It is recommended to setup the connection to the serial debug interface (DBGU). Use the supplied FTDI USB cable to connect both the PC and the DBGU interface of your board. On PanelA5, this is connector X20, on PortuxA5 it is X6. The pins are marked BL (black), OR (orange) and YE (yellow). Connect the color coded pins of the FTDI cable to the corresponding pins of the DBGU interface. See Figure 1.1, “PortuxA5 DBGU Connection” and Figure 1.2, “PanelA5 DBGU Connection” for reference.

Figure 1.1. PortuxA5 DBGU Connection

Figure 1.2. PanelA5 DBGU Connection

On the development host, the FTDI cable should normally be recognized as device /dev/ttyUSB0. The number can be different depending on how many USB serial converters are currently in use on the host.

To make use of the serial connection, we need serial terminal program. We will use picocom here, because it is relatively simple. To install it, open an X terminal programm, e.g. gnome-terminal and enter the following command:

sudo apt-get install picocom

It will most probably ask for your password to continue.

You can now start the serial terminal with the following command:

picocom -b 115200 /dev/ttyUSB0

If you get a permission denied message, you will have to add your user to the dialout group. You can do that with the following command (it is assumed, that your user account is called developer; change the command, if you used another name):

sudo adduser developer dialout

Again, you might be asked to provide your password. For this change to be effective, you have to logout and relogin again. Picocom should now start without problems.

If you had already plugged in the power supply, you can now press the enter key in the terminal, where you started picocom, and a login prompt should become visible.

stampa5d36 login:

You can now login with username root. No password will be needed. You should now be on the command prompt.

root@stampa5d36:~#

During the development, you will need to have access to the device via the network interface. Therefore you should set up the network to have the correct settings. If you have a DHCP server and have no problem with checking the currently used IP address, you can skip the network configuration step. You can discover the IP address using the ifconfig command.

root@stampa5d36:~# ifconfig eth0
eth0      Link encap:Ethernet  HWaddr CE:29:C2:BB:D9:A6
          inet addr:192.168.0.50  Bcast:0.0.0.0  Mask:255.255.255.0
          inet6 addr: fe80::cc29:c2ff:febb:d9a6/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:2726 errors:0 dropped:0 overruns:0 frame:0
          TX packets:158 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000
          RX bytes:275050 (268.6 KiB)  TX bytes:32214 (31.4 KiB)
          Interrupt:42 Base address:0xc000

For a static configuration, you need to edit the file /etc/network/interface.

root@stampa5d36:~# vi /etc/network/interfaces

Add the following section to the file. Adjust the values to match your network.

iface eth0 inet static
        address 192.168.0.50
        netmask 255.255.255.0
        gateway 192.168.0.1

Now comment out the following line to disable DHCP for eth0.

# iface eth0 inet dhcp

To finish the configuration, save the file and reinitialize the interface.

root@stampa5d36:~# ifdown eth0
root@stampa5d36:~# ifup eth0

If you connect the device directly to your development computer, set up its network configuration accordingly.

By default, no password is set for the root account. That is not only dangerous for a final product, but also prevent you from logging into the system via SSH. As SSH/SCP is later needed, you should set a password for the root account on the device.

root@stampa5d36:~# passwd
Changing password for root
Enter the new password (minimum of 5 characters)
Please use a combination of upper and lower case letters and numbers.
New password:
Re-enter new password:
passwd: password changed.

Install the toolchain from the DVD to you development PC. The DVD contains a shell script within the directory "toolchain" called

oecore-x86_64-cortexa5t2hf-vfp-toolchain-nodistro.0.sh
				

which will unpack the tar archive of the toolchain to the PC. Default directory for the unpacked files is

/usr/local/oecore-x86_64
				

After installing the toolchain, call the following shell script using "source":

source environment-setup-cortexa5t2hf-vfp-oe-linux-gnueabi
				

This will set important environment variables like

ARCH=arm
CROSS_COMPILE=arm-oe-linux-gnueabi-
				

necessary for the ARM-Linux cross compiler. As these setting are not persistent, the script has to be run once for every compiling session.

	Note
	The "menuconfig" program for the Linux kernel configuration will not work any more after running the script. This can be "repaired" by unsetting the variables PKG_CONFIG_PATH and PKG_CONFIG_SYSROOT_DIR. unset PKG_CONFIG_PATH PKG_CONFIG_SYSROOT_DIR Don't do this, when you actually compile applications, as they actually may need these variables to detect and link libraries.