In the default configuration, U-Boot operates in an interactive mode
which provides a simple command line-oriented user interface using a
serial console on port UART1.
In the simplest case, this means that U-Boot shows a prompt (default:
=>) when it is ready to receive user input. You
then type a command, and press enter. U-Boot will try to run the
required action(s), and then prompt for another command.
To see a list of the available U-Boot commands, you can type
help (or simply
?). This will
print a list of all commands that are available in your current
configuration. [Please note that U-Boot provides a
lot of configuration options; not all options are
available for all processors and boards, and some options might be
simply not selected for your configuration.]
=>
=> hel
With the command
help <command>
you can get additional information about most commands:
=> help tftpboot
tftpboot - boot image via network using TFTP protocol
Usage:
tftpboot [loadAddress] [[hostIPaddr:]bootfilename]
=> help setenv printenv
setenv - set environment variables
Usage:
setenv name value ...
- set environment variable 'name' to 'value ...'
setenv name
- delete environment variable 'name'
printenv - print environment variables
Usage:
printenv
- print values of all environment variables
printenv name ...
- print value of environment variable 'name'
=>
Most commands can be abbreviated as long as the string remains
unambiguous (and notice how you can ask for help for more than one command at a time):
=> help fli tftp
flinfo - print FLASH memory information
Usage:
flinfo
- print information for all FLASH memory banks
flinfo N
- print information for FLASH memory bank # N
tftpboot - boot image via network using TFTP protocol
Usage:
tftpboot [loadAddress] [[hostIPaddr:]bootfilename]
=>
