1.1 System Initialization Overview

The C_INIT(1M) actor plays an important role in the part of system initialization that concerns file systems.

When a ChorusOS system is booted, the C_INIT(1M) actor creates a virtual root file system in order to be able to create two directories, /dev and /image. The role of these directories is as follows:

/dev

Contains special files.

The C_INIT(1M) actor mounts a pseudo file system in the /dev directory and populates this file system with special file nodes.

It does this even when no real file system, such as an NFS, UFS, or MS-DOS file system, is mounted. In fact, as physical device drivers in this release are managed at the level of the board support package (BSP) framework, it is necessary to link device drivers in some way into the input/output manager (IOM) subsystem. Also, each driver managed by the IOM component must be bound to the underlying physical device managed by the BSP.

In order to bind drivers managed by the IOM component with physical devices managed by the BSP, the system needs to determine which drivers correspond to which devices. C_INIT(1M) therefore scans both the device tree built at boot time by the kernel, and the system initialization script, sysadm.ini(4CC). Based on the information from the device tree and the system initialization script, C_INIT(1M) informs the IOM component about the correspondence between device names and physical devices. C_INIT(1M) also creates the appropriate device nodes in the /dev directory.

/image

Contains the boot system image.

This makes it possible to execute actors included in the system image dynamically. This also makes it possible to store configuration files needed by actors loaded at boot time, such as sysadm.ini(4CC), which is used by C_INIT(1M).

The boot image is mounted as an MS-DOS file system.