Dawn-Line Loading Procedure

To down-line load a target machine, you must make the VAXELN system image file available to the network software on the host development system and have the down-line load bootstrap loader running on the target machine.

When you build the system with the System Builder, be sure to specify Downline as the Boot method entry of the System Characteristics Menu.

Use the NCP facility to store the file name of the VAXELN system image in the host system's network node data base, thus making the image's name available to the network software. For example:

NCP> SET NODE FRED LOAD FILE ELN$:ICP_DOWNLINE.SYS

The debugger can perform the same operation if you specify the EDEBUG command as follows:

$ EDEBUG/LOAD=ELN$:ICP.DOWNLINE.SYS

Start the down-line load bootstrap loader by specifying the console boot command (B) and the target machine. For example, to start the DEUNA loader on an 11/730, enter: 8800, enter the following boot command at the console:

>>> BOOT xxx

where xxx is ETA for systems with a DEBNT and XEA for systems with a DEUNA.

When the loader starts, it sends a load-request message to the host system. The network software on the host system responds by creating a Maintenance Operation Monitor (MOM) process that reads the specified V AXELN system image file and sends it to the target bootstrap loader.

When down-line loading a machine (in contrast to booting it from a disk or ROM), you do not have to set the node name or node address with the System Builder; the target machine receives its proper node name and address automatically. If you use this feature and have a system that runs on multiple processors in a network, you can use the same system image for each machine.

The following sections explain how to:

• Reload a machine that is running the Network Service

• Down-line load during debugging

• Reload production machines

• Down-line load from multiple hosts

4.2.2.1 Reloading a Machine That Is Running the Network Service

Once a VAXELN system is initialized, is running the Network Service, and has trigger booting enabled, use the remote boot command TRIGGER to boot the target machine. To use this feature, you must change the default bootstrap loader to the down-line load bootstrap loader by setting the default bootstrap selection switches to the correct read-only loader. On the 11/730, you perform this setting by using the NEWBOOT command procedure. On an 11/750, set the default boot device switch to A. On a MicroVAX, set the CPU configuration DIP switch number 1 to ON.

To trigger a target machine, use the NCP TRIGGER command. For example:

NCP> TRIGGER NODE FRED

The TRIGGER command sends a boot-request message to the target ma-chine, which causes the VAXELN datalink device driver to halt execution of VAXELN and begin execution of the down-line load bootstrap loader (default bootstrap).

NOTE

You can configure the DEUNA controller on an 11/750 target machine to process the boot-request message and cause the machine to halt by causing a power-failure sequence. To en-sure that the 11/750 restarts, you must put the Auto Restart switch in the BOOT position. This implies that a machine re-quiring unattended triggering cannot also restart using memory with battery backup (that is, it will reboot when the power is restored).

If you encounter problems loading your target machine, you can use the network event-logging facility on the host system to locate the prob-lem. To enable event logging on your host system, use the NCP SET LOGGING commands.

For example, to enable network event logging to your host's console terminal, use the following commands:

NCP> SET LOGGING MONITOR KNOWN EVENTS NCP> SET LOGGI~G MONITOR STATE ON

The console displays maintenance messages and network state changes observed by the MOM network process, problems opening the VAXELN system image file, and problems communicating with the target machine.

4.2.2.2 Down-Line Loading During Debugging

During the V AXELN programming and development cycle, the target machine is likely to be down-line loaded and debugged remotely. To facilitate this operation, the VAXELN debugger can down-line load targets that are running the network and have trigger booting enabled.

The /LOAD qualifier of the EDEBUG command stores the specified V AXELN system image file name in the network node data base and triggers the target machine's down-line load bootstrap loader. In the following example, the system TEST.5YS is loaded on node FRED during an EDEBUG session:

$ EOEBUG/LOAD-TEST FRED

See Chapter 5 for a complete description of the debugger.

4.2.2.3 Reloading Production Machines

After you debug and install a VAXELN application for production use, you can continue to use the down-line loading facilities to load target ma-chines. The host node's data base needs to contain a description of each V AXELN machine and system in the network. The description should contain the information described in the previous sections, including the file name of the production VAXELN system image file.

The default bootstrap loader on the target machines should be set to the down-line load bootstrap loader, as described previously. Whenever a target machine is rebooted (for example, after a power failure or a hardware or software crash), it must be reloaded from the host system.

4.2.2.4 Down-Line Loading from Multiple Hosts

When down-line loading target systems from multiple host systems, you can set down-line loading parameters for the target system on only one host system. If two or more hosts are capable of responding to a target system's request for down-line loading, the first to respond performs the load independently of the host that initiated the load with an NCP TRIGGER command or an EDEBUG /LOAD command.

The loading parameters are LOAD FILE, SERVICE CIRCUIT, and HARDWARE ADDRESS. If the last two parameters are set, the host attempts to load the target, even though it may not have the LOAD FILE name needed to complete the load. For example, if SERVICE CIRCUIT and HARDWARE ADDRESS are set, but LOAD FILE is not set (the typical case), the VAX/VMS MOM program still attempts to load the target sys-tem (load volunteer). This atsys-tempt blocks other hosts from loading; only later in the process will the program discover that it does not have the LOAD FILE name.

Unfortunately, this configuration error is difficult to diagnose. This error might be the problem if the system displays the following message:

%SYSTEM-F-TIMEOUT, Device timeout

If this configuration error is the problem, check the node data bases on the hosts and ensure that only one data base has the load parameters specified for the target.

For example, if you have loaded target system ABC from host XYZ and then decide to load ABC from host XXX, you should execute the following NCP command on node XYZ:

NCP> CLEAR NODE ABC SERVICE CIRCUIT HARDWARE ADDRESS and execute the following command on node XXX:

NCP> SET NODE ABC SERVICE CIRCUIT UNA-O HARDWARE ADDRESS AA-OO-03-01-2B-OD For a MicroVMS system, use QNA-O instead of UNA-O for the service circuit. For an 8800, 8700, 8550, or 8500 system, use BNA-O.

These commands ensure one node data base has the load parameters specified for the target ABC.

Chapter 5