| Variable | Description |
|---|---|
| auto_action | Sets the console action following an error, halt, or power-up. The action can be halt, boot, or restart. Halt is the default. |
| bootdef_dev | Sets the default device or device list from which the system will attempt to boot. If the system shipped with its software installed, the variable is pre-set to point to the device containing the software. Otherwise, the default value is null. |
| boot_file | Sets the file name to be used when a bootstrap requires a filename. The default setting is null. |
| boot_osflags | Sets additional parameters to be passed
to system software. The default setting is 0,0. OpenVMS boot flags. DIGITAL UNIX boot flags. |
| bus_probe_algorithm | This variable is used to determine the method used to size the PCI bus. The values are old (for OpenVMS) or new (for DIGITAL UNIX). The default is new. |
| console | This variable routes the console output to either the graphics controller or the serial line port. |
| control_disfd | When set to enable, this variable write protects the floppy diskette drive. When set to disable, writes are enabled. |
| control_irq11 | This variable controls the source of IRQ11. When set to irq11, the interrupt is from an ISA IRQ11 device. When set to scsi, the SCSI controller is the source. |
| control_irq12 | This variable controls the source of IRQ12. When set to irq12, the interrupt is from an ISA IRQ12 device. When set to mouse, the mouse controller is the source. |
| control_scsi_term | Unused in the au-Series system. |
| control_idema | When set to enable, IDE devices are allowed to make requests. When set to disable, IDE device requests are blocked. The IDE is not supported by the DIGITAL UNIX operating system. |
| ewa0_inet_init | Used when booting over a TCP/IP network. The value is normally BOOTP. |
| ewa0_mode | This variable is set to the appropriate
Ethernet media type being used by the system. The possible values are: Twisted-Pair Full Duplex,Twisted-Pair AUI (Default) BNC Fast (for FAST Ethernet controllers) FastFD (for FAST Ethernet controllers that support full duplex) |
| ewa0_protocols | The possible values are BOOTP and MOP. The default is MOP. |
| kbd_hardware_type | This variable specifies the keyboard type, LK411 or PCXAL. The default is PCXAL. |
| language | The language environment variable associates a language to the system. You can have the system prompt you for the language using the following command: >>>set language 0 and then >>>init. Select the desired language. Type >>>init again, then power cycle the system. |
| os_type | Set to the operating system (OS) running on the system. The possible values are OSF, UNIX, OpenVMS, VMS, and NT. |
| pci_parity | The pci_parity variable controls PCI parity
checking at the PCI bridge chip. The new value becomes effective after an init or power
cycle. Possible values are: On - parity checking is performed Off - parity checking is disabled Sniff - parity checking will be on for SCSI controllers (NCR53C810), if present at rev 2. Otherwise, parity checking is off. |
| pkao_fast | A value of 0 sets the SCSI mode to slow (5 Mbps); a value of 1 sets the SCSI mode to fast (10 Mbps). DIGITAL UNIX operating system users also must edit the configuration file and rebuild the kernel. |
The DIGITAL UNIX boot flags can be stored in the boot_osflags variable or typed in along with the boot command. The possible DIGITAL UNIX boot flags are:
| Flag | Description |
|---|---|
| a | Load OS from the specified boot device. Boot to multiuser mode. |
| i | Prompt for the name of a file to load and other options (Boot interactively). Boot to single user mode. |
| s | Stop in single user mode. Boot /vmunix to single user mode and stop at the # (root) prompt. |
| D | Full dump, implies "s" as well. |
The OpenVMS boot flags consist of two portions separated by a comma: root , bootflag. The value may be stored in the boot_osflags variable or typed in when booting. The default value is 0,0. The left half specifies the directory to boot from (0 = [SYS0], 1 = [SYS1] and so forth). The right half can be used to enable specific functions during booting as shown below:
| Value | Bit | Description |
|---|---|---|
| 1 | 0 | Conversational boot (SYSBOOT>). |
| 2 | 1 | Maps XDELTA to a running system. |
| 4 | 2 | Stops at the initial system breakpoint. |
| 8 | 3 | Performs a diagnostic bootstrap. |
| 10 | 4 | Stops at the bootstrap breakpoints. |
| 20 | 5 | Omits header from secondary boot image. |
| 80 | 7 | Prompts for the name of the secondary bootfile. |
| 100 | 8 | Halts the system before secondary bootstrap. |
| 2000 | 13 | Marks corrected read data error pages as bad. |
| 10000 | 16 | Displays extensive debug messages during booting. |
| 20000 | 17 | Displays selected user messages during booting. |