Creating a System File

Creating a System File

This file resides in the /var/sysgen/system directory and contains the instructions that lboot uses to add the software module to the kernel. This normally consists of the VECTOR directive; in fact, the system file may consist of one or more VECTOR directives. The filename must end in .sm for lboot to recognize and include the software module. Typically, the filename is the software module's name with the .sm suffix, as in gbd.sm.

If the current system contains the GIO device, lboot includes the driver; otherwise, it saves memory by leaving it out. Use the VECTOR directive to include a GIO device conditionally. In addition to the module name, the VECTOR directive requires that you fill out these fields:

vector

The interrupt vector value, as described previously. The interrupt vector for GIO devices is set using the setgiovector() function (see "setgiovector"). Therefore, the vector in the VECTOR statement must always be 0x0 for GIO devices.

unit

The device number that differentiates between more than one device of the same type. This value is related to VME-style devices. For GIO devices, this value can be anything, but for consistency, make it 0.

base

The device address(es) on the GIO bus, determined by the slot in which the board is installed. This is a K1 address (see the kvtophys(D3X) man page).

base2, base3

Additional addresses passed to driver edtinit() routine through the edt structure. These are K1 addresses (see the kvtophys(D3X) man page).

exprobe

The address read when lboot determines the existence of the device. This address is often the same as the base address. If you do not specify a probe address, the module is automatically included in the kernel. For GIO bus devices, the exprobe() call is used in place of the probe call. The fields used for this call are:

operation read (r) or write (w)
address address to probe
# of bytes number of bytes to read or write
value expected response value (the GIO ID number)
mask mask to apply to value

operation	read (r) or write (w)
address	address to probe
# of bytes	number of bytes to read or write
value	expected response value (the GIO ID number)
mask	mask to apply to value