eisa_config(1M)

Assigning Resources

Depending on their design, internal capabilities, and their role in system operation, E/ISA boards use various combinations of one or more system resources such as DMA channels, interrupt lines, memory, etc. Also, given boards do not always use a full set of system resources; for example, EISA provides 11 interrupt lines, but a given board might be able to use only lines 3, 5, and 6. Thus a means for the board to determine what resources are to be used must be provided.

ISA boards use physical switches or jumpers on the board to specify what resources are to be used. The person installing the board sets the switches or jumpers as specified by the board's manufacturer and based on system needs. There are thousands of different kinds of ISA boards, but unfortunately there are no standard conventions for switch and jumper usage. This results in much confusion and numerous configuration problems. For example, it is easy to inadvertently assign a given resource to two different boards, but often very difficult to diagnose the problem.

EISA boards usually have no switches or jumpers for resource assignment. Instead, each EISA board has a corresponding configuration (CFG) file that tells the system how the board can be used and what resources it needs. eisa_config is the HP-UX system program that interprets the various CFG files for all boards in the system, then builds a conflict-free configuration.

Configuration Files

All EISA boards have a corresponding CFG file. ISA boards, when used in HP-UX systems, must also have a corresponding CFG file. Although eisa_config cannot automatically configure an ISA board, it can use the contents of the CFG file to determine what switch or jumper settings on an ISA board can be used to prevent resource conflicts.

eisa_config expects to find a CFG file for each E/ISA board connected to the workstation. The administrator is responsible for making sure that these CFG files are present in directory /sbin/lib/eisa. CFG files corresponding to boards being used should always be kept in this directory. Do not remove them after eisa_config is run the first time, because they will be needed every time the configuration is changed, such as when a new board is added or one is removed. Do not change the file names of the CFG files. The file name has a specific format which is used by eisa_config to automatically match a board with its CFG file.

CFG files are normally supplied by the E/ISA board manufacturer. Two scenarios apply:

All CFG files must follow a grammar specified in the EISA bus specification. The most basic building block in the CFG grammar is the board. Each board has several attributes including board ID (to match with a board's ID register), manufacturer, ASCII text describing what the board does, what kinds of slots the board can go in, whether the board has a readable ID register, and various other capability attributes.

Each file can also contain lists of board-wide resources (such as I/O registers, switches, and jumpers) and how they should be initialized.

A board can be treated as a set of one or more functions where a given board contains a single function or multiple functions. An example of a two-function board is one having both a serial port and a parallel printer port. Each function has a separate block in that board's CFG file. Each function has a name, a type, and a set of configuration choices.

Each choice block has a name and a set of attributes. These attributes include what resources the choice requires and whether the function is enabled or disabled by that choice. Initialization is also usually specified within a choice. A given choice might require that certain registers be initialized to a specified value and that switches be set in a certain way.

Configuration Processing

E/ISA configuration is handled as follows:

If a board is currently present in the system, but has no corresponding configuration data in NVM, the EISA board cannot be used until the eisa_config program is run again and the new board is accounted for in NVM. A newly installed or existing E/ISA board is not usable until eisa_config has added it and the system has been rebooted with the necessary drivers and device special files installed. See EXAMPLES for an illustration of how to add a new board to the system.

It is possible to add EISA boards that do not have switches or jumpers to the configuration without running eisa_config interactively. The /sbin/bcheckrc script invokes eisa_config with automatic mode during each system initialization. If a board has been added since the last time eisa_config was executed, eisa_config attempts to add the new board to the configuration. If the new board is successfully added, the system may need to be rebooted (/sbin/bcheckrc does this automatically). If the new board could not be added to the configuration, a warning is written to the system console and /etc/eisa/config.err.

In addition to writing to NVM, eisa_config also automatically saves the current configuration to an SCI file called /etc/eisa/system.sci. SCI files can also be created by the interactive save command (see below). The E/ISA subsystem can also be initialized from an SCI file, rather than from NVM by using the eisa_config -n command form discussed earlier. SCI files are quite useful when a site has several identically-configured workstations. Run eisa_config on one system and save the configuration in an SCI file. Copy this file to other systems, then use it to initialize those systems. Remember that the configuration must be saved to NVM and the system rebooted before the E/ISA boards can be used.

Drivers and Device Files

Running eisa_config is not the only task necessary when adding an E/ISA board to a system. Corresponding I/O drivers must be added to the kernel and appropriate device files must be created. These steps are the same as is required for any I/O card, and can be performed either before or after running eisa_config. The important thing to remember is that the E/ISA board cannot be used until all necessary tasks are complete.

Interactive Commands

If the command form eisa_config is used, eisa_config runs in interactive mode. Interactive mode conducts configuration changes by using a series of keyboard commands. eisa_config prompts for a command, executes it, displays the results of executing the command, then prompts for the next command. Interactive commands are broadly grouped into five categories:

The action commands are:

The show (display) commands are:

There are two kinds of cfg commands:

comment commands extract the help and comments text provided in the specified CFG file or files. Both help and comments are displayed if they are available. Each command form accepts as an argument either a CFG file or a slot number identifying which board you want help for.

The help commands explain how to use the eisa_config interactive commands. If no other arguments are given, help is displayed for all of the interactive commands. Alternatively, any valid command can be used as a argument to the help command. Help is then given for the specified command only.