mmc ${bootmmc} ${bootkaddr} boot/${bootkfile}' setenv 'bootcmd' 'setenv bootargs ${bootargs_console} ${bootargs_video} ${bootargs_root} ${bootargs_extra}; run bootkload_sd; bootm ${bootkaddr}' ################ Boot on MMC (SDcard) with initrd ###### setenv 'bootargs_root' 'root=/dev/ram0 ramdisk_size=16384' setenv 'bootmmc' '1:1' setenv 'bootkload_sd' 'ext4load mmc ${bootmmc} ${bootkaddr} boot/${bootkfile}' setenv 'bootiload_sd' 'ext4load mmc ${bootmmc} ${bootiaddr} boot/${bootifile}' setenv 'bootcmd' 'setenv bootargs ${bootargs_console} ${bootargs_video} ${bootargs_root} ${bootargs_extra}; run bootkload_sd; run bootiload_sd; bootm ${bootkaddr} ${bootiaddr}' ################ Netboot through TFTP+NBD ################## # replace <IP> addresses by appropriate addresses setenv 'ipaddr' '<board_IP>' setenv 'serverip' '<server_IP>' setenv 'bootargs_root' 'root=/dev/ram0 ramdisk_size=16384 ip=dhcp' setenv 'bootkload_net' 'tftp ${bootkaddr} porter/${bootkfile}' setenv 'bootiload_net' 'tftp ${bootiaddr} porter/${bootifile}' setenv 'bootcmd' 'setenv bootargs ${bootargs_console} ${bootargs_video} ${bootargs_root} ${bootargs_extra} nbd.server=${serverip}; run bootkload_net; run bootiload_net; bootm ${bootkaddr} ${bootiaddr}'