Device Autoconfiguration

Autoconfiguration offers many advantages over the manual configuration method used in earlier versions of Unix, in which device drivers were manually added to the kernel, the kernel was recompiled, and the system had to be restarted. Now, with autoconfiguration, the administrator simply connects the new device to the system and performs a reconfiguration startup. To perform a reconfiguration startup, follow the steps in Step by Step 1.1.

Step By Step 1.1: Performing a Reconfiguration Startup 1. Create the /reconfigure file with the following command: touch /reconfigure The /reconfigure file causes the Solaris software to check for the presence of any newly installed devices the next time you turn on or start up your system. 2. Shut down the system using the shutdown procedure described in Chapter 3. If you need to connect the device, turn off power to the system and all peripherals after Solaris has been properly shut down. After the new device is connected, restore power to the peripherals first and then to the system. Verify that the peripheral device has been added by attempting to access it.

An optional method of performing a reconfiguration startup is to type boot -r at the OpenBoot prompt.

During a reconfiguration restart, a device hierarchy is created in the /devices file system to represent the devices connected to the system. The kernel uses this to associate drivers with their appropriate devices.

Autoconfiguration offers the following benefits:

• Main memory is used more efficiently because modules are loaded as needed.

• There is no need to reconfigure the kernel if new devices are added to the system. When you add devices such as disks or tape drives other than USB and hot-pluggable devices, the system needs to be shut down before you connect the hardware so that no damage is done to the electrical components.

• Drivers can be loaded and tested without having to rebuild the kernel and restart the system.

Occasionally, you might install a new device for which Solaris does not have a supporting device driver. Always check with the manufacturer to make sure any device you plan to add to your system has a supported device driver. If a driver is not included with the standard Solaris release, the manufacturer should provide the software needed for the device to be properly installed, maintained, and administered.

Third-party device drivers are installed as software packages using the pkgadd command. At a minimum, this software includes a device driver and its associated configuration (.conf) file. The .conf file resides in the /kernel/drv directory. Table 1.2 describes the contents of the module subdirectories located in the /kernel directory.

Table 1.2. Kernel Module Subdirectories

Directory	Description
drv/sparcv9	Contains loadable device drivers and pseudo device drivers
exec/sparcv9	Contains modules used to run different types of executable files or shell scripts
fs/sparcv9	Contains file system modules such as ufs, nfs, procfs, and so on
misc/sparcv9	Contains miscellaneous system-related modules such as swapgeneric and usb
sched/sparcv9	Contains operating system schedulers
strmod/sparcv9	Contains System V STREAMS loadable modules (generalized connection between users and device drivers)
sys/sparcv9	Contains loadable system calls such as system semaphore and system accounting operations