Use U-Boot

• Block Maps (blkmap)
• Device Firmware Upgrade (DFU)
• Environment Variables
• Device Tree Overlays
• Flat Image Tree (FIT)
• Network console
• Partitions
• Command-line Parsing
• Semihosting

Shell commands

• acpi command
• addrmap command
• askenv command
• base command
• bdinfo command
• blkcache command
• bootd command
• bootdev command
• bootefi command
• bootflow command
• booti command
• bootmenu command
• bootmeth command
• button command
• bootz command
• cat command
• cbsysinfo
• cls command
• cmp command
• coninfo command
• conitrace command
• cp command
• cyclic command
• dm command
• ebtupdate command
• echo command
• efi command
• eficonfig command
• env command
• event command
• exception command
• extension command
• exit command
• false command
• fatinfo command
• fatload command
• fdt command
• font command
• for command
• fwu_mdata_read command
• gpio command
• host command
• load command
• loadb command
• loadm command
• loadx command
• loady command
• mbr command
• md command
• mmc command
• mtest command
• panic command
• part command
• pause command
• pinmux command
• printenv command
• pstore command
• qfw command
• read and write commands
• reset command
• rng command
• sbi command
• sf command
• scp03 command
• seama command
• setexpr command
• size command
• sleep command
• sound command
• source command
• sm command
• temperature command
• tftpput command
• trace command
• true command
• ums command
• ut command
• wdt command
• wget command
• write command
• xxd command

Booting OS

• Plan 9
• VxWorks