The kernel configuration editor provides an alternate way to configure your hardware. It is particularly useful when a misconfiguration is preventing your firewall from booting.
To access the editor, reboot the firewall, and enter `-c' at the `Boot:' prompt. The kernel will load, and you will be prompted for a command. Entering `visual' will take you to the visual editor.
The screen is divided horizontally into three sections. The top section contains the list of devices that are enabled in the kernel, the middle section contains those that are disabled, while the bottom section is used for changing the hardware settings associated with a device. The TAB key switches between the top and middle sections.
The devices are divided into separate categories for storage, network, communications, etcetera. Each category can be collapsed or expanded. If a category is collapsed and non-empty, this will be indicated by the label `collapsed': if this label is not present next to a section with no devices listed, then the section is empty. To expand a collapsed section, move the cursor to the section name and press ENTER.
To disable a device, move the cursor on to the device entry (in the top section) and press DEL. To enable a device, move the cursor on to the device entry (in the middle section) and press ENTER. To change the settings associated with a device, enable it if it is disabled, then move the cursor on to its entry in the top section and press ENTER. The cursor will switch to the bottom section, where you can edit the settings. Pressing `Q' will save the changed values and switch the cursor back to the top section. To exit the editor press `Q' while the cursor is in the top or middle sections. The boot process will then continue.
Be warned that if you disable the syscons driver, the firewall will boot, but you will not be able to log in at all (until such time as you re-enable the driver). If you experience such behaviour this could be the problem (of course, you may want to do this as an additional security measure).