System Administration Guide: Basic Administration

SPARC: The Boot Process

The following table describes the boot process on SPARC based systems.

Table 15–1 SPARC: Description of the Boot Process

Boot Phase 

Description 

Boot PROM 

1. The PROM displays system identification information and then runs self-test diagnostics to verify the system's hardware and memory. 

 

2. Then, the PROM loads the primary boot program, bootblk, whose purpose is to load the secondary boot program (that is located in the ufs file system) from the default boot device.

Boot Programs 

3. The bootblk program finds and executes the secondary boot program, ufsboot, and loads it into memory.

 

4. After the ufsboot program is loaded, the ufsboot program loads the kernel.

Kernel Initialization 

5. The kernel initializes itself and begins loading modules by using ufsboot to read the files. When the kernel has loaded enough modules to mount the root (/) file system, the kernel unmaps the ufsboot program and continues, using its own resources.

 

6. The kernel creates a user process and starts the /sbin/init process, which starts other processes by reading the /etc/inittab file.

init

7. The /sbin/init process starts the run control (rc) scripts, which execute a series of other scripts. These scripts (/sbin/rc*) check and mount file systems, start various processes, and perform system maintenance tasks.