Using a serial connection is a good way to test drivers. Use the tip(1) command to make a serial connection between a host and a test system. With this approach, the tip window on the host console is used as the console of the test system See the tip(1) man page for additional information.
A tip window has the following advantages:
Interactions with the test system and kernel debuggers can be monitored. For example, the window can keep a log of the session for use if the driver crashes the test system.
The test system can be accessed remotely by logging into a tip host system and using tip(1) to connect to the test ystem.
This connection must be made with a null modem cable.
The terminal entry must match the serial port that is used. The operating system comes with the correct entry for serial port B, but a terminal entry must be added for serial port A:
% tip debug connected
The shell window is now a tip window with a connection to the console of the test system.
Caution - Do not use STOP-A for SPARC systems or F1-A for x86 architecture systems on the host o stop the test system. This action actually stops the host. To send a break to the test system, type ~# in the tip window. Commands such as ~# are recognized only if these characters on first on the line. If the command has no effect, press either the Return key or Control-U.
A quick way to set up the test system on the SPARC platform is to unplug the keyboard before turning on the system. The system then automatically uses serial port A as the console.
Another way to set up the test system is to use boot PROM commands to make serial port A the console. On the test system, at the boot PROM ok prompt, direct console I/O to the serial line. To make the test system always come up with serial port A as the console, set the environment variables: input-device and output-device.Example 124 Setting input-device and output-device With Boot PROM Commands
ok setenv input-device ttya ok setenv output-device ttya
The eeprom command can also be used to make serial port A the console. As superuser, execute the following commands to make the input-device and output-device parameters point to serial port A. The following example demonstrates the eeprom command.Example 125 Setting input-device and output-device With the eeprom Command
# eeprom input-device=ttya # eeprom output-device=ttya
The eeprom commands cause the console to be redirected to serial port A at each subsequent system boot.
On x86 platforms, use the eeprom command to make serial port A the console. This procedure is the same as the SPARC platform procedure. See Setting Up a Target System on the SPARC Platform. The eeprom command causes the console to switch to serial port A (COM1) during reboot.