Specifications

The default configuration of the console port on the m28 board uses a baudrate of 115200/8N1 (115200 bps, 8
Bit per character, no parity, 1 stop bit, no handshake).
If you are running Linux on your host system we recommend either kermit or cu as terminal emulation
programs. Do not use minicom, since this has caused problems for many users, especially for software
download over the serial port.
For the configuration of your terminal program see section 4.1. Serial Console Access
Make sure that both hardware and software flow control are disabled.
5.7. Initial Steps
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 ttyAMA0.
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:
=> help printe tftp
printenv - print environment variables
Usage:
printenv
5.7. Initial Steps 40