Digital Signal Processing Reference
In-Depth Information
18.8 Exploring µClinux on the DE Board
Once µClinux has booted properly, you can use console window on your PC
(connected to the FPGA via a serial cable) or the terminal window display on
the VGA monitor and a PS/2 keyboard attached to the DE2 board to explore
µClinux. Standard Linux commands such as ls, cd, more, ps, kill, free, and stty
all work. In particular, type
ls -al
to get a listing of the files and directories
on the root filesystem (being implemented in SDRAM). Because the root
filesystem, program memory, and data memory are all utilizing the single 8MB
SDRAM chip on the DE board, this implementation is very tight on memory.
Before running a new command, be sure to run the
free
command to check
how much memory is available. If too many processes are running
simultaneously, the kernel will run out of memory and crash. Table 18.2
contains a summary of useful commands and programs are supported in this
µClinux kernel image. Additional commands are available in the /bin directory
and via the busybox application (type
busybox
for more information).
Table 18.2 Selected Supported Commands in Clinux
Command/Program
Description
ls
List the files and folders in the current directory.
List information about the currently running processes
including the PID number for each process.
ps
Stops a running process. The PID for the process that
will be halted must be specified.
kill
free
Lists the amount of used and available memory.
Starts a network utility that can be used to test network
communication.
ping
ifconfig
Displays and sets network configuration settings.
Starts a DHCP client daemon that will automatically
acquire an IP address and other the network settings
from a DHCP server.
dhcpcd
Starts an FTP server daemon that can be used to access
files on the Clinux system from over the network.
ftpd
Starts a telnet server daemon that can be used to access
a Clinux console terminal over the network.
telnetd
Starts a lightweight web server on the Clinux system.
The root web page is stored in /home/httpd/.
boa
Used to mount/access different filesystems including
USB memory sticks.
mount
nanoX
Starts a windowing environment in Clinux.
Starts a window manager that runs in the nanoX
environment.
nanowm
nxterm
Starts a terminal program in nanoX.
ntetris
Starts a graphical version of the Tetris game in nanoX.
nxview
Displays a JPEG image in a window in nanoX.
In additional to the standard Linux shell commands and typical user
applications, a custom application targeting the DE boards has been added to
