4.1.2 Using a Serial Cable for Kernel Debugging
The hardware requirements of a cable for kernel debugging require only to connect RXD to TXD, TXD to RXD, and GND to GND. The following table lists the pin numbers of these signals for 9-pin and 25-pin connectors.
| Signal | Pin numbers for 9-pin connector | Pin numbers for 25-pin connector |
| RXD (Receive Data) | 2 | 3 |
| TXD (Transmit Data) | 3 | 2 |
| GND (Signal Ground) | 5 | 7 |
Once a connection has been made using a cable as described above, the connection should then be tested using an available serial communications package (e.g. terminal.exe). The communications application should be started on both the target and the host. Type a few keystrokes from both machines to make sure that the data is received on both ends.