The eCos Developer’s Kit package comes with a ROM which provides GDB support for the Fujitsu SPARClite Evaluation Board by way of CygMon.
An image of this ROM is also provided at BASE_DIR/loaders/sparclite-sleb/cygmon.bin. The ROM is installed in socket IC9 on the evaluation board. Attention should be paid to the correct orientation of the ROM during installation.
The GDB stub allows communication with GDB using a TCP channel via the ethernet port at connector J5.
The ethernet setup is described in the board’s manual, but here is a recapitulation.
Set the board’s ethernet address using SW1 on the motherboard:
SW1-4 SW1-3 SW1-2 SW1-1 Ethernet Address ----- ----- ----- ----- ---------------- OFF OFF OFF OFF No ethernet, use serial OFF OFF OFF ON 00:00:0E:31:00:01 OFF OFF ON OFF 00:00:0E:31:00:02 OFF OFF ON ON 00:00:0E:31:00:03 OFF ON OFF OFF 00:00:0E:31:00:04 OFF ON OFF ON 00:00:0E:31:00:05 OFF ON ON OFF 00:00:0E:31:00:06 OFF ON ON ON 00:00:0E:31:00:07 ON OFF OFF OFF 00:00:0E:31:00:08 ON OFF OFF ON 00:00:0E:31:00:09 ON OFF ON OFF 00:00:0E:31:00:0A ON OFF ON ON 00:00:0E:31:00:0B ON ON OFF OFF 00:00:0E:31:00:0C ON ON OFF ON 00:00:0E:31:00:0D ON ON ON OFF 00:00:0E:31:00:0E ON ON ON ON 00:00:0E:31:00:0F |
Configure the BOOTP or DHCP server on the network to recognize the evaluation board’s ethernet address so it can assign the board an IP address. Below is a sample DHCP server configuration from a Linux system (/etc/dhcpd.conf). It shows a setup for three evaluation boards.
#
# DHCP server configuration.
#
allow bootp;
subnet 192.168.1.0 netmask 255.255.255.0 {
host mb831evb {
hardware ethernet 00:00:0e:31:00:01;
fixed-address mb831evb;
}
host mb832evb {
hardware ethernet 00:00:0e:31:00:02;
fixed-address mb832evb;
}
host mb833evb {
hardware ethernet 00:00:0e:31:00:03;
fixed-address mb833evb;
}
} |
Even when configured to use a TCP channel, CygMon will still print a boot message to the serial channel. If the BOOTP process was successful and an IP address was found, a message “BOOTP found xxx.xxx.xxx.xxx” will be printed where xxx.xxx.xxx.xxx is the IP address assigned by the BOOTP or DHCP server. If the BOOTP process fails, a message indicating failure will be printed and the serial port will be used as the debug channel.
Once the board finds an IP address it will respond to ICMP echo request packets (ping). This gives a simple means to test the health of the board.
As described in “Ethernet Setup” on page 72, it should now be possible to connect to the SPARClite board from within GDB by using the command:
(gdb) target remote <host>:1000 |
The CygMon stubs also allow communication with GDB by way of the serial port at connector CON1. The communication parameters are fixed at 19200 baud, 8 data bits, no parity bit and 1 stop bit (8-N-1). No flow control is employed. Connection to the host computer should be made using a null modem cable. A gender changer may also be required.