Setting Up a tip Connection (Writing Device Drivers)

Writing Device Drivers

Setting Up a `tip` Connection

A serial connection can be made between a test system (the machine executing the code to be debugged) and a host system using tip(1). This connection enables a window on the host system, called a tip window, to be used as the console of the test machine. See the tip(1) man page for additional information.

Using a tip window confers the following advantages:

Interactions with the test system or kadb 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 machine can be accessed remotely by logging into a host machine (often called a tip host) and using tip(1) to connect to the test machine.

Note –

A tip connection (and a second machine) is not required to debug a Solaris 9 device driver, but is recommended.

To Set Up the Host System

To set up the host system, do the following:

Connect the host system to the test machine using serial port A on both machines.

This connection must be made with a null modem cable.

On the host system, make an entry in /etc/remote for the connection if it is not already there (see the remote(4) man page for details).

The terminal entry must match the serial port being used. The Solaris 9 operating environment comes with the correct entry for serial port B, but a terminal entry must be added for serial port A:
```
debug:\
        :dv=/dev/term/a:br#9600:el=^C^S^Q^U^D:ie=%$:oe=^D:
```
Note –
The baud rate must be set to 9600.

In a shell window on the host, run tip(1) and specify the name of the entry:
```
% tip debug
connected
```
The shell window is now a tip window connected to the console of the test machine.

Caution –
Do not use STOP-A for SPARC machines or F1-A for IA (Intel architecture) machines on the host machine to send a break to stop the test machine. This action actually stops the host machine. To send a break to the test machine, type ~# in the tip window. Commands such as this are recognized only if they are the first characters on a line, so press the Return key or Control-U first if there is no effect.

Setting Up the Test System for SPARC Platforms

A quick way to set up the test machine is to unplug the keyboard before turning on the machine. The machine then automatically uses serial port A as the console.

Another way to set up the test machine is to use boot PROM commands to make serial port A the console. On the test machine, at the boot PROM ok prompt, direct console I/O to the serial line. To make the test machine always come up with serial port A as the console, set the environment variables input-device and output-device.

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.

# eeprom input-device=ttya
# eeprom output-device=ttya

Executing the eeprom commands causes the console to be redirected to serial port A at each subsequent system boot.

Setting Up the Test System for IA Platforms

On IA platforms, use the eeprom command to make serial port A the console. The procedure for this is the same as for SPARC platform and is discussed above. Executing the eeprom commands causes the console to switch to serial port A (COM1) during reboot.

Note –

Unlike SPARC machines, where the tip connection maintains console control throughout the boot process, IA machines don't transfer console control to the tip connection until an early stage in the boot process.